191 research outputs found
Camera traps at northern river otter latrines enhance carnivore detectability along riparian areas in eastern North America
AbstractWe evaluated the efficacy of placing camera traps at river otter (Lontra canadensis) latrines (discrete sites in riparian areas where otters regularly deposit scats, urine, and anal secretions) to detect other carnivores occupying Great Swamp National Wildlife Refuge, New Jersey, USA. We postulated that scents at latrines may serve as an attractant to other carnivores and evaluated this premise by using camera traps to compare carnivore detection rates (overall and by species) and richness (overall and for each survey month) between latrine (n=5) and non-latrine riparian areas (n=5). On average carnivore richness was about 1.7 times higher than that of a non-latrine, and mean richness was higher at latrines for all survey months. Likewise, the overall carnivore detection frequency was 3.5 times greater at latrines, and the detection frequencies for red foxes (Vulpes vulpes), northern raccoons (Procyon lotor), river otters, mink (Neovison vison), long-tailed weasels (Mustela frenata), and Virginia opossums (Didelphis virginiana) were greater at latrines. American black bears (Ursus americanus) and eastern coyotes (Canis latrans) where detected more frequently at non-latrines. Our study provides evidence that placement of camera traps at otter latrines may serve as a new and novel approach for monitoring carnivore populations in riparian areas
Do Juvenile Nearctic River Otters (Lontra canadensis) Contribute to Fall Scent Marking?
We present photographic evidence in support of the hypothesis that juvenile Nearctic River Otters (Lontra canadensis) contribute to the observed fall peak in scent marking
Long-term Survival and Reproduction in a North American River Otter (Lontra canadensis) with an Intraperitoneal Radio-Transmitter
Intraperitoneal implantation of radio-transmitters is a useful method of monitoring free-ranging aquatic and semi-aquatic mammals; however, some researchers are concerned about the physiological effects of such implants. Few studies have investigated the long-term consequences of intraperitoneal implants on survival or reproductive performance. An adult female North American River Otter (Lontra canadensis) surgically equipped with an intraperitoneal radio-transmitter and released in northwestern Pennsylvania in June 1990 as part of a reintroduction project was killed in March 1999. The North American River Otter was estimated to be 10 years old and was pregnant with two fetuses at the time of her death. Our observation suggests that wild North American River Otters surgically equipped with intraperitoneal radio-transmitters can live long after implantation of the radio-transmitter and continue to reproduce successfully
Genetic Variation Among Populations of River Otters in North America: Considerations For Reintroducing Projects
Horizontal starch gel electrophoresis was used to assess variability at 23 presumptive gene loci of 732 river otters obtained from fur-trappers in 18 states and three Canadian provinces. States and provinces providing otters were sorted into eight geographic regions for genetic comparisons. Multilocus heterozygosity and polymorphism ranged from 0.018 to 0.032 and 0.044 to 0.087, respectively. One locus, esterase-2, (EST-2) demonstrated a high level of polymorphism throughout all regions. Malate dehydrogenase-1 (MDH-1) was polymorphic throughout the Mississippi drainage but not elsewhere. Heterozygosity, occurrence of rare alleles, and mean number of alleles per locus were associated positively with estimated population sizes. Average heterozygosity and polymorphism values for otters within regions were lower than overall averages reported for mammals but similar to the range of those observed in other mammalian carnivores. Patterns of gene flow suggested by the distribution of polymorphism at the MDH-1 locus do not concur with the current taxonomic classification of river otters. Levels of genetic variation detected in this investigation present a positive outlook for the maintenance of genetic diversity in river otter populations, if sound management principles are applied for reintroductions
Both Reintroduction and Recolonization Likely Contributed to the Re-establishment of a Fisher Population in East-central Alberta
Recently, Stewart et al. (2017) investigated the origins of contemporary fisher populations in the Cooking Lake Moraine (CLM) of east-central Alberta, Canada, where fishers (Pekania pennanti) from Ontario and Manitoba, Canada were reintroduced in the early 1990s. To address this objective, Stewart et al. (2017) compared microsatellite alleles from extant fisher populations in the CLM to those from Ontario, Manitoba, and other Alberta populations. They reported that the CLM population clustered with adjacent native Alberta populations, consistent with recolonization, but also that 2 of 109 microsatellite alleles in the CLM occurred only in the source populations from Ontario and Manitoba. Rather than allowing for the possibility that these alleles descended from reintroduced fishers, the authors speculated that they represented random mutations among fishers that recolonized the area naturally from nearby populations in Alberta, and concluded that the reintroduction had failed completely. We disagree with this conclusion for 2 reasons. We contend it is more likely that the 2 alleles represent a genetic signature from the individuals released during the reintroduction, rather than being the result of mutations. We further suggest that, irrespective of the genetic legacy of introduced fishers in the recovered population, the presence of reintroduced fishers in the CLM may have helped facilitate natural recolonization of the area by fishers from surrounding areas. In our view, Stewart et al.âs (2017) findings do not demonstrate conclusively that the reintroduction program failed; on the contrary, we argue that their findings indicate that reintroduced fishers likely contributed to the long-term persistence of fishers in the CLM. The uncertainty surrounding this case underscores the importance of genetic monitoring following reintroductions.https://digitalcommons.snc.edu/faculty_staff_works/1032/thumbnail.jp
Evidence of American Martens Populating the Turtle Mountains of North Dakota
American martens (Martes americana) were native to northeastern North Dakota but were considered extirpated by the early 1800s. Although there is no historic evidence of martens occurring beyond the northeast, forested habitat potentially suitable for martens exists in the Turtle Mountains region of northcentral North Dakota and southwestern Manitoba. From 1989â 1991, the Turtle Mountain Trappers Association translocated 59 martens into the Canadian portion of the Turtle Mountains. During summer 2007, we used covered track-plates and/or remotely-triggered cameras placed at 123 survey sites distributed among 41 1-km2 grid cells (a GIS-generated layer imposed on electronic maps of the study region) to determine if martens occupied the Turtle Mountains in North Dakota. Martens were detected at 26 (21%) sites, representing 20 of the 41 sample cells (49%) widely dispersed throughout the study area. Our study provided the first evidence of martens occurring in North Dakota since the early 1800s
International mammal trapping standards ̶ Part II: Killing Trap Systems
In this paper, we propose standards for killing trap systems based on Proulx et al.âs
(2022) prerequisites, which provide context and explanations for our approach. Our aim is to
identify assessment protocols that are based on the scientific method, and that include evaluation
parameters and threshold levels of acceptation, and laboratory and field procedures, to recognize
mammal trapping systems that are acceptable from an animal welfare, and capture efficiency and
selectivity, point of view. The testing of killing trap systems consists of 4 steps: 1) Mechanical
evaluation; 2) Approach tests in semi-natural environments; 3) Kill tests in semi-natural
environments; and 4) Kill tests on traplines. Based on the normal approximation to the binomial
distribution, acceptable killing trap systems are expected, at a 95% confidence level, to render
â„85% of the animals irreversibly unconscious in †90 sec for most mammal species, and â€30 sec
for small mammals (mouse, vole, etc.). We recommend that standards be continuously updated
based on the development of new designs and technology
International mammal trapping standards ̶ Part I: Prerequisites
In this paper, we set out the prerequisites for the development of killing and
restraining trap systems to capture mammals for research, wildlife management and conservation,
fur trapping, animal control, and any other activity involving the trapping of a mammal in a
mechanical trapping device. We selected them with the main intent of developing new trapping
standards that will improve animal welfare as per our current state of knowledge, and with realistic,
achievable objectives based on state-of-the-art trapping technology. The proposed new standards
should be applicable to all terrestrial and semi-aquatic mammal species. They should be based on
animal testing in semi-natural environments and on traplines, with high trap thresholds of
acceptance, low times to irreversible unconsciousness for killing trap systems, an understanding of
the impacts of trapping on physical form, behaviour and physiological function, adequate trap
checking times and handling of the captured animals, and high capture selectivity. Furthermore,
the implementation of improved trapping standards would include the mandatory publication of
findings for peer-review and public education. We believe that the prerequisites that we lay out for
the development of new mammal trapping standards will address many of the welfare concerns
voiced by the scientific community and the public in the last two decades. It will lead to improved
animal welfare and spur continuous improvement in the efficacy and innovation in trapping
technology
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at âs=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qqÌ
continuum events near the ΄(4S) resonance are presented. Using 20.8 fb-1 of data on the ΄(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(BâDs+X)=(10.93±0.19±0.58±2.73)% and B(BâDs*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+âÏÏ+ branching fraction uncertainty. The production cross sections Ï(e+e-âDs+X)ĂB(Ds+âÏÏ+)=7.55±0.20±0.34pb and Ï(e+e-âDs*±X)ĂB(Ds+âÏÏ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the ΄(4S) mass. The branching fractions ÎŁB(BâDs(*)+D(*))=(5.07±0.14±0.30±1.27)% and ÎŁB(BâDs*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
- âŠ