scholarly journals Occupancy of Semi-Aquatic Mammals in an Urban Landscape

2021 ◽  
Author(s):  
Devin Hoffer ◽  
Clayton Nielsen ◽  
Andrew Rutter ◽  
Stefano Anile
Keyword(s):  
Forest Cover ◽  
Castor Canadensis ◽  
Single Species ◽  
Lontra Canadensis ◽  
River Otter ◽  
Occupancy Models ◽  
Lake County ◽  
River Otters ◽  
Restoration Practices ◽  
Aquatic Mammals

Abstract Throughout midwestern North American ecosystems, semi-aquatic mammals including beaver (Castor canadensis), mink (Neovision vision), muskrat (Ondatra zibethicus), and river otter (Lontra canadensis) co-exist in wetlands. These species are ecologically important through their manipulation of habitats and interactions with other species present. Although natural resource managers in urban ecosystems are interested in semi-aquatic mammals and factors affecting their ecology, few such studies exist in the literature. We studied impacts of restoration practices and other environmental covariates on detection and occupancy of the 4 aforementioned focal species on forest preserves managed by the Lake County Forest Preserve District (Lake County, Illinois, USA). Sign surveys were conducted during December-April in 2018-19 and 2019-20. We quantified 12 variables representing bank measurements, temperature, precipitation, soil type, and survey replicate to inform the detection process and quantified 12 variables representing forest cover measurements, aquatic plant measurements, dominant landcover, restoration practices, and anthropogenic disturbances for the occupancy process. Single species, multi-season occupancy models were run in RStudio using the package unmarked. Detection probabilities ranged from 0.10 ± 0.07 for river otters to 0.60 ± 0.03 for muskrats; occupancy probabilities ranged from 0.28 ± 0.18 for river otters to 0.90 ± 0.05 for muskrats. Detection and occupancy were influenced by similar environmental factors (bank measurements, precipitation, and survey replicate for detection; and stream measurements and food availability for occupancy) compared to more rural locations. We provide further evidence that muskrats are urban adapters and document the initial stages of river otter recolonization in the Chicago Metropolitan Area.

Unequal summer use of beaver ponds by river otters: influence of beaver activity, pond size, and vegetation cover

2007 ◽  
Vol 85 (7) ◽  
pp. 774-782 ◽  
Author(s):  
F.A. LeBlanc ◽  
D. Gallant ◽  
L. Vasseur ◽  
L. Léger
Keyword(s):  
Vegetation Cover ◽  
Castor Canadensis ◽  
Freshwater Ecosystems ◽  
Lontra Canadensis ◽  
Beaver Ponds ◽  
River Otters ◽  
Pond Size ◽  
Source Sink ◽  
The Relationship ◽  
Aquatic Mammals

River otters ( Lontra canadensis (Schreber, 1777)) and beavers ( Castor canadensis Kuhl, 1820) are semi-aquatic mammals that can occur sympatrically in freshwater ecosystems of North America, including beaver ponds. Although little research has been done on the relationship between these species, it has been described as commensal. Relatively little is known about what pond characteristics potentially influence otter use. During the summer of 2004, we documented otter activity signs (i.e., feces) at 56 beaver ponds located in Kouchibouguac National Park of Canada, along the east coast of New Brunswick. We sought to identify which of 16 variables describing pond attributes were related to otter use. Otter activity at beaver ponds was positively associated with beaver presence, pond size, and vegetation cover. We discuss how these pond characteristics can benefit otters in terms of two key habitat needs, availability of prey and shelter. Our results are a first indication that the source–sink dynamic of beavers, whereby ponds are created, expanded, and abandoned, will create a mosaic of ponds that ultimately influences the river otter’s own pattern of habitat use and distribution.

scholarly journals A River Otter's, Lontra canadensis, Capture of a Double-crested Cormorant, Phalacrocorax auritus, in British Columbia's Gulf Island Waters

2007 ◽  
Vol 121 (3) ◽  
pp. 325
Author(s):  
Michael H. H. Price ◽  
Clare E. Aries
Keyword(s):  
Lontra Canadensis ◽  
Phalacrocorax Auritus ◽  
River Otter ◽  
Freshwater Lakes ◽  
Marine Bird ◽  
River Otters

Direct and apparent predation events by River Otters (Lontra canadensis) on birds have been recorded on marine islands and freshwater lakes. We add to this the first known observation of a River Otter capturing a marine bird on the ocean.

scholarly journals River Otter Distribution and Food Habits in Grand Teton National Park as Part of an Ongoing Project in the GYE

2015 ◽  
Vol 38 ◽  
pp. 75-78
Author(s):  
Kelly Pearce ◽  
Tom Serfass
Keyword(s):  
National Park ◽  
Activity Patterns ◽  
Public Support ◽  
Primary Objective ◽  
Camera Traps ◽  
Lontra Canadensis ◽  
Flagship Species ◽  
River Otter ◽  
Grand Teton National Park ◽  
River Otters

Grand Teton National Park is part of the known range of the North American river otter, however not much is known about this semi-aquatic mammal within the park. The results presented here are part of a larger project to investigate the potential of the river otter (Lontra canadensis) to serve as an aquatic flagship (species that engender public support and action) for the Greater Yellowstone Ecosystem. River otters, known for their charismatic behavior have the potential to serve as an aquatic flagship species to promote conservation of aquatic ecosystems. The primary objective of this portion of the study was to identify river otter latrines on portions of the Snake River, between Flagg Ranch and Jackson Lake, and between Jackson Lake Dam and Pacific Creek, collect river otter scats to determine diet of the river otter, and employ remote cameras to determine activity patterns of the river otters. Between 20 June and 1 July 2015, 26 river otter latrines were identified during shoreline surveys, 186 river otter scats were collected, and cameras were deployed at 6 latrines between 7 July and 24 August 2015. River otter scats have been cleaned and prepared for analysis, but have not all been processed to date. Camera traps recorded 222 images, of which 7% (n = 14) were of carnivores, 70% (n = 155) were of non-carnivore mammals, and 9% (n = 22) were of birds. River otters were detected at 1 of the 6 latrines, a total of 5 independent times during the study.

scholarly journals Welfare Performance of Three Foothold Traps for Capturing North American River Otters Lontra canadensis

2021 ◽  
Author(s):  
Matthew J. Lovallo ◽  
H. Bryant White ◽  
John D. Erb ◽  
Matthew S. Peek ◽  
Thomas J. Deliberto
Keyword(s):  
Animal Welfare ◽  
Best Management Practices ◽  
Management Practices ◽  
Scientific Basis ◽  
International Standards ◽  
Lontra Canadensis ◽  
River Otter ◽  
River Otters ◽  
Best Management ◽  
International Standards Organization

Abstract Foothold traps are effective tools for the live capture and restraint of wildlife for management and research. Successful river otter Lontra canadensis restoration programs throughout North America used them extensively. Restoration programs used a variety of methods and models of foothold traps, but comprehensive efforts to describe and quantify injuries associated with river otter captures have been limited. We evaluated injuries of river otters caught in three commercially available models of foothold traps including the number 11 double long-spring with standard jaws, the number 11 double long-spring with double jaws, and the number 2 coil-spring trap. Based on examinations of 70 captured river otters, we classified 78% of the total inj uries detected as “mild” (n = 174 injuries) and 17% were classified as “moderate” (n = 37 injuries). We classified less than 3% of the injuries observed as “moderately severe” or “severe.” We focused only on the animal welfare performance of traps; the three trap types we tested met the animal welfare criteria required for inclusion in the best management practices for trapping river otter. The criteria based on International Standards Organization guidelines used in this assessment of trap performance provides a scientific basis for future evaluations of river otter welfare when foothold traps are used for restoration, research, and population management.

scholarly journals Functionality of a New Live-Capture Device for River Otters

2019 ◽  
Vol 11 (1) ◽  
pp. 238-244
Author(s):  
Andrew U. Rutter ◽  
Alex T. Hanrahan ◽  
Clayton K. Nielsen ◽  
Eric M. Schauber
Keyword(s):  
Water Levels ◽  
Capture Efficiency ◽  
Lontra Canadensis ◽  
River Otter ◽  
Traumatic Injuries ◽  
Weather Patterns ◽  
River Otters ◽  
American River ◽  
Capture Techniques ◽  
Capture Technique

Abstract Assessments of novel capture techniques are important to wildlife research. We used Comstock traps, a new live-capture technique, to capture North American river otters Lontra canadensis. We measured Comstock trap functionality in terms of river otter capture efficiency, furbearer capture efficiency, nonfurbearer capture efficiency, and malfunction rate. During 2014–2016, we captured 36 river otters (19 male, 17 female) in Comstock traps during 2,533 trap nights (1 capture/63 trap nights) at Crab Orchard National Wildlife Refuge in southern Illinois, USA. Eleven of 20 (55%) river otters assessed for capture-related injuries received an injury as a result of capture in a Comstock trap. The most common injury was claw loss (45%), followed by tooth fracture (25%) and lacerations (10%). The ease of setting Comstock traps and of releasing nontarget captures made them an appealing option for river otter live capture; however, two river otters died because of hypothermia, two died because of drowning, and one died because of traumatic injuries sustained during capture. Special care should be taken when selecting locations to set Comstock traps with regard to temperature and fluctuating water levels. Researchers attempting to live-capture river otters using this method would benefit by restricting their use to locations with predictable water levels and seasons with mild weather patterns.

Relative abundance of coyotes influences gray fox occupancy across the eastern United States

2020 ◽  
Author(s):  
Michael Egan ◽  
Casey Day ◽  
Todd E Katzner ◽  
Patrick A. Zollner
Keyword(s):  
United States ◽  
Large Scale ◽  
Forest Cover ◽  
Interspecific Interactions ◽  
Single Species ◽  
Camera Trap ◽  
Eastern United States ◽  
Occupancy Models ◽  
Urocyon Cinereoargenteus ◽  
Gray Fox

Gray fox (Urocyon cinereoargenteus Schreber, 1775) populations in portions of the eastern United States have experienced declines whose trajectories differ from those of other mesocarnivore populations. One hypothesis is that gray fox declines may result from interspecific interactions, particularly competition with abundant coyotes (Canis latrans Say, 1823). Alternatively, gray foxes may respond negatively to increased urbanization and reduced forest cover. To evaluate these hypotheses, we used single-species occupancy models of camera trap data to test the effects of habitat covariates, such as the amount of urbanization and forest, on coyote and gray fox occupancy. Additionally, we test the effect of an n-mixture based index of the number of coyotes at each camera trap site on gray fox occupancy. Results indicate that occupancy probabilities of coyote and gray fox relate positively to the amount of forest, but they provided no evidence urban cover impacts gray foxes. Additionally, gray fox occupancy was negatively related to the index of the number of coyotes at each site. Our models support the idea that interactions with coyotes impact gray fox occupancy across the eastern U.S. These results illustrate how large scale studies can relate mechanisms identified within specific landscapes to phenomena observed at larger scales.

scholarly journals Assessing the Potential of the River Otter to Promote Aquatic Conservation in the Greater Yellowstone Ecosystem: A Unique Approach for Developing a Long-Term Aquatic Flagship

2014 ◽  
Vol 37 ◽  
pp. 108-113
Author(s):  
Kelly Pearce ◽  
Tom Serfass
Keyword(s):  
National Park ◽  
Public Awareness ◽  
Lontra Canadensis ◽  
Snake River ◽  
Greater Yellowstone Ecosystem ◽  
River Otter ◽  
The Public ◽  
River Otters ◽  
Trout Lake ◽  
Greater Yellowstone

Charismatic “flagship” species are used in many parts of the world to raise public awareness or financial support for conservation, both among local people living in the area and among potential donors living far away. Flagship species can serve as symbols to stimulate conservation awareness and action and have been particularly valuable because of their potential to change citizen behavior, including involvement in conservation and support of fundraising. For a flagship to be successful, however, the target audience and conservation objectives must be established and understood before implementing the concept. Researchers have suggested that a successful flagship should possess traits that endear it to the public, should not be feared or disliked, nor have been used to convey conflicting messages of conservation. Therefore, critical to the flagship approach is understanding attitudes, species preferences, level of wildlife knowledge of people living near and living far away for which support is sought. To determine if the river otter (Lontra canadensis) could be a successful flagship for the Greater Yellowstone Ecosystem (GYE), we conducted social science surveys with visitors to Grand Teton National Park who participated in guided-raft trips on the Snake River (n = 768), visitors of Oxbow Bend (n = 254), a popular turn-out for viewing aquatic wildlife, and visitors to Trout Lake in Yellowstone National Park (n = 298). Preliminary results showed that familiarity with the river otters is area dependent (e.g., Trout Lake visitors were more familiar with the species than those visiting Oxbow Bend or rafting the Snake River), river otters are not controversial, but education is needed to better inform the public about river otters’ occurrence and ecosystem function in GYE.

Intraocular muscles of the Canadian river otter and Canadian beaver and their optical function

1989 ◽  
Vol 67 (2) ◽  
pp. 469-474 ◽  
Author(s):  
K. A. Ballard ◽  
J. G. Sivak ◽  
H. C. Howland
Keyword(s):  
Ciliary Body ◽  
Castor Canadensis ◽  
Optical Function ◽  
River Otter ◽  
Microscopic Anatomy ◽  
River Otters ◽  
Refractive Power ◽  
Lutra Canadensis ◽  
Corneal Refractive Power

The gross morphology and microscopic anatomy of the ciliary and iris musculature of the Canadian river otter (Lutra canadensis) and Canadian beaver (Castor canadensis) were studied to help evaluate whether either species has an exaggerated accommodative mechanism for use underwater. The intraocular muscles of the otter are of a size and organization indicative of an extreme lens-deforming accommodative ability involving both the ciliary body and iris. By contrast, the intraocular muscles of the beaver eye indicate that accommodation is not significant in this animal. Thus, the intraocular musculature of the class Mammalia is not homogeneous, even within the amphibious mammals. Refractive and corneal measurements on two living river otters confirm that this animal is capable of an accommodative range that can neutralize the loss of corneal refractive power when the eye is in water.

scholarly journals River Otter Status, Management, and Distribution in the United States: Evidence of Large-Scale Population Increase and Range Expansion

2020 ◽  
Vol 11 (1) ◽  
pp. 279-286 ◽  
Author(s):  
Nathan M. Roberts ◽  
Matthew J. Lovallo ◽  
Shawn M. Crimmins
Keyword(s):  
United States ◽  
Geographic Distribution ◽  
Large Scale ◽  
The United States ◽  
Lontra Canadensis ◽  
Population Increase ◽  
River Otter ◽  
River Otters ◽  
Scale Population ◽  
Management Approaches

Abstract River otter Lontra canadensis populations in the United States have expanded during the past 50 y as a result of improvements in habitat quality and effective management programs implemented by state and federal agencies and native tribes. Periodic assessments of river otter status, population trends, and geographic distribution are needed to detect changes in populations, assess management approaches, and to identify and prioritize conservation efforts. We surveyed state wildlife agency experts to assess the current population and regulatory status of river otters in their jurisdictions. River otters were legally harvested in 40 states as of 2016. Twenty-two states reported increasing populations while 25 reported stable populations. Most states used multiple methods to monitor river otter populations including harvest-based surveys, presence–absence surveys, and empirically derived population model predictions; harvest-based surveys were the most commonly used monitoring approach. As populations have expanded, river otter reintroduction efforts have become less frequent; two additional states had conducted reintroductions since 1998 and only one state had conducted a reintroduction since 2010. We estimated that river otter distribution increased by 10.2% in the continental United States and by 13.7% in the contiguous United States during an 18-y period. Although populations may continue to increase numerically, river otters may be approaching their potential maximum geographic distribution in the United States.

scholarly journals Camera Trapping to Assess Status and Composition of Mammal Communities in a Biodiversity Hotspot in Myanmar

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 880
Author(s):  
Giacomo Cremonesi ◽  
Francesco Bisi ◽  
Lorenzo Gaffi ◽  
Thet Zaw ◽  
Hla Naing ◽  
...  
Keyword(s):  
Human Disturbance ◽  
Habitat Degradation ◽  
Single Species ◽  
Wildlife Trade ◽  
Ecosystem Functions ◽  
Occupancy Models ◽  
Apex Predators ◽  
Disturbed Area ◽  
The Status ◽  
Mammal Communities

Tropical forests comprise a critically impacted habitat, and it is known that altered forests host a lower diversity of mammal communities. In this study, we investigated the mammal communities of two areas in Myanmar with similar environmental conditions but with great differences in habitat degradation and human disturbance. The main goal was to understand the status and composition of these communities in an understudied area like Myanmar at a broad scale. Using camera trap data from a three-year-long campaign and hierarchical occupancy models with a Bayesian formulation, we evaluated the biodiversity level (species richness) and different ecosystem functions (diet and body mass), as well as the occupancy values of single species as a proxy for population density. We found a lower mammal diversity in the disturbed area, with a significantly lower number of carnivores and herbivores species. Interestingly, the area did not show alteration in its functional composition. Almost all the specific roles in the community were present except for apex predators, thus suggesting that the effects of human disturbance are mainly effecting the communities highest levels. Furthermore, two species showed significantly lower occupancies in the disturbed area during all the monitoring campaigns: one with a strong pressure for bushmeat consumption and a vulnerable carnivore threatened by illegal wildlife trade.

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