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Vincent A. Slabe

Publications and source records attributed to Vincent A. Slabe.

9 recordsLinked to original sources
USGS2026

Lead exposure of snakes near recreational and military shooting areas in a sagebrush steppe ecosystem

Lead exposure has been documented in a multitude of bird and mammal species but less frequently in reptiles. Of the studies that have evaluated lead concentrations in reptiles, few have focused on snakes. We analyzed lead concentrations in liver and two types of bone from 24 gophersnakes ( Pituophis catenifer; Pc) and 12 Great Basin rattlesnakes ( Crotalus oreganus lutosus; Col) found dead along roads in the Morley Nelson Snake River Birds of Prey National Conservation Area in southwestern Idaho, U.S.A from 2018 to 2021. Because this area has been heavily impacted by both military and recreational activity, we also quantified lead concentrations in the soil near where the dead snakes were found. All soil samples had detectable lead (median: 12.53 µg/g; range: 0.07–16.77). Within individuals of both species, dry weight lead concentrations in liver generally were lower than those in bone (n samples < LOQ Liver: 9 of 13 ( Pc ), 9 of 10 ( Col ) (only a subset of individuals were in good enough condition to provide liver samples); Bone: 0 of 24 ( Pc ), 3 of 12 ( Col ). We did not detect any differences in lead concentrations between the species for either tissue type, nor between bone from the front (anterior) or back (posterior) of the snake skeleton. Additionally, we did not detect any correlation between lead concentration in soil collected at the roadkill sites and the tissue in the snakes. These data provide baseline information for lead exposure of two snake species in southwestern Idaho and demonstrate how lead is present in higher trophic levels within this ecosystem.

Idaho↗
USGS2024

Lead exposure of a fossorial rodent varies with the use of ammunition across the landscape

Exposure to heavy metals has been documented in a wide range of wildlife species, but infrequently in ground squirrels. This is despite their tendency to be targets of recreational shooters and the accumulation of lead ammunition in the soil environments they inhabit. We analyzed lead and copper concentrations in liver (n Pb = 116, n Cu = 101) and femur (n Pb = 116, n Cu = 116) of Piute ground squirrels ( Urocitellus mollis ) and in soil ( n = 75) on public lands in southwestern Idaho to understand how lead exposure may vary across a gradient of intensities and histories of shooting activity. The liver and femur of squirrels from areas used for recreational shooting for greater than 30 years had elevated lead concentrations relative to areas where shooting was rare or did not occur (our negative control), but as expected, lower than areas used for military target training for greater than 70 years (our positive control). Lead concentration in soils were higher in areas used for military target training than in those used for recreational shooting. There were no differences in copper concentrations in biological or soil samples among sites. These data suggest that ground squirrels can be influenced by the history of lead use in their local environment, and they illustrate another pathway by which human activity can influence toxicant exposure to wildlife.

Science ot the Total Environment↗
USGS2022

Open-source intelligence for conservation biology

Open-source intelligence (OSINT) evolved in spy agencies but now is rapidly changing many fields of study, from anthropology to zoology. Despite the fact that OSINT occasionally is used in conservation biology, there is little recognition that some tools and frameworks used by conservation professionals are drawn from this well-established field. The history and conceptual foundations of OSINT stem from the intelligence community, although OSINT tools are rapidly being applied in other fields. In conservation biology, OSINT is sometimes used to evaluate wildlife crime, human-wildlife and human-environment interactions, animal behavior, and questions of distribution and abundance. Recognizing the conceptual foundations of the field would allow expansion of conservation biology, not only in the areas noted above, but also, for example, in study of habitat use, habitat change, and animal behavior. This recognition would also provide frameworks for conceptual advancement, especially in terms of data and privacy management. Failure to recognize the underpinnings of OSINT tools in conservation biology harms the field because it limits how research is framed, thought about, and implemented. Likewise, taking an OSINT perspective to conservation problems, rather than simply thinking in terms of big data, can enrich the field, expand science, and increase knowledge and understanding of biology and biodiversity.

Conservation Biology↗
USGS2022

Demographic implications of lead poisoning for eagles across North America

Lead poisoning occurs worldwide in populations of predatory birds, but exposure rates and population impacts are known only from regional studies. We evaluated the lead exposure of 1210 bald and golden eagles from 38 US states across North America, including 620 live eagles. We detected unexpectedly high frequencies of lead poisoning of eagles, both chronic (46 to 47% of bald and golden eagles, as measured in bone) and acute (27 to 33% of bald eagles and 7 to 35% of golden eagles, as measured in liver, blood, and feathers). Frequency of lead poisoning was influenced by age and, for bald eagles, by region and season. Continent-wide demographic modeling suggests that poisoning at this level suppresses population growth rates for bald eagles by 3.8% (95% confidence interval: 2.5%, 5.4%) and for golden eagles by 0.8% (0.7%, 0.9%). Lead poisoning is an underappreciated but important constraint on continent-wide populations of these iconic protected species.

Science↗
USGS2020

Feeding ecology drives lead exposure of facultative and obligate avian scavengers in the eastern United States

Lead poisoning of scavenging birds is a global issue. However, the drivers of lead exposure of avian scavengers have been understood from the perspective of individual species, not cross‐taxa assemblages. We analyzed blood ( n = 285) and liver ( n = 226) lead concentrations of 5 facultative (American crows [ Corvus brachyrhynchos ], bald eagles [ Haliaeetus leucocephalus ], golden eagles [ Aquila chrysaetos ], red‐shouldered hawks [ Buteo lineatus ], and red‐tailed hawks [ Buteo jamaicensis ]) and 2 obligate (black vultures [ Coragyps atratus ] and turkey vultures [ Cathartes aura ] avian scavenger species to identify lead exposure patterns. Species and age were significant ( α < 0.05) predictors of blood lead exposure of facultative scavengers; species, but not age, was a significant predictor of their liver lead exposure. We detected temporal variations in lead concentrations of facultative scavengers (blood: median = 4.41 µg/dL in spring and summer vs 13.08 µg/dL in autumn and winter; p = <0.001; liver: 0.32 ppm in spring and summer vs median = 4.25 ppm in autumn and winter; p = <0.001). At the species level, we detected between‐period differences in blood lead concentrations of bald eagles ( p = 0.01) and red‐shouldered hawks during the winter ( p = 0.001). During summer, obligate scavengers had higher liver lead concentrations than did facultative scavengers (median = 1.76 ppm vs 0.22 ppm; p = <0.001). These data suggest that the feeding ecology of avian scavengers is a determinant of the degree to which they are lead exposed, and they highlight the importance of dietary and behavioral variation in determining lead exposure.

Alabama, Georgia, Maryland, New Jersey, New York, ↗
USGS2019

Lead in piscivorous raptors during breeding season in the Chesapeake Bay region of Maryland and Virginia, USA

Sources of lead exposure of many bird species are poorly understood. We analyzed blood lead concentrations from osprey (n = 244; Pandion haliaetus ) and bald eagles (n = 68; Haliaeetus leucocephalus ) and documented potential sources of lead they may encounter. Adult bald eagles had higher blood lead concentrations than did adult osprey. However, blood lead concentrations of nestlings were similar for both species. Although 62% of osprey had detectable lead concentrations (x ̅ = 1.99 µg/dL ± 4.02; mean; ± SD), there was no difference in the detection frequency or lead concentrations between osprey adults and nestlings. Likewise, we found no differences in the detection frequency or lead concentrations in osprey adults and nestlings from high and low salinity areas. Of the bald eagle samples tested, 55% had detectable lead levels (x ̅ = 6.23 µg/dL ± 10.74). Adult bald eagles had more detectable and higher lead concentrations than did nestlings or pre-adults. Among environmental samples, paint had the highest lead concentrations, followed by sediment, blue catfish ( Ictalurus furcatus ), and gizzard shad ( Dorosoma cepedianum ). There was no correlation between blood lead concentrations of osprey adults and their offspring. Our work indicates that, in the Chesapeake Bay region, there are multiple sources by which piscivorous raptors may be exposed to lead.

Maryland, Virginia↗
USGS2019

An improved mechanical owl for efficient capture of nesting raptors

Scientific study of raptors often requires the use of a lure to capture individuals for marking or collecting various data and samples. Live lure owls in the genus Bubo are commonly used with mist nets or dho-gazas to trap nesting raptors, but the use of these live lures presents ethical, logistical, and financial challenges. Although owls mounted by taxidermists and mechanical owls have been used in place of a live bird, the success of these types of lures varies widely. We created a more realistic mechanical owl with a greater range of motion than previous models, and then tested the owl on six raptor species in a variety of habitats. For all but one species, capture rates using our mechanical owl were similar to or slightly higher than those reported in studies using live lure owls or previously designed mechanical owls. Time to capture of Northern Goshawks ( Accipiter gentilis ) was, on average, 8 min faster when using our mechanical owl compared to a live owl. Cost analysis revealed that both the initial expense and long-term maintenance of a mechanical owl were less than that of a live lure owl. Mechanical owls can be a useful tool for capturing raptors. Although there are some drawbacks to using a mechanical owl, our results suggest that mechanical birds are comparable to live lure owls and we believe the benefits of using a mechanical owl often outweigh the costs.

Journal of Raptor Research↗
USGS2018

The use of lead isotope analysis to identify potential sources of lead toxicosis in a juvenile bald eagle (Haliaeetus leucocephalus) with ventricular foreign bodies

A male juvenile bald eagle (Haliaeetus leucocephalus) was admitted to the Wildlife Center of Virginia with a left humeral fracture a large quantity of anthropogenic debris in the ventriculus, a blood lead level of 0.616 ppm, and clinical signs consistent with chronic lead toxicosis. Because of the poor prognosis for recovery and release, the eagle was euthanatized. Lead isotope analysis was performed to identify potential anthropogenic sources of lead in this bird. The lead isotope ratios in the eagle's femur (0.8773), liver (0.8761), and kidneys (0.8686) were most closely related to lead paint (0.8925), leaded gasoline (0.8450), and zinc smelting (0.8240). The lead isotope ratios were dissimilar to lead ammunition (0.8179) and the anthropogenic debris in the ventriculus. This case report documents foreign body ingestion in a free-ranging bald eagle and demonstrates the clinical utility of lead isotope analysis to potentially identify or exclude anthropogenic sources of lead poisoning in wildlife patients.

Journal of Avian Medicine and Surgery↗