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Journal articles on the topic 'Sightings along transect'

Author: Grafiati

Published: 3 June 2025

Last updated: 31 July 2025

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1

Moore, Sue E., Janice M. Waite, Lori L. Mazzuca, and Roderick C. Hobbs. "Mysticete whale abundance and observations of prey associations on the central Bering Sea shelf." J. Cetacean Res. Manage. 2, no. 3 (2023): 227–34. http://dx.doi.org/10.47536/jcrm.v2i3.912.

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Visual surveys for cetaceans were conducted along transect lines in the central Bering Sea in association with a groundfish stock assessment survey from 5 July to 5 August 1999. There were 125 sightings of single or groups of mysticete whales during 6,043km of survey effort. Fin whales were most common (60% of all sightings), with distribution clustered along the outer continental shelf break near the 200m isobath. In addition, there were 27 sightings of minke whales and 17 sightings of humpback whales. Minke whales were primarily found along the upper slope in water 100-200m deep, while humpb

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Read, Andrew J., Susan Barco, Joel Bell, et al. "Occurrence, distribution and abundance of cetaceans in Onslow Bay, North Carolina, USA." J. Cetacean Res. Manage. 14, no. 1 (2023): 23–35. http://dx.doi.org/10.47536/jcrm.v14i1.520.

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In this paper the occurrence, distribution and abundance of cetaceans in offshore waters of Onslow Bay, North Carolina, USA is described. Between June 2007 and June 2010 monthly aerial and shipboard line-transect surveys were conducted along ten 74km transects placed perpendicular to the shelf break. In total 42,676km of aerial trackline (218 sightings) and 5,209km of vessel trackline (100 sightings) were observed. Seven species of cetaceans were observed, but the fauna was dominated strongly by common bottlenose and Atlantic spotted dolphins. Both species were present year-round in the study

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Jean, Claire, Stéphane Ciccione, Katia Ballorain, Jean-Yves Georges, and Jérôme Bourjea. "Ultralight aircraft surveys reveal marine turtle population increases along the west coast of Reunion Island." Oryx 44, no. 2 (2010): 223–29. http://dx.doi.org/10.1017/s003060530999072x.

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AbstractReunion Island in the south-west Indian Ocean once had significant nesting populations of marine turtles but they declined rapidly after human colonization. In 1996, after regular sightings of turtles offshore, an aerial survey programme was initiated to monitor the occurrence of marine turtles and their distribution along the west coast of the island. Between 1998 and 2008, along a 30-km coastline transect between Saint Leu and Saint Paul, a total of 1,845 marine turtle sightings were recorded during 146 flights with an ultralight aircraft. The mean number of turtle sightings per surv

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4

Waring, Gordon T., Leif Nottestad, Erik Olsen, Henrik Skov, and Gisli Vikingsson. "Distribution and density estimates of cetaceans along the midAtlantic Ridge during summer 2004." J. Cetacean Res. Manage. 10, no. 2 (2023): 137–46. http://dx.doi.org/10.47536/jcrm.v10i2.648.

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During 4 June-2 July 2004, the Norwegian R/V G.O. Sars conducted a multi-disciplinary survey along the mid-Atlantic Ridge (MAR) from the Reykjanes Ridge to north of the Azores. This provided the first systematic survey information on MAR cetacean populations. Using naked eye or 7350 hand-held binoculars, observers searched in a 140° arc centred along the ships’ heading. Eleven cetacean species and 10 other taxonomic groups were identified along 2,321km of transect effort. The sei whale (Balaenoptera borealis) and sperm whale (Physeter macrocephalus) were the most commonly sighted species (53 a

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Kiffner, Christian, Filipa M. D. Paciência, Grace Henrich, et al. "Road-based line distance surveys overestimate densities of olive baboons." PLOS ONE 17, no. 2 (2022): e0263314. http://dx.doi.org/10.1371/journal.pone.0263314.

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Estimating population density and population dynamics is essential for understanding primate ecology and relies on robust methods. While distance sampling theory provides a robust framework for estimating animal abundance, implementing a constrained, non-systematic transect design could bias density estimates. Here, we assessed potential bias associated with line distance sampling surveys along roads based on a case study with olive baboons (Papio anubis) in Lake Manyara National Park (Tanzania). This was achieved by comparing density estimates of olive baboons derived from road transect surve

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Lomac-MacNair, Kate S., Ann M. Zoidis, Darren S. Ireland, Meghan E. Rickard, and Kim A. McKown. "Fin, Humpback, and Minke Whale Foraging Events in the New York Bight as Observed from Aerial Surveys, 2017-2020." Aquatic Mammals 48, no. 2 (2022): 142–58. http://dx.doi.org/10.1578/am.48.2.2022.142.

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The fin whale (Balaenoptera physalus), humpback whale (Megaptera novaeangliae), and minke whale (Balaenoptera acutorostrata) are known to occur in the New York Bight (NYB). The primary North Atlantic feeding grounds for these large whale species are commonly recognized to be further north in waters of the Gulf of Maine, eastern Canada, West Greenland, and the eastern North Atlantic (e.g., Iceland, Norway, Ireland, Scotland). Although much is known about their feeding activities in the North Atlantic, relatively little is known about their occurrence and foraging behaviors in mid-Atlantic regio

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7

SANTORO, R., E. SPERONE, M. L. TRINGALI, et al. "Summer Distribution, Relative Abundance and Encounter Rates of Cetaceans in the Mediterranean Waters off Southern Italy (Western Ionian Sea and Southern Tyrrhenian Sea)." Mediterranean Marine Science 16, no. 3 (2015): 613. http://dx.doi.org/10.12681/mms.1007.

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In summer 2010 and summer 2011, weekly cetacean surveys were undertaken in “passing mode”, using ferries as platform of opportunity, along the “fixed line transect” between Catania and Civitavecchia (Southern Italy). Of the 20 species of cetaceans confirmed for the Mediterranean sea, 8 were sighted within the survey period: 7 species represented by Mediterranean subpopulations (Balaenoptera physalus, Physeter macrocephalus, Stenella coeruleoalba, Delphinus delphis, Grampus griseus, Tursiops truncatus and Ziphius cavirostris) and one considered visitor (Steno bredanensis). We had a total of 220

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Makbul, Nur Syamimi, Anna Wong, and Lawrence Alan Bansa. "Population assessment and conservation insights of Helmeted Hornbill (Rhinoplax vigil) in Imbak Canyon Conservation Area, Sabah, Malaysian Borneo." Malayan Nature Journall 77, no. 1 & 2 (2025): 53–67. https://doi.org/10.62613/mnj.257712.04.

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Sabah is home to eight of Malaysia's ten hornbill species, yet critical gap remain regarding their distribution and ecology. This study provides a rapid assessment of the Helmeted Hornbill (Rhinoplax vigil) within the Imbak Canyon Conservation Area (ICCA) in Sabah, focusing on its population status, potential threats, and the cultural significance of hornbills among local communities. Using a transect survey method, hornbill presence was recorded through direct and indirect sightings and interviews were conducted with ICCA rangers. While Helmeted Hornbill calls were frequently heard along the

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Bellingham, Mark, and Alison Davis. "Forest bird communities in Western Samoa." Notornis 35, no. 2 (1988): 117. https://doi.org/10.63172/744759lglkpx.

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The birds of Upolu and Savai’i, Western Samoa, were surveyed in August 1984. Birds were counted along a 2 km transect in 0 le Pupu-Pu’e National Park and 5-minute bird index counts were used in upland and lowland Savai’i. There was a significant difference in the composition and density of bird communities between partly logged and unmodified tava (Pomeria pinnata) forest. The composition of bird communities differed at varying altitudes both in the national park and in Savai’i. There were more species at higher altitudes on Savai’i, and rare species were recorded at only the higher altitudes

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10

Behangana, Mathias, Wilber Lukwago, Daniele Dendi, Luca Luiselli, and David Ochanda. "Population surveys of Nile crocodiles (Crocodylus niloticus) in the Murchison Falls National Park, Victoria Nile, Uganda." European Journal of Ecology 3, no. 2 (2017): 67–76. http://dx.doi.org/10.1515/eje-2017-0015.

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Abstract1. A 12-month-long survey (April 2013 to March 2014) for Nile crocodiles (Crocodylus niloticus) was conducted along a section of the Victoria Nile/Ramsar site of Murchison Falls National Park, in order to update the historic information on crocodile populations in the area, locating nesting areas, determining seasonality patterns and habitat use, and assess the current abundance and the population size trends since the 1960s. The methods employed included visual encounter surveys, transect counts and opportunistic methods, by using boats. 2. In general, there were diurnal and seasonal

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Sagar, H. S. Sathya Chandra, and P. U. Antoney. "Measuring Indian Blackbuck Antilope cervicapra (Mammalia: Cetartiodactyla: Bovidae) abundance at Basur Amruth Mahal Kaval Conservation Reserve, Chikkamagaluru, southern India." Journal of Threatened Taxa 9, no. 7 (2017): 10468. http://dx.doi.org/10.11609/jott.2971.9.7.10468-10472.

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Grasslands are among the most critically endangered ecosystems in the tropics, but they are often treated as wastelands and conservation efforts are seldom directed towards these landscapes. The Blackbuck Antilope cervicapra is a large wild herbivore found in most grassland ecosystems across India. Despite their critical role in their trophic web, there are no reliable estimates of Blackbuck populations from their geographic range that takes detection probability into consideration. In this study, we conducted field surveys to estimate Blackbuck density in Basur Amruth Mahal Kaval Conservation

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12

Smith, Brain D., and Mya Than Tun. "A note on the species occurrence, distributional ecology and fisheries interactions of cetaceans in the Mergui (Myeik) Archipelago, Myanmar." J. Cetacean Res. Manage. 10, no. 1 (2023): 37–44. http://dx.doi.org/10.47536/jcrm.v10i1.658.

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A vessel-based line-transect survey for cetaceans conducted during 23 February-6 March 2005 of the nearshore waters (to a depth of 40- 60m) of the Mergui (Myeik) Archipelago of southern Myanmar searched along 955km of trackline resulting in 30 cetacean sightings. These included Indo-Pacific bottlenose dolphins Tursiops aduncus (n=15), Indo-Pacific humpback dolphins Sousa chinensis (n=3), spinner dolphins Stenella longirostris (n=4; the largest of these was mixed with pantropical spotted dolphins Stenella attenuata), Irrawaddy dolphins Orcaella brevirostris (n=1), finless porpoises Neophocaena

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Akbar, N., I. Marus, R. Ridwan, et al. "Feeding ground indications are based on species, seagrass density and existence of Dugong dugon in Hiri Island Sea, North Maluku, Indonesia." IOP Conference Series: Earth and Environmental Science 890, no. 1 (2021): 012058. http://dx.doi.org/10.1088/1755-1315/890/1/012058.

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Abstract Seagrass ecosystems are located between mangrove ecosystems and coral reefs. Seagrass ecosystems are habitats and foraging area for many marine organisms. Eco-biological cycles in seagrass ecosystems are important for maintaining populations of many organisms. Seagrass at Hiri Island is distributed horizontally along the coast. This island is also a location where Dugong dugon is found North Maluku. Dugong dugon is a vurneable species that has been included in the IUCN and Appendix I Cites. This study aimed to identify species, density of seagrass and existence of Dugong dugong. The s

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Koski, William R., Mads Peter Heide-Jørgensen, and Kristin L. Laidre. "Winter abundance of bowhead whales, Balaena mysticetus, in the Hudson Strait, March 1981." J. Cetacean Res. Manage. 8, no. 2 (2023): 139–44. http://dx.doi.org/10.47536/jcrm.v8i2.710.

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Satellite tracking studies of bowhead whales (Balaena mysticetus) in West Greenland and the eastern Canadian Arctic have documented that Hudson Strait is an important wintering ground for animals summering in the Baffin Bay-Davis Strait area and the Hudson Bay-Foxe Basin area. In light of this new information, data were re-examined on abundance of bowhead whales at this wintering ground derived from a systematic strip census survey conducted in March 1981. Three strata in Hudson Strait were covered by equally spaced north-south transect lines. Most sightings were in the western stratum, with o

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15

Andama, Edward, Jane Bemigisha, and Turyahabwe Remigio. "Relationships between Anthropogenic Activities and Distribution of Medium to Large Mammal Species Assemblage in Madi Wildlife Corridor: Implication for Biodiversity Conservation in Uganda." East African Journal of Environment and Natural Resources 7, no. 1 (2024): 124–40. http://dx.doi.org/10.37284/eajenr.7.1.1908.

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Wildlife corridors between protected areas increase connectivity by integrating populations into single demographic units, thereby increasing gene flows within populations and thus probability of survival. This study assessed the relationship between anthropogenic activities and mammal species assemblage within and around Madi wildlife corridor. The study adopted recce walks along a zig-zag line transect and straight line transect methods of game tracking. Global Position System (GPS) was used to map locations of direct mammal sightings, vocalizations, tracks, dung/droppings, diggings, carcass

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Di Tommaso, Andrea, Sureerat Sailar, Francesco Luigi Leonetti, Emilio Sperone, and Gianni Giglio. "A Proposed Method for Assessing the Spatio-Temporal Distribution of Carcharhinus melanopterus (Quoy and Gaimard, 1824) in Shallow Waters Using a UAV: A Study Conducted in Koh Tao, Thailand." Diversity 16, no. 10 (2024): 606. http://dx.doi.org/10.3390/d16100606.

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In this study, we propose a method for assessing the temporal and spatial distribution of Carcharhinus melanopterus in shallow waters using unmanned aerial vehicles (UAVs). Aerial surveys were conducted in Tien Og Bay (Koh Tao, Thailand) thrice daily (morning, afternoon, evening) along a 360 m transect at a 30 m altitude. Environmental factors, including cloudiness, sea conditions, wind, tide, and anthropogenic disturbance, were recorded for each time slot. We developed a Python/AppleScript application to facilitate individual counting, correlating sightings with GPS data and measuring pixel-b

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17

Gadelha, José Ramon, Éverton Renan de Andrade Melo, Maria Nazaré Domingos da Silva, Antonio Paulo da Silva Júnior, Bruno Karol Cordeiro Filgueiras, and Antonio Rossano Mendes Pontes. "Habitat heterogeneity as a local and regional-scale driver of primate assemblage structure in northernmost Brazilian Amazonia." Animal Biology 67, no. 3-4 (2017): 263–86. http://dx.doi.org/10.1163/15707563-00002536.

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We performed line transect surveys in two fishbone human settlements (defined as clearings cut through forests in a fishbone pattern, extending along secondary roads from a main road) in different vegetation types, as well as in one protected area. A total of 410 sightings of eight primate species were recorded in the three study areas. The mean total primate abundance was 3.28 groups/10 km walked, and there were significant differences between areas with different plant physiognomies. The abundance of the larger primate speciesAlouatta macconnelliandAteles paniscus(Atelidae) was higher in the

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18

Odzer, Michael N., Annabelle M. L. Brooks, Michael R. Heithaus, and Elizabeth R. Whitman. "Effects of environmental factors on the detection of subsurface green turtles in aerial drone surveys." Wildlife Research 49, no. 1 (2022): 79–88. http://dx.doi.org/10.1071/wr20207.

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Abstract Context Aerial video surveys from unpiloted aerial systems (UAS) have become popular in wildlife research because of increased accessibility to remote areas, reduction of anthropogenic disruption to habitats and wildlife, low operating costs, and improved researcher safety. In shallow marine systems, they can provide opportunities to rapidly survey species that cannot easily be surveyed using boat- or land-based techniques. However, detectability of subsurface animals in marine habitats may be affected by environmental factors. Aims We investigated the effects of water depth, seagrass

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19

Smith, Brian D. S., Benazir Ahmed, Rubaiyat Mansur Mowgli, and Samantha Strindberg. "Species occurrence and distributional ecology of nearshore cetaceans in the Bay of Bengal, Bangladesh, with abundance estimates for Irrawaddy dolphins Orcaella brevirostris and finless porpoises Neophocaena phocaenoides." J. Cetacean Res. Manage. 10, no. 1 (2023): 45–58. http://dx.doi.org/10.47536/jcrm.v10i1.659.

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A vessel-based line-transect survey conducted during February 2004 along 1,018km of systematic trackline in the nearshore waters of Bangladesh resulted in 111 ‘on-effort’ cetacean sightings including: Irrawaddy dolphins, Orcaella brevirostris (n=75, mean group size=2.2); finless porpoises, Neophocaena phocaenoides (n=11, mean group size=2.6); Indo-Pacific humpback dolphins, Sousa chinensis (chinensisform; n=6, mean group size=16.2); Indo-Pacific bottlenose dolphins, Tursiops aduncus (n=3, mean group size=36.1); pantropical spotted dolphins, Stenella attenuata (n=1, best, high and low group siz

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Andriolo, A., C. C. A. Martins, M. H. Engel, et al. "The first aerial survey to estimate abundance of humpback whales (Megaptera novaeangliae) in the breeding ground off Brazil (Breeding Stock A)." J. Cetacean Res. Manage. 8, no. 3 (2023): 307–11. http://dx.doi.org/10.47536/jcrm.v8i3.728.

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In the Southern Hemisphere, humpback whales (Megaptera novaeangliae) were heavily exploited from both coastal stations and in pelagic waters in all major ocean basins. About 200,000 whales were taken after 1900, causing declines of populations to small percentages of their pre-exploitation levels. The study presented here aimed to investigate humpback whale abundance in the Brazilian coastal breeding ground, in order to provide information to support further analysis of the population recovery. Between 25 August and 2 September 2001, a fixed wing, flat window, aircraft was used to survey trans

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Hema, Emmanuel M., Tinsgnimi Dialla, Djidama Sirima, Yaya Ouattara, Ismael Tou, and Luca Luiselli. "Preliminary data on density and habitat of carnivores in two protected areas of Burkina Faso (West Africa)." Mammalia 84, no. 1 (2019): 69–73. http://dx.doi.org/10.1515/mammalia-2019-0026.

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Abstract Apparent density [determined as kilometric index of abundance (KIA), by direct sightings and by droppings along line transects] and habitat use of some species of carnivore mammals were studied in two protected areas of Burkina Faso (Comoé-Leraba and Nazinga). Despite the fact that the dataset was collected throughout several years and with a very high field effort, the amount of data collected was relatively small, and confined just to a few species. There was no effect of the year on the average KIA estimates of the carnivores at this study area, and data from direct sightings along

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Thorstrom, R., and R. T. Watson. "Avian inventory and key species of the Masoala Peninsula, Madagascar." Bird Conservation International 7, no. 2 (1997): 99–115. http://dx.doi.org/10.1017/s0959270900001453.

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SummaryFrom mid-September 1993 to February 1994 avian species were inventoried at eight sites selected to sample the major biogeographic areas and threatened habitats of Masoala Peninsula of north-eastern Madagascar. The sites ranged from 10 to 1100 m elevation. Three forest types were inventoried: six sites included primary lowland rainforest (0–700 m), one site was characterized as moist montane forest (above 700 m), and one site was classified as littoral forest. Bird species and distribution were sampled using point counts and line transects, tree observations and opportunistic sightings;

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Bardiani, Marco, Stefano Chiari, Emanuela Maurizi, et al. "Guidelines for the monitoring of Lucanus cervus." Nature Conservation 20 (August 28, 2017): 37–78. https://doi.org/10.3897/natureconservation.20.12687.

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Lucanus cervus is one of the most charismatic saproxylic beetles, widely distributed in Europe. The species is typical of mature deciduous forests, especially oak woodlands. Loss and fragmentation of suitable habitats is one of the major threats for this species which is included in Annex II of the Habitats Directive. Despite several studies carried out in the last years for the monitoring methods of the species, an analytical comparison between them is still lacking. The aims of this paper are (i) to review the current knowledge about systematics, ecology and conservation practices on L. cerv

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Valsecchi, J., TM Vieira, JS Silva Júnior, ICM Muniz, and AA Avelar. "New data on the ecology and geographic distribution of Saguinus inustus Schwarz, 1951 (Primates, Callitrichidae)." Brazilian Journal of Biology 70, no. 2 (2010): 229–33. http://dx.doi.org/10.1590/s1519-69842010000200001.

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Saguinus inustus (Schwarz, 1951) is one of the neotropical primates least studied. The distribution of the species ranges from the north of the Solimões River, between the Negro and Japurá Rivers in Brazil, and Guayabero-Guaviare Rivers in Colombia. Nevertheless, due to the low number of specimens collected from the lower Japurá and lower Negro Rivers areas, the geographic distribution is so far poorly delineated. In this study, field data was composed of sightings and the collection of specimens during a survey of mammal diversity in the Amana Sustainable Development Reserve (ASDR). For this

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Saba, Maria, Sangam Khalil, Majid Hussain, et al. "Spatiotemporal variation in population size and relative abundance of Kalij pheasant (Lophura leucomelanos) in scrub forest." PLOS ONE 19, no. 12 (2024): e0312809. https://doi.org/10.1371/journal.pone.0312809.

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Most species of pheasants (Galliformes: Phasianidae) occur in Asia. In Pakistan, pheasants occur from 245–3050 m in altitude, and one of these, the Kalij pheasant (Lophura leucomelanos) is a large-bodied, brightly-colored habitat quality indicator species. The present study was designed to determine spatiotemporal variation, population size, and the relative abundance of Kalij pheasants in Haripur, Pakistan. The line transects and point count methods were used to collect direct (physical observations) and indirect signs (feathers and calls) to avoid double counting. Twenty field surveys were c

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Skern-Mauritzen, Mette, Hans Julius Skaug, and Nils Øien. "Line transects, environmental data and GIS: Cetacean distribution, habitat and prey selection along the Barents Sea shelf edge." NAMMCO Scientific Publications 7 (September 1, 2009): 179. http://dx.doi.org/10.7557/3.2713.

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Cetacean observations obtained during sighting surveys for abundance estimation can also be used to investigate cetacean habitat and prey selection, the principal processes underlying cetacean distributions. In this paper, we investigate habitat and prey selection of minke (Balaenoptera acutorostrata), fin (B. physalus) and sperm (Physeter macrocephalus) whales and Lagenorhynchus (Atlantic white-sided L. acutus and white-beaked L. albirostris) dolphins observed along predetermined cruise tracks along the Barents Sea shelf edge in 2000, 2001 and 2002. The observations were combined with simulta

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Rosa, Ierecê Lucena, Tacyana P. R. Oliveira, André L. C. Castro, et al. "Population characteristics, space use and habitat associations of the seahorse Hippocampus reidi (Teleostei: Syngnathidae)." Neotropical Ichthyology 5, no. 3 (2007): 405–14. http://dx.doi.org/10.1590/s1679-62252007000300020.

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This paper provides a case study of a threatened seahorse species, Hippocampus reidi, highlighting the importance of using ecological information to assist conservation and management initiatives. Underwater visual sighting data (50 x 2m transect) gathered along the NE, SE and S portions of the Brazilian coast revealed an unequal distribution across localities, perhaps related to harvesting pressure, and a mean density of 0.026 ind.m-2. Our findings suggest some restricted spatial use by H. reidi, which was consistent with its estimated home range, and with re-sighting of specimens. Reproducti

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Put, Julia Elizabeth, Laurens Put, and Clair Colleen Cassady St. "Caching behaviour by red squirrels may contribute to food conditioning of grizzly bears." Nature Conservation 21 (August 30, 2017): 1–14. https://doi.org/10.3897/natureconservation.21.12429.

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We describe an interspecific relationship wherein grizzly bears (Ursus arctos horribilis) appear to seek out and consume agricultural seeds concentrated in the middens of red squirrels (Tamiasciurus hudsonicus), which had collected and cached spilled grain from a railway. We studied this interaction by estimating squirrel density, midden density and contents, and bear activity along paired transects that were near (within 50 m) or far (200 m) from the railway. Relative to far ones, near transects had 2.4 times more squirrel sightings, but similar numbers of squirrel middens. Among 15 middens i

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Cripps, Jemma K., Jenny L. Nelson, Michael P. Scroggie, Louise K. Durkin, David S. L. Ramsey, and Linda F. Lumsden. "Double-observer distance sampling improves the accuracy of density estimates for a threatened arboreal mammal." Wildlife Research 48, no. 8 (2021): 756. http://dx.doi.org/10.1071/wr19136.

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Abstract ContextDetermining population size or density is often fundamental for wildlife conservation. For nocturnal species, indices are commonly used in place of abundance estimates, with spotlighting indices (e.g. sighting rate per km) being prevalent. Distance sampling is a collection of techniques that provide estimates of wildlife abundance from line-transect data, by correcting raw counts for imperfect detection. These methods have rarely been used to assess the abundance of nocturnal arboreal mammals. AimsTo develop and evaluate a method for estimating the abundance and density of noct

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Cui, Shaopeng, Xiao Luo, Daiqiang Chen, et al. "The adder (Vipera berus) in Southern Altay Mountains: population characteristics, distribution, morphology and phylogenetic position." PeerJ 4 (August 16, 2016): e2342. http://dx.doi.org/10.7717/peerj.2342.

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As the most widely distributed snake in Eurasia, the adder (Vipera berus) has been extensively investigated in Europe but poorly understood in Asia. The Southern Altay Mountains represent the adder’s southern distribution limit in Central Asia, whereas its population status has never been assessed. We conducted, for the first time, field surveys for the adder at two areas of Southern Altay Mountains using a combination of line transects and random searches. We also described the morphological characteristics of the collected specimens and conducted analyses of external morphology and molecular

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Dharma, Fernando, Wilson Novarino, and Jabang Nurdin. "Sumatran Hornbills in Fragmented Forest Areas in Oil Pam Plantation in South Solok, West Sumatra." Sarawak Museum Journal LXXIX, no. 100 (2018): 159–66. http://dx.doi.org/10.61507/smj22-2018-ft1q-12.

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A study on hornbill populations in fragmented forest areas within oil palm plantations in Tidar Kerinci Agung (TKA) Company, West Sumatra was carried out from July to August 2015 in 60 Hectare fragmented forest areas. The objective of this study was to document hornbill species richness using the transect method on three main lines along two km and using call recognition for population census of hornbill. During the study, we recorded 82 individuals of eight species after 60 km walk. We encountered using two methods (Sighting and Calls Methods); Anorrhinus galeritus twenty-one encounters, Bere

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Hema, Emmanuel M., Massimiliano Di Vittorio, Fabio Petrozzi, Luca Luiselli, and Wendengoudi Guenda. "First assessment of age and sex structures of elephants by using dung size analysis in a West African savannah." European Journal of Ecology 3, no. 1 (2017): 1–8. http://dx.doi.org/10.1515/eje-2017-0001.

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Abstract1. An age and sex structure study of the West African savannah elephant (Loxodonta africana africana) population of the Nazinga Game ranch (Burkina Faso) was carried out using direct sightings of individuals near water points, where they group during hot periods of the day, and droppings circumference measurements of dung pile along line transects, during the dry seasons of 2007 and 2008. The age structure, from direct observation data, was estimated by classifying the individuals into 9 age-class-categories based on body size and eruption (length) of tusks.2. The frequency distributio

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Ngene, Shadrack, Elephus Bitok, Joseph Mukeka, et al. "Census and ear-notching of black rhinos (Diceros bicornis michaeli) in Tsavo East National Park, Kenya." Pachyderm 49 (June 30, 2011): 61–69. http://dx.doi.org/10.69649/pachyderm.v49i.251.

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This paper updates the status of the black rhino population in Tsavo East National Park (NP). Data were acquired through aerial counts of the black rhino between 3 and 9 October 2010 using three fixed-wing husky aircrafts and a Bell 206L helicopter in an area of about 3,300 km 2 . Based on previous sightings of rhinos, the area was divided into 14 blocks, with each block subdivided into 400 m transects. An aircraft flying at about 500 m above the ground was assigned to carry out the aerial survey following these transects within each block. Observers scanned for rhinos about 200 m on either si

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D. Walsh, Pete, J. Michael Fay, Steve Gulick, and Guy Phillipe Sounguet. "Humpback whale activity near Cap Lopez, Gabon." J. Cetacean Res. Manage. 2, no. 1 (2000): 63–67. http://dx.doi.org/10.47536/jcrm.v2i1.489.

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Two days of aerial transects were flown in mid-August 1998, just below the equator near Cap Lopez, Gabon. Two groups of humpback whales (Meagaptera novaeangliae) were sighted to the north of Cap Lopez and eighteen groups were sighted to the south. A large proportion of whales in the southern sector engaged in display behaviour. Similar observations were made during brief boat surveys on 14 August 1998 and 6-12 September 1999. Three surface-active groups were also observed, suggesting that humpback whales mate in the waters surrounding Cap Lopez. Three calves were observed during surveys. Histo

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Chiarello, Adriano, Ana Srbek-Araujo, Hermano Del-Duque Jr., Eduardo de Coelho, and Carlos Rocha. "Abundance of tegu lizards (Tupinambis merianae) in a remnant of the Brazilian Atlantic forest." Amphibia-Reptilia 31, no. 4 (2010): 563–70. http://dx.doi.org/10.1163/017353710x518441.

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AbstractWe investigated the abundance of the tegu lizard (Tupinambis merianae) in a 21 787 ha Brazilian Atlantic forest fragment (Reserva Natural Vale, RNV). This remnant has a highly irregular perimeter and an extensive network (126 km) of internal unpaved roads. We hypothesized that the high proportion of these edge habitats might benefit active heliothermic lizards like tegus due to greater incidence of sunlight. We estimated population density using the program DISTANCE, and compared sighting frequency of tegus along twelve 500 m long transects located at three distances (25, 200 and 400 m

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Salas, Leonardo A. "Habitat use by lowland tapirs (Tapirus terrestris L.) in the Tabaro River valley, southern Venezuela." Canadian Journal of Zoology 74, no. 8 (1996): 1452–58. http://dx.doi.org/10.1139/z96-160.

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This study presents an analysis of habitat use by lowland tapirs (Tapirus terrestris L.) in the Tabaro River valley of southern Venezuela. Five different habitat types were recognized in the study area and their proportions determined. Treefall gaps within these habitats were also analyzed as a distinctive type. The presence of tapirs was determined by following fresh tracks, counting tracks found by walking along transects and creeks, and checking gaps and closed-canopy areas of equal size for browsing signs. The numbers of tracks and sightings recorded near to and away from the water were co

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Rathod, Ganesh, Erach Bharucha, and Kranti Yardi. "Population density and nesting behaviour of Indian Giant Squirrel Ratufa indica (Erxlebeln, 1777) in Bhimashankar Wildlife Sanctuary, Western Ghats of Maharashtra, India." Journal of Threatened Taxa 14, no. 9 (2022): 21786–96. http://dx.doi.org/10.11609/jott.7816.14.9.21786-21796.

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The Indian Giant Squirrel Ratufa indica (Erxlebeln, 1777) has been officially designated as Maharashtra’s state animal. It is restricted to the eco-sensitive Western Ghats region and is currently classified as Least Concern species on the IUCN Red List. However, the species is dependent on intact habitat and is negatively impacted by habitat fragmentation. Population density and nesting behavior were studied in a major habitat in the tropical semi-evergreen and evergreen forest of India’s Bhimashankar Wildlife Sanctuary. Two-hundred-and-twenty-three direct sighting along 60 km line transects w

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Southwell, Colin J., Charles G. M. Paxton, David L. Borchers, et al. "Estimating population status under conditions of uncertainty: the Ross seal in East Antarctica." Antarctic Science 20, no. 2 (2008): 123–33. http://dx.doi.org/10.1017/s0954102007000879.

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AbstractThe Ross seal (Ommatophoca rossii) is the least studied of the Antarctic ice-breeding phocids. In particular, estimating the population status of the Ross seal has proved extremely difficult. The Protocol on Environmental Protection to the Antarctic Treaty currently designates the Ross seal as a ‘Specially Protected Species’, contrasting with the IUCN's classification of ‘Least Concern’. As part of a review of the Ross seal's classification under the Protocol, a survey was undertaken in 1999/2000 to estimate the status of the Ross seal population in the pack ice off East Antarctica bet

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Sy, Luan Mai. "Ecological notes on the Cát Bà gecko Goniurosaurus catbaensis, a species endemic to the limestone karst islands of northern Vietnam." Herpetological Bulletin, Issue 157, Autumn 2021 (October 1, 2021): 1–5. http://dx.doi.org/10.33256/hb157.15.

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The Cát Bà gecko Goniurosaurus catbaensis is endemic to Cát Bà and Ha Long islands of Vietnam. The ecology of this species is still scarcely studied but previous reports have suggested that the species is Endangered due to small population size and low ecological plasticity. We studied aspects of the ecology of this species between May 2019 and June 2020, along seven transects on Cát Bà island. At least 173 different individuals (possibly as many as 189) were recorded, with an equal sexratio and apparently no intersexual differences in adult body size. The species was clearly more widely distr

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Anderson, PK. "Dugong distribution, the seagrass Halophila spinulosa, and thermal environment in winter indeeper waters of eastern Shark Bay, WA." Wildlife Research 21, no. 4 (1994): 381. http://dx.doi.org/10.1071/wr9940381.

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Five aerial survey transects in eastern Shark Bay, along which dugongs (Dugong dugon) had been reported in deep water in July 1989, were flown on 3 and 14 July 1992. As in 1989, dugong sightings were concentrated between 9- and 15-m depth contours. Thermal patterns shown on images obtained from NOAA satellites, and direct measurement of temperatures in the water column, confirmed that temperatures were at least 19�C where dugongs were concentrated. Although no seagrass had previously been reported in this zone, examination of benthic communities using a remotely controlled underwater video sys

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Alves, Maria Danise, Paul Gerhard Kinas, Miriam Marmontel, et al. "First abundance estimate of the Antillean manatee (Trichechus manatus manatus) in Brazil by aerial survey." Journal of the Marine Biological Association of the United Kingdom 96, no. 4 (2015): 955–66. http://dx.doi.org/10.1017/s0025315415000855.

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We estimated the abundance of Antillean manatees (Trichechus manatus manatus) through a large-scale project conducted in 2010 in north-eastern Brazil and evaluated the efficacy of an aerial survey for conservation purposes. Two observers conducted the survey via flights that maintained an altitude of 150 m and an air speed of 140 km h−1, covering over 2590.2 km2of the coastline. Strip transects were flown in a zigzag pattern. A total of 67 manatees (on- and off-effort) were recorded in 55 sightings. Historical published records of occurrence were formally incorporated using a Bayesian approach

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Vernazzani, Barbara Galletti, Carole A. Carlson, Elsa Cabrera, and Robert L. Brownell Jr. "Chilean blue whales off Isla Grande de Chiloe, 2004-2010: distribution, site-fidelity and behaviour." J. Cetacean Res. Manage. 12, no. 3 (2023): 353–60. http://dx.doi.org/10.47536/jcrm.v12i3.567.

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A collaborative research program (the Alfaguara Project) has collected information on Chilean blue whales (Balaenoptera musculus) off Isla Grande de Chiloe, in southern Chile, through eight aerial and 85 marine surveys. A total of 363 individual blue whales was photo-identified from 2004 to 2010. Approximately 20% of all catalogued individuals were resighted within the same season and 31% were resighted between years. Recaptures of photo-identified individuals from other areas to the north and south of the main study area support the hypothesis that the feeding ground off southern Chile is ext

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Ismail, Norradihah, Maryati Mohamed, Kahirol Mohd Salleh, Phon Chooi Khim, and Lili Tokiman. "Butterflies (Lepidoptera: Papilionoidea) diversity at Endau-Rompin Johor National Park, Malaysia and prioritising the potential groups for nature tourism product." Journal of Wildlife and Parks 33 (July 6, 2018): 31–55. https://doi.org/10.64291/v6bwd685.

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From a total of 17,461 species of butterfly described worldwide, at least twothird are from the tropics. Peninsular Malaysia is home to 1038 butterfly species. Endau-Rompin Johor National Park (ERJNP) in particular recorded 349 species as analysed from collections of 1987 to 2015. It represents 34% of butterfly fauna in Peninsular Malaysia. This paper aims (i) to document the diversity of butterfly in ERJNP and (ii) identify potential groups of butterfly that satisfy six criteria for good nature tourism product. The criteria are reliability of sighting, safe, with unique morphology and behavio

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Tadesse, Solomon A., and Burt P. Kotler. "Habitat Choices of Nubian Ibex (Capra Nubiana) Evaluated with A habitat Suitability Modeling and Isodar Analysis." Israel Journal of Ecology and Evolution 56, no. 1 (2010): 55–74. http://dx.doi.org/10.1560/ijee.56.1.55.

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The value of a habitat for a forager may be affected by habitat characteristics related to food availability, energetic costs of foraging, predation costs, and the foraging opportunities available in other habitats. Nubian ibex (Capra nubiana) are stout, sure-footed social wild goats that inhabit arid landscapes with steep terrain. We investigated their habitat selection behavior using indicators to (1) develop a habitat suitability index (HSI) model that would account for the variation in the activity densities of Nubian ibex across habitat types and seasons, (2) apply the isodar technique to

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Omifolaji, James Kehinde, Sunday Opeyemi Adedoyin, Emmanuel Tersea Ikyaagba, et al. "Population Abundance and Density Estimates of Poorly Documented Near-Threatened Calabar Angwantibo (Arctocebus calabarensis) in Oban Hills Region." Animals 14, no. 9 (2024): 1374. http://dx.doi.org/10.3390/ani14091374.

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Population abundance and density estimates play important roles in biodiversity conservation assessment and can lead to prioritization of conservation efforts, strategies, and management. The Calabar angwantibo (Arctocebus calabarensis) is a poorly studied, Near-Threatened nocturnal, arboreal mammal species occurring only in the lowland moist tropical rainforest blocks of southeastern Nigeria and southwestern Cameroon. Like other arboreal nocturnal mammals, there are gaps in knowledge of the distribution and abundance of this species, which may be facing population declines due to habitat loss

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Baltazary, Angelamercy, Eivin Roskaft, and Anna C. Treydte. "Vigilance Behaviour of Wild Herbivores when Foraging With or Without Livestock." Environment and Natural Resources Research 9, no. 1 (2019): 64. http://dx.doi.org/10.5539/enrr.v9n1p64.

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In African savannas, and many other rangelands around the world, wildlife presently find themselves interacting with livestock. Many studies have been conducted on vigilance behaviour in response to presence of predators on foraging grounds, but few scientists have included the presence of livestock and how this affects vigilance when foraging together with wild herbivores. As Ngorongoro Conservation Area (NCA) is an important example of wildlife grazing together with livestock, this phenomenon must be understood to achieve a sustainable land use management plan, particularly in Ngorongoro Con

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Suthar, Prakash, Hem Singh Gehlot, Tapan Adhikari, and Gaurav Gaurav. "Mammalian and Avian Diversity and Lurking Threats at Guda Vishnoiyan Conservation Reserve in the Bank of Luni River, Jodhpur, Rajasthan." Indian Journal Of Science And Technology 17, no. 45 (2024): 4756–64. https://doi.org/10.17485/ijst/v17i45.3477.

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Objectives: This study investigates the biodiversity of Guda Vishnoiyan Conservation Reserve (GVCR), focusing on mammalian and avian diversity and their threats. Methods: The region was assessed using the line transect method for mammals and the point count method for avian fauna. Garmin eTrex GPS, Bushnell binoculars, Canon 90 D camera, and Range finder were used. The Q-GIS and Google Earth Pro were used for map development and analyzing GPS data. The PAST 4.03 and MS-Excel were used to analyze the region's diversity indices. Findings: This study recorded 114 avian species with 43 families of

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Prakash, Suthar, Singh Gehlot Hem, Adhikari Tapan, and Gaurav. "Mammalian and Avian Diversity and Lurking Threats at Guda Vishnoiyan Conservation Reserve in the Bank of Luni River, Jodhpur, Rajasthan." Indian Journal of Science and Technology 17, no. 45 (2024): 4756–64. https://doi.org/10.17485/IJST/v17i45.3477.

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Abstract <strong>Objectives:</strong> This study investigates the biodiversity of Guda Vishnoiyan Conservation Reserve (GVCR), focusing on mammalian and avian diversity and their threats. <strong>Methods:</strong> The region was assessed using the line transect method for mammals and the point count method for avian fauna. Garmin eTrex GPS, Bushnell binoculars, Canon 90 D camera, and Range finder were used. The Q-GIS and Google Earth Pro were used for map development and analyzing GPS data. The PAST 4.03 and MS-Excel were used to analyze the region's diversity indices. <str

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Valsecchi, Elena. "Scanning ferry routes: looking for eDNA traces of marine mammals and their preys." ARPHA Conference Abstracts 4 (March 4, 2021): e65448. https://doi.org/10.3897/aca.4.e65448.

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Marine environmental DNA (eDNA) surveys are becoming a promising approach to monitor biodiversity status and its variation over time. However, monitoring offshore areas could be extremely costly when using dedicated vessels, beside the impossibility to sample simultaneously geographically distant (even if adjacent) areas. The unexplored possibility of availing on operating ferries as an opportunistic platform for eDNA sampling offers several advantages besides opening limitless opportunities for systematic surveys on marine biodiversity.We present the results of both metabarcoding and barcodin

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Murwanyi, Peter Happy, Robert Kityo, Enock Ssekuubwa, and Mnason Tweheyo. "Sitatunga (Tragelaphus spekii) food sources and habitat use in Marsh–Savannah‐cultivation mosaics." African Journal of Ecology 62, no. 1 (2023). http://dx.doi.org/10.1111/aje.13246.

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AbstractWetland conversion threatens wetland specialists by reducing their core habitat. The sitatunga is a wetland specialist with declining populations. However, knowledge of sitatunga ecology and threats is limited, particularly outside protected areas. We examined sitatunga food sources, and habitat use in undisturbed Marshes and Marsh–Savannah transition blocks, and a Cultivated (disturbed) block in River Mayanja wetland, central Uganda. We recorded indirect indices and sightings of sitatunga along a 10 km transect in each block, and surveyed food sources in 34 plots along the transects.

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