Gray Squirrels Research Articles

Effects of urbanization on population genetic structure of western gray squirrels

Habitat loss and fragmentation due to urbanization are key contributors to the decline of biodiversity. The consequence of these factors is small, isolated populations that are more susceptible to deterministic and stochastic threats of extinction. There is an increasing trend in population reductions of the western gray squirrel (Sciurus griseus) in urban areas of Southern California, USA. Griffith Park (GP) contains one of the last urban populations of western gray squirrels (WGS) present in Los Angeles. We used hairtubes to collect hair of WGS at 3 sites within GP and at 5 sites outside of GP. Twelve microsatellite loci and a 550 bp segment of the mitochondrial control region were used to examine the genetic diversity within GP and among all sample sites, and to determine gene flow within GP. Results revealed subpopulations within GP have low levels of allelic richness at microsatellite loci (AR = 2.28–2.53) and low mitochondrial haplotype diversity (HD = 0.000–0.271). We found significant genetic differentiation (FST = 0.109–0.156, p < 0.001), high levels of relatedness within each GP subpopulation (0.399–0.633), and a lack of private alleles (AP = 0.09–0.27) at microsatellite loci. Mode shifts in microsatellite allele frequencies and positive M-ratio tests provide evidence of bottlenecks within a GP subpopulation. The effective population size for GP (Ne = 9.1) highlights the effects of genetic drift on this isolated population. We suggest conservation efforts that could maintain these last extant populations of a native species in urban Los Angeles.

Comments on: What should you do with an orphaned baby grey squirrel?

In PracticeVolume 42, Issue 9 p. 535-535 Opinion Comments on: What should you do with an orphaned baby grey squirrel? First published: 13 November 2020 https://doi.org/10.1136/inp.m3866Read the full textAboutPDF ToolsRequest...

Does Use of Backyard Resources Explain the Abundance of Urban Wildlife?

While urbanization is clearly contributing to biodiversity loss, certain wildlife assemblages can paradoxically be diverse and abundant in moderately developed areas. One hypothesis to explain this phenomenon is that abundant anthropogenic resources for wildlife (i.e. food and shelter) outweigh the costs associated with urbanization. To test this hypothesis, we used camera traps to measure mammal species richness, diversity, and relative abundance (i.e., detection rate) in 58 residential yards in Raleigh, North Carolina, focusing on six types of features that might be used as resources: animal feeding, vegetable gardens, compost piles, chicken coops, brushpiles, and water sources. We also placed cameras at random control sites within each yard and sampled forests in nearby suburban and rural areas for comparison. We fit mixed-effects Poisson models to determine whether yard features, yard-scale characteristics, or landscape-scale landcover predicted mammal relative abundance for eight species. We also tested if the relative abundance of native canid predators in yards was related to the number of prey (rodents and lagomorphs). Species richness, diversity, and relative abundance of most mammal species was higher in yards and suburban forests than in rural forests. Within a yard, purposeful feeding had the strongest effect on animal relative abundance, with eastern gray squirrels (Sciurus carolinensis) being the most common (32.3 squirrels/day at feeders; 0.55 at control sites; 0.29 in suburban forests; and 0.10 in rural forests). We observed species using (e.g., eating) most yard features, although canids were less likely than other taxa to use resources in yards. The presence of a yard feature did not strongly affect the abundance of species at the control site in the yard, suggesting the influence of these features was highly localized. The relative abundance of predators had a positive association with prey relative abundance, and predators were less common in yards with fences. These results demonstrate that there is high use of anthropogenic resources, especially supplemental feeding by urban wildlife, and this increase in prey species may then attract predators, which supports the hypothesis that use of supplemental food resources explains the abundance of urban wildlife.

Cross-sectional evaluation of multiple epidemiological cycles of Leptospira species in peri-urban wildlife in California.

To perform a cross-sectional survey to estimate prevalence of and potential risk factors for Leptospira spp infection and exposure in peri-urban wildlife throughout California. 723 animals representing 12 wildlife species. Blood and urine samples were obtained from wildlife in California from 2007 to 2017. Live animals were captured in humane traps, anesthetized, and released. Carcasses were donated by wildlife services and necropsied for urine, blood, and kidney tissue samples. Samples were tested for antibodies against 6 serovars of Leptospira spp with a microscopic agglutination test and for pathogenic Leptospira spp DNA with a real-time PCR assay targeting the LipL32 gene. Potential risk factors for Leptospira spp exposure were assessed by logistic regression. Genetic relatedness of Leptospira spp were assessed with DNA sequencing of the rrs2 gene and multiple locus sequence analysis. Statewide Leptospira spp seroprevalence was 39.1%, and prevalence of positive PCR assay results for Leptospira spp DNA was 23.0%. Risk factors for Leptospira spp exposure included being an adult, being from northern California, and being a western gray squirrel, coyote, striped skunk, raccoon, gray fox, or mountain lion. Antibodies against serovar Pomona predominated in most species, followed by serovar Copenhageni. Complete rrs2 sequences were identified as Leptospira interrogans and multiple locus sequence type analysis revealed sequence type 140. Pathogenic Leptospira spp appeared to be common and widespread among peri-urban wildlife in California. Our data highlight the potential for exposure to infectious disease for both humans and domestic animals at the urban-wildland interface.

What should you do with an orphaned baby grey squirrel?

![Graphic][1] Aneesa Malik qualified as a veterinary nurse from Warwickshire College in 2008. Her main interests include veterinary ethics and welfare, emergency and critical care patients, end of life care...

Using Q‐methodology to understand stakeholder perspectives on a carnivore translocation

Abstract Reversing global declines in predator populations is a major conservation objective, though people frequently come into conflict over carnivore conservation. As part of a national recovery programme for the pine marten Martes martes, a protected mesocarnivore in the UK, we used Q‐methodology to understand the perspectives of residents living in an area in which a pine marten translocation project was planned. In contrast to binary ‘for or against’ characterizations of debates surrounding such projects, we identified four perspectives with distinct priorities and concerns. A single perspective, ‘Concerned Manager’, opposed the translocation and marten recovery more generally, was apprehensive about impacts and favoured traditional predator management practices. Support was characterized by three perspectives: ‘Environmental Protectionist’, ‘Natural Resource Steward’ and ‘Cautious Pragmatist’. Two explicitly supported the translocation but differed in their priorities: Environmental Protectionist framed marten restoration as an ethical imperative, whereas Natural Resource Steward emphasized ecological and economic benefits. Cautious Pragmatist supported marten recovery, but expressed ambivalence about the translocation. We identified areas of divergence between the four perspectives, particularly surrounding risks posed by martens and need for predator control. We identified two areas of consensus among the four perspectives: support for a biodiverse environment and translocations as a means of achieving this (though this was contingent on the species), and agreement there would be economic and ecological benefits if martens controlled non‐native grey squirrels Sciurus carolinensis. We highlight that perspectives on this project were influenced by wider issues of wildlife management and conservation, particularly the impact and management of increasing populations of another mesocarnivore, the badger Meles meles. Negative experiences and perceptions of badgers were germane to the Concerned Manager perspective, and their fear that protected status would preclude marten population control. ‘Rewilding’ emerged as a divisive background issue, against which some participants evaluated the translocation. In facilitating understanding of perspectives and establishing the contexts through which they were formed, we found that Q‐methodology enabled us, as a team comprising conservation practitioners and researchers, to engage meaningfully with affected residents. We recommend the tool as a useful step in assessing social feasibility of conservation translocations. A free Plain Language Summary can be found within the Supporting Information of this article.

Seasonal Expression of NGF and Its Cognate Receptors in the Ovaries of Grey Squirrels (Sciurus carolinensis).

Simple SummaryInvasive alien species pose a significant threat to biodiversity, as once they have adapted to their new environment, they cause the reduction and even extinction of native species. In this framework, the American grey squirrel (Sciurus carolinensis) poses a serious threat to the European red species squirrel (Sciurus vulgaris), especially in the Umbria region of Italy. In fact, an invasive grey squirrel population has adapted well to the Umbrian territory, showing high reproductive success. In addition to its role in the development of the vertebrate nervous system, nerve growth factor (NGF) has recently been found to play an important role in reproduction. In order to investigate the reproductive physiology of female grey squirrels, the ovarian presence, distribution, and gene expression of NGF and its cognate receptors were evaluated during both breeding and nonbreeding seasons. The presence and gene expression of this system at the ovarian level, mainly during the breeding season, confirm the possible involvement of NGF and its receptors in the gonadal activity of this invasive grey squirrel population.The grey squirrel is an invasive alien species that seriously threatens the conservation of the native red squirrel species. With the aim of characterizing the reproductive physiology of this species due to its great reproductive success, the function of the ovarian nerve growth factor (NGF) system was analyzed in a grey squirrel population living in central Italy. During the breeding and nonbreeding seasons, the ovarian presence, distribution, and gene expression of NGF, neurotrophic tyrosine kinase receptor 1 (NTRK1), and nerve growth factor receptor (NGFR), as well as NGF plasma concentrations, were evaluated in female grey squirrels. NGF was found in the luteal cells and in the thecal and granulosa cells of follicles, while NTRK1 and NGFR were only observed in follicular thecal and granulosa cells. NGF and NGFR transcripts were almost two-fold greater during the breeding season, while no seasonal differences were observed in NTRK1 gene expression. During the breeding season, NGFR was more expressed than NTRK1. Moreover, no changes were observed in NGF plasma levels during the reproductive cycle. The NGF system seems to be involved in regulating the ovarian cycle mainly via local modulation of NGF/NGFR, thus playing a role in the reproductive physiology of this grey squirrel population.

Effect of Lure on Detecting Mammals with Camera Traps

ABSTRACTMotion‐triggered camera traps are subject to imperfect detection and thus camera‐trapping surveys often try to increase species detectability as part of the study design. One possible way to increase detectability is to use lures, which may encourage a species to investigate a given area. Yet the effectiveness of lures is primarily grounded in anecdotal support. We quantified the effect of a common olfactory carnivore lure on the detectability of mammals near Chicago, Illinois, USA, during 27 August 2018–25 September 2018. We deployed 2 camera traps per site, spaced apart by 100 m, to assess whether lure can modify detectability both within and between sites. At each camera location, we changed lure treatments every 7 days and placed either a lure or a non‐lure control in view of each camera following a fully crossed design. For analysis, we developed single‐season occupancy models with 3 distinct observational models to quantify whether lure increased the number of days a species was detected, decreased the amount of time to first detection, and increased the number of images collected. Lure induced a subtle change in detectability. Virginia opossum (Didelphis virginiana) responded most to the presence of lure; their daily detection probability rose by roughly 5% and the number of opossum images nearly doubled. However, the effect of lure was often negative for prey species. When lure was present, eastern cottontail (Sylvilagus floridanus) daily detection probability decreased by 5% and they were photographed 63% less often. Likewise, eastern gray squirrel (Sciurus carolinensis) arrived 70% later to a camera trap if lure was present and were photographed 14% less. By using multiple criteria, we were able to better understand how wildlife respond to lure while camera‐trapping more thoroughly than would be possible with a single metric. Our results show that lure may not be as effective as expected in terms of increasing detectability, but the choice to use lure should depend on several factors, including the density of the study species, species life history, and the dynamics between the species studied. © 2020 The Wildlife Society.

Reinstating trophic cascades as an applied conservation tool to protect forest ecosystems from invasive grey squirrels (Sciurus carolinensis)

Red squirrel (Sciurus vulgaris) range within the United Kingdom (UK) has retracted significantly due to the spread of an Invasive Alien Species, the North American Eastern grey squirrel (Sciurus carolinensis). Where grey squirrels are sympatric, red squirrel populations decline through inter-specific competition and squirrelpox virus (SQPV) infection. Grey squirrel eradication from the island of Anglesey facilitated the complete restoration of native red squirrels. Although native species recovery delivered significant ecological and economic benefits, the eradication extended only to a narrow sea-channel boundary, across which grey squirrel dispersal continues to occur. Hence, the long-term sustainability of Anglesey's red squirrel population is vulnerable to grey squirrel re-establishment without continuous intervention. Recent research has demonstrated that as pine marten (Martes martes) landscape use intensity increases, so too does red squirrel occupancy, likely linked to parallel declines in grey squirrel occupancy. Restoration of this mustelid predator is a potential tool to deliver sustainable grey squirrel control by restoring a missing trophic component, depressing grey squirrel incursion rates onto Anglesey, reducing red squirrel exposure to SQPV. Recent UK pine marten translocations have sourced animals under licence from wild Scottish populations. We explore the alternative use of captive-bred founders, simultaneously introducing new genetic variability against a limited diversity within extant populations. A current conservation translocation is paired with an ongoing assessment of founder behaviour and ‘personality’ measured before release. We then highlight the multi-disciplinary approach to delivering applied red squirrel conservation programmes in the face of invasive species.

A Comparative Study of Intramuscular Alfaxalone- or Ketamine-Based Anesthetic Mixtures in Gray Squirrels Undergoing Gonadectomy: Clinical and Physiologic Findings.

Simple SummaryThe loss of biodiversity is continuing at an alarming rate worldwide and continuous efforts are required to conserve and protect species and habitats. In 2011, Europe adopted the EU Biodiversity Strategy, aiming to halt the loss of biodiversity and ecosystem services. The increasing number of alien species is one of the leading environmental emergencies. The gray squirrel, introduced to Europe from the USA, is one of the most common and feared invasive species. The introduction of this non-native species is endangering the survival of the smaller native squirrel, called the “common European” or “red” squirrel. The gray squirrel has a devastating impact on native populations of red squirrels as it outcompetes them for food and territory, in addition to carrying diseases. Sterilization is an indirect and humane method for the eradication of gray squirrels; however anesthetic protocols have not yet been standardized. This study describes two anesthetic protocols used to induce chemical immobilization for safe handling, in order to perform the gonadectomy, simultaneously allowing a fast recovery, followed by re-introduction in urban parks. The two anesthetic protocols included a combination of dexmedetomidine and midazolam with either alfaxalone or ketamine. Comparisons of their efficacy and evaluations of their physiologic effects are reported.The gray squirrel is one of the most common invasive species in Europe, whose presence is dangerous for the survival of the European red squirrel. To cope with this biological invasion and to safeguard biodiversity, the LIFE+U-SAVEREDS project aims to protect the red squirrel, by limiting the growth of the current population of gray squirrels and simultaneously promoting their eradication with surgical sterilization. This study compares two different anesthetic protocols, including dexmedetomidine (40 µg/kg) and midazolam (0.3 mg/kg) associated with ketamine (15 mg/kg; n = 25 squirrels) or alfaxalone (5 mg/kg; n = 22 squirrels). A blinded investigator evaluated the quality and onset of sedation, intraoperative anesthesia, and recovery, as well as the physiologic parameters for each animal. Alfaxalone provided a good quality of anesthesia with limited cardiovascular effects (p < 0.05) and good intraoperative myorelaxation. Ketamine induced complete relaxation in a shorter time (p < 0.05) and a rapid (p < 0.001) and excellent (p < 0.05) recovery. Despite the overall superiority of ketamine, alfaxalone appeared to be an adequate alternative anesthetic drug that can be administered without requiring intravascular access. It should be rapidly metabolized and excreted; however, it requires the combination of longer acting sedatives/myorelaxants to prevent a poor recovery quality.

Assessing the potential impacts of non-native small mammals in the South African pet trade

The pet trade is one of the most important pathways by which small mammals are introduced to non-native areas. To prevent the introduction and invasion of non-native pets, an impact assessment protocol is useful in understanding which pets might have potential negative impacts should they escape or be released from captivity. In this study, we used the Generic Impact Scoring System (GISS) to assess the potential effects associated with 24 non-native small mammal species sold in the South African pet trade. European rabbits Oryctolagus cuniculus, house mice Mus musculus, Norwegian rats Rattus norvegicus and eastern grey squirrels Sciurus carolinensis had the highest potential impacts for both socio-economic and environmental categories. We found no statistically significant difference between the overall environmental and socio-economic impact scores. Impacts on agricultural and animal production (livestock) were the main mechanisms in the socio-economic category, while the impacts on animals (predation), competition and hybridisation prevailed for environmental impacts. The non-native mammal pet species with high impacts should be strictly regulated to prevent the potential impacts and establishment of feral populations in South Africa.

Introduced Canadian Eastern grey squirrels: squirrelpox virus surveillance and why nothing matters

Introduced Canadian Eastern grey squirrels: squirrelpox virus surveillance and why nothing matters

Woody Cover Mediates Fox and Gray Squirrel Interactions

Human activities are changing the environments that animal communities utilize, altering competition and co-existence dynamics as well as changing species distributions. A global consequence of human activity is increased woody cover, which changes environmental conditions on landscape, local, and fine spatial scales. These multi-scale processes are likely to change species interactions and distributions in unexpected ways. To elucidate these effects, we investigated the co-occurrence of two interacting species in a rapidly changing ecosystem. Eastern fox (Sciurus niger) and gray (S. carolinensis) squirrels occur sympatrically throughout the southeastern United States. We used single-season, two-species occupancy modeling to understand what factors influence competition between the squirrels at three spatial scales. We found evidence that fox and gray squirrels compete at fine scales but not at local and landscape scales. The best model to explain fox and gray squirrel co-occurrence at fine scales was an additive fine scale understory and tree canopy closure model. Increased fine-scale canopy closure correlated with increased fox and gray squirrel occupancy while increased fine-scale understory cover correlated with decreased gray and fox squirrel occupancy. Fox squirrel occupancy probability declined in the presence of gray squirrels. The intensity of interaction was modified by fine-scale canopy cover and understory density. These findings support the hypothesis that species interactions can be an important factor in structuring biotic communities, however the strength of the effect changes across spatial scales. Our results support the importance of considering species interactions at multiple scales when predicting community composition in human modified and managed systems.

Into the drink: observation of a novel hunting technique employed by an Eastern Gray Squirrel (Sciurus carolinensis)

Observations of typically herbivorous species have shown that animals will opportunistically eat animal tissue that is either scavenged or hunted. Squirrels from a number of genera have been observed to hunt prey and consume meat in terrestrial ecosystems. Here we provide evidence of a novel hunting strategy employed by an Eastern Gray Squirrel (Sciurus carolinensis), which has not previously been observed hunting aquatic prey. More rigorous observational studies are needed to determine the extent of this behaviour in Eastern Gray Squirrel populations and whether fishing is a common foraging behaviour for this species.

Complex relationships between physiological stress and endoparasite infections in natural populations.

Short-term elevation of glucocorticoids (GCs) is one of the major physiological mechanisms by which vertebrates cope with challenging environmental or social factors (stressors). However, when exposure to stressors occurs repeatedly or over a prolonged period of time, animals may experience chronic elevation of GCs, which reduces the immune response efficiency and can lead to higher intensity of parasitic infection. Here, we used invasive gray squirrels Sciurus carolinensis introduced in Northern Italy and their 2 most prevalent gastrointestinal parasites, the nematode Strongyloides robustus and coccidia of the genus Eimeria, as a model to investigate relationships among macroparasite infection and concentrations of fecal glucocorticoid metabolites (FGMs), an integrated measure of circulating GCs. Our results revealed an association of FGMs with infection by St. robustus, but not with coccidia. Individuals with higher FGMs appear to be responsible for the greatest St. robustus egg shedding within gray squirrel populations, thus possibly acting as superspreaders. However, FGMs were negatively associated with adult St. robustus, suggesting that the abundance of adults of this nematode species does not induce elevation in FGMs, but is only affected by it through immune-mediated effects on its fecundity. Finally, the relationship between St. robustus (both eggs and adult parasites) and FGMs was not linear, suggesting that only high levels of physiological stress influence parasite infection. Our findings highlight that the direction and magnitude of the stress–infection relationship may depend not only on the specific host–parasite system, but also on the different life stages of the same parasite.

Declining invasive grey squirrel populations may persist in refugia as native predator recovery reverses squirrel species replacement

Abstract Invasive species pose one of the most serious global threats to biodiversity. Investigations into the interactions of native and non‐native species focus on the impacts of single species, despite being embedded in a network of direct and indirect interactions between multiple species and their environments. We developed 1‐km2 resolution, single‐species and multi‐species occupancy models using quantitative camera trap data collected by citizen scientists at 332 sites in a regional survey comprising the 14,130 km2 of Northern Ireland. Recent research suggests that native red and invasive grey squirrels in Britain and Ireland are linked by resource and disease‐mediated competition, and by a shared enemy, the European pine marten. We demonstrate that the presence of the pine marten reverses red squirrel replacement by grey squirrels on a regional basis, with red squirrel occupancy positively affected by exposure to pine marten. In contrast, the grey squirrel has a strongly negative response to the presence of pine marten. Modelling habitat suitability of pine marten and both squirrel species suggests that, despite the potentially strong effect of a recovering population of pine martens in controlling grey squirrel distribution, the latter is likely to persist in urban refugia that are either inaccessible or avoided by the pine marten. Synthesis and applications. Sustainable recovery of both the red squirrel and the pine marten across the wider landscapes of Ireland, Scotland and Northern England seems probable, while in Southern England and Wales, although possible, chances are more remote. Increasing native woodland cover on a landscape scale to facilitate pine marten recovery may assist in realizing this scenario. Despite the ongoing recovery of the pine marten, and resultant declines in grey squirrels, isolated populations are likely to persist in urban areas. Human‐lead control of grey squirrel populations in urban refugia requires urgent funding and implementation to avoid the development of novel genotypes in grey squirrel source populations that enable the species to better avoid predation by the pine marten.

PROGNOSTIC INDICATORS FOR SURVIVAL OF ORPHANED EASTERN GRAY SQUIRRELS (SCIURUS CAROLINENSIS).

The eastern grey squirrel (EGS), Sciurus carolinensis, is a tree squirrel native to the eastern United States. This species commonly presents to wildlife medical clinics for a variety of human-related injuries including confrontations with road traffic and pet predation. The purpose of this study was to assess initial examination findings as prognostic indicators for survival in EGS. The medical record database of the University of Illinois Wildlife Medical Clinic was searched from January 2012 through December 2018 for records of EGS weighing <300 g. The squirrels were identified as survivors (individuals surviving, released, or transferred to a rehabilitator within 72 hr of intake) or nonsurvivors (individuals euthanized or dying within 72 hr of intake after receiving medical care). Presenting weight, health status, method of feeding, and singleton versus group presentation were categorically recorded for each case. The data were modeled using a series of candidate logistic regression models fitted using the generalized linear model. An information theoretical approach determined the best fit model. A total of 955 EGS were included in this study. Factors that predicted a nonsurvivor status included EGSs that presented with any health system abnormality (odds ratio [OR], 4.81; 95% confidence interval [CI], 3.34-6.72), EGSs that presented between December and May (OR, 1.60; 95% CI, 1.12-2.27) rather than between June and November, and individuals with neurologic signs (OR, 2.61; 95% CI, 1.51-4.51) compared with EGSs without neurologic signs. Despite not being included in the final model, the presence of respiratory signs (OR, 3.43; 95% CI, 2.41-4.89) and diarrhea (OR, 4.01; 95% CI, 1.59-10.09) were significantly associated with a higher likelihood of nonsurvival status. Wildlife medical clinics and rehabilitation centers may use this information by initiating more aggressive therapies or instituting distinct euthanasia protocols for EGS that present with body system abnormalities, particularly neurologic clinical signs, and those that present in the winter months.

Novel enteric viruses in fatal enteritis of grey squirrels.

Astro- and kobuviruses infect both humans and animals. Here, we report on the disease history, detection and genomic characterization of novel astro- and kobuviruses from fatal diarrhoea of two juvenile grey squirrels. The virus particles had enterovirus-like morphology and a diameter of 28-32 nm. Next-generation sequencing confirmed astro- and kobuviruses and sequence analysis revealed typical astrovirus and picornavirus genome organizations. The astrovirus ORF2 sequence clustered with a clade of unassigned astroviruses, with marmot and rodent mamastroviruses as closest relatives. For the kobuvirus, divergences greater than 49.4 % for P1 and 43.5 % in the non-structural proteins indicated a novel species. However, phylogenetic analysis of the 3D polymerase showed that it clustered with that of the newly classified ludopivirus A1, suggesting a previous recombination event in the evolution of the kobuvirus. Our data provide further insights into the diversity of astro- and kobuviruses and broaden the spectrum of viruses infecting grey squirrels.

Wildlife response to recreational trail building: An experimental method and Appalachian case study

Trail networks are common infrastructure in protected areas for visitors to exercise, connect with nature, and learn about natural and cultural resources. However, there are concerns that the presence and construction of trails affect the quality of wildlife habitats, extending human disturbance into secluded areas. In this study, we developed a before-after control-impact experimental design to investigate the impacts of new trail construction on six terrestrial vertebrate species in an Appalachian protected area in the U.S. Using camera traps, we monitored animal use of the study area before, during, and after construction, on the trail, near the trail, and at a control site. Our results indicate statistically significant impacts of trail building and presence on four common species. During trail construction, white-tailed deer (Odocoileus virginianus) and coyotes (Canis latrans) decreased their activity on and/or near the trail, while raccoons (Procyon lotor) increased activity on the trail. These three species returned to the area at pre-building levels once trail construction was complete. After trail building, eastern gray squirrel (Sciurus carolinensis) showed decreased use of the trail area. We also observed altered timing of daily activity patterns for squirrels and deer, both diurnal species. Deer activity became more spread throughout the day within the near-trail zone during construction. After the trail was complete, squirrels shifted activity to earlier in the day, after sunrise and prior to the peak of recreational activity. We conclude that while trail building may alter habitat quality for some species, this mostly occurred during the construction phase, and was fairly minor for our study species. To minimize impacts, we suggest that trail building be restricted to a short time period during a season when species of concern are least sensitive. Our use of control sites allowed us to distinguish experimental effects from natural population fluctuations, and should serve as a foundation for future work investigating the effects of trails and other linear human disturbances on wildlife communities, especially in sensitive habitats and ecosystems.

Correction to: Fire impacts on a forest obligate: western gray squirrel response to burn severity

Correction to: Fire impacts on a forest obligate: western gray squirrel response to burn severity