Conservation and Ecology of Mammals I

Contributed Paper
ROOM: HCCC, Room 22
SESSION NUMBER: 14
 

8:10AM Estimating Fosa Population Parameters in the Rainforests of Madagascar
Cullen C. Anderson; Zach Farris; Sarah Zohdy
Understanding population parameters and dynamics of carnivores is vital to protecting these threatened species and the ecosystems they inhabit. Across the globe, carnivores are especially vulnerable to various anthropogenic pressures (e.g. deforestation, habitat fragmentation, competition with exotic carnivores) due to their relatively small populations and large home ranges. The carnivores of Madagascar (Family Eupleridae) are no exception as they are among the least-studied and most-threatened carnivores in the world. Though research is sparse on this group’s populations throughout the country, to date no studies have been conducted on populations occupying one of Madagascar’s most important protected regions: the Andasibe-Mantadia landscape. We conducted the first study of carnivore populations in this area using photographic sampling across three protected forests (Analamazaotra, Mitsinjo, and VOI forests). We focused on fosa (Cryptoprocta ferox), Madagascar’s largest and most wide-spread carnivore and an umbrella species for this threatened region. We estimated single-season occupancy and detection using human (Homo sapiens) trap success, dog (Canis familiaris) trap success, and distances between camera stations and human-altered environments (e.g. villages, roads, forest edge) as site covariates. We found fosa trap success was 2.35 with 29 total captures and a naïve occupancy estimate of 52.1. Our results indicate fosa are negatively affected by humans and human-altered environments, which in turn likely threaten other endemic wildlife of this region. This study and its findings have direct implications for management decisions relating to this tourist-driven conservation area in Madagascar, as well as similarly managed areas world-wide.
8:30AM Hydrogeomorphology Influences Swamp Rabbit Habitat Selection in a Fragmented Blh Ecosystem
Elizabeth M. Hillard; Joanne C. Crawford; Clayton K. Nielsen; John W. Groninger; Eric M. Schauber
Bottomland hardwood (BLH) forests throughout the Lower Mississippi Alluvial Valley have been degraded due to habitat loss, fragmentation, and altered hydrology. These ecosystems tend to exist at lower elevations that were not suitable for agricultural conversion and are associated with long flood duration that can preclude the development of dense understory vegetation and/or the availability of terrestrial habitat. Flood refugia and dense understory vegetation are important habitat characteristics for the swamp rabbit (Sylvilagus aquaticus), a BLH forest obligate. A better understanding of swamp rabbit selection of habitat types based on hydrogeomorphic (HGM) metrics would provide a better understanding of how current conditions in BLH forest systems influence wildlife to better inform land use and vegetation management decisions. We evaluated winter (20 Dec-21 Mar) habitat selection of 75 radiomarked swamp rabbits across 7 study sites in Cypress Creek National Wildlife Refuge, southern Illinois, USA, 2010-2016. We investigated habitat selection by creating resource selection functions with generalized linear mixed models based on distances (m) to 9 HGM habitat types (Cypress-Tupelo, herbaceous-wetland, low-BLH, mesic-upland, open water, riverfront-forest, shallow-BLH, slope-forest, terrace-hardwoods) developed based on historic maps, soil data, flood duration, geomorphology, and floral community. We obtained 850 locations (11.3 ± 0.7 [SE] locations/rabbit). Swamp rabbit habitat selection was higher in habitats closer to herbaceous-wetland, riverfront-forest, shallow-BLH, and farther from terrace-hardwoods. Swamp rabbit habitat use on our study area was driven hydrogeomorphic conditions. We suggest management for swamp rabbit habitat ensure the continuous availability of critical habitat elements regardless of water level and flooding extent across the BLH landscape and include a sufficient area of drier forest classes.
8:50AM Genetic Structure and Diversity Among Historic and Modern Populations of the Sumatran Rhinoceros (Dicerorhinus Sumatrensis)
Jessica R. Brandt; Peter J. van Coeverden de Groot; Kelsey E. Witt; Paige K. Engelbrektsson; Kristofer M. Helgen; Ripan S. Malhi; Oliver A. Ryder; Alfred L. Roca
Genetic structure and diversity among historic and modern populations of the Sumatran rhinoceros (Dicerorhinus sumatrensis) Jessica R. Brandt, Peter J. Van Coeverden de Groot, Kelsey E. Witt, Paige K. Engelbrektsson, Kristofer M. Helgen, Ripan S. Malhi, Oliver A. Ryder and Alfred L. Roca Abstract The Sumatran rhinoceros (Dicerorhinus sumatrensis), once widespread across Southeast Asia, now consists of as few as 30 individuals within Sumatra and Borneo. To aid in conservation planning, we sequenced 218 bp of control region mitochondrial (mt) DNA, identifying 17 distinct mitochondrial haplotypes across modern (N = 13) and museum (N = 26) samples. Museum specimens from Laos and Myanmar had divergent mtDNA, consistent with the placement of western mainland rhinos into the distinct subspecies D. s. lasiotis (presumed extinct). Haplotypes from Bornean rhinos were highly diverse, but dissimilar from those of other regions, supporting the distinctiveness of the subspecies D. s. harrissoni. Rhinos from Sumatra and Peninsular Malaysia shared mtDNA haplotypes, consistent with their traditional placement into a single subspecies D. s sumatrensis. Modern samples of D. s. sumatrensis were genotyped at 18 microsatellite loci. Rhinos within Sumatra formed two sub-populations, likely separated by the Barisan Mountains, though with only modest genetic differentiation between them. There are so few remaining Sumatran rhinoceros that separate management strategies for subspecies or subpopulations may not be viable, while each surviving rhino pedigree is likely to retain alleles found in no other individuals. Given the low population size and low reproductive potential of Sumatran rhinos, rapid genetic erosion is inevitable, while an under-appreciated concern is the potential for fixation of harmful genetic variants. Both concerns underscore two overriding priorities for the species: (1) translocation of wild rhinos to ex situ facilities, and (2) collection and storage of gametes and cell lines from every surviving captive and wild individual.
9:10AM Overlooked Dietary Overlap between Populations of Two Medium-Sized Mammalian Carnivores in Urban and Suburban Habitats
Irene Castañeda; Diane Zarzoso-Lacoste; Elsa Bonnaud
Red foxes and domestic cats are among the most abundant urban carnivores worldwide. Both, are generalist and able to exploit a wide range of food resources. Diet similarities are expected between them in similar habitats. Their diet composition has been simultaneously studied only once and their diet overlap has never been calculated in urban and suburban habitats. Here we assessed diet composition, breadth and overlap between red foxes and domestic cats considering different habitats and seasons. Red fox and domestic scats were recovered seasonally over two years in three urban and suburban habitats. We estimated Biomass Ingested per Scat (BIS) and Minimum Number of prey Individuals (MNI) to describe red fox and domestic cat diets. We used BIS to fit multivariate GLMs to assess the effect of predators, habitats and seasons and MNI to calculate diet breadth (B) and overlap (O) between predators, habitats and seasons. Both red fox and domestic cat diet composition varied significantly according to habitats and seasons. In MNI, red fox diet was mainly composed by underground invertebrates while domestic cat diet was principally composed by underground invertebrates and small mammals. In BIS, both red fox and domestic cat diets were principally constituted by small mammals. We detected a relative narrow niche breadth for both predators (B < 0.500) and a strong dietary overlap between them (O = 0.781). Our results suggest that these two predators have a cumulative predation pressure focused on the same main prey groups. Further field studies monitoring simultaneously both predator diets and prey abundances will contribute to determine predators’ feeding behavior (e.g. prey selectivity), quantify predator impacts on prey populations and evaluate the strength of a possible competition between predators.
9:30AM Ecological Correlates of the Spatial Co-Occurrence of Sympatric Mammalian Carnivores Worldwide
Courtney L. Davis; Lindsey N. Rich; Zach J. Farris; Marcella J. Kelly; Mario S. Di Bitetti; Yamil Di Blanco; Sebastian Albanesi; Mohammad S. Farhadinia; Navid Gholikhani; Sandra Hamel; Bart J. Harmsen; Claudia Wultsch; Mamadou D. Kane; Quinton Martins; As
The composition of local mammalian carnivore communities has far-reaching effects on terrestrial ecosystems worldwide. To better understand how carnivore communities are structured, we analyzed camera trap data for 108,087 trap days across 12 countries spanning 5 continents. We estimate local probabilities of co-occurrence among 768 species pairs from the order Carnivora and evaluate how shared ecological traits correlated with probabilities of co-occurrence. Within individual study areas, species pairs co-occurred more frequently than expected at random. Unexpectedly, co-occurrence probabilities were greatest for species pairs that shared ecological traits including similar body size, temporal activity pattern, and diet. However, co-occurrence decreased as compared to other species pairs when the pair included a large-bodied carnivore. Our results suggest that a combination of shared traits and top-down regulation by large carnivores shape local carnivore communities globally.

 

Contributed Paper
Location: Huntington Convention Center of Cleveland Date: October 8, 2018 Time: 8:10 am - 9:50 am