Corrigendum to: Estimates of abundance and apparent survival of coastal dolphins in Port Essington harbour, Northern Territory, Australia

2015 ◽  
Vol 42 (4) ◽  
pp. 371
Author(s):  
Carol Palmer ◽  
Lyndon Brooks ◽  
Guido J. Parra ◽  
Tracey Rogers ◽  
Debra Glasgow ◽  
...  
Keyword(s):  
Population Size ◽  
Coastal Waters ◽  
Conservation Status ◽  
Northern Territory ◽  
Systematic Sampling ◽  
Northern Australia ◽  
Apparent Survival ◽  
Impact Studies ◽  
Sampling Program ◽  
Repeated Sampling

Context Three dolphin species occur in coastal waters of monsoonal northern Australia: the Australian snubfin (Orcaella heinsohni), humpback (Sousa sp.) and the bottlenose (Tursiops sp.). Their overall population size and trends are poorly known, and their conservation status has been difficult to resolve, but can be expected to deteriorate with likely increased development pressures. Aims We sought to provide an estimate of abundance, and apparent survival, of the three dolphin species at the largely undeveloped harbour of Port Essington (325km2), Northern Territory, with repeated sampling over a 2.9-year period. Given increasing obligations to undertake population assessments for impact studies at proposed development sites, we assess the strengths and limitations of a systematic sampling program.

scholarly journals Estimates of abundance and apparent survival of coastal dolphins in Port Essington harbour, Northern Territory, Australia

2014 ◽  
Vol 41 (1) ◽  
pp. 35 ◽  
Author(s):  
Carol Palmer ◽  
Lyndon Brooks ◽  
Guido J. Parra ◽  
Tracey Rogers ◽  
Debra Glasgow ◽  
...  
Keyword(s):  
Population Size ◽  
Conservation Status ◽  
Local Population ◽  
Northern Territory ◽  
Systematic Sampling ◽  
Northern Australia ◽  
Apparent Survival ◽  
Photo Identification ◽  
Population Size Estimates ◽  
Sampling Protocols

Context Three dolphin species occur in coastal waters of monsoonal northern Australia: the Australian snubfin (Orcaella heinsohni), humpback (Sousa sp.) and the bottlenose (Tursiops sp.). Their overall population size and trends are poorly known, and their conservation status has been difficult to resolve, but can be expected to deteriorate with likely increased development pressures. Aims We sought to provide an estimate of abundance, and apparent survival, of the three dolphin species at the largely undeveloped harbour of Port Essington (325 km2), Northern Territory, with repeated sampling over a 2.9-year period. Given increasing obligations to undertake population assessments for impact studies at proposed development sites, we assess the strengths and limitations of a systematic sampling program. Methods We used photo-identification data collected during systematic boat-based transect surveys undertaken from 2008 to 2010 and Pollock’s robust capture–recapture design model. Key results Total abundance estimates for the three species were variable across different sampling periods. The estimated number of individuals in the sampled area varied per sampling episode from 136 (s.e. 62) to 222 (s.e. 48) for snubfin, from 48 (s.e. 7) to 207 (s.e. 14) for humpbacks and from 34 (s.e. 6) to 75 (s.e. 9) for bottlenose dolphins. Apparent survival was estimated for snubfin at 0.81 (s.e. 0.11), humpbacks at 0.59 (s.e. 0.12) and bottlenose at 0.51 (s.e. 0.17) per annum. Key conclusions (1) The values derived here provide some of the only estimates of local population size for these species across monsoonal northern Australia; (2) population-size estimates varied considerably among seasons or sampling episodes; (3) the low apparent survival probabilities indicated that many individuals may move at scales larger than the study area; (4) density of snubfin and humpback dolphins in the present study area exceeded the few other estimates available for these species elsewhere in Australia. Implications The present study provided the first baseline estimates of abundance and apparent survival for three coastal dolphin species in monsoonal northern Australia. Such information is becoming increasingly important as development pressures intensify in coastal areas. Sampling protocols for future monitoring and impact assessment need an enhanced consideration of seasonality and scale issues.

Observations of the 'Critically Endangered' bare-rumped sheathtail bat Saccolaimus saccolaimus Temminck (Chiroptera: Emballonuridae) on Cape York Peninsula, Queensland.

2001 ◽  
Vol 23 (2) ◽  
pp. 185 ◽  
Author(s):  
S Murphy
Keyword(s):  
Papua New Guinea ◽  
Solomon Islands ◽  
Conservation Status ◽  
New Guinea ◽  
Fire Regimes ◽  
Wide Distribution ◽  
Northern Territory ◽  
Critically Endangered ◽  
Northern Australia ◽  
Cape York

THE bare-rumped sheathtailed bat Saccolaimus saccolaimus is a poorly understood species that has a wide distribution covering parts of India, Sri Lanka, Thailand, Myanmar, Malaya, Indonesia, New Guinea, the Solomon Islands and Northern Australia (Bonaccorso 1998). First collected in Australia by De Vis near Cardwell, the current known distribution in Queensland (Qld) extends from Bowen to Cooktown with one isolated specimen collected near Coen on Cape York Peninsula (Hall 1995; Duncan et al. 1999). It has also been recorded in the Alligator River area in the Northern Territory (McKean et al. 1981). The conservation status of S. saccolaimus in Qld has recently been defined as ?Critically Endangered?, and the species has not been recorded anywhere in Australia for at least 18 years (Duncan et al. 1999; Menkhorst and Knight 2001). The likely reasons for the apparent decline are unclear, but may involve land-clearing and changed fire regimes in the coastal zone where it is thought to occur (Duncan et al. 1999). In contrast, Bonaccorso (1998) considers S. saccolaimus to be secure, albeit also poorly known in Papua New Guinea.

Targeted sampling successfully detects the cryptic and declining arboreal marsupial (Phascogale pirata) in northern Australia

2020 ◽  
Vol 26 (4) ◽  
pp. 395
Author(s):  
Hayley M. Geyle ◽  
Leigh-Ann Woolley ◽  
Hugh F. Davies ◽  
John C. Z. Woinarski ◽  
Brett P. Murphy
Keyword(s):  
Conservation Status ◽  
Study Finding ◽  
Northern Territory ◽  
Northern Australia ◽  
Wet Season ◽  
Breast Height ◽  
Nest Boxes ◽  
Targeted Sampling ◽  
Large Trees ◽  
Survey Effort

The threatened northern brush-tailed phascogale (Phascogale pirata) is one of the most poorly known mammals in Australia. While the few available records indicate a decline in its distribution and abundance, it has not previously been subject to intensive targeted survey. Here, we trialled a specifically tailored methodology for detection of P. pirata, with the aim of informing ongoing survey and monitoring of this species. We deployed 50 motion-sensor cameras (spaced closely together in a grid 500×1000m) on Melville Island (Northern Territory, Australia), between June 2018 and May 2019. Cameras were baited and secured to trees ~3m above the ground on a bracket facing the trunk. We selected for large (>30cm diameter at breast height [DBH]) trunks of the dominant tree species (Eucalyptus miniata, E. tetrodonta and Corymbia nesophila). We detected P. pirata 16 times on eight cameras over the duration of the study, finding that detection was most likely on large (DBH >41.5cm) E. tetrodonta trees during the wet season. Our results indicate that survey effort for this species should be seasonally targeted and focussed on large trees. However, the efficacy of additional methods (nest boxes, Elliott traps) and a comparison between detections on arboreal versus ground-based cameras requires further investigation. We highlight the importance of conducting additional work on this species, as little is known about its ecology, population trends and threats, making it difficult to assess its conservation status. Without more targeted work, P. pirata is at risk of slipping into extinction unnoticed.

Distribution and conservation status of the rare plants Melaleuca triumphalis and Stenostegia congesta (Myrtaceae), Victoria River district, northern Australia

2006 ◽  
Vol 54 (7) ◽  
pp. 641 ◽  
Author(s):  
Beth Crase ◽  
Ian D. Cowie ◽  
Carrie R. Michell
Keyword(s):  
National Park ◽  
Conservation Status ◽  
Landscape Scale ◽  
Northern Territory ◽  
Rare Plants ◽  
Habitat Requirements ◽  
Northern Australia ◽  
Digital Elevation ◽  
Rivers And Streams ◽  
Scale Data

Targeted searches of approximately 150 km of cliff lines for two rare sandstone shrubs, Melaleuca triumphalis Craven and Stenostegia congesta A.R.Bean, thought to be restricted to the Victoria River gorge system within Gregory National Park, increased the number of known populations from 3 and 6 to 31 and 37, respectively. Both species occur predominantly in rocky and often fire-protected niches on sandstone cliffs and scree slopes, and are frequently associated with permanent drip-lines and seepage areas. Although their broad habitat requirements are similar, the two species do occur in slightly different niches. The data presented here suggest that M. triumphalis is reasonably fire tolerant, whereas S. congesta appears to be more fire sensitive. Weeds and introduced animals are not thought to pose a threat to these rare species. Models developed using remotely sensed and landscape-scale data (digital elevation models, radiometrics, geology and distance to rivers and streams) suggest that these species may also occur outside Gregory National Park in other areas of the Northern Territory such as on Bullo River and Bradshaw stations and in Keep River National Park. It is suggested that both species be regarded as Vulnerable under the IUCN guidelines.

scholarly journals Giant otter Pteronura brasiliensis density and abundance in Llanos Orientales de Colombia in the Orinoco basin

Oryx ◽  
2020 ◽  
pp. 1-4
Author(s):  
Germán Garrote ◽  
Beyker Castañeda ◽  
Jose Manuel Escobar ◽  
Laura Pérez ◽  
Brayan Marín ◽  
...  
Keyword(s):  
South America ◽  
Population Size ◽  
20Th Century ◽  
Conservation Status ◽  
Species Conservation ◽  
Iucn Red List ◽  
Red List ◽  
Recreational Fishing ◽  
Pteronura Brasiliensis ◽  
Direct Counts

Abstract The giant otter Pteronura brasiliensis, categorized as Endangered on the IUCN Red List, was once widely distributed throughout South America. By the middle of the 20th century the giant otter had become locally extinct along the main rivers of the Orinoco basin. Although some populations seem to have recovered, the paucity of information available does not permit a full evaluation of the species' conservation status. The objective of this study was to estimate the abundance and density of the giant otter population along the Orinoco river in the municipality of Puerto Carreño, Vichada, Colombia, where there is important commercial and recreational fishing. Thirty-nine linear km were surveyed, repeatedly, with a total of 315 km of surveys. Population size was estimated by direct counts of individuals. All individuals detected were photographed and identified individually from their throat pelage patterns. In total, 30 otters were identified, giving a minimum density of 0.77 individuals per km, one of the highest reported for the species in Colombia. Given the high density in this well-developed area, our results highlight the importance of this population for the conservation of the species.

scholarly journals An assessment of the distribution, population size and conservation status of the Santa Marta Foliage-gleaner Automolus rufipectus: a Sierra Nevada de Santa Marta endemic

2015 ◽  
Vol 25 (4) ◽  
pp. 451-465 ◽  
Author(s):  
ESTEBAN BOTERO-DELGADILLO ◽  
NICHOLAS BAYLY ◽  
CAMILA GÓMEZ ◽  
PAULO C. PULGARÍN-R. ◽  
CARLOS ANDRÉS PÁEZ
Keyword(s):  
Population Size ◽  
Sierra Nevada ◽  
Forest Cover ◽  
Conservation Status ◽  
Bird Species ◽  
Environmental Niche ◽  
Coffee Plantations ◽  
Habitat Transformation ◽  
Elevation Range ◽  
Area Of Occupancy

SummaryThe Santa Marta Foliage-gleaner Automolus rufipectus is one of 19 endemic bird species found in the Sierra Nevada de Santa Marta (SNSM) in northern Colombia but until recently it was considered a sub-species of the Ruddy Foliage-gleaner Automolus rubiginosus. Consequently, published information on its distribution and ecology is lacking, and while it is classified as near- threatened, this designation was based on limited quantitative data. To improve our knowledge of the Santa Marta Foliage-gleaner’s geographical distribution, elevation range, population density, habitat use and conservation status, we analysed both historical and recent site locality records and carried out variable distance transects within forested habitats and shade coffee plantations. We modelled the environmental niche of the species and subsequently estimated its extent of occurrence and area of occupancy, as well as population size. Our results consistently showed that the distribution of the Santa Marta Foliage-gleaner is more restricted than previously considered, both geographically and by elevation (we redefine elevation range as 600–1,875 m). This suggests that the species is more at risk of habitat transformation and combined with our estimates of population size (< 10,000 individuals), it is likely that the species will be uplisted to a higher threat category. More positively, and contrary to published accounts, we found that approximately 40% of the species’ range lies within protected areas. Nevertheless, we recommend the implementation of strategies to maintain forest cover on the western flank of the SNSM and further research to better define the species’ habitat needs and population dynamics.

Investigation into the diet of the central rock-rat (Zyzomys pedunculatus)

2003 ◽  
Vol 30 (5) ◽  
pp. 513 ◽  
Author(s):  
Theresa J. Nano ◽  
Cate M. Smith ◽  
Elizabeth Jefferys
Keyword(s):  
Sample Size ◽  
Conservation Status ◽  
Microscopic Analysis ◽  
Faecal Pellet ◽  
Northern Territory ◽  
The West ◽  
Major Food ◽  
Seasonal Shift ◽  
Leaf Consumption

The diet of the rare central rock-rat, Zyzomys pedunculatus, was assessed by microscopic analysis of 18 faecal pellet samples collected from four different sites in the west MacDonnell Ranges in the Northern Territory. Samples were collected from the four sites in summer (n = 13), one site in winter (n = 3), and two sites in spring (n = 2). Four major food categories were observed in the samples: seed, leaf, stem and insect. Seed was by far the most dominant food in the overall diet of Z. pedunculatus, making up 72% of identifiable particles, leaf was secondary (21%), while stem and insects contributed only 3% and 4% respectively. Although the sample size was small, no major seasonal shift between seed and invertebrate dominance was evident. Seed dominated the diet in both summer and winter, though winter seed consumption was lower (78% v. 58%). The level of seed consumption in the two spring samples was highly divergent (38% v. 93%), stressing the need for more samples to be collected from dry periods. Lowered rates of seed consumption during winter and in one of the spring samples were accompanied by increases in leaf consumption. Insect consumption remained low across all sampled seasons, suggesting that this species is not an omnivore. Rather, the dominance of seed in the diet suggests that Z. pedunculatus is primarily a granivore, a finding that has implications for the conservation status and management of this little-known species.

scholarly journals Update of distribution, habitats, population size, and threat factors for the West African crocodile in Mauritania

2016 ◽  
Vol 37 (3) ◽  
pp. 325-330 ◽  
Author(s):  
João Carlos Campos ◽  
Fernando Martínez-Freiría ◽  
Fábio Vieira Sousa ◽  
Frederico Santarém ◽  
José Carlos Brito
Keyword(s):  
Population Size ◽  
Conservation Status ◽  
West African ◽  
Conservation Strategies ◽  
Temperature Extremes ◽  
Local Conservation ◽  
The West ◽  
Water Abstraction ◽  
New Localities ◽  
Domestic Use

The West African crocodile (Crocodylus suchus) is an emblematic species from the Sahara-Sahel with scarce knowledge on distribution and conservation status. This study updated the knowledge on distribution, occupied habitats, population size, and factors that threaten C. suchus and its habitats in Mauritania. Five field expeditions to Mauritania (2011-2016), allowed the detection of 26 new localities, increasing by 27% the current number of all known locations (adding up to ). In most localities less than five individuals were observed, and in all visiting sites the number of observed individuals ranged from one to 23. Eleven threat factors were identified, being droughts and temperature extremes (100% localities affected) and water abstraction for domestic use and nomadic grazing (94%) the most frequent. These findings suggest that crocodiles are apparently vulnerable in Mauritania and that future local conservation strategies are needed to assure the continuity of its fragile populations and preserve their habitats.

scholarly journals Overview on the distribution of gorgonian species in Tunisian marine coastal waters (central Mediterranean)

2018 ◽  
Vol 82 (1) ◽  
pp. 55 ◽  
Author(s):  
Raouia Ghanem ◽  
Emna Soufi Kechaou ◽  
Jamila Ben Souissi ◽  
Joaquim Garrabou
Keyword(s):  
Coastal Waters ◽  
Local Ecological Knowledge ◽  
Conservation Status ◽  
Ecological Knowledge ◽  
Central Mediterranean ◽  
Management Actions ◽  
Conservation Actions ◽  
Gorgonian Species ◽  
Species Richness And Abundance ◽  
And Function

Gorgonian species play an important ecological role in the structure and function of marine communities. Human activities are negatively affecting the conservation status of gorgonian populations in the Mediterranean. Acquiring knowledge of gorgonian distribution is therefore a key step required to promote efficient management and conservation actions. However, information on the distribution of gorgonian species is lacking in many Mediterranean areas. This study aimed to provide an overview of the geographic and bathymetric distributions of gorgonians in the coastal waters of the Tunisian coast (1136 km). The sampling design encompassed three sectors, 27 localities and 87 sites. Information was collected from scuba diving (26 sites) and local ecological knowledge surveys of fishermen and divers (132 interviews), as well as from a literature review. Overall, the occurrence of eight gorgonians was confirmed at 54 out of the 87 sites surveyed in Tunisian coastal waters (7-120 m depth). The species that were found were Eunicella singularis, Eunicella cavolini, Paramuricea clavata, Paramuricea macrospina, Leptogorgia sarmentosa, Eunicella verrucosa, Corallium rubrum and Ellisella paraplexauroides. The highest gorgonian species richness and abundance was recorded in northern, followed by eastern Tunisian waters. In the southern areas only one species was recorded. This pattern was related to the rocky substrate that characterizes the northern and eastern coasts of Tunisia. This study is the first to report the occurrence of E. singularis, E. cavolini, E. verrucosa and Leptogorgia sarmentosa in northern and eastern Tunisian waters. The results are discussed in the hope of guiding future conservation and management actions for gorgonian assemblages in Tunisia.

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