Predators

Contributed Paper
ROOM: CC, Room 26B
SESSION NUMBER: 40
 

8:10AM Extinction Vortex Dynamics of Urban Top Predators
John F. Benson; Peter J. Mahoney; T. Winston Vickers; Jeff A. Sikich; Paul Beier; Seth P.D. Riley; Holly B. Ernest; Walter M. Boyce
Extinction risk is elevated in small, isolated populations due to demographic and genetic interactions. We conducted population viability analysis (PVA) for two small mountain lion populations isolated by urbanization in southern California to predict population growth, extinction probability, and loss of genetic diversity. Specifically, we 1) provided the first PVA for isolated mountain lions in the Santa Ana Mountains (SAM) that considers both demographic and genetic risk factors, and 2) tested the hypothesis that variation in abundance and mortality of mountain lions between the SAM and Santa Monica Mountains (SMM) result in differences in population growth, loss of heterozygosity, and extinction probability. Our models predicted 16-21% probability of local extinction in the SAM due purely to demographic processes over 50 years. Our models also predicted that genetic diversity will continue to erode in the SAM such that concern regarding inbreeding depression is warranted unless gene flow is increased, and that if inbreeding depression occurs, rapid local extinction is likely. Dynamics of the two populations were broadly similar, but they also exhibited interesting differences. Density-independent scenarios predicted a rapidly increasing population in the SMM, whereas growth potential did not differ from a stable trend in the SAM. Demographic extinction probability and loss of heterozygosity were greater in the SMM for density-dependent scenarios without immigration. However, higher levels of immigration had stronger, positive influences on both demographic viability and retention of genetic diversity in the SMM driven by lower abundance and higher adult survival. Our results elucidate demographic and genetic threats to small populations within the extinction vortex, and how these vary relative to demographic structure. Importantly, simulating seemingly attainable increases in connectivity was sufficient to greatly reduce extinction probability. Our work highlights that conservation of large carnivores within urbanized landscapes requires land protection, connectivity, and strategies to promote coexistence with humans.
8:30AM Movement Ecology and Resource Selection of Three Large Carnivores in a Prey-Deficient, Highly Degraded Ecosystem
Mark W. Chynoweth; Josip Kusak; Emrah Coban; Cagan H. Şekercioğlu
Conservation and management of wildlife populations is becoming increasingly complex in a world where novel and hybrid ecosystems are emerging from human-dominated landscapes. As human impact intensifies, it is important to consider movement and resource selection of wildlife to inform sustainable management decisions in highly-modified landscapes. Resource selection models can identify important habitat for species and guide conservation efforts to increase protected area coverage. To understand how large carnivores are able to coexist with people in heavily modified landscapes, we deployed GPS collars on 16 adult Eurasian brown bears, 7 gray wolves, and 2 Caucasian lynx in eastern Turkey to study their movement ecology. We developed species-specific seasonal resource selection functions to identify high-priority habitat in the area, and to identify suitable habitat for increasing protected area coverage. All three species’ habitat selection varied between seasons. Brown bears selected for areas closer to paved roads, further from human settlements, and located on steeper slopes throughout the year. During spring, bears preferred lower elevations and more open areas, and during summer and fall, bears preferred higher elevations. Wolves selected for forested areas, areas closer to roads, farther from villages, and steeper slopes throughout the year. Wolves selected for higher elevations during summer and lower elevations during winter. Lynx selected for steeper slopes throughout the year. During summer, lynx selected for forested areas, areas farther from villages, and higher elevations, while during winter, they selected for areas slightly closer to forests. Using predictive maps, we identified important habitat in the area for all three species and propose a new protected area designation in the region.
8:50AM Regional Comparison of Snow Leopard Dependence on Livestock Using Molecular Diet Analysis
Charlotte Hacker; Matt Jevit; Dr. Jan E. Janecka; Dr. Shafqat Hussain; Ghulam Muhammad; Dr. John Farrington; Azat Almanov; Farida Balbakova; Dr. Bariushaa Munkhtsog; Dr. Rodney Jackson
Snow leopards (Panthera uncia) are threatened predators in central Asia where livestock depredation causes financial burdens that encourage retaliation. Domestic animal prevalence in snow leopard diet may be indicative of persecution risk and prey-base depletion. DNA metabarcoding followed by Next-Generation Sequencing (NGS) avoids complications with classic diet approaches. However, previous use of 12S (MT-RNR1) for snow leopard diet was unable to differentiate domestic and wild sheep without an additional primer pair and sequencing, or could not resolve all caprids to species level. Thus livestock dependency remains unknown. This study sought to identify a suitable gene segment to discern domestic versus wild ungulates and to examine diet throughout snow leopard range. In total, 160 snow leopard scats were amplified using novel MT-CO1 primers and sequenced on an Illumina NextSeq500 to yield a mean of 289,774 reads per sample. Of the 102 samples that met the 94% species identity criteria, livestock DNA was in 20.6% and wild prey DNA in 79.4%. Livestock composition was 47.6% goat (Capra hircus), 33.3% cattle (Bos taurus/B. grunniens), 14.3% sheep (Ovis aries), and 4.8% horse (Equus caballus). Wild prey composition included 53.08% ungulate with 26.5% Markhor (Capra falconeri), 45.7% rodent with 28.4% mouse (Mus musculus), and 1.2% avian all Tibetan snowcock (Tetraogallus tibetanus). Pakistan had the highest prevalence of livestock in snow leopard diet with 27.1% of the scats having a domestic animal present, while in Kyrgyzstan no livestock DNA was detected. Results show that the designed MT-CO1 primers are a robust marker for discerning wild versus domestic ungulates in high-altitude regions of Asia. Based on higher livestock dependency, snow leopards in Pakistan may be at increased risk for retaliation and facing locally reduced prey populations. Studies to assess native biomass and programs such as livestock insurance and incentive initiatives should be applied to reduce such risk.
9:10AM Comparing Population Density Estimates of Florida Panthers on Private and Public Lands Via a Spatial Mark-Resight Model
Dave Onorato; Marc Criffield; Brian Kelly; Lara Cusack; David B. Shindle; Darrell Land; Colin Shea
A long-standing conundrum for many studies that involve endangered large carnivores is the need to obtain accurate estimates of the population size or density, given that recovery criteria often rely on those numbers. The application of non-invasive techniques, such as the use of trail camera photos, to collect data for population density estimates have become commonplace for species that are easily identified as unique individuals in photographs. Unfortunately, this non-invasive technique is not as effective for species that do not have natural identifiers, such as puma (Puma concolor). The endangered Florida panther (P. c. coryi) is the only breeding population of pumas east of the Mississippi River and is completely isolated in South Florida. Current USFWS recovery criteria set specific numeric goals for the population size. From 2014-2017, we applied a spatial mark-resight (SMR) model to trail camera and telemetry data collected on panthers from three study areas in South Florida: Florida Panther National Wildlife Refuge and adjacent state-owned lands, the northern Addition Lands of Big Cypress National Preserve, and a large private ranch. A portion of the population on each study area was marked (i.e., unique radiocollars and ear-tags) prior to deployment of 50 cameras within each 225-km2 study area. We incorporated data from 22,462 camera trap days and 6249 telemetry locations (VHF and GPS) into an SMR model for a partially marked population to derive density estimates. Densities varied between the three study areas, likely due to variation in habitat, prey densities, and land management regimes. The focus of ongoing research with these SMR models includes deriving a range-wide population estimate for panthers to supplant historic protocols used to monitor recovery.
9:30AM Using Two-Species Co-Occurrence Models to Uncover Sex-Mediated Trends in Occupancy and Detection
Brogan E. Holcombe; Dr. Ben Augustine; Christopher Rowe; Dr. Marcella Kelly
Jaguars (Panthera onca), pumas (Puma concolor), and ocelots (Leopardus pardalis) are the main sympatric predators within Belize, Central America. In this study, we adapted 2-species, co-occurrence models to determine whether occupancy and/or detection were influenced by sex within a species. We hypothesized males would have higher occupancy and/or detection at camera stations where females were present as they are driven to find mates. Alternatively, we expected females would have lower occupancy and/or detection at stations where males were present, potentially to avoid aggressive interactions. We formatted raw photo data into weekly capture histories for sexes separately for each species at 112 camera stations across contiguous rainforest sites in 2016. We used program PRESENCE to determine occupancy, detection, species (i.e. sex) interaction factors (SIFs) and detection interaction factors (DIFs) and compared the results from 16 apriori models for each species’ sex pairing via AIC. We found that occupancy was too high for all species to effectively model sex interactions and that detection rates between sexes were highly variable. For jaguars, both sexes had lower site detection when the opposite sex was present, counter to expectations for males but matching expectations for females. For pumas, competing models gave opposing results, likely due to the very small female sample size. Ocelots matched expectations, with male detection increasing from 6% to 28% when females were present, and female detection decreasing slightly from 27% to 25% when males were present. However, the DIFs were all greater than 1, indicating a strong co-detection between sexes. Our results provide insight into the potential to use camera traps and co-occurrence models to uncover sex-mediated detection within species. We suggest that a more fine-scale analyses (i.e. analyzing daily captures rather than weekly) would give better insight into how sex impacts detection and occupancy for elusive carnivores.

 

Contributed Paper
Location: Cleveland CC Date: October 9, 2018 Time: 8:10 am - 9:50 am