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Geology topics

Shannon Barber-Meyer

Publications and source records attributed to Shannon Barber-Meyer.

At least 19 recordsLinked to original sources
USGS2022

Automatic recorders monitor wolves at rendezvous sites: do wolves adjust howling to live near humans?

We used automatic sound recorders to study spontaneous vocalizations of wild wolves during the pup-rearing season around rendezvous sites from 24 wolf packs in six study areas across North America, Asia, and Europe. Between 2018 and 2021, for a total of 1225 pack-days, we recorded 605 spontaneous wolf chorus howls and 224 solo-howl series. Howling occurrence varied across areas, from 12.50 to 94.12% days with howling. Daily howling ranged from 0.00 to 3.47 solo howls/day and 0.13 to 5.29 chorus howls/day. Generally, spontaneous chorus howls peaked between sunset and sunrise. Howling rate depended on area, pack size, and density of people living nearby, being greater where fewer people lived. High rates in Yellowstone National Park, (800,000+ visitors during the study) could reflect accommodation to human activities such as wolf watching. One to six automatic recorders per site within 1000 m of rendezvous sites needed 4–15 days to detect the pack (average 9.5) and 5–21 days (average 11.3) to detect pups, both with a probability of 95%. Our results may guide wolf-monitoring programs using automatic sound recorders, a promising method offering advantages over howling surveys, especially in human-dominated landscapes.

Biodiversity and Conservation↗
USGS2022

Can non-invasive methods replace radiocollar-based winter counts in a 50-year wolf study? Lessons learned from a three-winter trial

Context: Monitoring low-density, elusive predators such as grey wolves ( Canis lupus ) has often been undertaken via live-capture and radio-collaring. Recent advances in non-invasive methods suggest live-captures may not be necessary for adequate monitoring. Further, non-invasive methods are considered best practice when possible. Aims: I evaluated whether a suite of non-invasive methods could replace aerial radiotelemetry to census resident pack wolves. Methods: I employed aerial snow-tracking, ground snow-tracking, camera-trapping, non-invasive genetic surveys, and community-scientist reports during three winters (2019–2021) in north-eastern Minnesota, USA to census pack wolves in a 2060 km 2 area. I attempted to enumerate individual pack sizes as has been historically undertaken to compile the census. Traditional aerial radiotelemetry methods were also conducted for comparison. Key results: Ground snow-tracking and camera-trapping provided the most similar information to radiotelemetry for determining pack counts and territory information, and, in some cases, documented higher pack counts than those obtained by aerial radiotelemetry. Radiotelemetry was the best method for determining pack territories, but was limited to radioed packs. A staggered application of both approaches resulted in increased precision and additional pack-level information without greatly increasing overall field effort. Non-invasive methods allowed trapping for radio-collaring to be reduced to every other year (a 50% reduction), but depending on trapping success, survival of animals, and radio-collar battery life, might even be reduced to every third year. Conclusions: In this 3-year trial, non-invasive methods were not sufficient to completely replace radio-collaring. Nevertheless, non-invasive methods allowed for a 50% reduction in trapping, increased the annual wolf-count precision, and increased community involvement. Anticipated technological improvements in non-invasive methods should reduce some issues encountered – but others will likely persist, in part, because of the fundamental nature of non-invasive methods. Implications: Less reliance on captures, enhanced pack information, and increased public involvement are all successful outcomes of this 3-year trial of non-invasive methods for monitoring wolf populations. Non-invasive methods continue to broaden and improve technologically, and information from trials such as this will help guide others as they increasingly implement non-invasive methods as partial or complete replacements for traditional capture-based methods.

Wildlife Research↗
USGS2022

Are wild wolves southpaws? Including potential conservation implications

Lateralization, or a left-right bias in behavior (e.g., handedness), was originally thought to exclusively exist in humans, but is now known to be widespread. Lateralization can exist at the individual or group level. In dogs ( Canis lupus familiaris ), tests of paw preference have produced inconsistent results. Because wolves ( C. l. ) differ genetically, morphologically, and behaviorally from dogs, I was interested in assessing them for lateralization. I examined lateralization (right versus left) of the foot captured (a step test analog) of wild wolves ( n = 93) trapped for radiocollaring purposes in the Superior National Forest, Minnesota from 2011 – 2017 and 2019. No support was found for lateralization, and sex and age class were not significant predictors of which foot was captured. Because many mammals demonstrate lateralization, and because population-level lateralization is thought to convey increased social cohesion, it is surprising that wild wolves did not demonstrate population level lateralization. This step test analog may not have been an appropriate measure (as lateralization is task dependent) and / or wolf lateralization may exist at the individual level, but not the population level. Future work on wolf lateralization at both the individual and population levels examining pawedness via multiple tasks while accounting for potential confounding factors (such as different rearing conditions and methods) could provide clarification. Examining potential trade-offs between the costs and benefits of lateralization that these highly social animals may incur would be very interesting in terms of evolution and in comparison with dogs. Furthermore, because lateralization has been connected to emotional functioning and animal welfare, baseline lateralization data from wild wolves may inform captive wolf management and conservation, including the captive breeding programs for endangered Mexican wolves ( C. l. baileyi ) and red wolves ( C. rufus ) and other programs (e.g., educational facilities).

Animal Behavior and Cognition↗
USGS2021

Assessing spontaneous howling rates in captive wolves using automatic passive recorders

We studied the spontaneous vocal behaviour of captive wolves at the International Wolf Center (IWC) in Minnesota (spring 2019 and winter 2020), and the Centro del Lobo Ibérico Félix Rodríguez de la Fuente (CLIFRF) in Spain (winter 2020). We used AudioMoth recording devices to record wolf howling 24 hr/day. We identified 412 solo howl series and 403 chorus howls and found differences between wolves at the two centres. Vocal rates for North American wolves at the IWC (7.8 chorus howls/day in spring and 4.8 chorus howls/day in winter) were higher than rates obtained for Iberian wolves from CLIFRF (3.8 chorus howls/day in winter). Howling rates obtained in our study were similar to those obtained for captive Mexican wolves and greater than those reported for wild wolves. Hourly distribution of howling was also different between centres. The greatest howling activity identified at IWC was at pre-sunrise, while at CLIFRF the peak occurred at sunset. Weather conditions had little influence on the vocal behaviour of the captive wolves we studied. We show the potential of passive recorders to study topics of animal acoustic communication, such as vocal rates and temporal patterns, that have not been deeply addressed due to technological constraints.

Minnesota↗
USGS2021

Patterns and processes of pathogen exposure in gray wolves across North America

The presence of many pathogens varies in a predictable manner with latitude, with infections decreasing from the equator towards the poles. We investigated the geographic trends of pathogens infecting a widely distributed carnivore: the gray wolf ( Canis lupus ). Specifically, we investigated which variables best explain and predict geographic trends in seroprevalence across North American wolf populations and the implications of the underlying mechanisms. We compiled a large serological dataset of nearly 2000 wolves from 17 study areas, spanning 80° longitude and 50° latitude. Generalized linear mixed models were constructed to predict the probability of seropositivity of four important pathogens: canine adenovirus, herpesvirus, parvovirus, and distemper virus—and two parasites: Neospora caninum and Toxoplasma gondii . Canine adenovirus and herpesvirus were the most widely distributed pathogens, whereas N. caninum was relatively uncommon. Canine parvovirus and distemper had high annual variation, with western populations experiencing more frequent outbreaks than eastern populations. Seroprevalence of all infections increased as wolves aged, and denser wolf populations had a greater risk of exposure. Probability of exposure was positively correlated with human density, suggesting that dogs and synanthropic animals may be important pathogen reservoirs. Pathogen exposure did not appear to follow a latitudinal gradient, with the exception of N. caninum . Instead, clustered study areas were more similar: wolves from the Great Lakes region had lower odds of exposure to the viruses, but higher odds of exposure to N. caninum and T. gondii ; the opposite was true for wolves from the central Rocky Mountains. Overall, mechanistic predictors were more informative of seroprevalence trends than latitude and longitude. Individual host characteristics as well as inherent features of ecosystems determined pathogen exposure risk on a large scale. This work emphasizes the importance of biogeographic wildlife surveillance, and we expound upon avenues of future research of cross-species transmission, spillover, and spatial variation in pathogen infection.

Alaska, Alberta, Arizona, British Columbia, Michig↗
USGS2021

Historic population estimates for bottlenose dolphins (Tursiops truncatus) in Aragua, Venezuela indicate monitoring need

This study reports historic capture-mark-recapture survival and abundance estimates of common bottlenose dolphins ( Tursiops truncatus ) based on photo-identification surveys of coastal Venezuela (along the Aragua coast between Turiamo Bay and Puerto Colombia). We used the most recent data available: dolphins identified by unique dorsal fin marks during wet and dry season surveys conducted from 2004 to 2008. Dolphin encounter histories were analyzed in the Closed Capture Robust Design framework, with the top model including random movement, constant survival, and capture-recapture probabilities that varied by secondary periods. Survival of marked adults was estimated at 0.99 (95% CI = 0.97 to 1.00). Population estimates for all adults (marked and unmarked) averaged 31 animals (SD = 13.8), and for all dolphins (all adults and calves), 41 animals (SD = 17.2). Coastal bottlenose dolphins face numerous threats, including ship strikes, oil spills, conflict with recreational and industrial fisheries, other negative human interactions, biotoxins, chemicals, noise, freshwater discharge, and coastal development. Further, small populations are, in general, at increased risk due to reduced resiliency and recovery potential when exposed to such threats and to expected environmental and demographic stochasticity. These historic estimates of abundance and survival are critical for establishing a reference state and indicate a need for ongoing monitoring of the small dolphin population while the Aragua coast is still, as of yet, relatively little impacted by humans. Should coastal development increase (as is the global trend) and/or environmental catastrophes (e.g., harmful algal blooms, hurricanes, and oil spills) occur, these historic estimates will be essential for assessing impacts and guiding management and conservation interventions. Our results show year-round dolphin presence and highlight the Venezuelan coastal–oceanic landscape as an area of both future research and conservation importance.

Aragua↗
USGS2021

The importance of wilderness to wolf (Canis lupus) survival and cause-specific mortality over 50 years

We assessed the relative importance of wilderness to gray wolf (Canis lupus) population dynamics over 50 years in a population that 1) was long extant (i.e., not reintroduced or recolonized), 2) was not subject to harvest in our study area until recently, and 3) used both wilderness and adjacent, mainly public, non-wilderness. We analyzed the survival of radiocollared wolves (n = 756 collared-wolf tenures) during 1968–2018 in the Superior National Forest, Minnesota, USA, including the Boundary Waters Canoe Area Wilderness. Over 50 years, adult annual survival was 78%. Wolves captured in wilderness tended to exhibit higher survival than those captured in nonwilderness, but the difference was more pronounced during harvest years and post-harvest years when wilderness wolf survival remained relatively high and non-wilderness wolf survival dropped (relative to pre-harvest). During Nov–Apr of pre-harvest years for adults, the natural mortality rate was similar for non-wilderness wolves and wilderness wolves (both 6%), but the anthropogenic mortality rate was higher for non-wilderness wolves than wilderness wolves (7% versus 1%), as was the illegal mortality rate (5% versus 1%). During Nov–Apr of preharvest years, wilderness wolves were less likely to die than non-wilderness wolves (p = 0.042; hazard ratio = 0.59), pups were more likely to die than adults (p = 0.002; hazard ratio = 1.84), and males were less likely to die than females (p = 0.053; hazard ratio = 0.73). Our long-term wolf survival, cause-specific mortality, and hazard results will inform management agencies whenever wolves are delisted, and jurisdiction for them passes to states.

Minnesota↗
USGS2021

Be a wolf researcher! Wolf pup ethogram

Ethology is the study of behavior, and an ethogram is a list of behaviors, typically of a single species. For this ethogram we have selected a few representative behaviors that pups will exhibit during various growth phases, and therefore, this ethogram is not exhaustive. You will likely observe behaviors not detailed in this booklet (be sure to keep notes of your observations on the pages in the back). We hope you will get a chance to observe all the representative behaviors of each growth phase (check them off on your ethogram’s checklist) by visiting the wolves here in Ely at the International Wolf Center or by “visiting” them online via the wolf cams.

Book↗
USGS2021

Ambassador wolves participate In scientific research

The International Wolf Center wolves are famous for providing unique educational opportunities to visitors to Ely and to people around the globe. Less known, are the contributions these wolves make to scientific research. Recently the Center’s Exhibit Pack were subjects of behavioral and acoustic research.

International Wolf↗
USGS2021

Acoustic interaction between a pair of owls and a wolf

During summer 2019, we recorded an apparent vocal interaction, lasting just under 4 min, between a pair of Great Horned Owls ( Bubo virginianus ) and a gray wolf ( Canis lupus ) in Yellowstone National Park. To our knowledge, this is the first report of such an acoustic interaction in the scientific literature. The increased use of passive acoustic recorders, which record spontaneous vocalizations emitted by animals over long periods, will allow us to better document and study the importance of such interspecific interactions.

Wyoming↗
USGS2020

Testing a new passive acoustic recording unit to monitor wolves

As part of a broader trial of noninvasive methods to research wild wolves ( Canis lupus ) in Minnesota, USA, we explored whether wolves could be remotely monitored using a new, inexpensive, remotely deployable, noninvasive, passive acoustic recording device, the AudioMoth. We tested the efficacy of AudioMoths in detecting wolf howls and factors influencing detection by placing them at set distances from a captive wolf pack and compared those recordings with real‐time, on‐site howling data between 22 May and 17 June 2019. We identified 1,531 vocalizations grouped into 428 vocal events (236 solo howl series and 192 chorus howls). The on‐site AudioMoth correctly recorded 100% of chorus and solo howls that were also documented in real‐time. The remote array detected 49.5% of chorus and 11.9% of solo howls (≥1 unit detected the event). The closest remote AudioMoth (0.54 km, 0.33 mi) detected 37% of choruses and 8.9% of solo howls. Chorus howls (9.4%) were detected at the farthest unit (3.2 km, 2.0 mi). Favorable wind (carrying source howls to the remote units) and calm (no wind) conditions increased detectability and detection distance of chorus howls. Temperature was inversely related to detection. Given the detection distances we observed, AudioMoths are probably useful in studying specific sites during periods when wolves move less frequently (e.g., during late spring and summer at homesites or potentially during winter at kill sites of very large prey). AudioMoths would also be useful in a passive sampling array (e.g., occupancy studies), especially when used in concert with other methods such as camera‐trapping. Additional research should be conducted in areas with different environmental variables (e.g., wind, temperature, habitat, topography) to determine performance under varying conditions and also when fitted with a parabolic dish.

Minnesota↗
USGS2020

Sixty years of White-tailed Deer (Odocoileus virginianus) yarding in a Gray Wolf (Canis lupus)–deer system

This article synthesizes information from over a six-decade period of studies of White-tailed Deer ( Odocoileus virginianus ) use of a winter yard and subject to Gray Wolf ( Canis lupus ) predation in northeastern Minnesota. It also adds spring migration data from 35 adult female deer and fawns studied there during 1998, 1999, 2001, 2014, and 2017. Twenty-nine of these deer migrated in spring a mean distance of 29 km (SE = 4), a maximum distance of 78 km, and at a mean bearing of 83° (SE = 12; range 21–348). These findings are similar to those from 49 deer (both sexes) from the same yard studied during 1974–1984, that migrated a mean distance of 25 km (SE = 1.8) and a mean bearing of 77° ± 4 SE. Between the two periods, the wolf population fluctuated considerably, the winter range of deer in the area where these deer spent summer greatly diminished, and both derechos and fires disturbed the habitat. This study attests to the selective advantage of the migratory tradition of deer in this yard.

Minnesota↗
USGS2020

Testing environmental DNA from wolf snow tracks for species, sex, and individual identification

Monitoring elusive, relatively low-density, large predators, such as the grey wolf (Canis lupus), has often been accomplished by live-capture and radiocollaring. Increasingly, non-invasive methods are considered best practice whenever it is possible to use them. Recently, environmental DNA (eDNA) deposited in snow tracks was demonstrated as useful for identifying lynx (Lynx canadensis), fisher (Pekania pennanti), wolverine (Gulo gulo), sika deer (Cervus nippon), red fox (Vulpes vulpes), and the Japanese marten (Martes melampus) to species level using mitochondrial DNA (mtDNA) markers. We tested whether eDNA from fresh wolf snow tracks collected in the Superior National Forest, Minnesota, USA during winter 2019 could be used to identify species, sex, and individual. Seven of the 8 snow track samples were successfully identified to “wolf-dog” species using mtDNA, with alleles amplifying in 5 of the samples at 1 or both of loci u250 and FH2096 in the allele range for wolves for this population. None yielded enough high-quality DNA to obtain genotypes to determine individual or sex. We recommend additional field trials to determine the minimum number of tracks required per individual to obtain sufficient, high-quality eDNA, as well as collecting associated urine or blood (from estrus) when possible. If individual wolves could be identified and sexed by the eDNA in their snow tracks, researchers should be able to determine population and family or group metrics with greater precision and less effort than typically required when conducting winter scat or hair-based genetic field studies of low density, elusive carnivores. Furthermore, this method would have applications to other areas of research and management, such as hunting quota determinations, validation of field methods and, in particular regards to wolves and other predators, livestock depredation issues. Overall, this technique holds significant future promise as field and laboratory methods are further refined for greater precision and optimized regarding the varying collection, filtration, and extraction protocols for different species in various environments.

Minnesota↗
USGS2020

Fish out of water: Insights from a case study of a highly social animal that failed the mirror self-recognition test

Mirror self-recognition (MSR) tests have been conducted with a variety of species with the aim of examining whether subject animals have the capacity for self-awareness. To date, the majority of animals that have convincingly passed are highly social mammals whose wild counterparts live in complex societies, though there is much debate concerning what constitutes passing and what passing means in terms of self-awareness. Amid recent reports that a fish (cleaner wrasse, Labroides dimidiatus ) passed, it is intriguing that a mammal as highly social, tolerant, attentive, and cooperative as the grey wolf ( Canis lupus ) reportedly failed the test. Given the many possible reasons for failure, we aimed to elucidate the wolves’ responses at various stages of the MSR test to pinpoint potential problem areas where species-appropriate modifications to the test may be needed. Thus, we evaluated 6 socialized, captive grey wolves as a case study of failed MSR in socially complex canids. At a minimum, wolves did not respond to their reflection as an unfamiliar conspecific. Unfortunately, the wolves rapidly lost interest in the mirror and were uninterested in the applied marks. We note limitations of the MSR test for this species, recommend changes for future MSR tests of wolves, discuss other emerging self-cognizance methods for socially complex canids, and highlight the need for a suite of ecologically relevant, potentially scalable self-cognizance methods. Our findings and recommendations may aid in understanding self-cognizance in other untested highly social, cooperatively-hunting, coursing, terrestrial carnivores such as African wild dogs ( Lycaon pictus ), spotted hyenas ( Crocuta crocuta ), and African lions ( Panthera leo ).

International Journal of Comparative Psychology↗
USGS2019

Comparison of beaver density estimates from aerial surveys of waterways versus transects

Historic beaver-sign (Castor canadensis) survey flights were often conducted over waterways to maximize beaver detections. However, densities determined from strip transect surveys are more useful to compare across and within study areas than waterway indices based on observations per distance flown because transects are more representative of the wider landscape. Yet, it is unknown if, and to what extent, aerial waterway surveys are reflective of transect densities. I conducted aerial surveys for active beaver sign each fall during 2015–2018 over two waterway routes and two corresponding strip-transect routes. The simple linear regression of transect densities on waterway densities (n=8) yielded a reasonable (R2=0.79) preliminary equation for converting historic waterway data to transect densities. Additionally, visual inspection indicated that converted waterway densities reasonably reflected the trend in transect densities in an area where the wider habitat was similar in terms of beaver harvest, land use, and proportion of water features. Although trend was well-reflected, individual waterway densities in this area were only 57-75% of transect densities. In other areas, where water features were limited, visual inspection suggested the trend of waterway densities was less reflective of transect density trend and individual waterway densities overestimated transect densities (up to 309%). Nevertheless, while transect densities are better for comparisons within and across study areas, waterway surveys are still important for timely and specific within-study area insights. This research provides useful benchmark examples of reliability regarding waterway observation indices converted to densities for conservation, research, and management of beaver and their ecosystems. Because these conclusions are based on a small sample, additional research is recommended to better define this relationship especially in areas with differing habitat, beaver harvest, land use patterns, etc.

Minnesota↗