Comparing Global Positioning System and Very High Frequency Telemetry Home Ranges of White-Tailed Deer

ABSTRACT Use of Global Positioning System (GPS) collars on free-ranging ungulates overcomes many limitations of conventional very high frequency (VHF) telemetry and offers a practical means of studying space use and home range estimation. To better understand winter home ranges of white-tailed deer (Odocoileus virginianus), we evaluated GPS collar performance, and we compared GPS- and VHF-derived diurnal home ranges (for the same animals) and GPS-derived home range estimates for diurnal and nocturnal locations. Overall, the mean fix success rate of our GPS collars was 85% (range = 14–99%). Kernel density estimates of home range (using the 95% probability contour) derived from GPS and VHF locations were generally similar, as were GPS-derived diurnal and nocturnal home ranges. Overlap indices between GPS and VHF utilization distributions (UDs) ranged from 0.49 to 0.78 for the volume of intersection (VI) index and from 0.67 to 0.94 for Bhattacharyya's affinity (BA); overlap indices for GPS-diurnal and nocturnal UDs ranged from 0.29 to 0.81 for VI and from 0.56 to 0.94 for BA. Despite similarities of home ranges estimated from GPS versus VHF locations and GPS-diurnal versus nocturnal locations, our data also indicate that differences may have important implications for studies focused on deer use of space, habitat, and resources at a finer scale.     

A Conservation-Based Approach to Compensation for Livestock Depredation: The Florida Panther Case Study

Calf (Bos taurus) depredation by the federally endangered Florida panther (Puma concolor coryi) on ranches in southwest Florida is an important issue because ranches represent mixed landscapes that provide habitat critical to panther recovery. The objectives of this study were to (1) quantify calf depredation by panthers on two ranches in southwest Florida, and (2) develop a habitat suitability model to evaluate the quality of panther hunting habitat on ranchlands, assess whether the model could predict predation risk to calves, and discuss its potential to be incorporated into an incentive-based compensation program. We ear-tagged 409 calves with VHF transmitters on two ranches during 2011–2013 to document calf mortality. We developed a model to evaluate the quality of panther hunting habitat on private lands in southwest Florida using environmental variables obtained from the Florida Natural Areas Inventory (FNAI) Cooperative Landcover Database and nocturnal GPS locations of panthers provided by the Florida Fish and Wildlife Conservation Commission (FWC). We then tested whether the model could predict the location of calf depredation sites. Tagged calf loss to panthers varied between the two ranches (0.5%/yr to 5.3%/yr) and may have been influenced by the amount of panther hunting habitat on each ranch as the ranch that experienced higher depredation rates contained a significantly higher probability of panther presence. Depredation sites of tagged calves had a significantly greater probability of panther presence than depredation sites of untagged calves that were found by ranchers in open pastures. This suggests that there may be more calves killed in high risk environments than are being found and reported by ranchers and that panthers can hunt effectively in open environments. It also suggests that the model may provide a means for evaluating the quality of panther hunting habitat and the corresponding risk of depredation to livestock across the landscape. We suggest that our approach could be applied to prioritize and categorize private lands for participation in a Payment for Ecosystem Services program that compensates landowners for livestock loss and incentivizes conserving high quality habitat for large carnivores where livestock depredation is a concern.     

First ocelot (Leopardus pardalis) monitored with GPS telemetry

We report the first study to monitor ocelot (Leopardus pardalis) spatial patterns with Global Positioning System (GPS) telemetry. The study area was in southern Texas in areas of dense thornshrub (closed habitat) and open grasslands interspersed with small patches of dense thornshrub cover (open habitat). We used a 200-g GPS-Posrec collar (Televilt, TVP Positioning AB, Lindesberg, Sweden). We obtained 61% of GPS fixes from the ocelot GPS collar. The ocelot preferred closed habitat, even with GPS bias against closed habitat, and used small patches and corridors of dense thornshrub. Due to the success of this pilot study, we recommend that GPS telemetry be used to monitor ocelots.     

Natal Den Selection by Florida Panthers

ABSTRACT Information regarding habitat types selected by federally endangered Florida panthers (Puma concolor coryi) at natal den sites is needed because habitats used for parturition and kitten rearing potentially influence fitness of individuals and viability of the population. We located 51 natal den sites of 30 female panthers and performed a Euclidean distance analysis to determine which habitat types were selected and avoided at dens in south Florida, USA. Panther dens were closer to upland hardwoods, pinelands, and mixed wet forests (P ≤ 0.003) and farther from freshwater marsh-wet prairie (P = 0.009). We recommend that habitat protection efforts prioritize blocks of land that have abundant patches of upland hardwood, pinelands, and mixed wet forests to maintain preferred panther denning habitat.     

Fix Success and Accuracy of Global Positioning System Collars in Old-Growth Temperate Coniferous Forests

Abstract: Global Positioning System (GPS) telemetry is used extensively to study animal distribution and resource selection patterns but is susceptible to biases resulting from data omission and spatial inaccuracies. These data errors may cause misinterpretation of wildlife habitat selection or spatial use patterns. We used both stationary test collars and collared free-ranging American black bears (Ursus americanus) to quantify systemic data loss and location error of GPS telemetry in mountainous, old-growth temperate forests of Olympic National Park, Washington, USA. We developed predictive models of environmental factors that influence the probability of obtaining GPS locations and evaluated the ability of weighting factors derived from these models to mitigate data omission biases from collared bears. We also examined the effects of microhabitat on collar fix success rate and examined collar accuracy as related to elevation changes between successive fixes. The probability of collars successfully obtaining location fixes was positively associated with elevation and unobstructed satellite view and was negatively affected by the interaction of overstory canopy and satellite view. Test collars were 33% more successful at acquiring fixes than those on bears. Fix success rates of collared bears varied seasonally and diurnally. Application of weighting factors to individual collared bear fixes recouped only 6% of lost data and failed to reduce seasonal or diurnal variation in fix success, suggesting that variables not included in our model contributed to data loss. Test collars placed to mimic bear bedding sites received 16% fewer fixes than randomly placed collars, indicating that microhabitat selection may contribute to data loss for wildlife equipped with GPS collars. Horizontal collar errors of >800 m occurred when elevation changes between successive fixes were >400 m. We conclude that significant limitations remain in accounting for data loss and error inherent in using GPS telemetry in coniferous forest ecosystems and that, at present, resource selection patterns of large mammals derived from GPS telemetry should be interpreted cautiously.     

Gastrointestinal helminths of free-ranging Florida panthers (Puma concolor coryi) and the efficacy of the current anthelmintic treatment protocol

Thirty-five Florida panthers (Puma concolor coryi [Bangs, 1899]) collected from six counties in southern Florida between 1978 and 2003 were examined at necropsy for gastrointestinal helminths. The panthers were placed into two groups: 1) treated with anthelmintics (n = 17), and 2) untreated (n = 18). Nine species of helminths (one trematode, six nematodes, and two cestodes) were identified in the untreated panthers. The most prevalent helminths were Alaria marcianae (LaRue, 1917) (100%), Spirometra mansonoides (Mueller, 1935) (91%), and Ancylostoma pluridentatum (Alessandrini, 1905) (89%). Ancylostoma caninum (Ercolani, 1859) is reported from the Florida panther for the first time. The intensities of helminths with prevalences >10% did not differ between untreated panthers collected in 1978-1983 and 1996-2003. Treated panthers had helminth faunas similar to those of untreated panthers. The current anthelmintic treatment being used reduced the intensity of both A. marcianae and A. pluridentatum in panthers < or =6 mo posttreatment (PT); however, treated panthers between 6 and 9 mo PT, and >9 mo PT were similar to untreated panthers. Treatment was less effective on S. mansonoides and Taenia omissa Lühe, 1910. Treated panthers had slightly lower intensities of S. mansonoides at < or =6 mo PT; however, between 6 and 9 mo PT and >9 mo PT they had significantly higher intensities than untreated panthers. At all periods PT, the intensity of T. omissa for the treated panthers was similar to that of untreated panthers. We suggest that Mesocestoides sp. may not be present in the Florida panther population as reported earlier by Forrester et al. (1985), due to parasite misidentification by those authors.     

Effects of Species Behavior on Global Positioning System Collar Fix Rates

ABSTRACT Use of Global Positioning System (GPS) telemetry is increasing in wildlife studies and has provided researchers and managers with new insight into animal behavior. However, performance of GPS collars varies and a major concern is the cause of unsuccessful fixes. We examined possible factors causing missed fixes in GPS collars on sympatric free-ranging Eurasian lynx (Lynx lynx) and wolverines (Gulo gulo) in northern Sweden. We tested for effects of species, activity, habitat, individual, and collar on fix rate. Species was the most important factor affecting fix rate. Fix rate of GPS collars on lynx (80%) was almost twice as high as on wolverines (46%). Fix rate decreased during periods of low activity (day beds) for both species. Fix rate also decreased for females (both lynx and wolverine) for a period after they gave birth. We found no effect of proportion of forest within individual home range on fix rate. We conclude that species behavior, characteristics, and activity pattern are important factors affecting fix rate that we recommend be taken into consideration prior to analyzing GPS location data.     

Vitamin A concentrations in serum and liver from Florida panthers

Many of the anomalies and clinical signs afflicting the Florida panther (Felis concolor coryi) are suggestive of vitamin A deficiency. Our objectives in this study were to determine if a vitamin A deficiency exists in the free-ranging panther population and to determine if there are differences in vitamin A levels among various subgroups of free-ranging panthers. Retinol concentrations were used as an index to Vitamin A concentrations and were determined in serum and liver from free-ranging (serum, n = 45; liver, n = 22) and captive (serum, n = 9; liver, n = 2) juvenile and adult Florida panthers from southern peninsular Florida (USA), and in liver from free-ranging cougars (F. concolor subspp.) from Washington (USA) and Texas (USA) between November 1984 and March 1994. Combined juvenile (6- to 24-mo-old) and adult (> 24-mo-old) free-ranging Florida panthers had mean +/- SD serum retinol concentrations of 772.5 +/- 229 pmol/ml. Adult free-ranging Florida panthers had mean liver retinol concentrations of 4794.5 +/- 3747 nmol/g. Free-ranging nursing Florida panther kittens (age < 1 mo) had mean serum retinol concentrations of 397.9 +/- 69 pmol/ml. Among subgroups of free-ranging Florida panthers, females had higher corrected mean serum retinol concentrations than males and adult free-ranging Florida panthers had higher mean liver retinol concentrations than juveniles. Retinol concentrations in free-ranging Florida panthers did not differ significantly from those in captive panthers (liver and serum) or other free-ranging cougars (liver). Based on limited published values and our controls, a vitamin A deficiency could not be demonstrated in the Florida panther population nor were any subgroups or individuals considered deficient.     

Understanding the effect of landscape fragmentation and vegetation productivity on elephant habitat utilization in Amboseli ecosystem,Kenya

Understanding factors affecting the distribution of the African elephant is important for its conservation in increasingly human‐dominated savannah landscapes. However, understanding how landscape fragmentation and vegetation productivity affect elephant habitat utilization remains poorly understood. In this study, we tested whether landscape fragmentation and vegetation productivity explain elephant habitat utilization in the Amboseli ecosystem in Kenya. We used GPS (Global Positioning System) telemetry data from five elephants to quantify elephant habitat utilization. Habitat utilization was determined by calculating the time elephants spent within a unit area. We then used generalized additive models (GAMs) to model the relationship between time density and landscape fragmentation, as well as vegetation productivity. Results show that landscape fragmentation and vegetation productivity significantly (P < 0.05) explain elephant habitat utilization. A significant (P < 0.05) unimodal relationship between vegetation productivity and habitat utilization was observed. Results suggest that elephants spend much of their time in less fragmented landscapes of intermediate productivity.     

Evaluation of a Global Positioning System backpack transmitter for wild turkey research

Radiotelemetry is the standard method for monitoring wild turkey (Meleagris gallapavo) movements and habitat use. Spatial data collected using telemetry-based monitoring are frequently inaccurate due to triangulation error. However, new technology, such as Global Positioning Systems (GPS) has increased ecologists' ability to accurately evaluate animal movements and habitat selection. We evaluated the efficacy of micro-GPS backpack units for use on wild turkeys. We tested a micro-GPS developed specifically for avian species that incorporated a GPS antenna with a lightweight rechargeable battery and a very high frequency (VHF) transmitter. We conducted a series of static tests to evaluate performance in varying types of vegetative canopy cover and terrain. After static testing, we deployed micro-GPS on 8 adult male Rio Grande wild turkeys (M. g. intermedia) trapped in south Texas and 2 adult females trapped in the Texas panhandle. Micro-GPS units collected 26,439 locations out of 26,506 scheduled attempts (99.7% fix rate) during static testing. Mean distance error across all static tests was 15.5 m (SE = 0.1). In summer 2009, we recovered micro-GPS from 4 tagged males and both females to evaluate data collection. Units on males acquired approximately 2,500 locations over a 65-day test period (94.5% fix rate). We recovered units from the 2 females after 19 days and 53 days; those units acquired 301 and 837 locations, respectively, for a 96% fix rate. Cost analysis indicated that VHF will be cost effective when 1 location per day is required up to 181 days, but micro-GPS becomes less expensive as frequency of daily locations increases. Our results indicate that micro-GPS have the potential to provide increased reliable data on turkey movement ecology and habitat selection at a higher resolution than conventional VHF telemetric methods. © 2011 The Wildlife Society.     

Cost comparison between GPS- and VHF-based telemetry: case study of feral cats

Improvements in technology now make it possible to track animals of cat size using Global Positioning System (GPS)-telemetry. GPS technology has important advantages over traditional Very High Frequency (VHF)-radio tracking, but does incur higher per-tag costs. Budget is a limiting factor in experimental research; thus, an evaluation of the costs associated with both technologies according to the targets of a project should be undertaken before making any final decisions on the purchase of units and final experimental design. We simulated and compared the relative costs associated with the use of GPS and VHF telemetry applied to the study of the spatial ecology of feral cats (Felis catus) in the Tasman Valley (South Island, New?Zealand) as a test case. We assessed different project durations and location acquisition rates. Cost analysis revealed that GPS-telemetry is the less expensive method to quantify the spatial ecology of feral cats when long-term (>1-year duration) projects and/or high acquisition rates (>1 location/day) are required.     

Screening GPS telemetry data for locations having unacceptable error

Technological improvements in battery life and physical dimensions of Global Positioning System (GPS) telemetry have increased the number of locations one can collect, but due to relatively unimproved GPS accuracy this also increases the number of locations with unacceptable measurement error. We propose and show an example of a new method for screening data for locations with unacceptable error. We also propose a new screening metric: estimated elevation error (EEE). EEE identifies unacceptable xy-coordinate error in some cases better than do methods that use horizontal dilution of precision (HDOP) or fix dimension (2-D or 3-D). Our screening method combines test data and a model-averaging information-theoretic framework that uses a priori candidate models of telemetry measurement error. We demonstrate this method using experimental data collected on banded mongooses (Mungos mungo). One can adapt this screening method to any GPS data.     

Performance of Spread Spectrum Global Positioning System Collars on Grizzly and Black Bears

ABSTRACT Global Positioning System (GPS) telemetry is a prevalent tool now used in the study of large mammals. Global Positioning Systems either store the data on board the collar or contain a remote-transfer system that allows for data recovery at more frequent intervals. Spread spectrum (S-S) technology is a new mode of data transfer designed to overcome interference problems associated with narrow-band very high frequency and ultra high frequency data-transfer systems. We evaluated performance of S-S GPS radiocollars deployed on grizzly (Ursus arctos) and black bears (U. americanus). We also evaluated variables that influenced GPS fix success rates, with particular focus on animal activity, time of year, and temperature. The S-S GPS collars performed to our expectations and met study objectives; we did not experience any major problems with the data-transfer system. We observed varying rates of fix success that were directly related to recorded activity counts. Using logistic regression, we verified that activity counts were a reasonable measure of resting or feeding-traveling in both bear species. Our results showed that 73% and 79% of missed fixes, respectively, occurred when we predicted black and grizzly bears to be resting. Temperatures measured in the canister of the collar were not correlated with air temperature, suggesting posture and activity influenced canister temperature. Both measures of temperature were predictive of fix success. We did not find that fix success was related to body morphology (i.e., neck circumference, mass, and chest girth), fix interval, position of the GPS antenna relative to the sky, or sex of the bear. We conclude that fix success for both species is strongly related to activity patterns and time of year. Activity counters appear to be a reasonable measure of this behavior, and we recommend researchers consider including an activity-count system when deploying GPS collars. We also recommend researchers explore building separate models of habitat selection based upon categories of activity to account for bias in fix success associated with bear behavior.     

Performance of differential GPS collars in temperate mountain forest

To determine the performance of Global Positioning System (GPS) for habitat studies in free-ranging animals, we tested differential 6- and 8-channel GPS collars under six representative canopies and one open-field reference site in the 'Parc national des Cévennes', southern France. The proportion of successful locations decreased under taller trees and worsened with snow accumulation in mixed coniferous habitats. The mean location success of seven free-ranging red deer fitted with 6-channel GPS collars in the same study area increased with a shorter interval between location attempts and during the leaf-off period. Our data suggested that the differences in location success between leaf-on and leaf-off periods might reflect shifts in habitat use rather than a leaf effect under deciduous trees.     

Does genetic introgression improve female reproductive performance? A test on the endangered Florida panther

Genetic introgression has been suggested as a management tool for mitigating detrimental effects of inbreeding depression, but the role of introgression in species conservation has been controversial, partly because population-level impacts of genetic introgressions are not well understood. Concerns about potential inbreeding depression in the endangered Florida panther (Puma concolor coryi) led to the release of eight female Texas pumas (P. c. stanleyana) into the Florida panther population in 1995. We used long-term reproductive data (1995–2008) collected from 61 female Florida panthers to estimate and model reproduction probability (probability of producing a litter) and litter size, and to investigate the influence of intentional genetic introgression on these parameters. Overall, 6-month probability of reproduction (±1SE) was 0.232 ± 0.021 and average litter size was 2.60 ± 0.09. Although F₁ admixed females had a lower reproduction probability than females with other ancestries, this was most likely because kittens born to F₁ females survive better; consequently, these females are unavailable for breeding until kittens are independent. There was no evidence for the effect of ancestry on litter size or of heterozygosity on probability of reproduction or litter size. In contrast, earlier studies have shown that genetic introgression positively affected Florida panther survival. Our results, along with those of earlier studies, clearly suggest that genetic introgression can have differential effects on components of fitness and highlight the importance of examining multiple demographic parameters when evaluating the effects of management actions.     

The genetic rescue of the Florida panther

We examine the consequences of panthers introduced from Texas into south Florida, an area housing a small, isolated, inbred and distinct subspecies ( Puma concolor coryi ). Once part of a continuous, widespread population, panthers became isolated in south Florida more than a century ago. Numbers declined and the occurrence of genetic defects increased. Hoping to reverse the genetic damage, managers introduced eight female panthers from Texas into south Florida in the mid-1990s. This action was highly controversial and we explain the arguments for and against the intervention. We synthesized data systematically collected on the Florida panthers from before, during and after this management intervention. These data include information on movements, breeding, mortality, survivorship and range. There is no evidence that purebred Florida females produce fewer kittens at a later age or less often than do hybrid cats (i.e. those with a Texas ancestor). Hybrid kittens have about a three times higher chance of becoming adults as do purebred ones. Hybrid adult females survive better than purebred females; there is no obvious difference between the males. Males die younger than females, are more often killed by other males and are more likely to disperse longer distances into habitats that are dangerous to them. Hybrids are expanding the known range of habitats panthers occupy and use.     

Causes of mortality of free-ranging Florida panthers

The Florida panther (Puma concolor coryi) is one of the most endangered mammals, with the entire population estimated to consist of only 30-50 adult animals. Between 1978 and 1999, 73 free-ranging Florida panther carcasses were submitted for postmortem evaluation, of which 47 (64%) were radiocollared and 26 (36%) were uncollared cats. Overall, mortality of panthers > 6-mo-old was due to vehicular trauma in 25 (35%), intraspecific aggression in 19 (26%), illegal kill in seven (10%), research activities in two (3%), infectious diseases in two (3%), esophageal tear in one (1%), pleuritis in one (1%), pyothorax in one (1%), aortic aneurysm in one (1%), atrial septal defect in one (1%), and causes of death were undetermined in 13 (18%) due to autolysis. Of the 25 panthers that were killed by vehicular trauma, 20 (80%) died between October and April. This coincides with increased number of winter visitors to south Florida. Among radiocollared panthers, intraspecific aggression was the primary cause of mortality for 19 (41%) dead cats. Of these cats, 16 (84%) were males and 14 (88%) were either less than 3 or more than 8-yr-old. These animals were probably fighting to establish or retain territory. Among the 26 uncollared panthers, vehicular trauma was the primary cause of mortality and was responsible for 16 (62%) deaths. This study documents the causes of mortality and the age, sex, and seasonal mortality trends for both radiocollared and uncollared free-ranging endangered Florida panthers over a 21-yr-period.     

Evaluation of fast-acquisition GPS in stationary tests and fine-scale tracking of green turtles

Fastloc GPS (FGPS) is a variant of Global Positioning System (GPS) technology that offers important new utility for investigating fine-scale movements of marine animals like green turtles that surface too briefly for effective use of standard GPS. I report here on the accuracy and efficiency of this novel technology, compare it with two alternative methods, namely boat-based ultrasonic tracking and Argos Platform Transmitter Terminals (PTTs), and provide new data on the vagility and habitat selection of green turtles in shallow coastal foraging habitat. I used a combined FGPS receiver and PTT transmitter (Sirtrack, Havelock North, New Zealand) mounted together with an ultrasonic transmitter and time-depth recorder in a tether-attached housing that allowed automatic detachment and subsequent retrieval of the equipment without the requirement to recapture turtles. With this equipment I conducted short deployments (4.5 to 16.8 d) on 3 free-living adult-size green turtles in coastal foraging habitat in Queensland, Australia. In addition, stationary tests in air and afloat were conducted at the same site. FGPS location error (mean ± SD) increased as the number of satellites used in each computation decreased, from 26 m ± 19.2 (8 satellites) to 172 m ± 317.5 (4 satellites). During live tracking the frequency of FGPS locations greatly exceeded Argos PTT, such that screened data comprised about 50 times more FGPS locations despite a much tighter screening threshold for FGPS (250 m) than for Argos PTT (1000 m). FGPS locations showed the three study turtles used modest short-term activity ranges with Minimum Convex Polygon area mean ± SD 662 ha ± 293.9. They all remained within < 4.7 km of their capture-release locations and favoured shallow water, with 86% of locations at charted depths ≤ 3 m and the deepest location at 5.9 m. Fine-scale movements of each turtle varied from day to day with respect to tortuosity and areas traversed. Statistically significant day-night differences were evident in average rates of movement (greater by day) and in habitat selection, where diurnal locations had greater seagrass density while nocturnal locations featured deeper bathymetry. Individual turtles revisited some of their centres of activity (identified from 50% fixed kernel utilisation distributions) on multiple occasions but none of the study turtles travelled consistently between the same day-night pair of sites as has been reported elsewhere. Such disparity and the day-to-day variation in movements revealed by these short-term findings highlight the need for detailed tracking over longer periods at multiple locations. Fastloc GPS technology proved an effective new tool for this area of research.     

Intentional genetic introgression influences survival of adults and subadults in a small, inbred felid population

1. Inbreeding and low genetic diversity can cause reductions in individual fitness and increase extinction risk in animal populations. Intentional introgression, achieved by releasing genetically diverse individuals into inbred populations, has been used as a conservation tool to improve demographic performance in endangered populations. 2. By the 1980s, Florida panthers (Puma concolor coryi) had been reduced to a small, inbred population that appeared to be on the brink of extinction. In 1995, female pumas from Texas (P. c. stanleyana) were released in occupied panther range as part of an intentional introgression programme to restore genetic variability and improve demographic performance of panthers. 3. We used 25 years (1981-2006) of continuous radiotelemetry and genetic data to estimate and model subadult and adult panther survival and cause-specific mortality to provide rigorous sex and age class-specific survival estimates and evaluate the effect of the introgression programme on these parameters. 4. Genetic ancestry influenced annual survival of subadults and adults after introgression, as F(1) generation admixed panthers ( = 0·98) survived better than pre-introgression type panthers ( = 0·77) and other admixed individuals ( = 0·82). Furthermore, heterozygosity was higher for admixed panthers relative to pre-introgression type panthers and positively influenced survival. 5. Our results are consistent with hybrid vigour; however, extrinsic factors such as low density of males in some areas of panther range may also have contributed to higher survival of F(1) panthers. Regardless, improved survival of F(1) subadults and adults likely contributed to the numerical increase in panthers following introgression, and our results indicate that intentional admixture, achieved here by releasing individuals from another population, appears to have been successful in improving demographic performance in this highly endangered population.     

Roles of maternal condition and predation in survival of juvenile Elk in Oregon

Abundant evidence supports the benefits accrued to the Florida panther (Puma concolor coryi) population via the genetic introgression project implemented in South Florida, USA, in 1995. Since then, genetic diversity has improved, the frequency of morphological and biomedical correlates of inbreeding depression have declined, and the population size has increased. Nevertheless, the panther population remains small and isolated and faces substantial challenges due to deterministic and stochastic forces. Our goals were 1) to comprehensively assess the demographics of the Florida panther population using long-term (1981–2015) field data and modeling to gauge the persistence of benefits accrued via genetic introgression and 2) to evaluate the effectiveness of various potential genetic management strategies. Translocation and introduction of female pumas (Puma concolor stanleyana) from Texas, USA, substantially improved genetic diversity. The average individual heterozygosity of canonical (non-introgressed) panthers was 0.386 ± 0.012 (SE); for admixed panthers, it was 0.615 ± 0.007. Survival rates were strongly age-dependent (kittens had the lowest survival rates), were positively affected by individual heterozygosity, and decreased with increasing population abundance. Overall annual kitten survival was 0.32 ± 0.09; sex did not have a clear effect on kitten survival. Annual survival of subadult and adult panthers differed by sex; regardless of age, females exhibited higher survival than males. Annual survival rates of subadult, prime adult, and old adult females were 0.97 ± 0.02, 0.86 ± 0.03, and 0.78 ± 0.09, respectively. Survival rates of subadult, prime adult, and old adult males were 0.66 ± 0.06, 0.77 ± 0.05, and 0.65 ± 0.10, respectively. For panthers of all ages, genetic ancestry strongly affected survival rate, where first filial generation (F1) admixed panthers of all ages exhibited the highest rates and canonical (mostly pre-introgression panthers and their post-introgression descendants) individuals exhibited the lowest rates. The most frequently observed causes of death of radio-collared panthers were intraspecific aggression and vehicle collision. Cause-specific mortality analyses revealed that mortality rates from vehicle collision, intraspecific aggression, other causes, and unknown causes were generally similar for males and females, although males were more likely to die from intraspecific aggression than females. The probability of reproduction and the annual number of kittens produced varied by age; evidence that ancestry or abundance influenced these parameters was weak. Predicted annual probabilities of reproduction were 0.35 ± 0.08, 0.50 ± 0.05, and 0.25 ± 0.06 for subadult, prime adult, and old adult females, respectively. The number of kittens predicted to be produced annually by subadult, prime adult, and old adult females were 2.80 ± 0.75, 2.67 ± 0.43, and 2.28 ± 0.83, respectively. The stochastic annual population growth rate estimated using a matrix population model was 1.04 (95% CI = 0.72–1.41). An individual-based population model predicted that the probability that the population would fall below 10 panthers within 100 years (quasi-extinction) was 1.4% (0–0.8%) if the adverse effects of genetic erosion were ignored. However, when the effect of genetic erosion was considered, the probability of quasi-extinction within 100 years increased to 17% (0–100%). Mean times to quasi-extinction, conditioned on going quasi-extinct within 100 years, was 22 (0–75) years when the effect of genetic erosion was considered. Sensitivity analyses revealed that the probability of quasi-extinction and expected time until quasi-extinction were most sensitive to changes in kitten survival parameters. Without genetic management intervention, the Florida panther population would face a substantially increased risk of quasi-extinction. The question, therefore, is not whether genetic management of the Florida panther population is needed but when and how it should be implemented. Thus, we evaluated genetic and population consequences of alternative genetic introgression strategies to identify optimal management actions using individual-based simulation models. Releasing 5 pumas every 20 years would cost much less ($200,000 over 100 years) than releasing 15 pumas every 10 years ($1,200,000 over 100 years) yet would reduce the risk of quasi-extinction by comparable amount (44–59% vs. 40–58%). Generally, releasing more females per introgression attempt provided little added benefit. The positive effects of the genetic introgression project persist in the panther population after 20 years. We suggest that managers contemplate repeating genetic introgression by releasing 5–10 individuals from other puma populations every 20–40 years. We also recommend that managers continue to collect data that will permit estimation and monitoring of kitten, adult, and subadult survival. We identified these parameters via sensitivity analyses as most critical in terms of their impact on the probability of and expected times to quasi-extinction. The continuation of long-term monitoring should permit the adaptation of genetic management strategies as necessary while collecting data that have proved essential in assessing the genetic and demographic health of the population. The prospects for recovery of the panther will certainly be improved by following these guidelines. © 2019 The Authors. Wildlife Monographs published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.