Wildlife in a politically divided world: insularism inflates estimates of brown bear abundance

-Political borders dictate how biological diversity is monitored and managed, yet wild animals often move freely between jurisdictions. We quantified bias in brown bear (Ursus arctos) abundance estimates introduced when analytical methods ignore that the same individuals may be accounted for in more than one jurisdiction. A spatially explicit population model revealed that up to 49% of female bears detected in Norway via microsatellite analysis of scat and hair samples have their center of activity in neighboring countries (Finland, Russia, and Sweden). Not accounting for detections of “foreign residents” resulted in abundance estimates that were inflated by as much as 119%. Like man- agement and conservation, monitoring of transboundary wildlife populations should take place at ecologically relevant scales to avoid biased abundance es- timates and a false sense of control. When political realities isolate jurisdictions from their neighbors, spatially explicit analytical approaches can allow local or national programs a glimpse beyond their borders. Jurisdiction; large carnivore management; natural resource policy; noninvasive genetic monitoring; spatially explicit capture-recapture; transboundary wildlife

Saving large carnivores, but losing the apex predator?

AbstractLarge terrestrial carnivores, e.g. wolves or bears, often play a key ecological role from their position at the apex of trophic systems. Changes to their populations reverberate through ecological communities; consequently their widespread decline in numbers and shrinking distribution due to human persecution has brought about a loss and reconfiguration of biological diversity in many systems. Although many large carnivore populations are now under conservation-minded management, political and economic constraints make compromises necessary. A common compromise is to permit limited harvests, with the premise of sustainability and the objective to increase tolerance and funding for carnivore recovery and conservation. Here we question whether a large carnivore that has to “look over its shoulder” for human hunters can still fully perform its ecological role at the apex of a trophic system. We use information about carnivore behavior, ecology, trophic interactions, and the effects of human exploitation to argue that exploitation of large carnivores, even if sustainable numerically, undermines the commonly expressed rationale for their conservation, namely the restoration and preservation of ecosystem functionality. Our argument centers around (i) the necessity of behavioral adjustments in large carnivores to anthropomorphic risk, which may limit their contribution to the “landscape of fear”, and (ii) the observation that many of the same features that put large carnivores at the apex of trophic systems also make them vulnerable to human exploitation and persecution, with implicit consequences for their ecological functionality and evolution. Although hunting large carnivores can improve public acceptance, managers must be aware of the trade-offs

Population Genetic Structure of Nebraska Paddlefish Based on Mitochondrial DNA Variation

Eighty-three paddlefish Polyodon spathula that were collected from 1995 to 1999 from the Missouri River Galvins Point Dam tailwater were analyzed for genetic variation in the mitochondrial DNA d-loop region. Additional samples from Montana, South Dakota, and Louisiana were used for comparative purposes. To facilitate the efficient analysis of numerous paddlefish samples, we applied a method that employs polyacrylamide gel electrophoresis (PAGE) to resolve restriction fragment length polymorphisms (RFLPs) amplified by polymerase chain reaction (PCR). DNA sequencing of 10 paddlefish revealed 22 polymorphic sites. Polymerase chain reaction–RFLP analysis of 93 paddlefish using three restriction enzymes detected six of the polymorphic sites and revealed six distinct haplotypes. All of the observed haplotypes were found in the Missouri River Galvins Point Dam tailwater. No temporal differentiation was observed among the 1995, 1998, and 1999 samples from the Missouri River Galvins Point Dam tailwater. Polymerase chain reaction–RFLP, resolved with PAGE, provided an efficient method for population genetic analysis of paddlefish

Genetic Variation in the Midcontinental Population of Sandhill Cranes, \u3ci\u3eGrus Canadensis\u3c/i\u3e

Three subspecies of sandhill crane (Grus canadensis) are recognized in the Midcontinental population, the lesser (Grus c. canadensis), Canadian (G. c. rowani), and greater (G. c. tabida). Blood samples collected on the population’s primary spring staging area in Nebraska, U.S.A., were used to resolve the genetic relationship among these subspecies. Phylogenetic analysis of 27 G. canadensis, by DNA sequencing of a 675 bp region of the mtDNA, supports the subspecies designations of G. c. canadensis and G. c. tabida. G. c. rowani individuals were intermediate with each of the other two subspecies. Genetic divergence ranged from 6.5 to 14.5% between G. c. canadensis and G. c. tabida, 0.5 to 6.6% within G. c. canadensis, and 0.1 to 6.0% within G. c. tabida. Sufficient DNA for analysis was obtained from shed feathers indicating a source of genetic material that does not require the capture or sacrifice of the birds. Other genetic markers and methods, including satellite telemetry, are required for obtaining detailed information on crane distributions as needed to establish effective management units for the MCP

Wolverine density distribution reflects past persecution and current management in Scandinavia

publishedVersio

Smartphone app reveals that lynx avoid human recreationists on local scale, but not home range scale

Outdoor recreation is increasing and affects habitat use and selection by wildlife. These effects are challenging to study, especially for elusive species with large spatial requirements, as it is hard to obtain reliable proxies of recreational intensity over extensive areas. Commonly used proxies, such as the density of, or distance to, hiking paths, ignore outdoor recreation occurring on other linear feature types. Here we utilized crowdsourced data from the Strava training app to obtain a large-scale proxy for pedestrian outdoor recreation intensity in southeast Norway. We used the proxy and GPS-tracking data from collared Eurasian lynx (Lynx lynx) to investigate how recreation affects habitat selection at the home range scale and local scale by lynx during summer. We fitted resource selection functions at the two scales using conditional logistic regression. Our analysis revealed that lynx avoided areas of recreational activity at the local scale, but not at home range scale. Nonetheless, lynx frequently used areas associated with recreation, and to a greater degree at night than during the day. Our results suggest that local-scale avoidance of recreation and temporal adjustments of habitat use by lynx mitigate the need for a home range-scale response towards recreation. Scale-dependent responses and temporal adjustments in habitat use may facilitate coexistence between humans and large carnivores

Smartphone app reveals that lynx avoid human recreationists on local scale, but not home range scale

The global incrOutdoor recreation is increasing and afects habitat use and selection by wildlife. These efects are challenging to study, especially for elusive species with large spatial requirements, as it is hard to obtain reliable proxies of recreational intensity over extensive areas. Commonly used proxies, such as the density of, or distance to, hiking paths, ignore outdoor recreation occurring on other linear feature types. Here we utilized crowdsourced data from the Strava training app to obtain a large-scale proxy for pedestrian outdoor recreation intensity in southeast Norway. We used the proxy and GPS-tracking data from collared Eurasian lynx (Lynx lynx) to investigate how recreation afects habitat selection at the home range scale and local scale by lynx during summer. We ftted resource selection functions at the two scales using conditional logistic regression. Our analysis revealed that lynx avoided areas of recreational activity at the local scale, but not at home range scale. Nonetheless, lynx frequently used areas associated with recreation, and to a greater degree at night than during the day. Our results suggest that local-scale avoidance of recreation and temporal adjustments of habitat use by lynx mitigate the need for a home range-scale response towards recreation. Scale-dependent responses and temporal adjustments in habitat use may facilitate coexistence between humans and large carnivorespublishedVersio

A flexible and efficient Bayesian implementation of point process models for spatial capture‐recapture data

Spatial capture–recapture (SCR) is now routinely used for estimating abundance and density of wildlife populations. A standard SCR model includes sub-models for the distribution of individual activity centers (ACs) and for individual detections conditional on the locations of these ACs. Both sub-models can be expressed as point processes taking place in continuous space, but there is a lack of accessible and efficient tools to fit such models in a Bayesian paradigm. Here, we describe a set of custom functions and distributions to achieve this. Our work allows for more efficient model fitting with spatial covariates on population density, offers the option to fit SCR models using the semi-complete data likelihood (SCDL) approach instead of data augmentation, and better reflects the spatially continuous detection process in SCR studies that use area searches. In addition, the SCDL approach is more efficient than data augmentation for simple SCR models while losing its advantages for more complicated models that account for spatial variation in either population density or detection. We present the model formulation, test it with simulations, quantify computational efficiency gains, and conclude with a real-life example using non-invasive genetic sampling data for an elusive large carnivore, the wolverine (Gulo gulo) in Norway. area search, binomial point process, continuous sampling, NIMBLE, non-invasive genetic sampling, Poisson point process, spatial capture–recapture, wolverinepublishedVersio

Estimating red fox density using non-invasive genetic sampling and spatial capture–recapture modelling

Spatial capture–recapture modelling (SCR) is a powerful tool for estimating density, population size, and space use of elusive animals. Here, we applied SCR modelling to non-invasive genetic sampling (NGS) data to estimate red fox (Vulpes vulpes) densities in two areas of boreal forest in central (2016–2018) and southern Norway (2017–2018). Estimated densities were overall lower in the central study area (mean=0.04 foxes per km2 in 2016, 0.10 in 2017, and 0.06 in 2018) compared to the southern study area (0.16 in 2017 and 0.09 in 2018). We found a positive efect of forest cover on density in the central, but not the southern study area. The absence of an efect in the southern area may refect a paucity of evidence caused by low variation in forest cover. Estimated mean home-range size in the central study area was 45 km2 [95%CI 34–60] for females and 88 km2 [69–113] for males. Mean home-range sizes were smaller in the southern study area (26 km2 [16–42] for females and 56 km2 [35–91] for males). In both study areas, detection probability was session-dependent and afected by sampling efort. This study highlights how SCR modelling in combination with NGS can be used to efciently monitor red fox populations, and simultaneously incorporate ecological factors and estimate their efects on population density and space use. Red fox · Density · Spatial capture–recapture · Non-invasive genetic samplingpublishedVersio