Research Papers by Sean M. Murphy
The Highlands–Glades subpopulation (HGS) of Florida, USA, black bears (Ursus americanus
floridanu... more The Highlands–Glades subpopulation (HGS) of Florida, USA, black bears (Ursus americanus
floridanus) is small, genetically depauperate, and resides primarily within the endangered Lake
Wales Ridge ecosystem, which has lost >85% of native habitat to land development. Habitat loss can
reduce availability of critical natural foods and cause bears to increase reliance on anthropogenic foods
(i.e., human-sourced); lands supporting the HGS are expected to lose >50% of remaining Florida
black bear habitat in coming decades. We used scat analysis to describe seasonal food habits, investigate
potential dietary responses to food shortages, and inform habitat conservation and human–bear
conflict management. Florida black bears in the HGS mostly relied on native soft and hard mast and
invertebrates, which are all available in endangered scrub habitat communities. Corn dispensed at
hunter-operated feeding stations was a dominant food item in scats; and other alternative foods, such
as citrus fruit and white-tailed deer (Odocoileus virginianus), were found in summer-collected scats
when soft mast should have been prevailing. Results indicate bears may respond to soft mast shortages
caused by mast failures or habitat loss by consuming anthropogenic foods (e.g., corn, deer chow, citrus
fruit, and garbage), which could increase human–bear conflicts. Florida carpenter ants (Camponotus
floridanus) appeared to provide a reliable compensatory food during such shortages, but they are arboreal
and largely dependent on imperiled bear habitat for proliferation. We strongly suggest remnant
scrub and other communities rich in soft and hard mast-producing flora be targeted for acquisition
and protection to ensure persistence of Florida black bears in this diverse ecosystem. We also suggest
non-lethal actions to mitigate bear habituation to anthropogenic foods be implemented to minimize
human–bear conflicts and prevent unnecessary losses to the already small HGS. Our study should be
repeated to investigate whether dietary shifts occur in response to impending habitat loss and to further
inform population conservation, habitat protection, and conflict management.
Loss and fragmentation of natural habitats caused by human land uses have subdivided several form... more Loss and fragmentation of natural habitats caused by human land uses have subdivided several formerly contiguous large carnivore populations into multiple small and often isolated subpopulations, which can reduce genetic variation and lead to precipitous population declines. Substantial habitat loss and fragmentation from urban development and agriculture expansion relegated the Highlands-Glades subpopulation (HGS) of Florida, USA, black bears (Ursus americanus floridanus) to prolonged isolation; increasing human land development is projected to cause ! 50% loss of remaining natural habitats occupied by the HGS in coming decades. We conducted a noninvasive genetic spatial capture-recapture study to quantitatively describe the degree of contemporary habitat fragmentation and investigate the consequences of habitat fragmentation on population density and genetics of the HGS. Remaining natural habitats sustaining the HGS were significantly more fragmented and patchier than those supporting Florida's largest black bear subpopulation. Genetic diversity was low (A R = 3.57; H E = 0.49) and effective population size was small (N E = 25 bears), both of which remained unchanged over a period spanning one bear generation despite evidence of some immigration. Subpopulation density (0.054 bear/km 2) was among the lowest reported for black bears, was significantly female-biased, and corresponded to a subpopula-tion size of 98 bears in available habitat. Conserving remaining natural habitats in the area occupied by the small, genetically depauperate HGS, possibly through conservation ease-ments and government land acquisition, is likely the most important immediate step to ensuring continued persistence of bears in this area. Our study also provides evidence that preferentially placing detectors (e.g., hair traps or cameras) primarily in quality habitat
Many large carnivores are recolonizing range as a result of improved management and conservation ... more Many large carnivores are recolonizing range as a result of improved management and conservation policy, habitat restoration, and reintroduction programs. American black bears (Ursus americanus) are projected to recolonize portions of the United States, but few studies have characterized or provided practical methods for monitoring this process. We used noninvasive hair sampling at 4 proximal study areas along the Kentucky–Virginia, USA, border during 2012–2013 to estimate demographics and population genetics, and investigate recolonization patterns of an American black bear population that was founded by 55 bears reintroduced to a fragmented mountainous landscape during the 1990s and subjected to harvest 6 years post-reintroduction. Using spatially explicit capture–recapture (SECR) models, we estimated a density of 0.26 bear/ km 2 , or minimum abundance of 482 bears, distributed among 2 primary core areas previously identified by occupancy analysis: a southern and northern core area. The southern core area was established by a founder adult female that exhibited post-release dispersal, but moderate asymmetrical gene flow (Nm ¼ 6 bears) from the northern core area mitigated deleterious genetic consequences typical of such founder events. Effective number of breeders (N B ¼ 62 bears) was similar to the number of founders, suggesting that genetically, the population remains mostly the product of reintroduction. Despite limited connectivity with other populations in the region, genetic diversity (H E ¼ 0.78) was retained because of rapid population growth during the 16 years post-reintroduction (l ¼ 1.14/year). This bear population exhibited demographic characteristics indicative of continued recolonization, including a significantly female-biased sex ratio (0.53M:1.00F) and female density decreasing with increasing distance from the reintroduction release areas in the northern core. Few bear detections at 2 peripheral study areas and results from SECR model detection function transformation suggested recolonization may continue to the southwest and northeast along prominent linear mountain ridges. Although the population has grown and is genetically stable, because of relatively low population density and recolonization direction, we suggest monitoring demographic vital rates to evaluate harvest sustainability and population viability. Our study demonstrates the utility of noninvasive genetic sampling in conjunction with SECR models to characterize and monitor recolonizing bear populations, which may also be useful for management of expanding populations of other large carnivores.
Animal reintroductions are important tools of wildlife management to restore species to their his... more Animal reintroductions are important tools of wildlife management to restore species to their historical range, and they can also create unique opportunities to study population dynamics and genetics from founder events. We used non-invasive hair sampling in a systematic, closed-population capture-mark-recapture (CMR) study design at the Big South Fork (BSF) area in Kentucky during 2010 and Tennessee during 2012 to estimate the demographic and genetic characteristics of the black bear (Ursus americanus) population that resulted from a reintroduced founding population of 18 bears in 1998. We estimated 38 (95% CI: 31–66) and 190 (95% CI: 170–219) bears on the Kentucky and Tennessee study areas, respectively.
Parasitology research, 2017
Toxoplasma gondii is an important protozoan parasite of mammals that impacts animal health and be... more Toxoplasma gondii is an important protozoan parasite of mammals that impacts animal health and behavior. Although this parasite has been documented in several cervid species, including red deer (Cervus elaphus) in Europe, little is known about T. gondii impacts on the closely related North American counterpart, the elk (wapiti, Cervus canadensis), which has increased in number and expanded in range during the past century. We assessed seroprevalence of T. gondii antibodies using a modified agglutination test (MAT) (1:25 titer) and blood collected from 142 free-ranging elk in Kentucky, USA, where the species was reintroduced during 1997-2002 after over a century of absence. Eighty of 142 (56.3%) elks were seropositive for T. gondii, but we found no infection or titer differences between sexes (U = 2146, P = 0.128). However, odds of T. gondii infection significantly increased with elk age (β = 0.429, P = 0.001) by a factor of 1.54 (95% CI 1.19-1.99), and titer increased commensurate w...
Books by Sean M. Murphy
Dissertation by Sean M. Murphy
Papers by Sean M. Murphy
Journal of Neuroscience Research
Conservation Letters
Concerns over red wolf (Canis rufus) extinction caused by hybridization with coyotes (C. latrans)... more Concerns over red wolf (Canis rufus) extinction caused by hybridization with coyotes (C. latrans) led to the capture and removal of remnant wild wolves from southwestern Louisiana and southeastern Texas, United States, during the 1970s. Here we show that despite decades of unmitigated hybridization, and declaration of endangered red wolves as functionally extinct in the wild, red wolf mitochondrial or nuclear DNA ancestry persists in ∼55% of contemporary wild canids sampled in southwestern Louisiana. Surprisingly, one individual had 78-100% red wolf ancestry, which is within the range for 75% red wolf, red wolf backcross, or putative red wolf, depending on estimation method. Our findings bolster support for designation of red wolves as a distinct species, demonstrate a critical need for the United States Government to consider adopting an existing but unimplemented hybrid policy, and suggest that immediate reassessment of canid management and taxonomic designation in southwestern Louisiana may be warranted.
Journal of Neurotrauma
Chronic neurological impairments can manifest from repetitive traumatic brain injury (rTBI), part... more Chronic neurological impairments can manifest from repetitive traumatic brain injury (rTBI), particularly when subsequent injuries occur before the initial injury completely heals. Herein, we apply post-traumatic sleep as a physiological biomarker of vulnerability, hypothesizing that a second TBI during post-traumatic sleep worsens neurological and histological outcomes compared to one TBI or a second TBI after post-traumatic sleep subsides. Mice received sham or diffuse TBI by midline fluid percussion injury; brain-injured mice received one TBI or rTBIs at 3hr or 9hr intervals. Over 40 hours post-injury, injured mice slept more than shams. Functional assessments indicated lower latencies on rotarod and increased Neurological Severity Scores for mice with rTBIs within 3-hrs. Anxiety-like behaviors in the open field task were increased for mice with rTBIs at 3hrs. Based on pixel density of silver accumulation, neuropathology was greater at 28 days post-injury (DPI) in rTBI groups than sham and single TBI. Cortical microglia morphology was quantified and mice receiving rTBI were de-ramified at 14 DPI compared to shams and mice receiving a single TBI, suggesting robust microglial response in rTBI groups. Orexin-A positive cells were sustained in the lateral hypothalamus with no loss detected, indicating loss of wake-promoting neurons did not contribute to post-traumatic sleep. Thus, the duration of post-traumatic sleep is a period of vulnerability that results in exacerbated injury from rTBI. Monitoring individual post-traumatic sleep is a potential clinical tool for personalized TBI management, where regular sleep patterns may inform rehabilitative strategies and return-to-play activity guidelines.
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Research Papers by Sean M. Murphy
floridanus) is small, genetically depauperate, and resides primarily within the endangered Lake
Wales Ridge ecosystem, which has lost >85% of native habitat to land development. Habitat loss can
reduce availability of critical natural foods and cause bears to increase reliance on anthropogenic foods
(i.e., human-sourced); lands supporting the HGS are expected to lose >50% of remaining Florida
black bear habitat in coming decades. We used scat analysis to describe seasonal food habits, investigate
potential dietary responses to food shortages, and inform habitat conservation and human–bear
conflict management. Florida black bears in the HGS mostly relied on native soft and hard mast and
invertebrates, which are all available in endangered scrub habitat communities. Corn dispensed at
hunter-operated feeding stations was a dominant food item in scats; and other alternative foods, such
as citrus fruit and white-tailed deer (Odocoileus virginianus), were found in summer-collected scats
when soft mast should have been prevailing. Results indicate bears may respond to soft mast shortages
caused by mast failures or habitat loss by consuming anthropogenic foods (e.g., corn, deer chow, citrus
fruit, and garbage), which could increase human–bear conflicts. Florida carpenter ants (Camponotus
floridanus) appeared to provide a reliable compensatory food during such shortages, but they are arboreal
and largely dependent on imperiled bear habitat for proliferation. We strongly suggest remnant
scrub and other communities rich in soft and hard mast-producing flora be targeted for acquisition
and protection to ensure persistence of Florida black bears in this diverse ecosystem. We also suggest
non-lethal actions to mitigate bear habituation to anthropogenic foods be implemented to minimize
human–bear conflicts and prevent unnecessary losses to the already small HGS. Our study should be
repeated to investigate whether dietary shifts occur in response to impending habitat loss and to further
inform population conservation, habitat protection, and conflict management.
Books by Sean M. Murphy
Dissertation by Sean M. Murphy
Papers by Sean M. Murphy
floridanus) is small, genetically depauperate, and resides primarily within the endangered Lake
Wales Ridge ecosystem, which has lost >85% of native habitat to land development. Habitat loss can
reduce availability of critical natural foods and cause bears to increase reliance on anthropogenic foods
(i.e., human-sourced); lands supporting the HGS are expected to lose >50% of remaining Florida
black bear habitat in coming decades. We used scat analysis to describe seasonal food habits, investigate
potential dietary responses to food shortages, and inform habitat conservation and human–bear
conflict management. Florida black bears in the HGS mostly relied on native soft and hard mast and
invertebrates, which are all available in endangered scrub habitat communities. Corn dispensed at
hunter-operated feeding stations was a dominant food item in scats; and other alternative foods, such
as citrus fruit and white-tailed deer (Odocoileus virginianus), were found in summer-collected scats
when soft mast should have been prevailing. Results indicate bears may respond to soft mast shortages
caused by mast failures or habitat loss by consuming anthropogenic foods (e.g., corn, deer chow, citrus
fruit, and garbage), which could increase human–bear conflicts. Florida carpenter ants (Camponotus
floridanus) appeared to provide a reliable compensatory food during such shortages, but they are arboreal
and largely dependent on imperiled bear habitat for proliferation. We strongly suggest remnant
scrub and other communities rich in soft and hard mast-producing flora be targeted for acquisition
and protection to ensure persistence of Florida black bears in this diverse ecosystem. We also suggest
non-lethal actions to mitigate bear habituation to anthropogenic foods be implemented to minimize
human–bear conflicts and prevent unnecessary losses to the already small HGS. Our study should be
repeated to investigate whether dietary shifts occur in response to impending habitat loss and to further
inform population conservation, habitat protection, and conflict management.