Dissertations / Theses on the topic 'Birds of prey Australia'

As a child growing up, I was always in love with the ritual of “dress up”. Whether it was my dolls, various reluctant pets, or myself, it was always an activity I loved. It is not surprising then that adornment has become the medium through which I express myself and bring my fantasy world to life. Jewelry and accessory have the potential to lead many lives. One particular piece can change entirely by putting it on one body as opposed to another, or by removing it to see it as an object. In fashion, the body is the canvas and the runway becomes the moment of performance. My work uses the body in much the same way where the wearer becomes performer. Through this act, we construct personal forms of armor, or “power suits”, to face the battlefield of the outside world. In harnessing this act of adorning and what it encompasses, I am consistently challenged as both designer and maker. Creating alter egos, whether subtly flirtatious or overtly sexual, demure or flamboyant, are some of the many ways in which these “power suits” can be concocted. The stories we project about ourselves daily, through how we adorn our naked bodies, become empowering. Myths versus reality, ascetic versus sensual, and beautiful versus ugly are some of the concepts from which I draw inspiration. These dualities are conceptually expressed in my work through physical combinations of opposing materials. Mixing mediums, through methods such as collaging, beading, needlepointing, knitting, and sewing, are integral in my designs. With alternative materials, such as feathers, textiles, and yarns, I add softness and new scintillating sensations when juxtaposed with the hard, cold qualities of metal. Through combining such materials, I construct pieces that not only challenge one’s notion of what “pretty” is, but also inspire the way one thinks about body adornment. The objects I create become vessels that actualize the dualities I strive to express. In producing hybrids of materials, my need to explore these dichotomies is satisfied.

Pursuit behaviours are vital in predator-prey interactions and in courtship for many flying animals. Existing research on target-directed flight behaviours in insects, birds and bats has aimed at identifying simple geometric rules describing the pursuit-flight trajectories. However, these geometric rules are only part of the picture as they only consider the outcome of the commanded changes in flight kinematics, and not the underlying guidance laws (dynamics) which generate these commands. To intercept a target, a pursuer implements a guidance law using sensory feedback to determine the required change in flight velocity, and the resulting kinematics determines the flight geometry. Most of the research until recently has examined insect flight systems, as the ethics of working with birds of prey are more complex and measuring their wide-ranging flight trajectories is difficult. Studies of predator-prey pursuit in birds have only described the geometrical rules for target interception, therefore overlooking the guidance laws which implement them. Therefore the aim of this thesis is to complete the picture by identifying the guidance laws used by birds of prey as they pursue and intercept targets both in the air and on the ground. I used onboard cameras and GPS to study attack flights in peregrine falcons (Falco peregrinus), and high-speed ground photogrammetry for attacks in Harris' hawks (Parabuteo unicinctus), to show that two different raptor species effectively implement the same guidance law of pure proportional navigation for intercepting manouevring and non-manouevring prey-targets. Proportional navigation is a feedback law whereby the bird's line-of-sight rate is fed back, in order to command a turn-rate in proportion to the change in line-of-sight rate, with a constant of proportionality N. Harris' hawks were found to use this guidance law in its simplest case with an N of approximately 1. This amounts to a pure pursuit course, meaning the bird maintains a heading angle of zero at all times (its velocity vector points at the target). Peregrine falcons were found to use a variety of values of N resulting in a quicker path to interception. A remarkable feature of most bird of prey eyes is that they possess two regions of high visual acuity - the shallow and deep foveae. The deep fovea is optimised for long-range vision, and is directed at approximately 45° to the side of the head. It has been proposed that the head is held in line with the body for streamlining, while the body is turned in flight to fixate the image of the prey on the deep fovea, resulting in a curved trajectory. My results contradict this theory, as falcons were seen to use saccadic head movements to maintain the image of the prey in their field of view whilst flying along curved trajectories - suggesting a different visual strategy. I provide the first quantitative analysis of how birds are able to guide their flight for successful prey capture. Not only does this provide new insights into animal behaviour and evolution, but this research has many applications in engineering, where there is a wide and growing interest in vision-based approaches to guidance and control in both civil and military spheres.

Abstract Relationships between predators and prey may affect population dynamics of both parties. Predators may also serve as a link between populations of different prey, e.g., small game and small mammals. I used available data on the diet and reproduction of birds of prey (mainly common buzzards Buteo buteo and goshawks Accipiter gentilis) and video surveillance of their nests, as well as multiannual data on numbers of grouse and small mammals for studying food habits and population dynamics of raptors and their links with population fluctuations of voles and grouse (capercaillie Tetrao urogallus, black grouse Tetrao tetrix and hazel grouse Bonasa bonasia) in western Finland during 1980–1990s when grouse and vole numbers fluctuated in regular cycles. Microtus voles were the main prey of the buzzards which partly switched their diet to small game (juvenile grouse and hares) in years when vole numbers declined. The nesting rate of buzzards also correlated with vole abundance, but the productivity rate and brood size tended to lag behind the vole cycle. This mismatch between the buzzards' functional and numerical responses resulted in a fairly small impact of buzzards on juvenile grouse, which did not correlate with vole density. The productivity of goshawks followed the fluctuations of grouse density closely whereas the occupancy rate of goshawk territories did so with a two-year lag. The annual numerical ratio of goshawk to grouse was inversely related to grouse density, suggesting that this predator may be a destabilising factor for grouse population dynamics. However, the goshawks' kill rate of grouse showed no clear relations to grouse density. In June–July, these birds of prey (including hen harriers Circus cyaneus) usually killed a relatively small number of grouse chicks. Losses to raptors constituted up to one quarter of grouse juvenile mortality during the two months. We did not find a strong effect of avian predators on grouse juvenile mortality. In boreal forests, predators and other factors of grouse mortality do not operate as one, and there is probably no single factor responsible for the reproductive success of grouse.

The interrelationships between species composition, resource-use and availability, breeding and competition were studied in two hill habitat raptor communities in a conserved reserve and an unprotected communal land in Zimbabwe in 1995 and 1996. The conserved Lonestar Study Area (LSA) and the unprotected Communal Land Study area (CLSA) had 38 and 31 raptor species, high and normal diversities for the area sizes respectively. An estimated 147 pairs of 21 raptor species bred in 40km² in the LSA compared to only 26 pairs of 22 raptor species per 40km² in the CLSA. Six species (African Hawk Eagle Hieraaetus spilogaster, Black Eagle Aquila verreauxii, Crowned Eagle Stephanoaetus coronatus, Little Banded Goshawk Accipiter badius, Barn Owl Tyto alba,and Barred Owl Glancidium capense made up 69% of breeding raptors in the LSA, while African Hawk Eagles, Little Banded Goshawks, Barn Owls and Barred Owls made up 58% of the breeding raptors in the CLSA. The abundance of Black, Crowned and African Hawk Eagles in the LSA was linked to abundant hyrax, Heterohyrax brucei and Procavia capensis and juvenile bushbuck Tragelaphus prey, and the high reproduction rates of Natal Francolin Francolinus natalensis (0.7 per ha when not breeding). Little Banded Goshawk and Barn Owl abundances were linked to their ability to change prey preferences according to prey availability. A fairly high rate of breeding attempts by eagles in the LSA in both years (60 - 76% of all pairs per year)was probably also linked to prey abundance, Most breeding failures were predator related, and were more common in areas of relatively low nesting densities indicating lower parental vigilance there. High eagle breeding densities were associated with small mean territory sizes in the LSA (7.7 - 10.7km² for the main eagle species). Eagles in the LSA usually nested closer to another eagle species than a conspecific, resulting in regular distributions of nests and no territory overlap within species. Differences in daily flight activity of eagles in both study areas, and in the onset of breeding between LSA eagles probably reduced interspecific aggression. Interspecific competition food and nest sites amongst LSA eagles was possibly lessened by slight ditferences in resource selection. Raptor resources were mostly unaffected by human activities in either study area during the study period. Differences in the raptor communities were probably as a result of natural habitat differences. The CLSA raptors potentially face resource loss through forest clearing and hunting. An expansion of the present CAMPFIRE program will protect the CLSA raptors.

The ability to accurately identify individuals is required for the detailed study of animals. Numerous artificial markers have been developed for this purpose. Negative effects on survival, reproductive success and behavior have been reported for most marking methods, significantly affecting the very parameters being studied.
Birds of prey have suffered the shortcomings of artificial marking methods. In light of the known and potential deleterious effects of marking, attention has been focused on developing new techniques to identify individual raptors without attaching artificial markers.
This study investigated the use of tarsal scale patterns as unique individual identifiers in birds of prey. The American kestrel (Falco sparverius) was chosen as a model. Both legs of seventy-five kestrels were photographed over a two-year period.
Photographic comparisons of 150 scale patterns demonstrated the uniqueness of each and therefore its ability to be used as an individual's natural identifier. Furthermore, patterns were found to remain unchanged from one year to the next. These findings support the hypotheses that tarsal scale patterns are unique to each bird and do not change over time.
A method of coding the tarsal scale patterns was developed. These codes can be used in a computerized data base to significantly enhance the speed of pattern searches.

Multiple-brooding (raising more than one brood of young in quick succession) occurs infrequently in raptors and is generally restricted to either smaller species with shorter nesting periods, co-operative breeders or species capable of capitalizing on conditions of prolonged food abundance whenever they occur. This paper presents the first recorded cases of multiplebrooding in the Black Sparrowhawk Accipiter melanoleucus from two distinct locales in South Africa. In the Western Cape (Cape Peninsula), four attempts to multiple-brood were recorded in four different years, involving three distinct pairs of birds, and in KwaZulu–Natal (Eshowe), three distinct pairs of Sparrowhawks successfully multiple-brooded on several occasions over a 5-year study period. These results establish the Black Sparrowhawk as one of only two relatively large, monogamous raptor species, and the only specialist bird-eating raptor, in which multiple-brooding has been recorded with any frequency. The species’ capacity to thrive in human-modified environments (i.e. alien plantations) and particularly to exploit associated foraging opportunities (e.g. high densities of doves and pigeons in suburban areas) may, at least partly, account for the instances of multiple-brooding reported here. We suggest that biologists be more vigilant for cases of multiple-brooding in raptors, as it is possible that this trait is more common than originally thought and has previously been overlooked.

Predation by exotic predators (cats Felis catus and foxes Vulpes vulpes) is believed to be one of the factors that has contributed to the decline of medium-sized mammals in arid Australia. Other factors include habitat degradation by introduced herbivores (rabbits Oryctolagus cuniculus and grazing stock) and altered fire regimes after Aboriginal people moved into permanent settlements. In general, the impact of exotic predators on arid zone mammals is believed to be significant only when predator numbers have been elevated by increased food availability from exotic prey species (rabbits, house-mice Mus domesticus, cattle carcasses) or when native prey populations have already been dramatically reduced by competition from introduced herbivores. In much of the spinifex grasslands of the central Australian deserts, pastoralism never occurred, rabbit colonisation was extremely patchy and in some areas, traditional burning was still being practised when the extinctions commenced. None of the current models of mammalian extinctions adequately explain the declines in this environment. In this study I examined predator-prey interactions in two areas of the Tanami Desert to investigate whether predation by exotic predators may be a primary agent of extinction in its own right, capable of causing mass declines even in the absence of other human-induced perturbations. If this were the case then the following would be expected: (i) cats and foxes would eat medium-sized mammals when they are available, but be able to survive on alternative prey when mammals are scarce; (ii) populations of cats and foxes would be buffered against the declines of mammals during droughts, or would be able to recover more quickly than medium-sized mammals after droughts; (iii) medium-sized mammals would be more vulnerable to predation by cats and foxes than by dingoes Canis lupus dingo and other native predators, and (iv) there would be a correlation between the timings of the extinctions and the colonisation (or sudden increase) of cats and foxes. These predictions were investigated by monitoring the diets and relative abundance of cats, foxes and dingoes in relation to fluctuating prey availability in two areas of the Tanami Desert at latitudes separated by approximately 400 km. Mean annual rainfall is higher and more reliable in the northern study area which was situated in the centre of bilby Macrotis lagotis distribution within the Northern Territory, whereas the southern study area was located on the southern edge of the bilby�s range. Within each study area, monitoring occurred at three sites, approximately 20 km apart. Each site contained a sub-plot in each of two habitat types. Field work was conducted between September 1995 and December 1997. When the study began, the southern study area was experiencing drought conditions, however both study areas received significant rainfall in early 1997. The population dynamics of a variety of potential prey groups were monitored to examine their resilience during droughts, patterns of recolonisation after rainfall, and use of two habitat types: the ubiquitous sandplain, and the moister, nutrient enriched palaeodrainage habitat which is believed to have provided a refuge for medium-sized mammals during droughts. Native mammals were uncommon throughout the study period. Bilbies and macropods were significantly more abundant in the northern study area, and tended to occur more frequently in palaeodrainage habitat than sandplain. However, the palaeodrainage habitat did not appear to provide adequate refuge for the medium and large mammals during drought conditions in the southern study area, as they disappeared from the study sites altogether. Small mammals were significantly more abundant in the southern study area but densities remained low (less than 2% trap success) throughout the study, and showed little response to improved seasonal conditions. In contrast, the abundance and species richness of birds showed a marked increase following rainfall in the southern study area. Flocks of nomadic birds arrived within several months of drought-breaking rains, increasing the relative abundance of birds from 9.3 per km of transect in December 1996 to 49/km in July 1997. Reptiles were the most resilient prey group during the drought conditions. Both varanids and smaller reptiles were equally abundant in the wet and dry years and showed no difference in abundance between study areas. However, reptiles showed marked temperature-related patterns in activity, with many species becoming inactive in the winter months. A total of 142 cat scats, 126 fox scats and 75 dingo scats were analysed to investigate predator diets in the two study areas. Unlike cat, fox and dingo diets elsewhere in Australia (and the world), mammalian prey did not dominate. Reptile was the prey category that was most frequently consumed by cats and foxes in �summer� (October-April) and by dingoes throughout the year, and was identified as a �seasonal staple� prey type for all three predators in the Tanami Desert. When biomass of prey was taken into account, the varanids (predominantly the sand goanna Varanus gouldii) were the most important prey sustaining predators in the two study areas. Birds were an important part of the diets of cats and foxes in winter when reptiles were less active. Small mammals were consumed by cats and foxes throughout the study, in proportion to their field abundances. Invertebrates were a major component of the diets of foxes, representing 31% of prey items consumed. There was considerable overlap in the diets of the three predator species, but dingoes ate more medium (100-999 g) and large (greater than 1000 g) prey than cats and foxes did. The scarcity of medium-sized mammals in the study areas provided little opportunity to find evidence of predation events on such prey. However, bilby remains were found in two cat scats and one dingo scat in the northern study area, mulgara Dasycercus cristicauda remains occurred in several cat and fox scats from the southern study area, and there were fourteen occurrences of marsupial mole Notoryctes typhlops in predator scats during the study, primarily in fox scats. Elsewhere in Australia, there is ample evidence that cats and foxes regularly consume medium-sized mammalian prey (e.g. rabbits and ringtail possums Pseudocheirus peregrinus) when it is available. Overall cats were the most abundant eutherian predators in the two study areas, and they were significantly more abundant in the northern study area than the southern study area. Surveys revealed that cats can persist into droughts by feeding on reptilian prey. When the study commenced, cats occurred on five of the six sub-plots in the southern study area, despite six consecutive years of below-average rainfall. However, by the end of the first year, they could only be detected on one sub-plot. Recolonisation of the sites rapidly occurred after significant rainfall (260 mm in 2 months), when nomadic birds colonised the sites and provided a plentiful food source. Foxes also declined to very low densities during drought in the southern study area, but they had recolonised all sites by the winter of 1997. This coincided with the increase in abundance of birds, which became their most frequently consumed prey item. Overall, foxes were equally abundant in the two study areas, but statistical analyses revealed a significant interaction between latitude and habitat because in the southern study area foxes tended to utilise the palaeodrainage habitat more than the sandplain, whereas in the northern study area the majority of fox sign was detected in the sandplain habitat. This may have been due to the abundance of dingoes in the palaeodrainage habitat in the northern study area. Dingoes were significantly more abundant in the northern study area than the southern, where they were usually only present at one of the three sites. The northern study area had higher densities of macropods (supplementary prey for dingoes) and more reliable access to drinking water, which persisted in the palaeodrainage channels for up to 6 months after significant rain events. Dingo numbers were relatively stable throughout the study and did not increase in response to improved seasonal conditions in the southern study area in 1997. This study revealed that the distribution of foxes extends further north into the Tanami Desert than has previously been reported, and is not necessarily tied to the distribution of rabbits in the Northern Territory. Furthermore, discussion with Aboriginal people who lived a traditional lifestyle in the area until the 1940s, revealed that foxes were already present in the northern Tanami desert at that time, before the disappearance of many medium-sized mammal species. The patterns of medium-sized mammalian extinctions in the northern and western deserts between 1940 and 1960 is thus consistent with the colonisation of the fox. Although cats had been present in central Australia for at least 50 years before the mammalian declines occurred, this does not discount them from contributing to the extinction process. It is postulated that during the early decades of their colonisation of the arid interior, cat populations may have been maintained at low levels by predation from dingoes and also Aboriginal people (for whom cats were a favoured food). But between 1920 and 1960 the western deserts were depopulated of Aboriginal people, and human hunting of cats diminished. This coincided with the introduction of the dingo bounty scheme, which encouraged many Aboriginal people to continue making regular excursions into the deserts to collect dingo scalps. In this study, cat remains occurred in 9% of dingo scats, suggesting that dingoes may be an important predator of cats. Thus, there may have been an increase in the cat population between 1930 and 1960, producing a more significant impact on native mammal populations than had previously occurred. Information collected during this study was used to construct a new model of mammalian extinctions in the spinifex grasslands of central Australia that promotes predation by cats and foxes as the primary agent of extinction. The model proposes that cats and foxes will eat medium-sized mammals when they are available, but are capable of subsisting on naturally occurring alternative prey when mammals are scarce. Thus, cats and foxes can persist into drought periods by feeding on reptilian prey, which remains an abundant resource regardless of rainfall (at least during the warmer months). Predator populations eventually decline after a series of dry winters. When the drought breaks, the rapid response of nomadic birds provides a readily available food source for cats and foxes as they recolonise areas and commence breeding. Predation by cats and foxes thereby has the potential to exacerbate the declines of native prey populations during droughts and delay their recovery when seasonal conditions improve. In this way, introduced predators are capable of causing local extinctions of medium-sized mammals when populations contract during drought periods, even in the absence of introduced herbivores and altered fire regimes. Although dingoes also prey upon medium-sized mammals, dingoes did not cause extinctions of medium-sized mammals in the spinifex grasslands because (i) they are more reliant on drinking water than foxes and cats, thus waterless areas would have provided some degree of predation refugia, and (ii) their social structure and territoriality prevent high densities accumulating, even when resources are abundant. If further extinctions of medium-sized mammals (such as the bilby) are to be prevented, it may be necessary for wildlife managers to establish a series of predation refugia where fox and cat populations can be controlled without extinguishing local dingo populations. This could be achieved with a combination of predator-proof enclosures, zones in which foxes are killed through poison baiting and areas where Aboriginal people are employed to utilise traditional hunting methods to control introduced predators.

The seasonal and diel feeding habits of the goosander, Mergus merganser, the red-breasted merganser, M. serrator, gulls (Larus canus, L. argentatus and L. fuscusj and terns, Sterna hirundo/paradisaea were studied at 64V05'N. Birds' activity patterns were influenced by the nocturnal spawning of the river lamprey (Lampetra fluviatilis). Food selection and food consumption by hand-raised mergansers together with aquarium studies of the diel activity patterns of their most important prey supplemented the field data. River lamprey dominated the diet of the goosander by weight and the sculpin Cottus gobio by number. The fish consumption of the goosanders was found to be about 12% of the available river lamprey biomass and about 17% of the sculpin biomass during the breeding season. In experimental situations the river lamprey was a low- pritority species compared with salmon , Salmo salar, brown trout, 53. trutta, and minnow, Phoxinus phoxinus, when presented to satiated birds of both Mergus species. When hungry, however, the birds caught the available prey irrespective of species, but they selected larger prey when two size classes were present. Experimental results were compared with field data on availability, consumption and the escape behaviour of the various fish species. The rivers emptying in the Bothnian Bay are regarded as important feeding areas for birds breeding along the coast. In early spring they get access to abundant and reliable food resources, e.g the river lamprey. Later on the three-spined stickleback, Gasterosteus aculeatus, supply both Mergus species with food in the river and also along the coast. From the middle of June potential food supply available to birds decreases in the rivers and becomes more abundant in the coastal area.

S. 1-41: sammanfattning, s. 43-227: 7 uppsatser

digitalisering@umu

This study aims to deconstruct current conceptions about animal-assisted interventions by investigating relationships between human beings and birds of prey. Interactions between birds of prey, or “raptors,” provide novel cases from which to reexamine failed attempts to provide empirical data in support of alternative therapies. Previous research addressing the efficacy of animal-assisted interventions is simply not robust enough to be considered a feasible treatment option by medical professionals. By extension, models of self-regulation in psychology are often presented using reductionist models and oversimplified therapeutic outcomes. Taken together, raptor-human relationships help to highlight the shortcomings of each, as well as potential solutions towards developing comprehensive frameworks for measuring efficacy of multispecies interactions. This study was conducted at a small nature park in Largo, FL where a number of native raptor species are housed, cared for, and trained each day by volunteers. These volunteers made up the sample size for this study with forty participants (n = 40) between the ages of eighteen and seventy five. Drawing on both my own experiences as a raptor handler, as well as the qualitative data collected from volunteers, I employed a neuroanthropological approach to reveal underlying dynamics of the program via a two-stage research plan. Stage 1 of the study addresses the Raptor Program itself in facilitating human-animal interactions. Stage 2 addresses the mechanisms at play during firsthand encounters with birds of prey. Findings suggest that programmatic and regulatory drivers within the program must operate together, often simultaneously, for an animal-assisted intervention organization to be successful. Further, this study calls for the ongoing development of novel methodological approaches in future research to determine the efficacy of animal-assisted interventions at large.

Odour plays an important role in many predator/prey interactions. In the northern hemisphere, many mammalian prey species have been shown to respond to predator odours. It is also widely assumed that mammalian predators utilise odours to locate their prey. This thesis explores the importance of odour in Australian mammalian predator/prey interactions. Responses of native Australian species to the faecal odour of two predators; the native tiger quoll Dasyurus maculatus and the introduced red fox Vulpes vulpes, were evaluated through live-trapping and focussed behavioural studies of captive animals. Tiger quoll responses to prey olfactory cues were investigated in a captive experiment. Native rodents (bush rats Rattus fuscipes, swamp rats R. lutreolus and eastern chestnut mice Pseudomys gracilicaudatus) equally avoided traps scented with either quoll or fox faeces, and in captive experiments, bush rats and swamp rats reduced their average speed in response to both predator odours. Of the marsupial species, northern brown bandicoots Isoodon macrourus and common brushtail possums Trichosurus vulpecula were captured more frequently in quoll-scented traps than unscented traps or foxscented traps, while captures of brown antechinus Antechinus stuarttii, long-nosed bandicoots Perameles nasuta and southern brown bandicoot I. obesulus were unaffected by the either predator odour. In captive experiments, brown antechinus, long-nosed and northern brown bandicoots decreased their foraging in response to both predator odours, and spent less time in areas scented with quoll faeces. Tiger quolls didn't appear to detect odour sources from a distance of >65 cm, but they did follow scent trails and spent more time in areas scented with the urine and faeces of potential prey. Chemical analysis revealed no common components in fox and quoll odour which prey species could be responding to. Therefore, these native species have evolved to respond to fox odour since foxes were introduced to Australia 130 years ago. The stronger response of native rodents to fox odour may be a legacy of their co-evolution with canid predators prior to entering Australia. A better understanding of how odour is utilised in Australian predator/prey interactions may lead to a greater ability to protect Australia's unique mammalian fauna from introduced predators.

This research advocates a multi-method approach to bioarts praxis, reflexively and critically questioning the contemporary contexts that frame our engagement with nonhuman life. In doing so, the research aims to generate further community engagement with nonhuman life and the environment, and engender critical discourse on the implications of developing biotechnologies. Hegemonic institutions influence the way culture is produced and how information is constructed and understood. Habermas (1987) suggests that these institutions will inevitably influence the individual’s lifeworld as they shape lived experience through the process of systemic colonisation. I assert that this process also shapes how individuals engage with or understand nonhuman life. Through the implementation of three major projects the research aims to develop the capacity of bioarts in challenging such institutions by providing the opportunity for hands-on life science activities and real-time interactions with nonhuman life. The research by employing such methods aims to counter-act the impact of urbanised living and indifference to environmental conservation. Each aspect of the creative praxis provides a reflexive case study to establish the research aims and answer the research agenda. This includes my creative bioartworks, an art-science secondary educational course and a curated group exhibition, symposium and workshop. This research provides an alternative communicative approach to hegemonic institutions such as the mass media, scientific biotechnological industries and traditional gallery spaces (Shanken, 2011).

The Puerto Rican coqui frog (Eleutherodactylus coqui) has been hypothesized to affect bird communities in Hawaii by 1) competing with insectivorous birds for prey, 2) providing prey for predatory birds, and 3) bolstering populations of non-native mammals by serving as prey. No previous studies have collected empirical data on these potential impacts. We investigated the impact of coquis on birds at two scales. For our first research question, we used stable isotope analyses to address whether three species of insectivorous bird, one native and two non-native, and coquis could compete for invertebrate prey. We found that the coquis overlapped in isotopic niche space with all three bird species, which suggests these species occupy a similar place in the food web. However, our Bayesian diet analysis suggests that coquis mostly feed on Acari, Amphipoda, and Blattodea (>90%), and only consume about 2% Araneae, the only diet source they share with birds. This result suggests that coquis do not heavily compete with these bird species for prey. For our second research question, we conducted avian point counts in coqui and non-coqui plots across 15 sites on the island of Hawaii. We modeled whether coqui presence or density explained patterns of insectivorous, vertebrate-preying, and native bird abundance. We estimated abundances of birds in coqui and non-coqui plots using hierarchical Bayesian N-mixture models with random effects. We tested whether habitat variables differed across coqui and non-coqui plots and whether coqui density was correlated with any habitat variable to more confidently attribute changes in bird abundance across coqui and non-coqui plots to the frogs. We found that coquis were associated with greater abundances of vertebrate-preying, generalist insectivorous, and non-native birds in Hawaii. Vertebrate-preying birds showed the strongest association, with a 0.97 probability of abundance being at least 50% higher in coqui plots. Native birds did not show differences in abundance across coqui and non-coqui plots. Because insectivorous bird and native bird abundance did not differ across coqui invasion fronts, our results suggest that coquis primarily affect Hawaiian birds by serving as a food resource for predatory birds, and not as competitors for invertebrate prey.

Understanding strategies of resource partitioning within populations is a fundamental aspect of the study of ecology, and one which has been well documented across various taxa. In seabirds, sex-specific differences in foraging behaviour are often thought to reflect strategies of resource partitioning to avoid intra-specific competition. At present Bird Island in Algoa Bay hosts the world’s largest breeding population of gannets, with recent population estimates numbering well over 90 000 breeding pairs. Given the large size of this colony, intense levels of intra-specific competition are expected during the breeding season, particularly in years of poor feeding conditions. In addition, continuous foraging around the breeding colony may lead to the local depletion of prey as the season progresses, calling for flexibility in the foraging behaviour and diet of breeding individuals. Therefore, the aim of this dissertation was to investigate resource partitioning in Cape gannets breeding at Bird Island through strategies of sex-specific foraging and intra-seasonal variability in foraging behaviour and diet. To achieve this, the spatial and temporal aspects of Cape gannet foraging behaviour were assessed during the early stages of chick rearing, over two consecutive breeding seasons (2011/12, 2012/13) using GPS tracking and VHF monitoring. In addition, intra-seasonal variability in foraging behaviour and diet were investigated, taking into account the influence of sex and chick age, to provide a comprehensive assessment of foraging behaviour throughout the chick rearing period. GPS tracking data for 79 birds revealed limited evidence for sex-specific differences over spatial dimensions. An extension in the foraging range of females during a year of lower prey availability (2012/13) was, however, evident. This suggests a possible sex-specific response to prey limitation, likely reflecting resource partitioning strategies or differences in nutritional requirements. VHF data for 95 additional birds revealed a clear pattern in temporal foraging behaviour. In general, females were more likely to be on a foraging trip during the early and mid-day hours, with the probability of males being on a foraging trip increasing towards the late afternoon. Continuous tracking of individuals throughout the 2015/16 breeding season further revealed little evidence for sex-specific differences in spatial distribution and forging effort during both the guard and post-guard stages of chick rearing. A clear increase in foraging range was evident during the early stages of chick rearing as the season progressed. However, birds attending chicks older than 50 days showed an unexpected contraction in foraging range, which appeared to coincide with a dietary shift. During the early stages of breeding the diet was comprised almost exclusively of anchovy, the proportion of which decreased progressively in the diet throughout the breeding season. This was mirrored by a substantial increase in the proportion of saury in the diet. These results suggest that Cape gannets increase their foraging range in response to local prey depletion as the breeding season progresses. However, when alternative prey becomes available they may shift their diet, allowing them to access prey closer to the breeding colony. Overall, this dissertation provides insight into sex-specific behaviour in a monomorphic seabird, suggesting a marginal degree of spatial segregation. The results provide the first support for sex-related temporal foraging segregation in gannets. Such separation could potentially be driven by resource partitioning, but could also relate to differential nutritional requirements. In addition, this study also provided the first comprehensive assessment of foraging behaviour throughout the guard and post guard stages of chick rearing in gannets. These results suggest that a combination of foraging and dietary flexibility may allow Cape gannets to buffer the effects of prey depletion during the breeding season. In conclusion, resource partitioning through sex-specific foraging appears to be limited in the Cape gannet population at Bird Island. Segregation via alternative pathways may however be possible and as such, future studies should consider the influence of individual level segregation and habitat specialization.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on May 6, 2009) Vita. Includes bibliographical references.

Evolution can occur rapidly, along timescales that are traditionally regarded as 'ecological'. Despite growing acceptance among biologists of rapid evolution, a strong paradigm of contemporary evolution is still absent in many sub-disciplines. Here I apply a contemporary evolution viewpoint to conservation biology. Specifically, I examine the impact of cane toads (Bufo marinus) on Australian snakes. Toads were introduced into Australia in 1935, have spread rapidly and represent a novel, extremely toxic prey item to na�ve Australian predators (including snakes). Based on dietary preferences and geographic distributions I find that 49 species of Australian snake are potentially at risk from the invasion of the toad. Furthermore, examination of physiological resistance to toad toxin in 10 of these �at risk� species strongly suggests that most species of Australian snake are poorly equipped to deal with a likely dose of toad toxin. Even species that are highly resistant to toad toxin (such as the keelback, Tropidonophis mairii) face indirect fitness costs associated with consuming toads. Within a population of snakes however, the impact of toads is unlikely to be random. For example, the examination of several component allometries describing the interaction between snakes and toads revealed that, within a species, smaller snakes are more likely to ingest a fatal dose of toad toxin than are larger snakes. Further consideration of the interaction between snakes and toads suggests that toads will not only be exerting differential impact on snakes based upon morphology, but also exert non-random selection on prey preference and resistance to toad toxin in snake populations. To examine the possibility of a morphological response by snakes to toads, I examined changes in the body size and relative head size of four species of snake as a consequence of time since exposure to toads. Two of the species (green treesnakes and red-bellied blacksnakes) are predicted to face strong impacts from toads. These two species showed an increase in mean body size and a decrease in relative head size as a consequence of time since exposure to toads; both changes in an adaptive direction. In contrast, the other two species (keelbacks and swampsnakes) are predicted to face much lower impact from toads, and these two species showed little or no evidence of morphological change associated with time since exposure to toads. These results indicate an adaptive change in morphology at a rate that is proportional to the predicted level of impact for each species, strongly suggesting an evolved response. Red-bellied blacksnakes (a toad-vulnerable species) were further assessed for evolved responses in prey preference and toxin resistance. Comparisons between toad-exposed and toad-na�ve populations of blacksnakes revealed that snakes from toad-exposed populations exhibited slightly higher resistance to toad toxin and a much-reduced tendency to eat toads, when compared with toad-na�ve snakes. Na�ve snakes exhibited no tendency to learn avoidance of toxic prey, nor were they able to acquire resistance to toxin as a result of several sub-lethal doses, suggesting that the observed differences between populations is evolved rather than acquired. Together, these results strongly suggest that blacksnakes are exhibiting an evolved shift in prey preference and toxin resistance as a consequence of exposure to toads. Thus, it appears that snakes are exhibiting adaptation at multiple traits in response to exposure to toads. Given the high likelihood that these adaptive shifts have an evolved basis, it appears that the impact of toads will decrease with time in many snake populations. But what about toads? Because the outcome of the interaction between a toad and a snake is also mediated by the body size and relative toxicity of toads, it is important to understand how these traits vary in space and time. Exploratory analysis revealed that toads exhibit a decrease in body size and a decrease in relative toxicity as a consequence of time since colonisation, indicating that their impact on native predators decreases with time. Additionally, there appears to be meaningful spatial variation in toad relative toxicity, indicating that some populations of native predators are facing higher impact from toads than others. Overall, these results clearly indicate the importance of assessing the potential for rapid evolutionary response in impacted systems. Doing so may provide evidence that some species are in less trouble than originally thought. Additionally, and as more data accumulate, it may be possible to characterise certain categories of environmental impact by their potential for eliciting adaptive response from �impacted� species. This approach has strong implications for the way conservation priorities are set and the way in which conservation dependent populations are managed.

House cat movements in Canberra suburbs adjacent to grassland and forest/woodland areas were examined using radio-telemetry over 9 months. Information on the composition of vertebrate prey caught by house cats in Canberra was also collected by recording prey items deposited at cat owners' residences over 12 months. Home range areas of 10 suburban house cats, and a colony of seven farm cats, were examined using 95% convex polygons. Nocturnal home range areas of the suburban cats varied between 0.02 and 27.93 ha (mean 7.89 ha), and were larger than diurnal home range areas (range 0.02 to 17.19 ha - mean 2.73 ha). Nocturnal home range areas of cats from the farm cat colony varied between 1.38 and 4.46 ha (mean 2.54 ha), and were also larger than diurnal home range areas (range 0.77 to 3.70 ha - mean 1.70 ha). Activity levels were greater at night than during the day, though diel activity patterns varied seasonally in response to ambient temperature. Four suburban house cats moved between 390 m and 900 m into habitat adjoining the suburb. Movements further than 100-200 m from the suburb edge were always made at night. Polygons describing the home ranges of these animals were strongly spatially biased away from the suburban environment, though the cats spent the majority of their time within the bounds of the suburb. In addition to nocturnal and diurnal effects, home range areas, and subsequently habitat utilisation, appeared primarily determined by the density and spatial distribution of cats utilising separate food resources, and the dominance of individual cats in local social hierarchies, rather than gender or neutering effects. Home ranges of cats in the farm cat colony overlapped extensively, as did those of cats living at the same suburban residence. There was little or no overlap between the home ranges of cats from different residences. Barriers, in the form of busy roads, appeared to also significantly influence home range size and shape. Within home range areas, house cat movements during the day appeared strongly influenced by available cover (drains, tall grass, fences and shrubs etc.), and the location of resting/sunning spots and hunting sites close to home. At night, movement patterns appeared influenced by the location of favoured hunting sites toward the outer edges of home range areas (in this study, tall grass and scrub/forest habitat, and farm buildings). Nineteen hundred and sixty one prey items representing 67 species were reported or collected. Sixty-four percent of the prey items were introduced mammals, with native birds comprising 14%, introduced birds 10%, unidentified birds 3%, reptiles 7%, amphibians 1% and native mammals 1%. Predation appeared to be largely opportunistic with respect to spatial and temporal (daily and seasonal) prey availability and accessibility. All amphibians and 62% of mammals taken by cats not confined at night, were caught at night. In contrast, 70% of birds caught, and 90% of reptiles, were taken during the day (45% of birds between 0600 h and 1200 h, and 61% of reptiles between 1200 h and 1800 h). There was some evidence that small mammals are preferred prey of house cats. The mean number of prey items reported per cat over 12 months - 10.2 � 2.66 (2SE, n=138) - was significantly lower than mean predation per cat per year - 23.3 � 6.16 (2SE, n=138) - estimated by cat owners before the prey survey began. Seventy percent of cats were observed to catch less than 10 prey items over 12 months, but for 6% of cats, more than 50 prey items were recorded. Because counts of the amount of prey caught per house cat per unit time were highly positively skewed, data assumptions and statistical parameters used to extrapolate results from the study sample of cats, to the house cat population of Canberra, had a significant effect on estimates of total predation in Canberra. The precision of the total predation estimate was low (± 25%), from a sample of 0.3% of the Canberra house cat population. The accuracy of such estimates are dependent on how representative the study cat sample is of the wider house cat population, and on the proportion of prey items not observed by cat owners. The total amount of prey taken was not significantly influenced by cat gender, age when desexed, or cat breed. Nor did belling or the number of meals provided per day have a significant influence on predatory efficiency. Cat age and the proportion of nights spent outside explained approximately 11 % of the variation in the amount of prey caught by individual cats. House cat density and distance to prey source areas (rural/grassland habitat) explained 43% of variation in predation on introduced mammals and birds. The impact of predation beyond suburb edges is likely to be most significant on populations of small to medium sized arboreal and ground-dwelling mammals, because of their nocturnal nature, and because they appear to be preferred prey types of house cats. Impacts on diurnally active prey, such as most birds and reptiles, are likely to be confined to within 200 m of residential housing (possibly further where good cover is available). Properly enforced nocturnal confinement should restrict the range sizes of cats that roam widely and utilisation of habitat beyond suburb edges, and also reduce predation on mammals and amphibians. Night-time curfews however, are unlikely to greatly reduce predation on diurnally active species, including most birds and reptiles. Curfews are currently neither widely adopted nor effectively practiced in Canberra. Estimates of predation by house cats, particularly extrapolated estimates, should be treated with caution. They do not necessarily reflect relative impacts on different prey types. Nor do high rates of predation prove prey populations are detrimentally effected, particularly in urban environments. Nonetheless, on a small (backyard) scale in suburban environments, and in habitat within 1 km of residential housing, including isolated private properties, predation by individual cats may threaten populations of native wildlife. Hunting by house cats is particularly undesirable in relatively undisturbed habitat because of fundamental differences in the ecological processes operating in these areas (especially isolated remnants) compared with contrived and modified suburban environments. Adverse impacts on native fauna will always be potentially greatest in undisturbed habitat adjacent to new residential developments

Giralang Pond was a water body, with little emergent or submerged vegetation, designed to trap fine sediment and buffer input of rising water to Ginninderra Wetland downstream. Ginninderra Wetland was designed to retain and use sediment nutrients and other potential hazardous materials in urban run-off. Water in the Wetland was more turbid and had lower magnesium concentration, redox potentials and dissolved oxygen concentration than did Giralang Pond. Water temperature was a minimum of 4 °C in the winter and reached a summer maximum of 30 °C Giralang Pond had more organisms but fewer taxa than Ginninderra Wetland. The greatest abundance in the pond resulted principally from high numbers of two numerically dominant species Calamoecia sp. and Micronecta sp.. More organisms were found in vegetated habitats of Ginninderra Wetland than open water habitats. The number of invertebrates and the number of taxa found in Typha domingensis did not differ significantly from similar estimates for Schoenplectus validus, Gambusia qffinis was the dominant predator in both water bodies. On one occasion, G. qffinis reached population densities of 35 individuals per m-2 . G. qffinis was five times more abundant in Gininnderra Wetland than in Giralang Pond and also showed a preference for vegetated areas. G. qffinis over-grazed it's prey on several occasions. G. qffinis, invertebrate predators and prey followed a pattern of a community in a stable predator-prey cycle. Prey in early spring increased population numbers and then decreased when G. qffinis and other predators increased their numbers. The pattern was further strengthened by occurring in both areas of open water and vegetated habitat types.

Doctor of Philosophy
Department of History
Donald J. Mrozek
During the Cold War, the United States’ foreign policy relied heavily on its ability to project military power. More often than not, the central component of force projection rested on the United States military’s effectiveness in employing air power both by establishing air superiority and through accurate delivery of ordnance. As the primary service tasked with conducting aerial warfare, the United States Air Force (USAF) was expected to maintain this capability either to achieve deterrence or, when necessary, to military action. In January 1973, the USAF seemed incapable of performing the latter task due to the North Vietnamese Integrated Air Defense System’s (NV-IAD’s) effectiveness in Operation Rolling Thunder and its successor, Operation Linebacker. Eighteen years later, Air Force aircraft spearheaded the Coalition’s air attack on the Iraqi Integrated Air Defense System (I-IADS) in January 1991. Considered by many to be the most effective air defense system outside the Soviet Union’s, the I-IADS was expected to exact heavy casualties from the allied forces. Instead, in less than twenty days, the USAF’s dominance was so complete that politicians, analysts and military historians quickly proclaimed a “Revolution in Military Affairs” (RMA). The majority of the current historiography credits advances in precision-guided munitions (PGMs), airframes, and computer technology as the impetus for the RMA. Others have claimed that the USAF’s training methodology and construction of advanced training sites such as the Red Flag complex at Nellis Air Force Base were the primary drivers for the Air Force’s success. While acknowledging the role all of these factors played, this dissertation also demonstrates the key role played by the development of Suppression of Enemy Air Defense (SEAD) doctrine from January 1973 through August 1991. In the aftermath of the American war in Vietnam, the Air Force considered defense suppression a tactical task that was secondary to the primary mission of putting ordnance on target. At the end of Desert Storm, proponents of the Air Force’s SEAD doctrine had convincing evidence that an enemy IADS was not just an ancillary weapons array, but functioned a critical national system just like manufacturing, government, or the people’s will. The process by which this viewpoint changed had effects on the development of the United States Air Force’s Cold War conventional capability in general, and the development of training methods, electronic warfare platforms, and modern airframes specifically.

Anthropogenic habitat modification is a significant threat to the conservation or global biodiversity. The fragmentation and alteration of woodland habitat has resulted in the substantial decline of many woodland bird species in the agricultural regions of southern Australia. The Rufous Treecreeper Climacteris rufaa, a once common woodland resident, has declined in abundance in the wheatbelt of Western Australia and appears to be sensitive to habitat fragmentation. The reasons for this are unclear because our knowledge of the species and the threats posed by fragmentation arc limited. In this study, I compared the social organisation, habitat selection, reproductive success, dispersal and population dynamics of two Rufous Treecreeper populations living in the Western Australian wheatbelt. The first population occupied a large (8,500 ha), relatively undisturbed and unfragmented landscape. The second occurred in an equivalent sized area that had been substantially modified by agriculture. I hypothesised that habitat fragmentation and alteration would adversely affect the viability of the population living in the agricultural landscape. In the unfragmented landscape, treecreepers lived in cooperatively breeding, territorial groups. A group usually comprised a primary (assumed to be breeding) male and female, and philopatric offspring (helpers) from previous breeding seasons. Helpers assisted in the feeding and caring of nestlings and there was a positive relationship between group size and reproductive output. Breeding groups often fanned interactive neighbourhoods whereby resident individuals from one territory would feed nestlings in adjacent territories. A total of 77.7% of 148 nesting attempts produced at least one fledgling. Annual productivity per breeding group (n = 90 group years) was 2.1 ± 0.18 fledglings. Fledgling and juvenile survival rates (0.76 ± 0.04 and 0.46 ± 0.03 respectively) were comparatively high, as was the annual survival rate of primary males (0.77 ± 0.06) and females (0.75 ± 0.05). A multi-scaled analysis of habitat use in the unfragmented landscape identified preferential habitat selection by the species at three spatial scales. At the landscape scale, treecreepers used Wandoo Eucalyptus wandoo woodland at a significantly higher rate than predicted by the availability of this woodland type. Territory selection was positively correlated with the density of hollow bearing logs and nest sites, and tree age. These structural characteristics were also positively correlated with reproductive success und survival in treecreepers, indicating that habitat structure may be a useful measure of territory quality. Nest sites (hollows) were preferentially used if they had a spout angle of ≥ 50° and an entrance size or 5-10 cm, but nest-site selection was not related to nest success. The ecological traits of the treecreeper population living in the agricultural landscape differed from the population in the unfragmented area in a number of ways. Habitat fragmentation in the agricultural landscape disrupted territory contiguity with adverse consequences for social interaction. Nest success and annual productivity were significantly lower in the agricultural landscape, although they varied between different categories of habitat remnants. Reproductive success was lowest in grazed remnants supporting comparatively high population densities. Landscape differences in success did not appear to be a result of a disparity in nest predation levels, but may be related to variation in food availability and habitat quality. The spatial structure and dynamics of the subdivided population in the agricultural landscape were consistent with certain aspects of metapopulation theory. Treecreepers lived in spatially discrete local populations that were unlikely to persist without immigration owing to low reproductive and survival rates. However, movement between habitat remnants appeared to be sufficient to rescue these local populations from extinction. Although declining in numbers during the study, the subdivided population in the agricultural landscape appeared to be fluctuating around equilibrium owing to immigration from outside the study area. The consequences of habitat fragmentation for the Rufous Treecreeper are complex and interactive. A reduction in habitat area and an increase in remnant isolation disrupts the social organisation of the species and results in small localised populations that are susceptible to extinction. Modification of the remaining vegetation may reduce habitat quality leading to poor reproductive success. In addition to increasing habitat area and maintaining landscape connectivity, future management of fragmented landscapes must focus on improving the quality of remnant vegetation by removing degrading process and ensuring the recruitment of endemic plant species.

Worldwide declines in populations of large elasmobranchs and the potential cascading effects on marine ecosystems have garnered considerable attention. Far less appreciated are the potential ecological impacts of changes in abundances of small to medium bodied elasmobranchs mesopredators. Crucial to elucidating the role of these elasmobranchs is an understanding of their habitat use and foraging ecology in pristine conditions. I investigated the trophic interactions and factors driving spatiotemporal variation in abundances of elasmobranch mesopredators in the relatively pristine ecosystem of Shark Bay, Australia. First, I describe the species composition and seasonal habitat use patterns of elasmobranch mesopredator on the sandflats of Shark Bay. Juvenile batoids dominated this diverse community and were extremely abundant in nearshore microhabitats during the warm season. Stomach content analysis and stable isotopic analysis revealed that there is a large degree of dietary overlap between common batoid species. Crustaceans, which tend to be found in seagrass habitats, dominated diets. Despite isotopic differences between many species, overlap in isotopic niche space was high and there was some degree of individual specialization. I then, investigated the importance of abiotic (temperature and water depth) and biotic (prey and predator abundance) factors in shaping batoid habitat use. Batoids were most abundant and tended to rest in shallow nearshore waters when temperatures were high. This pattern coincides with periods of large shark abundance suggesting batoids were seeking refuge from predators rather than selecting optimal temperatures. Finally, I used acoustic telemetry to examine batoid residency and diel use of the sandflats. Individual batoids were present on the sandflats during both the warm and cold seasons and throughout the diel cycle, suggesting lower sandflat densities during the cold season were a result of habitat shifts rather than migration out of Shark Bay. Combined, habitat use and dietary results suggest that batoids have the potential to seasonally impact sandflat dynamics through their presence, although foraging may be limited on the sandflats. Interestingly, my results suggest that elasmobranch mesopredators in pristine ecosystems probably are not regulated by food supply and their habitat use patterns and perhaps ecosystem impacts may be influenced by their predators.

Includes bibliographical references (leaves 150-161). Documents the historical distribution and subsequent decline of bush stone-curlews in South Australia, determines their current distribution and status on Kangaroo Island, their home range sizes and movements, the characteristics of foraging habitat, day roost areas and nest sites and the availability of habitat, the diet and food resources, and potential threats to the population. As a result of the findings of this survey, bush stone-curlews have been downgraded from endangered to vulnerable in South Australia.

The Cape gannet has undergone considerable population change and redistribution over the past 50 years. This has been linked to shifts in the abundance and distribution of their dominant prey, sardine and anchovy. Five breeding colonies, along the west coast of Southern Africa, have shown rapid population declines as a result of reduced prey availability. In contrast, a single colony (Bird Island, Algoa Bay) on the south coast of South Africa has, over the same period, grown fivefold and now supports approximately two thirds of the total population. Due to its conservation importance, and isolation from other breeding localities, it is important to assess the health of the Bird Island colony, and determine how foraging distribution relates to the environment to evaluate current measures of protection. This was achieved through two related studies; a long-term dietary analysis spanning 34 years, and a spatial foraging study, which related three years of tracking data to estimates of prey availability, oceanographic features and marine protected areas (MPAs). The results of the dietary study showed that the dietary constituents of Cape gannets breeding at Bird Island have remained similar over the last three decades, but the importance of sardine and anchovy has increased significantly. For sardine, in particular, this reflects an increased availability of this species (as deduced from hydroacoustic surveys) within the foraging range of the Bird Island colony. The dietary abundance of anchovy was found to be negatively correlated with that of sardine. Surprisingly,.the dietary abundance of anchovy was also negatively correlated with estimates of its availability based on acoustic surveys. The latter is likely to be due to sardine being a preferred prey item. Recent decreases in the dietary contribution of sardine (since 2005) suggest that this species is becoming less available to gannets, with profound implications in terms of nutrient gain associated with foraging. However, this has been mediated by an increase in the dietary contribution of anchovy, which now accounts for the vast majority of prey taken. Spatially, the foraging range of the Bird Island colony expanded during the three years of study, indicating an increase in effort. This increase was likely in an effort to track a distributional change of sardine and anchovy, which showed an apparent westward shift during the study period. There was, however, no evidence of birds tracking features associated with high productivity. This may have been partly due to anomalously warm conditions during the summer of 2012/2013, in which an absence of coastal upwelling prevented surface cooling. Nonetheless, low sea surface temperatures and high chlorophyll a concentrations do not seem to be reliable indicators of important Cape gannet foragingareas. Foraging effort was largely concentrated outside of MPAs, indicating that the current MPA network provides little protection for foraging gannets. This could change with the additional protection of the proposed Greater Addo Elephant National Park MPA expansion, as prey species are allowed to recover following the removal of fishing pressure. Overall, the colony appears to be in good condition as the diet is still dominated by live prey items, and the foraging range remains smaller than many of the colonies along the west coast. However, it is important that monitoring be continued, in particular with respect to changes in the availability of sardine and anchovy. Long-term shifts of these species out of the colony‘s foraging range could negatively influence the population in the future. This might be worsened by interspecific competition for prey resources. Considering the conservation importance of this population, maintenance of healthy prey stocks within the home range of breeding Cape gannets should be prioritised in order to prevent declines similar to those observed at west coast colonies.

For several decades now, seabirds have been considered to be useful indicators of the state of their prey resources because of how they reflect lower-level trophic variability through proxies such as diet or behaviour. However, collection of appropriate data is often challenging in the marine environment because of logistical or financial constraints. In this study, time-activity budgets were studied in the Cape gannet (Morus capensis), a seabird which has been advocated as a potential bioindicator for local epipelagic prey. VHF transmitters attached to PVC leg-rings were fitted to 50 adult breeding pairs during the 2011/2012 and 2012/2013 breeding seasons at Bird Island, Algoa Bay, to determine whether an automated method of continuously collecting time-activity budget data can replace conventional laborious direct observations. To validate that the foraging trip duration data generated from the automated method was a reflection of foraging effort, Time-Depth Recorders (TDRs) were simultaneously equipped to birds with VHF transmitters for three weeks. In order to assess the influence of factors other than prey availability on parent time-activity budgets, sex, chick age and body condition were measured. Additionally, chick growth and survival were recorded in order to investigate the gender-specific effects of parental time-activity budget variability on these parameters. Attachment of VHF transmitters to leg-rings of adult Cape gannets had no observable negative effects on the adults or their chicks in terms of adult body condition, nest attendance and foraging trip durations, or chick growth and survival. Furthermore, the frequency distribution of behaviour bout (foraging trip and nest attendance) durations was no different between automated and directly observed data. However, the automated method did record shorter behaviour bouts, largely attributed to the increased likelihood of direct observations missing birds returning briefly to their nests during older chick provisioning. Additionally, foraging trip duration was highly correlated to foraging effort in terms of time spent resting on the sea surface, flying and diving. The automated method therefore appears to be a good reflection of direct nest attendance observations and foraging effort. Cape gannet time-activity budgets were related to chick age and parental sex. Especially as chicks neared fledging, females spent significantly longer periods of time foraging than males, with males consequently provisioning their chicks more often. Furthermore, adults departing their nests earlier spent more time away from the nest foraging as more same-day daylight hours were available. Chick growth was a function of parent foraging trip duration and associated prey delivery rates. Chick survival was most strongly affected by the amount of time which chicks were left unattended by both parents and consequently exposed to predation by kelp gulls (Larus dominicanus) or to adverse weather conditions. Additionally, for females (but not males) there appeared to be a trade-off between foraging trip duration and chick survival. The Cape gannet appears to demonstrate a strategy whereby the costs of reproduction to the female are shifted towards male-dominated chick provisioning as the chick nears fledging. Drivers of time-activity budget variability such as chick age and parental sex therefore need to be considered if using data on foraging trip duration as a proxy of foraging effort and prey availability.

Despite increasing publicity, habitat loss and fragmentation remain a serious threat to biodiversity. The main objectives of this research were (i) to study the effects of forest fragmentation on the distribution and abundance of resident birds in the fragmented littoral forests of southeastern Madagascar and temperate woodlands of southeastern Australia at three spatial scales (patch, landscape and regional) and (ii) to place the results of these case studies within the realms of the equilibrium theory of island biogeography and its descendent theories, to ascertain whether it is appropriate to use these theories to derive conservation scenarios within these threatened regions. Deforestation of Madagascar's remaining forests is considered a global concern due to both its current high intensity and the small amount of forest claimed to be remaining on the island. Surprisingly, very few studies have considered the impacts of forest fragmentation on bird diversity in Madagascar. A multi-scale study on the effects of littoral forest fragmentation and degradation on birds is therefore a major step forward for bird conservation on the island. Furthermore, prior to this study no known work has been conducted on the avifauna within the threatened littoral forests of eastern Madagascar. My results indicated that (i) the littoral forests contained bird species assemblages that were unique when compared to neighbouring forest habitats, (ii) many forest-dependent bird species were significantly affected by habitat structure and especially proximity to forest edge and (iii) many forest-dependent species were affected by landscape factors such as remnant shape and remnant size. No relationship was found between measures of landscape composition, remnant 'isolation' and bird distribution within littoral forest remnants.

O presente relatório refere-se ao estágio realizado no CRASSA, Centro de Recuperação de Animais Selvagens de Santo André, no município de Santiago do Cacém, na área de clínica médica e cirúrgica de animais selvagens e silvestres, no período de 28 de outubro de 2020 e 29 de janeiro de 2021. Os principais objetivos do estágio foram aprofundar conhecimentos na clínica e medicina de recuperação de animais silvestres, sobretudo as espécies autóctones, e sobre cirurgia oftálmica e cuidados perioperatórios. No CRASSA foi possível acompanhar 72 novos casos, onde 66 pertenciam à classe das aves (91,6%), e os restantes 6 (8,4%) pertenciam à classe dos mamíferos. As causas de entrada variam desde traumas, debilitação, queda do ninho, desorientação, cativeiro e atropelamento. As atividades que a aluna mais realizou ao longo do estágio foram receção dos animais, contenção e exame físico, preparação e administração de medicação, acompanhamento no internamento e alimentação, limpeza das instalações dos animais e enriquecimento animal. Relacionado com o tema, foi possível acompanhar um caso de afeção ocular que precisou de terapêutica cirúrgica. A autora acompanhou de perto o pré, o durante e o pós cirúrgico da ave em questão, e por ser uma cirurgia complexa, despertou interesse na aluna. Um exame físico completo confirma se o animal está apto para cirurgia, e auxilia o profissional a escolher a técnica mais adequada. Os cuidados perioperatórios, como por exemplo, o jejum, a medicação e monitorização pré e pós cirúrgica, e o enriquecimento ambiental vão determinar a recuperação do paciente. Para que haja conservação das espécies selvagens, a criação de novos serviços para estes deveria ser ponderada, e, portanto, uma maior necessidade de profissionais com experiência nos mesmos.
This report refers to the internship carried out at CRASSA, Wild Animals Recovery Center of Santo André, in the municipality of Santiago do Cacém, in the area of a medical and surgical clinic for wild and wild animals, in October 28, 2020, and January 29, 2021. The main objectives of the internship were to deepen knowledge in the clinic and medicine for the recovery of wild animals, especially native species, and about ophthalmic surgery and perioperative care. In CRASSA it was possible to monitor 72 new cases, where 66 belonged to the bird class (91.6%), and the remaining 6 (8.4%) belonged to the mammal class. The causes of entry vary from traumas, debilitation, fall from the nest, disorientation, captivity, and being run over. The activities that the student most performed during the internship were reception of animals, restraint and physical examination, preparation and administration of medication, monitoring during hospitalization and feeding, cleaning of the animals' facilities and animal enrichment. Related to the theme, it was possible to follow a case of eye disease that required surgical therapy. The author closely monitored the pre, during and post-surgery of the bird in question, and because it is a complex surgery, aroused interest in the student. A complete physical examination confirms that the animal is fit for surgery, and helps the professional to choose the most appropriate technique. Perioperative care, such as fasting, medication and pre and post-surgical monitoring, and environmental enrichment will determine the patient's recovery. For there to be conservation of wild species, the creation of new services for them should be considered, and, therefore, a greater need for professionals with experience in them.
info:eu-repo/semantics/publishedVersion

I correlated the plasma titers of testosterone (T), estradiol (E), luteinizing hormone (LH), progesterone (P), corticosterone (B) and prolactin (Prl) with the reproductive behavior of breeders and adult and juvenal-plumaged helpers of the Harris' Hawk. During nest building, breeding males and adult male helpers had higher T levels than those in immature male helpers. Among females, only breeders had elevated T levels during nest building. During nest building, breeding females had higher E levels than those in adult and immature females helpers. Patterns of LH were similar to those of T and E. Concentrations of P and B varied only with handling time. During incubation, Prl titers were elevated only in breeding males and females. In contrast to other altricial species, all breeders showed no elevation in Prl levels during feeding of young. Among males, adult male helpers had the highest Prl levels while feeding young.

Highly pathogenic avian influenza (HPAI), caused by infection with H5N1 virus, is a transboundary disease which has had a significant socio-economic impact on the poultry production systems of Eurasia, and spillover events with mortality in humans and wild birds. In northern Australia, prior to the current study there was poor understanding of the ecology of avian influenza viruses (AIV) and the risks of H5N1 transmission by wild birds. In this study, the biological pathways of risk for HPAI H5N1 by migratory birds were estimated as a negligible to very low risk to the wild birds of northern Australia. Following stochastic modelling the highest mean frequency of outbreaks was 1 year in 36 years (range 1 in 25-53 years; annual incidence of 0.028) for the Little Curlew (Numenius minutus), followed by the Sharp-tailed Sandpiper (Calidris acuminata) (1 in 56 years, range 36 to 91 years). Three species of wild birds were challenged with a H6N2 low pathogenicity AIV (LPAIV). There was poor viral replication in the Ruddy Turnstones (Arenaria interpres) and Silver Gulls (Chroicocephalus novaehollandiae) with mostly low titre oropharyngeal (OP) excretion [median titre at 4 days post inoculation (DPI) of 101.43 and 102.09 50% embryo infectious dose (EID50)/0.1 mL respectively], with the exception of an OP sample from one Silver Gull (104.26 EID50/0.1 mL at 2 DPI), and one cloacal sample from a Ruddy Turnstone (103.14 EID50/0.1 mL at 10 DPI). In the Wandering Whistling Ducks (Dendrocygna arcuata), there was gastro-intestinal tropism with moderately high titre viral excretion to 6 DPI (highest median titre of 104.58 EID50/0.1 mL in cloacal swabs at 4 DPI). The anti-haemagglutinin (HA) antibody response was poor in the ducks and declined from 19-56 DPI [highest haemagglutination inhibition (HI) test reciprocal geometric mean titre (GMT) of 16.1 at 19 DPI to a GMT of 3.7 at 56 DPI]. In the ducks after 42 DPI, nucleoprotein (NP) c-ELISA antibodies waned slowly from a median of 81% inhibition, and were long-lived to at least 8 months with a 57% median inhibition value. The evaluation of a commercial NP c-ELISA, HI test, Taqman Type A RRT-PCR and embryonating chicken egg (ECE) virus isolation methods suggests high validity of these tests in wild birds, comparable to that reported in poultry. The NP c-ELISA in high AIV prevalence situations had a 100% diagnostic sensitivity (95% CI 81.5, 100) and in controls had 91% diagnostic specificity (95% CI 70.8, 98.9). In low AIV prevalence situations using a ≥60% inhibition threshold for positivity relative to the HI test, c-ELISA performed with 90.5% diagnostic sensitivity (95% CI 86.2, 93.8) and 41.2% diagnostic specificity (95% CI 38.1, 44.5). Assessment of the HI test suggests that a titre of ≥8 is a significant result in wild birds, and using this titre the HI test had 83.3% diagnostic sensitivity (95% CI 58.6, 96.4) in the challenged birds. The Type A RRT-PCR test performance for cloacal swabs had high diagnostic sensitivity that varied between 83.3-100% and diagnostic specificity that varied between 94.1-100% over 2-6 DPI when evaluated against ECE virus isolation, with substantial to outstanding agreement (Kappa statistic=0.8) and significant positive correlation (rs=0.82). The recommended thresholds for the Type A RRT-PCR at the Australian Animal Health Laboratory (AAHL) in poultry of CT <37 for positivity with an intermediate threshold (CT 37-40) were found to be valid in wild birds. The ECE virus isolation method performed well with 89% of virus positive birds positive on the first passage.