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USGS2021

Responses of vertebrate wildlife to oil and natural gas development: Patterns and frontiers

Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies ( n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.

Current Landscape Ecology Reports↗

USGS2015

Pairing call-response surveys and distance sampling for a mammalian carnivore

Density estimates accounting for differential animal detectability are difficult to acquire for wide-ranging and elusive species such as mammalian carnivores. Pairing distance sampling with call-response surveys may provide an efficient means of tracking changes in populations of coyotes ( Canis latrans ), a species of particular interest in the eastern United States. Blind field trials in rural New York State indicated 119-m linear error for triangulated coyote calls, and a 1.8-km distance threshold for call detectability, which was sufficient to estimate a detection function with precision using distance sampling. We conducted statewide road-based surveys with sampling locations spaced ≥6 km apart from June to August 2010. Each detected call (be it a single or group) counted as a single object, representing 1 territorial pair, because of uncertainty in the number of vocalizing animals. From 524 survey points and 75 detections, we estimated the probability of detecting a calling coyote to be 0.17 ± 0.02 SE, yielding a detection-corrected index of 0.75 pairs/10 km 2 (95% CI: 0.52–1.1, 18.5% CV) for a minimum of 8,133 pairs across rural New York State. Importantly, we consider this an index rather than true estimate of abundance given the unknown probability of coyote availability for detection during our surveys. Even so, pairing distance sampling with call-response surveys provided a novel, efficient, and noninvasive means of monitoring populations of wide-ranging and elusive, albeit reliably vocal, mammalian carnivores. Our approach offers an effective new means of tracking species like coyotes, one that is readily extendable to other species and geographic extents, provided key assumptions of distance sampling are met.

New York↗

USGS2012

Assessing sloth bears as surrogates for carnivore conservation in Sri Lanka

Bears are large, charismatic mammals whose presence often garners conservation attention. Because healthy bear populations typically require large, contiguous areas of habitat, land conservation actions often are assumed to benefit co-occurring species, including other mammalian carnivores. However, we are not aware of an empirical test of this assumption. We used remote camera data from 2 national parks in Sri Lanka to test the hypothesis that the frequency of detection of sloth bears (Melursus ursinus) is associated with greater richness of carnivore species. We focused on mammalian carnivores because they play a pivotal role in the stability of ecological communities and are among Sri Lanka's most endangered species. Seven of Sri Lanka's carnivores are listed as endangered, vulnerable, or near threatened, and little empirical information exists on their status and distribution. During 2002–03, we placed camera traps at 152 sites to document carnivore species presence. We used Poisson regression to develop predictive models for 3 categories of dependent variables: species richness of (1) all carnivores, (2) carnivores considered at risk, and (3) carnivores of least conservation concern. For each category, we analyzed 8 a priori models based on combinations of sloth bear detections, sample year, and study area and used Akaike's information criterion (AIC c ) to test our research hypothesis. We detected sloth bears at 55 camera sites and detected 13 of Sri Lanka's 14 Carnivora species. Species richness of all carnivores showed positive associations with the number of sloth bear detections, regardless of study area. Sloth bear detections were also positively associated with species richness of carnivores at risk across both study years and study areas, but not with species richness of common carnivores. Sloth bears may serve as a valuable surrogate species whose habitat protection would contribute to conservation of other carnivores in Sri Lanka.

Ursus↗

USGS1997

Imperiled mammalian fauna of aquatic ecosystems in the Southeast: A historical perspective

About 100 species of mammals are endemic to the southeastern United States, an area of diverse habitat types and high biodiversity. Many of these species are either formally considered aquatic or semi-aquatic, or they are otherwise closely associated with aquatic ecosystems. In the southeastern United States, greater than 80 percent of mammalian species are listed in some category of concern throughout all or at least a portion of their ranges (i.e., endangered, threatened, under review for possible listing as endangered or threatened, species of special concern, species deemed in need of management, etc.). Almost all of these species are imperiled because their populations have declined to dangerously low levels due to habitat loss, habitat degradation, or other human-related factors. Most imperiled mammal taxa can be categorized as belonging to one of two general groups: habitat generalists or habitat specialists. Typically, habitat generalists have become imperiled mainly due to human exploitation, while habitat specialists have suffered primarily from habitat loss or habitat degradation. The passage of the U.S. Endangered Species Act of 1973 resulted in an increased need for information concerning distribution and status of all native species. However, relatively little is known concerning the historical distribution and current status of many mammalian taxa, and this is particularly so for small non-game species. In this chapter we provide species accounts of mammals commonly associated with aquatic ecosystems that we consider to be imperiled in the southeastern United States. In these accounts we have included information which we feel is valuable toward best understanding the threats that challenge each considered taxon.

Book chapter↗

USGS2015

Toward a mechanistic understanding of human-induced rapid environmental change: A case study linking energy development, avian nest predation, and predators

Demographic consequences of human-induced rapid environmental change (HIREC) have been widely documented for many populations. The mechanisms underlying such patterns, however, are rarely investigated and yet are critical to understand for effective conservation and management. We investigated the mechanisms underlying reduced avian nest survival with intensification of natural gas development, an increasing source of human-induced rapid environmental change globally. We tested the hypothesis that energy development increased the local activity of important nest predator species, thereby elevating nest predation rates. During 2011–2012, we surveyed predators and monitored 668 nests of Brewer's sparrows Spizella breweri (BRSP), sagebrush sparrows Artemisiospiza nevadensis (SASPs) and sage thrashers Oreoscoptes montanus (SATHs) breeding at twelve sites spanning a gradient of habitat loss from energy development in western Wyoming, USA. Nine species, representing four mammalian and three avian families, were video-recorded depredating eggs and nestlings. Important nest predator species differed across songbird species, despite similar nesting habitats. Approximately 75% of depredation events were by rodents. Consistent with our predictions, detections of most rodent nest predators increased with surrounding habitat loss due to natural gas development, which was associated with increased probability of nest predation for our three focal bird species. An altered nest predator assemblage was therefore at least partly responsible for elevated avian nest predation risk in areas with more surrounding energy development. Synthesis and applications . We demonstrate one mechanism, that is the local augmentation of predators, by which human-induced rapid environmental change can influence the demography of local populations. Given the accelerating trajectory of global energy demands, an important next step will be to understand why the activity and/or abundance of rodent predators increased with surrounding habitat loss from energy development activities.

Journal of Applied Ecology↗

USGS2025

Fine-scale farming features drive resource selection of a small carnivore of conservation concern

Anthropogenic factors are accelerating species extinction, with small mammalian carnivores among the most affected. These species play vital ecological roles, yet their conservation needs are often overlooked. Our study focused on the plains spotted skunk ( Spilogale interrupta (Rafinesque, 1820)), a small carnivore that has experienced population declines. We hypothesized that their resource selection was influenced by factors expected to influence prey availability, protection from predators, and human activity. We tracked 14 plains spotted skunks in east-central South Dakota, USA, over 2 years during spring and summer. Using mixed-effects logistic regression, we identified seasonal habitat associations. In spring, plains spotted skunks selected areas near farming structures and human development, avoiding high wetland density and crop cover. In summer, they continued to select areas near farming structures and low human development, but also high wetland density and pasture, while avoiding hay bales and crop cover. Our first analysis of the species’ resource use in the Great Plains indicates that plains spotted skunks select habitats with permanent small-scale agricultural features and varying levels of human development across seasons. Our findings suggest that species’ persistence in the region may depend on conservation strategies that account for seasonal planning, habitat heterogeneity, and key agricultural structures.

Canadian Journal of Zoology↗

USGS1993

Distribution and abundance of predators that affect duck production--prairie pothole region

During 1983-88, the relative abundance of 18 species and species-groups of mammalian and avian predators affecting duck production in the prairie pothole region was determined in 33 widely scattered study areas ranging in size from 23-26 km2. Accounts of each studied species and species-group include habitat and history, population structure and reported densities, and information on distribution and abundance from the present study. Index values of undetected, scarce, uncommon, common, or numerous were used to rate abundance of nearly all species in each study area. Principal survey methods were livetrapping of striped skunks (Mephitis mephitis) and Franklin's ground squirrels (Spermophilus franklinii), systematic searches for carnivore tracks in quarter sections (0.65 km2), daily records of sightings of individual predator species, and systematic searches for occupied nests of tree-nesting avian predators. Abundances of predators in individual areas were studied 1-3 years.The distribution and abundance of predator species throughout the prairie pothole region have undergone continual change since settlement of the region by Europeans in the late 1800's. Predator populations in areas we studied differed markedly from those of pristine times. The changes occurred from habitat alterations, human-inflicted mortality of predators, and interspecific relations among predator species. Indices from surveys of tracks revealed a decline in the abundance of red foxes (Vulpes vulpes) and an albeit less consistent decline in the abundance of raccoons (Procyon lotor) with an increase in the abundance of coyotes (Canis latrans). Records of locations of occupied nests revealed great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) tended to nest 0.5 km apart, and American crows (Corvus brachyrhynchos) tended to avoid nesting 0.5 km of nests of red-tailed hawks. Excluding large gulls, for which no measurements of abundance were obtained, the number of predator species averaged 12.2 (SD = 1.60) per study area; common or numerous predator species averaged 6.0 (SD = 1.54) per study area (minimal because the abundance of weasels [Mustela erminea; M. frenata] in all areas and of minks [Mustela vison] and raptors in some areas was not rated). Major changes in relative abundance of individual predator species studied >1 year were few. Predator species most restricted to the aspen parkland were the Franklin's ground squirrel, black-billed magpie (Pica pica), American crow (Corvus brachyrlus), and red-tailed hawk; species most restricted to the prairie were the badger (Taxidea taxus), Swainson's hawk (Buteo swainsoni), and ferruginous hawk (B. regalis). The coyote, black-billed magpie, and American crow were most numerous in Canada, whereas the red fox, raccoon, mink, ferruginous hawk, and great horned owl were most numerous in the United States. The number of common or numerous egg-eating predator species (excludes large gulls and weasels, which were not rated) averaged 4.6 (SD = 0.90) per study area. The average numbers of common or numerous egg-eating species per study area did not differ among provinces and states, but birds gradually replaced mammals from southeast to northwest across the region. Investigators are urged to assess composition of predator populations and relative abundance of predator species for evaluations of waterfowl recruitment.

Resource Publication↗

USGS1997

Late quaternary regional geoarchaeology of Southeast Alaska Karst: A progress report

Karst systems, sea caves, and rock shelters within the coastal temperate rain forest of Alaska's Alexander Archipelago preserve important records of regional archaeology, sea level history, glacial and climatic history, and vertebrate paleontology. Two 14C AMS dates on human bone discovered in a remote cave (49-PET-408) on Prince of Wales Island document the oldest reliably dated human in Alaska to ca. 9800 B.P. A series of 14C AMS dates from cave deposits span the past 40,000 years and provide the first evidence of Pleistocene faunas from the northwest coast of North America. Other discoveries include sea caves and marine beach deposits elevated above modern sea level, extensive solution caves, and mammalian remains of species previously undocumented within the region. Records of human activity, including cave art, artifacts, and habitation sites may provide new insights into the early human colonization of the Americas. ??1997 John Wiley & Sons, Inc.

Alaska↗

USGS2013

Greater sage-grouse nest predators in the Virginia Mountains of northwestern Nevada

Greater sage-grouse Centrocercus urophasianus, hereafter sage-grouse, populations have declined across their range due to the loss, degradation, and fragmentation of habitat. Habitat alterations can lead not only to vegetative changes but also to shifts in animal behavior and predator composition that may influence population vital rates, such as nest success. For example, common ravens Corvus corax are sage-grouse nest predators, and common raven abundance is positively associated with human-caused habitat alterations. Because nest success is a central component to sage-grouse population persistence, research that identifies factors influencing nest success will better inform conservation efforts. We used videography to unequivocally identify sage-grouse nest predators within the Virginia Mountains of northwestern Nevada, USA, from 2009 to 2011 and used maximum likelihood to calculate daily probability of nest survival. In the Virginia Mountains, fires, energy exploration, and other anthropogenic activities have altered historic sage-grouse habitat. We monitored 71 sage-grouse nests during the study, placing video cameras at 39 nests. Cumulative nest survival for all nests was 22.4% (95% CI, 13.0–33.4%), a survival rate that was significantly lower than other published results for sage-grouse in the Great Basin. Depredation was the primary cause for nest failure in our study (82.5%), and common ravens were the most frequent sage-grouse nest predator, accounting for 46.7% of nest depredations. We also successfully documented a suite of mammalian and reptilian species depredating sage-grouse nests, including some predators never previously confirmed in the literature to be sage-grouse nest predators (i.e., bobcats Lynx rufus and long-tailed weasels Mephitis frenata). Within the high elevation, disturbed habitat of the Virginia Mountains, low sage-grouse nest success may be limiting sage-grouse population growth. These results suggest that management actions that restore habitat in the Virginia Mountains and decrease anthropogenic subsidies of ravens will benefit sage-grouse.

Nevada↗

USGS2005

Biology and conservation of Xantus's Murrelet: Discovery, taxonomy and distribution

The biology of Xantus's Murrelets Synthliboramphus hypoleucus is similar in many respects to better-studied Ancient Murrelets S. antiquus, especially regarding morphology and the species' precocial mode of post-hatching development. It nests mainly in rock crevices but also under shrubs on islands in southern California, United States, and northwestern Baja California, Mexico (27 o N to 34 o N). The species was discovered in 1859 by Janos Xantus. Two subspecies ( S. h. hypoleucus and S. h. scrippsi ) are recognized that show limited evidence of interbreeding. At sea, closely related Craveri's Murrelets S. craveri co-occur with Xantus's Murrelets off California and western Baja California during half the year, but the former species has a discrete breeding range in the Gulf of California, Mexico. Breeding was documented at 13 island groups between 1863 and 1976. Post-breeding dispersal as far north as central British Columbia, Canada (c. 52 o N) was observed in the 1940s to 1960s. A few Xantus's Murrelets disperse south of breeding colonies to Magdalena Bay, Baja California (c. 24 o N). The southernmost record is the type specimen collected by Xantus near Cabo San Lucas, Baja California (c. 23 o N). Chief threats to this species include introduced mammalian predators on breeding islands, heightened predation by natural predators in human-modified island habitats, and oil pollution. In January 2005, a Pacific Seabird Group special symposium, "Biology and conservation of the Xantus's Murrelet," highlighted conservation concerns and promoted publication of recent studies of this little-known alcid, with nine symposium papers published in this issue of Marine Ornithology. Much of what we know about Xantus's Murrelets has been learned in recent years, and many aspects of biology remain to be described.

Marine Ornithology: Journal of Seabird Research an↗

USGS1997

Imperiled mammalian fauna of aquatic ecosystems in the Southeast: A management perspective

Management of imperiled mammals associated with aquatic ecosystems in the southeastern United States ranges from almost no management for some species to intensive, high-profile programs for others. Aquatic mammals are notoriously difficult to census because they are often secretive, trap-wary, relatively rare, or have extensive movement patterns. As a result, conservation efforts aimed at these animals often have been greatly hampered by a general lack of comprehensive population data. Historically, certain high-profile, "flagship" species have been the primary beneficiaries of management efforts. One of the earliest examples involves beaver, Castor canadensis , which had been reduced to a low ebb due to unregulated harvest and were subsequently live-trapped by state game officials in the 1940s and repatriated throughout the southeastern states. The success of this restocking program has exceeded expectations, and today beaver numbers have reached what many consider to be nuisance proportions in most states. Similar restocking stories can be told for muskrats ( Ondatra zibethicus ) and, to a limited extent, for river otters ( Lutra canadensis ). Unfortunately, other imperiled species of lesser economic or recreational value have not been as fortunate. Efforts to conserve these lower-profile species have been minimal or conservation problems so immense that their complete recovery has been unsuccessful. Wilson (1992) suggested that 20 percent of all species on earth may be lost to extinction in the next four decades. If this disaster should occur, it would rival the greatest geological extinction episodes. Certainly, conservationists need to explore new methods for preserving mammalian diversity. In this chapter we will discuss the resource management history of aquatic mammals which are imperiled in the Southeast. In doing so we define an aquatic mammal as any mammal that is directly or indirectly associated with aquatic ecosystems. Imperiled mammals are any mammalian species, subspecies, or population listed as endangered, threatened, or of special concern on any state or federal list, and also includes mammals experiencing long-term population declines or significant range contractions.

Book chapter↗

USGS2015

Black-tailed and white-tailed jackrabbits in the American West: History, ecology, ecological significance, and survey methods

Across the western United States, Leporidae are the most important prey item in the diet of Golden Eagles ( Aquila chrysaetos ). Leporids inhabiting the western United States include black-tailed ( Lepus californicus ) and white-tailed jackrabbits ( Lepus townsendi i) and various species of cottontail rabbit ( Sylvilagus spp.). Jackrabbits ( Lepus spp.) are particularly important components of the ecological and economic landscape of western North America because their abundance influences the reproductive success and population trends of predators such as coyotes ( Canis latrans ), bobcats ( Lynx rufus ), and a number of raptor species. Here, we review literature pertaining to black-tailed and white-tailed jackrabbits comprising over 170 published journal articles, notes, technical reports, conference proceedings, academic theses and dissertations, and other sources dating from the late 19th century to the present. Our goal is to present information to assist those in research and management, particularly with regard to protected raptor species (e.g., Golden Eagles), mammalian predators, and ecological monitoring. We classified literature sources as (1) general information on jackrabbit species, (2) black-tailed or (3) white-tailed jackrabbit ecology and natural history, or (4) survey methods. These categories, especially 2, 3, and 4, were further subdivided as appropriate. The review also produced several tables on population trends, food habits, densities within various habitats, and jackrabbit growth and development. Black-tailed and white-tailed jackrabbits are ecologically similar in general behaviors, use of forms, parasites, and food habits, and they are prey to similar predators; but they differ in their preferred habitats. While the black-tailed jackrabbit inhabits agricultural land, deserts, and shrublands, the white-tailed jackrabbit is associated with prairies, alpine tundra, and sagebrush-steppe. Frequently considered abundant, jackrabbit numbers in western North America fluctuate temporally and spatially. We also reviewed methods used to investigate jackrabbit populations, including spotlight line transects, flushing transects, drive counts, pellet plot counts, collections, roadside counts, mark-recapture studies, and radio-telemetry studies. Our review of jackrabbit literature illustrates a number of deficiencies in our understanding of jackrabbits in general. As an example, a detailed quantitative description of habitat preferences is lacking, as is a thorough understanding of sympatric jackrabbit species interactions. Even the existence of the oft-cited jackrabbit “cycle” is a matter of debate. Survey methods generally do not address efficacy or accuracy in measuring jackrabbit density or abundance. In addition, there is a paucity of information about jackrabbits in the Mojave Desert, with no real understanding of home ranges, habitat preferences, and population dynamics or demographics in this region.

Arizona, California, Colorado, Idaho, Iowa, Kansas↗

USGS2006

Wild bird mortality and West Nile virus surveillance: Biases associated with detection, reporting, and carcass persistence

Surveillance targeting dead wild birds, in particular American crows (Corvus brachyrhynchos), plays a critical role in West Nile virus (WNV) surveillance in the United States. Using crow decoy surrogates, detection and reporting of crow carcasses within urban and rural environments of DeKalb County, Georgia were assessed for potential biases that might occur in the county's WNV surveillance program. In each of two replicated trials, during July and September 2003, 400 decoys were labeled with reporting instructions and distributed along randomly chosen routes throughout designated urban and rural areas within DeKalb County. Information-theoretic methods were used to compare alternative models incorporating the effects of area and trial on probabilities of detection and reporting. The model with the best empirical support included the effects of area on both detection and reporting of decoys. The proportion of decoys detected in the urban area (0.605, SE=0.024) was approximately twice that of the rural area (0.293, SE =0.023), and the proportion of decoys reported in the urban area (0.273, SE =0.023) was approximately three times that of the rural area (0.103, SE=0.028). These results suggest that human density and associated factors can substantially influence dead crow detection and reporting and, thus, the perceived distribution of WNV. In a second and separate study, the persistence and fate of American crow and house sparrow (Passer domesticus) carcasses were assessed in urban and rural environments in Athens-Clarke, Madison, and Oconee counties, Georgia. Two replicated trials using 96 carcasses of each species were conducted during July and September 2004. For a portion of the carcasses, motion sensitive cameras were used to monitor scavenging species visits. Most carcasses (82%) disappeared or were decayed by the end of the 6-day study. Carcass persistence averaged 1.6 days in rural areas and 2.1 days in urban areas. We analyzed carcass persistence rates using a known-fate model framework in program MARK. Model selection based on Akaike's Information Criteria (AIC) indicated that the best model explaining carcass persistence rates included species and number of days of exposure; however, the model including area and number of days of exposure received approximately equal support. Model-averaged carcass persistence rates were higher for urban areas and for crow carcasses. Six mammalian and one avian species were documented scavenging upon carcasses. Dead wild birds could represent potential sources of oral WNV exposure to these scavenging species. Species composition of the scavenger assemblage was similar in urban and rural areas but "scavenging pressure" was greater in rural areas. ?? Wildlife Disease Association 2006.

Journal of Wildlife Diseases↗

USGS2018

Carnivore hotspots in Peninsular Malaysia and their landscape attributes

Mammalian carnivores play a vital role in ecosystem functioning. However, they are prone to extinction because of low population densities and growth rates, and high levels of persecution or exploitation. In tropical biodiversity hotspots such as Peninsular Malaysia, rapid conversion of natural habitats threatens the persistence of this vulnerable group of animals. Here, we carried out the first comprehensive literature review on 31 carnivore species reported to occur in Peninsular Malaysia and updated their probable distribution. We georeferenced 375 observations of 28 species of carnivore from 89 unique geographic locations using records spanning 1948 to 2014. Using the Getis-Ord Gi*statistic and weighted survey records by IUCN Red List status, we identified hotspots of species that were of conservation concern and built regression models to identify environmental and anthropogenic landscape factors associated with Getis-Ord Gi* z scores. Our analyses identified two carnivore hotspots that were spatially concordant with two of the peninsula’s largest and most contiguous forest complexes, associated with Taman Negara National Park and Royal Belum State Park. A cold spot overlapped with the southwestern region of the Peninsula, reflecting the disappearance of carnivores with higher conservation rankings from increasingly fragmented natural habitats. Getis-Ord Gi* z scores were negatively associated with elevation, and positively associated with the proportion of natural land cover and distance from the capital city. Malaysia contains some of the world’s most diverse carnivore assemblages, but recent rates of forest loss are some of the highest in the world. Reducing poaching and maintaining large, contiguous tracts of lowland forests will be crucial, not only for the persistence of threatened carnivores, but for many mammalian species in general.

PLoS ONE↗

USGS2024

Sea level rise threatens Florida’s insular vertebrate biodiversity

Islands are some of the most biodiverse places on earth, but they are also hotspots of biodiversity loss. The coastline of Florida, U.S.A., is surrounded by thousands of islands, many of which are home to species that occur nowhere else. A rapidly emerging threat to these low-lying islands is inundation as sea levels rise. The capacity of island-dwelling species to adapt to climate change and sea level rise may be limited because many species do not have the ability to shift their distribution off the island to track favorable conditions. We assessed the vulnerability of Florida’s islands to inundation from sea level rise and estimated the terrestrial biodiversity on Florida’s islands that could be lost. Our models predicted that by 2100, over 80% and up to 90% of Florida’s islands could be completely inundated from sea level rise, depending on the sea level rise projection (1.2 m or 2.2 m). Of the 85 mammalian, reptilian, and amphibian species on our subset list of Florida’s Species of Greatest Conservation Need, over half occur on Florida’s islands for at least part of their range, highlighting the importance of these islands for housing Florida’s rich biodiversity. Notably, at least 12 mammal species and 7 reptile species have their entire distribution on Florida’s islands, and this count is likely an underestimate. Projections of future sea level rise mean that these island-endemic species face the threat of extinction in the wild if their island habitat is submerged.

Florida↗

USGS2019

Do parents synchronise nest visits as an antipredator adaptation in birds of New Zealand and Tasmania?

Birds with altricial offspring need to feed them regularly, but each feeding visit risks drawing attention to the nest and revealing its location to potential predators. Synchronisation of visits by both parents has been suggested as a behavioural adaptation to reduce the risk of nest predation. Under this hypothesis, higher risk of nest predation favours greater synchrony of parental feeding visits. We investigated this prediction over three timescales using nestling provisioning data from 25 passerine species in Tasmania and New Zealand. We estimated the extent to which parents actively synchronised their visits to the nest by comparing observed patterns of synchrony with those expected to occur at random. We found that in general, species did not synchronise visits more often than expected by chance. Species varied in the tendency to synchronise visits, but this variation was not explained by likely predation pressure in the distant evolutionary past: New Zealand endemic species, which evolved in the absence of mammalian nest predators, synchronised their visits as often as species which evolved with more diverse predatory guilds. Nest predation risk has increased over time in New Zealand due to introduced predators, but synchrony in visits also was not explained by manipulated predation risk: visit synchrony was equivalent between a predator-removal site and a site where predators remained. However, within one New Zealand species, visit synchrony was higher for mainland populations, which have been exposed to predatory mammals for c .800 years, than for a population on an offshore island to which predatory mammals were never introduced. We conclude that breeding birds may have some capacity to adapt the synchrony with which they provision over short evolutionary timescales. However, the lack of synchrony in most species suggests that either asynchrony provides benefits that outweigh the greater risk of predation, or synchrony incurs costs not compensated by reduced predation.

Tasmania↗

USGS2015

Can orchards help connect Mediterranean ecosystems? Animal movement data alter conservation priorities

As natural habitats become fragmented by human activities, animals must increasingly move through human-dominated systems, particularly agricultural landscapes. Mapping areas important for animal movement has therefore become a key part of conservation planning. Models of landscape connectivity are often parameterized using expert opinion and seldom distinguish between the risks and barriers presented by different crop types. Recent research, however, suggests different crop types, such as row crops and orchards, differ in the degree to which they facilitate or impede species movements. Like many mammalian carnivores, bobcats ( Lynx rufus ) are sensitive to fragmentation and loss of connectivity between habitat patches. We investigated how distinguishing between different agricultural land covers might change conclusions about the relative conservation importance of different land uses in a Mediterranean ecosystem. Bobcats moved relatively quickly in row crops but relatively slowly in orchards, at rates similar to those in natural habitats of woodlands and scrub. We found that parameterizing a connectivity model using empirical data on bobcat movements in agricultural lands and other land covers, instead of parameterizing the model using habitat suitability indices based on expert opinion, altered locations of predicted animal movement routes. These results emphasize that differentiating between types of agriculture can alter conservation planning outcomes.

California↗

USGS2006

Ecology and habitat of breeding Northern Goshawks in the inland Pacific Northwest: A summary of research in the 1990s

During the 1990s, we conducted research on the distribution, productivity, and habitat relationships of Northern Goshawks (Accipiter gentilis) in eastern Oregon and Washington. Our research was initiated primarily in response to concerns raised about the status of Northern Goshawks in the western US, and coincided with early attempts to list the species as threatened or endangered under the Endangered Species Act and the publication of management guidelines for goshawks in the southwestern US. To develop baseline information on the status, distribution, and habitat relationships of goshawks in eastside forests (i.e., east of the Cascade Mountain Range) in the Pacific Northwest, we established study areas on three national forests in eastern Oregon in 1992, adding a fourth study area in central Washington in 1994. We focused on the breeding season and nesting habitat because of its primary importance to goshawk ecology and the logistical feasibility of finding nests. Density of breeding pairs ranged from 0.03-0.09/100 ha, and annual productivity ranged from 0.3-2.2 young fledged/nest. Goshawks selected forest stands with trees of larger diameter and greater canopy closure for nesting than available in the landscape. Occasionally nests could be found in large trees in open-canopied stands. As distance increased from the nest site, forest type and structure became more heterogeneous and the prevalence of older-seral-stage forest declined. Dry or wet openings were present in most territories, often within close proximity to nest stands. Goshawks ate a variety of mammalian and avian prey. Mammal species made up a larger portion of prey biomass on two of the national forests, but avian species appeared to be more prevalent in the diet of goshawks in the most northern study area. We recommend that the existing management guidelines for goshawks in the Southwest form a basis for management in the inland Pacific Northwest, particularly with regard to nested spatial concepts, emphasis on management of prey, and the use of silviculture to promote the development and replacement of old growth or late-seral-stage forest. Our research and management recommendations can be used in concert with the Southwestern management guidelines to establish a mix of vegetation structural stages to support goshawk populations, their prey, and other forest wildlife species specifically for the inland Pacific Northwest.

Studies in Avian Biology↗