scholarly journals Multiple methods increase detection of large and medium-sized mammals: working with volunteers in south-eastern Oman

Oryx ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Marcelo Mazzolli ◽  
Taiana Haag ◽  
Beatriz G. Lippert ◽  
Eduardo Eizirik ◽  
Matthias L.A. Hammer ◽  
...  

AbstractWe compared the effectiveness of various methods for surveying medium and large wild mammals in southern Oman. Working with volunteers recruited by Biosphere Expeditions, wildlife professionals and local rangers, we used direct observation, camera traps, sign surveys (tracks and/or dung) and molecular scatology to study 66 sampling units of 2 × 2 km (grid cells) in an area of 32 × 36 km during a 4-week period in February–March 2011. Sixteen mammal species were recorded, and the largest numbers of species were recorded by sign surveys and camera traps (both n = 9); sign surveys, direct sightings and DNA scatology recorded species across the largest number of grid cells. For species with a sample size large enough for comparison (i.e. detected in ≥ 8 grid cells), DNA scatology proved most effective for detecting caracal Caracal caracal, signs for hyaena Hyaena hyaena, ibex Capra nubiana, porcupine Hystrix indica and hyrax Procavia capensis, and signs and direct sightings for mountain gazelle Gazella gazella. Clustering, in which records from multiple methods are either adjacent or overlapping, was highest (≥ 76%) for the wolf Canis lupus, porcupine, ibex and gazelle. Our results indicate the best methods to detect and record the distributions of individual species in the study area, and demonstrate the advantage of using multiple methods to reduce the risk of false absences or partial detections. Our findings also highlight the potential of clustering as a means of cross-checking results of observations that are skill-dependent, which is particularly useful when employing a large workforce.

2020 ◽  
Author(s):  
Brian Wood ◽  
Riccardo S. Millar ◽  
Nicholas Wright ◽  
Joshua Baumgartner ◽  
Hannah Holmquist ◽  
...  

In many regions of sub Saharan Africa large mammals occur in human-dominated areas, yet their community composition and species-specific densities have rarely been described in areas occupied by traditional hunter-gatherers and pastoralists. Surveys of mammal populations in such areas provide important measures of biodiversity and provide ecological context for understanding hunting practices. Using a sampling grid centered on a Hadza hunter-gatherer camp and covering 36 km² of semi-arid savannah in northern Tanzania, we assessed mammals using camera traps (n = 19 stations) for c. 5 months (2,182 trap nights). In the study area (Tli’ika in the Hadza language), we recorded 36 wild mammal species, resembling a near complete mammal community. Rarefaction curves suggest that sampling effort was sufficient to capture mammal species richness. Species-specific densities were estimated using a random encounter model and site- and species’ body mass- specific estimates of the area sampled at each camera; confidence intervals were estimated using bootstrapping. Point estimates of densities varied by c. four orders of magnitude, from 0.003 ind./km² (African wild dog) to 27.5 ind./km² (Kirk’s dik dik). Densities of livestock (cattle, donkey, sheep and goat) were high, particularly when estimated using directly observed herd sizes. Cumulative biomass density of herbivorous livestock species exceeded that of all wild mammals by a factor of 3.3-38.7. We compare our study’s data to camera trap rates recorded in a fully protected area of northern Tanzania with similar precipitation (Lake Manyara National Park), revealing that abundance indices of most wildlife species in Tli’ika were much lower. We discuss how these data inform studies of Hadza hunting and models of hunter-gatherer foraging ecology and diet.


2021 ◽  
Vol 13 (9) ◽  
pp. 19223-19231
Author(s):  
Anna Niang ◽  
Papa Ibnou Ndiaye

Wildlife in the Great Green Wall (GGW) area, northern Senegal, is threatened by the cumulative effects of anthropogenic activities, drought, and climatic changes. To support conservation planning in line with the GGW management objectives, we studied large mammal diversity in the Koyli Alpha Community Wildlife Reserve in the GGW extension area. We interviewed local communities, made reconnaissance & transect walks, placed camera traps, and carried out fixed point surveys to map the distribution of mammals & to estimate their relative abundance. The surveys were conducted between May 2017 and December 2019. We identified the presence of nine mammal species belonging to six families: one lagomorph, Cape Hare Lepus capensis; seven carnivores, Common Jackal Canis aureus, Pale/Sand Fox Vulpes pallida, Wild Cat Felis silvestris, Marsh Mongoose Atilax paludinosus, Honey Badger Mellivora capensis, Zorilla Ictonyx striatus, Common Genet Genetta genetta, and one primate, Patas Monkey Erythrocebus patas. Our results indicate that the most of the observed species range broadly across the Koyli Alpha Reserve. The Wild Cat and the Sand Fox were also found outside the reserve around the village of Koyli Alpha. Camera trapping events of humans and domestic animals were high throughout the survey area, and the majority of the large mammals observed were mainly nocturnal. The diversity of large wild mammals identified during this study points to the urgent need for the implementation of a management plan of the biodiversity in this area of the Ferlo. 


2014 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Tiberio C. Monterrubio-Rico ◽  
Juan Felipe Charre Medellín ◽  
Cristina Z. Colín-Soto ◽  
Livia León Paniagua

 RESUMEN Los mamíferos silvestres han sido estudiados en Michoacán desde el siglo XVIII por renombrados zoólogos y naturalistas. Sin embargo, todavía en 1949 se reconocía solo 85 especies, y hasta el año 2005 se proporcionó estimaciones completas basadas en integración de registros disponibles tanto nacionales como de colecciones científicas internacionales, ya que la información disponible para el estado se encontraba dispersa. Como resultado de proyectos recientes con nuevos registros, el objetivo de este análisis es proporcionar una cifra actualizada sobre la riqueza taxonómica de los mamíferos silvestres terrestres en el estado de Michoacán. Existen registros de 161 especies en 9 Ordenes, 25 familias, y 94 géneros que representan el 32% de las especies de México. El Orden con mayor número de especies es Chiroptera con 74 especies que representan el 53% de las especies del Orden en México. A pesar de la ubicación central de Michoacán en el país, y ser un estado muestreado por numerosos investigadores, todavía existe carencia de información para regiones remotas, y en algunos grupos de mamíferos. Por ejemplo, el jaguar, que a pesar de ser el mayor felino del país, se carecía de confirmación para el estado, afortunadamente durante 2010 se localizó una población en el estado. Otro aspecto limitante para la interpretación adecuada de la estimación actual, es la antigüedad de muchos registros, ya que los estudios más completos realizados a escala regional, como en la costa Michoacana son de hace 30 años, y durante ese periodo se ha incrementado la deforestación de selvas tropicales, por lo que desconocemos la situación actual que presentan las poblaciones de mamíferos en el estado. En Michoacán encuentran su límite más norteño en el Pacífico tres especies de amplia distribución en el Neotrópico, Tamandua mexicana,  Potos flavus y Sphiggurus mexicanus, por lo que deben limitarse áreas que protejan sus poblaciones. Palabras clave: Distribución, Mochoacán, mamíferos, especies.ABSTRACT The wild mammals in Michoacan state have been studied since the XVIII century by reknown zoologists and naturalists. However, still in 1949 only 85 mammals species were recognized, and until 2005 a complete estimate based on the integration of national and international data bases records available from Scientific collections, since all available information was scattered. As a result of recent surveys with new records, the aim of this analysis was to provide an updated statistic of the terrestrial wild mammals taxonomic richness in the Michoacan state. Available records correspond to 161 species in 9 Orders, 25 families and 94 genera which represent 32% of the Mexican mammal species. The Order with the major number of species is Chiroptera that includes 74 species thet represent 53% of the Order in Mexico. Despite its central location in the country, and considering that the state has been surveyed by several prestigious academics, there is still a lack of information for remote regions, and for some mammal groups. For example, the jaguar, even though constitute the largest wild felid in the country, no information was available for the state, fortunately during 2010 a population was localized in the state. Another limiting factor for the adequate interpretation of the current estimate is that many records are outdated, since the most complete studies performed at a regional scale, like in the Michoaca coast, are 30 years old, and during that time-frame, tropical forest loss increased dramatically, for instance, the current situation that present the mammal populations in the state are unknown. In Michoacan three species with a broad neotropical distribution present its northernmost limit on the Pacific, Tamandua mexicana, Potos flavus, and Sphiggurus mexicanus and there is the need to establish protected areas oriented to protect their populations. Key words: Distribution, Michoacan, mammals, species.


Author(s):  
Jason Fisher ◽  
Joanna Burgar ◽  
Melanie Dickie ◽  
Cole Burton ◽  
Rob Serrouya

Density estimation is a key goal in ecology but accurate estimates remain elusive, especially for unmarked animals. Data from camera-trap networks combined with new density estimation models can bridge this gap but recent research has shown marked variability in accuracy, precision, and concordance among estimators. We extend this work by comparing estimates from two different classes of models: unmarked spatial capture-recapture (spatial count, SC) models, and Time In Front of Camera (TIFC) models, a class of random encounter model. We estimated density for four large mammal species with different movement rates, behaviours, and sociality, as these traits directly relate to model assumptions. TIFC density estimates were typically higher than SC model estimates for all species. Black bear TIFC estimates were ~ 10-fold greater than SC estimates. Caribou TIFC estimates were 2-10 fold greater than SC estimates. White-tailed deer TIFC estimates were up to 100-fold greater than SC estimates. Differences of 2-5 fold were common for other species in other years. SC estimates were annually stable except for one social species; TIFC estimates were highly annually variable in some cases and consistent in others. Tests against densities obtained from DNA surveys and aerial surveys also showed variable concordance and divergence. For gregarious animals TIFC may outperform SC due to the latter model’s assumption of independent activity centres. For curious animals likely to investigate camera traps, SC may outperform TIFC, which assumes animal behavior is unaffected by cameras. Unmarked models offer great possibilities, but a pragmatic approach employs multiple estimators where possible, considers the ecological plausibility of assumptions, and uses an informed multi-inference approach to seek estimates from models with assumptions best fitting a species’ biology.


Therya ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 213-236
Author(s):  
Amanda K. Jones ◽  
Schuyler W. Liphardt ◽  
Jonathan L. Dunnum

A study of the mammals of the Gila region of New Mexico was conducted from 2012 through 2020, with 2,919 voucher specimens collected through fieldwork and collaborations with commercial trappers, in addition to data from camera traps, review of major holdings at 46 museums (n = 12,505 georeferenced specimens), and literature review.  Specimens cover a 170-year span, dating back to 1850 and were unevenly distributed spatially and temporally across the Gila region.  Most areas were very poorly represented and when summed across all mammal species, ranged from 0.02 to 3.7 specimens per km2.  The survey documented 108 species (104 now extant) for the region.  High species richness, greater than that reported for 38 states in the United States, is likely due to the juxtaposition of multiple biomes in the Gila, including the Sonoran, Chihuahuan, and Great Basin deserts, the Rocky Mountains and Sierra Madre Occidental, and nearby “sky islands’’ of the Southwest.  Two species, Leptonycteris yerbabuenae and Zapus luteus, are documented for the first time from the study area.  Expansions of the known range of these species, and Sciurus arizonensis are described from specimen and camera data.  Preliminary phylogeographic studies of four species (Notiosorex crawfordi, Neotoma albigula, Perognathus flavus, and Thomomys bottae) using the mitochondrial cytochrome-b gene reveal the dynamic biogeographic history of the region and reinforce how landscape complexity and climate change have jointly contributed to diversification and thus high mammalian diversity in the region.


2021 ◽  
Vol 71 (3) ◽  
pp. 311-327
Author(s):  
Mayra Zamora-Espinoza ◽  
Juan Carlos López-Acosta ◽  
Eduardo Mendoza

Abstract Studies of tropical mammal defaunation highlight the loss of species as well as their reduction in abundance and diversity; however, there is a complex series of effects associated with this anthropogenic disruption, including increases in the relative abundance of disturbance-tolerant mammals and the arrival of alien mammals whose effects on biotic interactions have been poorly studied. We compared the species richness, composition, interaction strength, and patterns of daily activity of mammals that consume the fruits of Pouteria sapota on the forest floor, both inside and outside of the Los Tuxtlas Field Station (LTFS) in Veracruz, southern Mexico. Using camera traps, we recorded eight mammal species interacting with the fruits inside the LTFS ( trees) and nine species interacting outside ( trees). Alien species such as Canis lupus familiaris were recorded both inside and outside of the LTFS, whereas Bos taurus was only recorded outside. Medium-sized generalist mammals were overrepresented both inside and outside of the LTFS, evidencing an impoverishment of the fauna, when compared to the mammal assemblage reported to interact with P. sapota fruits in a more intact forest. The daily activity patterns of the mammals that interacted strongly with P. sapota fruits were different inside and outside the LTFS, particularly in the case of Cuniculus paca. Our results show that the impact of human activity is highly pervasive, directly affecting the mammalian fauna at different levels and indirectly affecting the biotic interactions in which these animals are involved.


2020 ◽  
Vol 47 (4) ◽  
pp. 338
Author(s):  
Bracy W. Heinlein ◽  
Rachael E. Urbanek ◽  
Colleen Olfenbuttel ◽  
Casey G. Dukes

Abstract ContextCamera traps paired with baits and scented lures can be used to monitor mesocarnivore populations, but not all attractants are equally effective. Several studies have investigated the efficacy of different attractants on the success of luring mesocarnivores to camera traps; fewer studies have examined the effect of human scent at camera traps. AimsWe sought to determine the effects of human scent, four attractants and the interaction between attractants and human scent in luring mesocarnivores to camera traps. Methods We compared the success of synthetic fermented egg (SFE), fatty acid scent (FAS) tablets, castor oil, and sardines against a control of no attractant in luring mesocarnivores to camera traps. We deployed each attractant and the control with either no regard to masking human scent or attempting to restrict human scent for a total of 10 treatments, and replicated treatments eight to nine times in two different phases. We investigated whether: (1) any attractants increased the probability of capturing a mesocarnivore at a camera trap; (2) not masking human scent affected the probability of capturing a mesocarnivore at a camera trap; and (3) any attractants increased the probability of repeat detections at a given camera trap. We also analysed the behaviour (i.e. speed and distance to attractant) of each mesocarnivore in relation to the attractants. Key resultsSardines improved capture success compared with the control treatments, whereas SFE, castor oil, and FAS tablets had no effect when all mesocarnivores were included in the analyses. Masking human scent did not affect detection rates in the multispecies analyses. Individually, the detection of some species depended on the interactions between masking (or not masking) human scent and some attractants. ConclusionsSardines were the most effective as a broad-based attractant for mesocarnivores. Mesocarnivores approached traps baited with sardines at slower rates, which allows for a higher success of capturing an image of the animal. ImplicationsHuman scent may not need to be masked when deploying camera traps for multispecies mesocarnivore studies, but researchers should be aware that individual species respond differently to attractants and may have higher capture success with species-specific attractants.


2015 ◽  
Vol 15 (4) ◽  
Author(s):  
Leonardo de Paula Gomes ◽  
Clarisse Rezende Rocha ◽  
Reuber Albuquerque Brandão ◽  
Jader Marinho-Filho

At least 251 mammal species are recorded for the Brazilan cerrado, which, therefore, is the third richest Brazilian biome. Most mammal surveys in Brazilian cerrado result from studies performed opportunistically and in short time periods. The aims of the present study were (1) provide a checklist for the mammalian fauna based on a five-year sampling in Serra do Facão region, Southeastern Goiás state; (2) compare small non-flying mammals diversity in open and forest areas and (3) compare species diversity before and after the flood caused by a hydroelectric reservoir filling. The data was gathered in 19 sampling periods, from May 2008 to September 2013. We sampled open and forest habitats and captured non-flying small mammals with Sherman and Tomahawk live traps and pitfalls; bats were sampled with mist-nets; large mammals were recorded with camera traps, and by direct observations and track surveys in field. We found 20 species of small non-flying mammals, 10 species of bats and 33 species of larger mammals. Species diversity was greater for forest than open habitats, and was also greater before than after the complete reservoir filling. About 10% of the recorded species are included in the Brazilian official list of threatened species. The total richness represents 25% of all cerrado mammal fauna, highlighting the importance of this area for regional mammal fauna conservation.


2018 ◽  
Vol 45 (6) ◽  
pp. 518 ◽  
Author(s):  
Jaime Heiniger ◽  
Skye F. Cameron ◽  
Graeme Gillespie

Context Feral cats are a significant threat to native wildlife and broad-scale control is required to reduce their impacts. Two toxic baits developed for feral cats, Curiosity® and Hisstory®, have been designed to reduce the risk of baiting to certain non-target species. These baits involve encapsulating the toxin within a hard-shelled delivery vehicle (HSDV) and placing it within a meat attractant. Native animals that chew their food more thoroughly are predicted to avoid poisoning by eating around the HSDV. This prediction has not been tested on wild native mammals in the monsoonal wet–dry tropics of the Northern Territory. Aim The aim of this research was to determine whether northern quolls (Dasyurus hallucatus) and northern brown bandicoots (Isoodon macrourus) would take feral cat baits and ingest the HSDV under natural conditions on Groote Eylandt. Methods We hand-deployed 120 non-toxic baits with a HSDV that contained a biomarker, Rhodamine B, which stains animal whiskers when ingested. The species responsible for bait removal was determined with camera traps, and HSDV ingestion was measured by evaluating Rhodamine B in whiskers removed from animals trapped after baiting. Key results During field trials, 95% of baits were removed within 5 days. Using camera-trap images, we identified the species responsible for taking baits on 65 occasions. All 65 confirmed takes were by native species, with northern quolls taking 42 baits and northern brown bandicoots taking 17. No quolls and only one bandicoot ingested the HSDV. Conclusion The use of the HSDV reduces the potential for quolls and bandicoots to ingest a toxin when they consume feral cat baits. However, high bait uptake by non-target species may reduce the efficacy of cat baiting in some areas. Implications The present study highlighted that in the monsoonal wet–dry tropics, encapsulated baits are likely to minimise poisoning risk to certain native species that would otherwise eat meat baits. However, further research may be required to evaluate risks to other non-target species. Given the threat to biodiversity from feral cats, we see it as critical to continue testing Hisstory® and Curiosity® in live-baiting trials in northern Australia.


2020 ◽  
Vol 47 (2) ◽  
pp. 158 ◽  
Author(s):  
Remington J. Moll ◽  
Waldemar Ortiz-Calo ◽  
Jonathon D. Cepek ◽  
Patrick D. Lorch ◽  
Patricia M. Dennis ◽  
...  

Abstract ContextCamera traps are one of the most popular tools used to study wildlife worldwide. Numerous recent studies have evaluated the efficiency and effectiveness of camera traps as a research tool. Nonetheless, important aspects of camera-trap methodology remain in need of critical investigation. One such issue relates to camera-trap viewshed visibility, which is often compromised in the field by physical obstructions (e.g. trees) or topography (e.g. steep slopes). The loss of visibility due to these obstructions could affect wildlife detection rates, with associated implications for study inference and management application. AimsWe aimed to determine the effect of camera-trap viewshed obstruction on wildlife detection rates for a suite of eight North American species that vary in terms of ecology, commonness and body size. MethodsWe deployed camera traps at 204 sites throughout an extensive semi-urban park system in Cleveland, Ohio, USA, from June to September 2016. At each site, we quantified camera-trap viewshed obstruction by using a cover-board design. We then modelled the effects of obstruction on wildlife detection rates for the eight focal species. Key resultsWe found that detection rates significantly decreased with an increasing viewshed obstruction for five of the eight species, including both larger and smaller mammal species (white-tailed deer, Odocoileus virginianus, and squirrels, Sciurus sp., respectively). The number of detections per week per camera decreased two- to three-fold as visibility at a camera site decreased from completely free of obstruction to mostly obstructed. ConclusionsThese results imply that wildlife detection rates are influenced by site-level viewshed obstruction for a variety of species, and sometimes considerably so. ImplicationsResearchers using camera traps should address the potential for this effect to ensure robust inference from wildlife image data. Accounting for viewshed obstruction is critical when interpreting detection rates as indices of abundance or habitat use because variation in detection rate could be an artefact of site-level viewshed obstruction rather than due to underlying ecological processes.


Sign in / Sign up

Export Citation Format

Share Document