scholarly journals Using occupancy-based camera-trap surveys to assess the Critically Endangered primate Macaca nigra across its range in North Sulawesi, Indonesia

Oryx ◽  
2020 ◽  
Vol 54 (6) ◽  
pp. 784-793
Author(s):  
Caspian L. Johnson ◽  
Harry Hilser ◽  
Matthew Linkie ◽  
Rivo Rahasia ◽  
Francesco Rovero ◽  
...  
Keyword(s):  
Protected Areas ◽  
Fragment Size ◽  
Camera Trap ◽  
Camera Traps ◽  
Critically Endangered ◽  
Anthropogenic Factors ◽  
Forest Fragment ◽  
Conservation Action ◽  
Term Survival ◽  
Macaca Nigra

AbstractPrimates are one of the most threatened groups of mammals. Understanding their patterns of population occurrence and abundance, especially in response to threats, is critical for informing conservation action. The crested black macaque Macaca nigra is the only Critically Endangered species of Sulawesi's seven endemic macaques. Little is known about its distribution or its response to deforestation and hunting. We conducted a camera-trap survey across the entire species range using an occupancy-based analytical approach to (1) establish the first range-wide baseline of occurrence, (2) investigate how environmental and anthropogenic factors influence occurrence, (3) identify priority conservation subpopulations, and (4) test the efficacy of the sampling and analytical protocol for temporal monitoring of M. nigra using occupancy as the state variable. From 9,753 camera-trap days, M. nigra was detected on 473 days at 77 of the 111 camera locations. Species occupancy was 0.66 and highest inside protected areas and closed canopy forest. We identified eight distinct subpopulations, based on distribution and forest fragment size. To inform future monitoring, we used a power analysis to determine if our effort would allow us to detect inter-annual occupancy declines of 10%, and found that 90 camera locations surveyed for 3 months (8,100 camera days) across three consecutive seasons is the effort required to detect such change with 80% certainty. Our study underscores the importance of well-managed protected areas and intact forests for the long-term survival of the crested black macaque, and tests the effectiveness of camera traps to monitor primates at the landscape scale.

scholarly journals Ongoing decline of suitable habitat for the Critically Endangered Gurney's pitta Hydrornis gurneyi

Oryx ◽  
2021 ◽  
pp. 1-7
Author(s):  
Tommaso Savini ◽  
Nay Myo Shwe ◽  
Niti Sukumal
Keyword(s):  
Industrial Development ◽  
Large Scale ◽  
Legal Protection ◽  
Critically Endangered ◽  
Suitable Habitat ◽  
Conservation Action ◽  
Term Survival ◽  
Long Term Survival ◽  
Lowland Forests

Abstract From 1999 onwards, level, lowland forests (altitude < 150 m, slopes < 10°) in the Tanintharyi Region of southern Myanmar have been cleared on a large scale and replaced by oil palm plantations. This has resulted in a drastic decline in suitable habitat for several species, including Gurney's pitta Hydrornis gurneyi (Passeriformes, Pittidae). The habitat for this species has decreased by > 80%, leading to its categorization as Critically Endangered on the IUCN Red List in 2019. As threats in the region have continued, we updated information on the status of the species’ habitat in January 2020, and examined forest loss in the three strongholds where the species still persists in the wild. Since the previous estimate in 2017, suitable habitat in these locations has decreased by 8% (from 656 to 603 km2), with > 10% of the remaining area now in fragments of < 1 km2, which are unsuitable for the mid- to long-term survival of the species. Forest degradation and edge effects from increased fragmentation have led to further loss of suitable habitat in these strongholds. Projections indicate that unless conservation action is taken, all suitable habitat will disappear by 2080. The main threat to the long-term survival of Gurney's pitta is the lack of legal protection of primary lowland forests, resulting in uncontrolled clearance for small- and large-scale agriculture and industrial development. We provide recommendations to reduce the rate of loss of the remaining suitable habitat for the species.

scholarly journals Status and conservation of the only population of the Vulnerable owl-faced monkey Cercopithecus hamlyni in Rwanda

Oryx ◽  
2011 ◽  
Vol 45 (3) ◽  
pp. 435-438 ◽  
Author(s):  
Julian Easton ◽  
Nerissa Chao ◽  
Felix Mulindahabi ◽  
Nicolas Ntare ◽  
Louis Rugyerinyange ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Camera Traps ◽  
Bamboo Forest ◽  
Conservation Action ◽  
Term Survival ◽  
Illegal Harvesting ◽  
Tree Cutting ◽  
International Border ◽  
Blue Monkey

AbstractThe elusive, Vulnerable owl-faced monkey Cercopithecus hamlyni is a rare and little studied species and one of the least known of the African Cercopithecidae. This study describes the distribution and relative abundance of the only known population in East Africa, in Nyungwe National Park, Rwanda. This species is restricted to a small (32 km2) area of bamboo and bamboo–forest mix in the southern sector of the Park, close to the international border with Burundi. We present the first empirical data of its abundance in the bamboo forests of Nyungwe. A total length of 185 km of transect were surveyed to estimate relative abundance of diurnal primates. Encounter rates with the owl-faced monkey were 0.081 groups km-1 (n = 15). Mean group size was 3.6 individuals. Eight independent photographs of C. hamlyni were obtained from five camera traps during 182 camera-days. Four other species of primates occur in the bamboo forest: eastern chimpanzee Pan troglodytes schweinfurthii, Angola colobus Colobus angolensis, L’Hoest’s monkey Cercopithecus l’hoesti and blue monkey Cercopithecus mitis. The main threats to the bamboo forest are from the illegal harvesting of bamboo, trapping and tree-cutting. These threats originate from both Rwanda and Burundi. There is an urgent need for conservation action to halt the destruction and degradation of the bamboo forest and to ensure the long-term survival of the owl-faced monkey in Rwanda.

scholarly journals Citizen science, computing, and conservation: How can “Crowd AI” change the way we tackle large-scale ecological challenges?

2021 ◽  
Vol 8 (2) ◽  
pp. 54-75
Author(s):  
Meredith S. Palmer ◽  
Sarah E. Huebner ◽  
Marco Willi ◽  
Lucy Fortson ◽  
Craig Packer
Keyword(s):  
Machine Learning ◽  
Big Data ◽  
Citizen Science ◽  
Large Scale ◽  
Camera Trap ◽  
Camera Traps ◽  
Machine Learning Algorithms ◽  
Anthropogenic Factors ◽  
Spatial And Temporal Scales ◽  
The Way

Camera traps - remote cameras that capture images of passing wildlife - have become a ubiquitous tool in ecology and conservation. Systematic camera trap surveys generate ‘Big Data’ across broad spatial and temporal scales, providing valuable information on environmental and anthropogenic factors affecting vulnerable wildlife populations. However, the sheer number of images amassed can quickly outpace researchers’ ability to manually extract data from these images (e.g., species identities, counts, and behaviors) in timeframes useful for making scientifically-guided conservation and management decisions. Here, we present ‘Snapshot Safari’ as a case study for merging citizen science and machine learning to rapidly generate highly accurate ecological Big Data from camera trap surveys. Snapshot Safari is a collaborative cross-continental research and conservation effort with 1500+ cameras deployed at over 40 eastern and southern Africa protected areas, generating millions of images per year. As one of the first and largest-scale camera trapping initiatives, Snapshot Safari spearheaded innovative developments in citizen science and machine learning. We highlight the advances made and discuss the issues that arose using each of these methods to annotate camera trap data. We end by describing how we combined human and machine classification methods (‘Crowd AI’) to create an efficient integrated data pipeline. Ultimately, by using a feedback loop in which humans validate machine learning predictions and machine learning algorithms are iteratively retrained on new human classifications, we can capitalize on the strengths of both methods of classification while mitigating the weaknesses. Using Crowd AI to quickly and accurately ‘unlock’ ecological Big Data for use in science and conservation is revolutionizing the way we take on critical environmental issues in the Anthropocene era.

scholarly journals The fate of tropical forest fragments

2020 ◽  
Vol 6 (11) ◽  
pp. eaax8574 ◽  
Author(s):  
Matthew C. Hansen ◽  
Lei Wang ◽  
Xiao-Peng Song ◽  
Alexandra Tyukavina ◽  
Svetlana Turubanova ◽  
...  
Keyword(s):  
Land Use ◽  
Southeast Asia ◽  
Tropical Forest ◽  
Protected Areas ◽  
Land Use Planning ◽  
Fragment Size ◽  
Biodiversity Loss ◽  
Primary Forest ◽  
Forest Fragments ◽  
Forest Fragment

Tropical forest fragmentation results in habitat and biodiversity loss and increased carbon emissions. Here, we link an increased likelihood of tropical forest loss to decreasing fragment size, particularly in primary forests. The relationship holds for protected areas, albeit with half the rate of loss compared with all fragments. The fact that disturbance increases as primary forest fragment size decreases reflects higher land use pressures and improved access for resource extraction and/or conversion in smaller fragments. Large remaining forest fragments are found in the Amazon and Congo Basins and Insular Southeast Asia, with the majority of large extent/low loss fragments located in the Amazon. Tropical areas without large fragments, including Central America, West Africa, and mainland Southeast Asia, have higher loss within and outside of protected areas. Results illustrate the need for rigorous land use planning, management, and enforcement in maintaining large tropical forest fragments and restoring regions of advanced fragmentation.

scholarly journals First census of the white-shouldered ibis Pseudibis davisoni reveals roost-site mismatch with Cambodia's protected areas

Oryx ◽  
2012 ◽  
Vol 46 (2) ◽  
pp. 236-239 ◽  
Author(s):  
Hugh L. Wright ◽  
Nigel J. Collar ◽  
Iain R. Lake ◽  
Net Norin ◽  
Rours Vann ◽  
...  
Keyword(s):  
Protected Areas ◽  
Population Size ◽  
Critically Endangered ◽  
Population Estimate ◽  
Term Survival ◽  
Long Term Survival ◽  
Global Population

AbstractThe population size of the Critically Endangered white-shouldered ibis Pseudibis davisoni has always been poorly known. The first-ever census across Cambodia in 2009–2010 using simultaneous counts at multiple roost sites found substantially more birds than previously estimated, with a minimum of 523 individuals. The census allowed us to make a revised global population estimate of 731–856 individuals, increasing hope for the species' long-term survival. However, the largest subpopulations are imminently threatened by development and c. 75% of the birds counted in Cambodia were outside protected areas.

Effectiveness of Protected Areas in Conserving the Highly Hunted Mammal Species as Bushmeat in Southern Benin

2018 ◽  
Vol 11 (1) ◽  
pp. 14-24
Author(s):  
Chabi A.M.S. Djagoun ◽  
Etotépé A. Sogbohossou ◽  
Barthélémy Kassa ◽  
Christian B. Ahouandjinou ◽  
Hugues A. Akpona ◽  
...  
Keyword(s):  
Protected Areas ◽  
Habitat Degradation ◽  
Habitat Type ◽  
Cell System ◽  
Anthropogenic Factors ◽  
Mammal Species ◽  
Occupancy Model ◽  
Habitat Occupancy ◽  
Anthropogenic Habitat ◽  
Lama Forest

Background: The habitat degradation together with fragmentation and illegal hunting represent a major threat for biodiversity conservation in Lama protected areas. Method: We used a combination of questionnaire survey with local communities for ranking the hunted mammal species as bushmeat and track surveys in gridded-cell system of 500x500 m2 (n=268) to assess at what extend the management design, the anthropogenic factors and habitat type affect the occupancy model of those mammal species. Results: Twenty mammal species have been predominantly reported by the local inhabitants to consume bushmeat species and 5 of them have been identified as the most preferable as hunted game mammals. The selection of the preferred habitat among the swampy forest, the dense forest, the tree plantations and cropland for the prioritized game species varies between species but looks similar when grouping in different orders. Some bushmeat species were found to select the more secure habitat (natural forest); suggesting the zoning system in the Lama forest can passively protect those species. However, some species such as T. swinderianus although highly hunted showed preference to anthropogenic habitat, avoiding the well secured core zone in Lama Forest. Conclusion: Our findings highlighted the importance of the zoning system with different management objectives in the habitat occupancy model of the highly hunted wildlife species.

scholarly journals Leopard Density Estimation within an Enclosed Reserve, Namibia Using Spatially Explicit Capture-Recapture Models

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 724
Author(s):  
Noack ◽  
Heyns ◽  
Rodenwoldt ◽  
Edwards
Keyword(s):  
Management Strategies ◽  
Camera Traps ◽  
Spatially Explicit ◽  
Conservation Areas ◽  
Term Survival ◽  
New Class ◽  
Capture Recapture ◽  
Wildlife Populations ◽  
Effective Conservation

The establishment of enclosed conservation areas are claimed to be the driving force for the long-term survival of wildlife populations. Whilst fencing provides an important tool in conservation, it simultaneously represents a controversial matter as it stops natural migration processes, which could ultimately lead to inbreeding, a decline in genetic diversity and local extinction if not managed correctly. Thus, wildlife residing in enclosed reserves requires effective conservation and management strategies, which are strongly reliant on robust population estimates. Here, we used camera traps combined with the relatively new class of spatially explicit capture-recaptured models (SECR) to produce the first reliable leopard population estimate for an enclosed reserve in Namibia. Leopard density was estimated at 14.51 leopards/100 km2, the highest recorded density in Namibia to date. A combination of high prey abundance, the absence of human persecution and a lack of top-down control are believed to be the main drivers of the recorded high leopard population. Our results add to the growing body of literature which suggests enclosed reserves have the potential to harbour high densities and highlight the importance of such reserves for the survival of threatened species in the future.

scholarly journals Microsatellite analysis reveals low genetic diversity in managed populations of the critically endangered gharial (Gavialis gangeticus) in India

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Surya Prasad Sharma ◽  
Mirza Ghazanfarullah Ghazi ◽  
Suyash Katdare ◽  
Niladri Dasgupta ◽  
Samrat Mondol ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Indian Subcontinent ◽  
Population Decline ◽  
Mitochondrial Control Region ◽  
Critically Endangered ◽  
Term Survival ◽  
Low Level ◽  
Genetic Status ◽  
In The Wild ◽  
Gavialis Gangeticus

AbstractThe gharial (Gavialis gangeticus) is a critically endangered crocodylian, endemic to the Indian subcontinent. The species has experienced severe population decline during the twentieth century owing to habitat loss, poaching, and mortalities in passive fishing. Its extant populations have largely recovered through translocation programmes initiated in 1975. Understanding the genetic status of these populations is crucial for evaluating the effectiveness of the ongoing conservation efforts. This study assessed the genetic diversity, population structure, and evidence of genetic bottlenecks of the two managed populations inhabiting the Chambal and Girwa Rivers, which hold nearly 80% of the global gharial populations. We used seven polymorphic nuclear microsatellite loci and a 520 bp partial fragment of the mitochondrial control region (CR). The overall mean allelic richness (Ar) was 2.80 ± 0.40, and the observed (Ho) and expected (He) heterozygosities were 0.40 ± 0.05 and 0.39 ± 0.05, respectively. We observed low levels of genetic differentiation between populations (FST = 0.039, P < 0.05; G’ST = 0.058, P < 0.05 Jost’s D = 0.016, P < 0.05). The bottleneck analysis using the M ratio (Chambal = 0.31 ± 0.06; Girwa = 0.41 ± 0.12) suggested the presence of a genetic bottleneck in both populations. The mitochondrial CR also showed a low level of variation, with two haplotypes observed in the Girwa population. This study highlights the low level of genetic diversity in the two largest managed gharial populations in the wild. Hence, it is recommended to assess the genetic status of extant wild and captive gharial populations for planning future translocation programmes to ensure long-term survival in the wild.

scholarly journals Small mammal glucocorticoid concentrations vary with forest fragment size, trap type, and mammal taxa in the Interior Atlantic Forest

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah A. Boyle ◽  
Noé U. de la Sancha ◽  
Pastor Pérez ◽  
David Kabelik
Keyword(s):  
Atlantic Forest ◽  
Small Mammals ◽  
Acute Stress ◽  
Physiological Stress ◽  
Fragment Size ◽  
Hair Shaft ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Trapping Methods ◽  
Free Ranging

AbstractSpecies that live in degraded habitats often show signs of physiological stress. Glucocorticoid hormones (e.g., corticosterone and cortisol) are often assessed as a proxy of the extent of physiological stress an animal has experienced. Our goal was to quantify glucocorticoids in free-ranging small mammals in fragments of Interior Atlantic Forest. We extracted glucocorticoids from fur samples of 106 small mammals (rodent genera Akodon and Oligoryzomys, and marsupial genera Gracilinanus and Marmosa) from six forest fragments (2–1200 ha) in the Reserva Natural Tapytá, Caazapá Department, Paraguay. To our knowledge, this is the first publication of corticosterone and cortisol levels for three of the four sampled genera (Akodon, Oligoryzomys, and Marmosa) in this forest system. We discovered three notable results. First, as predicted, glucocorticoid levels were higher in individuals living withing small forest fragments. Second, animals captured live using restraint trapping methods (Sherman traps) had higher glucocorticoid levels than those animals captured using kill traps (Victor traps), suggesting that hair glucocorticoid measures can reflect acute stress levels in addition to long-term glucocorticoid incorporation. These acute levels are likely due to urinary steroids diffusing into the hair shaft. This finding raises a concern about the use of certain trapping techniques in association with fur hormone analysis. Finally, as expected, we also detected genus-specific differences in glucocorticoid levels, as well as cortisol/corticosterone ratios.

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