Source: UNIVERSITY OF KENTUCKY submitted to NRP
DISTRIBUTION AND ECOLOGY OF THE NORTH AMERICAN RIVER OTTER (LONTRA CANADENSIS) IN KENTUCKY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
MCINTIRE-STENNIS
Reporting Frequency
Annual
Accession No.
0216578
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Nov 1, 2008
Project End Date
Sep 30, 2013
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF KENTUCKY
500 S LIMESTONE 109 KINKEAD HALL
LEXINGTON,KY 40526-0001
Performing Department
Forestry
Non Technical Summary
The North American river otter (Lontra canadensis) was historically distributed throughout most major drainages in the continental United States and Canada, from the arctic in Alaska south to Texas and as far east as Florida. The largest populations of river otters in the United States existed in areas with abundant aquatic habitat including coastal marshes, the Great Lakes region, and glaciated areas of New England. Excessive trapping and a lack of proactive population management have resulted in population declines and local eradication of otters in many areas across their almost, continent-wide distribution. In Kentucky, river otters were distributed widely until populations declined during the early 1900s due to unregulated harvest and human destruction of forested-riparian habitat. By the 1950s, the distribution of river otter populations in Kentucky was limited to the Jackson Purchase physiographic region in far western portions of the state. The Tennessee Valley Authority and the Kentucky Department of Fish and Wildlife Resources (KDFWR) conducted an experimental restocking of river otters in the Land-Between-the-Lakes (LBL) area of western Kentucky in 1982 and 1983. Results demonstrated that river otters could naturally repopulate and expand their range in the Jackson Purchase physiographic region. Encouraged by the successful release of river otters at LBL, KDFWR began a program to restore self-sustaining populations of river otters throughout suitable habitat in Kentucky. During 1991-1994, 355 river otters were released among 14 sites in central and eastern Kentucky. Sightings and reports of nuisance river otters have subsequently increased in areas where otters were reintroduced, and the remnant population in the western portion of the state appears to have become widespread. The increased frequency of otter sightings, incidental trappings, roadkills, and complaints about nuisance river otters by landowners throughout Kentucky suggests that the statewide otter population is growing, and experimental harvests, conducted in 2004 (west Kentucky only),and again in 2006 and 2007 (statewide), have met with considerable capture success. Thus, there is an immediate need to determine the distribution and abundance of river otters throughout all watersheds in Kentucky, along with an analysis of the growth potential of populations across differing habitats and regions of the state. This project will employ presence/absence surveys along watersheds to determine the extent to which otters are distributed across the state, develop habitat models of preferred otter habitat based on associated presence/absence data, and use necropsies of otter carcasses to assess reproductive potential of otters and to use this information to develop predictive models of population growth of river otters in Kentucky. The overall goal of this project is to assist KDFWR in determining whether a carefully regulated harvest of river otters is an appropriate management strategy for this furbearing species in the state.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1350330107020%
1350840107030%
3010330107020%
3010840107030%
Knowledge Area
135 - Aquatic and Terrestrial Wildlife; 301 - Reproductive Performance of Animals;

Subject Of Investigation
0840 - Fur-bearing animals; 0330 - Wetland and riparian systems;

Field Of Science
1070 - Ecology;
Goals / Objectives
This project will: determine the distribution and relative abundance of the river otter in Kentucky through surveys of otter sign along forested-riparian corridors; determine population demographics, particularly reproductive characteristics, of the river otter in Kentucky based on analysis of carcasses provided by trappers; evaluate dietary patterns of the river otter in Kentucky using stomach contents extracted from carcasses provided by trappers and fecal samples collected during otter surveys; develop predictive habitat models (presence/absence) for the river otter in Kentucky using multiple logistic regression, AIC techniques, and habitat data collected during field surveys; and apply population growth models developed for the river otter in Missouri to data from Kentucky to determine growth projections and identify harvest rates suited to restored populations of the river otter in Kentucky. Data collection has been in process for two years, with survey data, carcasses of river otters, and stomach and fecal samples obtained during 2006 and 2007. The remaining timetable is as follows. Year 1: complete the third year of survey sampling and collection of river otter carcasses, stomachs, and fecal samples. Habitat characteristics of survey sampling sites will be measured. Complete necropsies of river otter carcasses. Year 2: analyze survey data, and information from otter carcasses for use in developing population-growth models. Develop a statewide map of otter distribution and abundance by watershed basins. Process stomachs removed from otter carcasses and fecal samples collected during survey sampling and determine dietary patterns of river otters in Kentucky. Year 3: develop logistic regressions of river otter habitat use. Test population-growth models using data from river otter necropsies. Year 4: derive an appropriate population-growth model for river otters in Kentucky and submit manuscripts.
Project Methods
The distribution and relative abundance of river otters will be determined using two field sampling techniques for otter sign: shoreline segment surveys and bridge-crossing surveys. Using U.S. Geologic Survey delineated watersheds, the state of Kentucky will be partitioned into 8 sub-regions and 11 basins and a stratified random sampling scheme used for shoreline segment sampling with sampling intensity allocated proportional to the relative percentage of the state that each basin comprises. Field sampling protocols will include walking 1-2 km stream and shoreline segments for river otter sign or observations. Bridge-crossing sampling will also be conducted among major watersheds throughout the state. Bridge-crossing protocols will include walking 100-300 m upstream and downstream sections of shore for otter sign. Population demographics and reproductive characteristics will be determined by analysis of carcasses provided by the Kentucky Department of Fish and Wildlife Resources. Reproductive tracts will be removed from female carcasses and examined for the presence of embryos, corpora lutea, and blastocysts, depending on season of mortality. Uterine horns will be inspected and flushed to look for embryos and blastocysts. Ovaries will be removed and 1 mm sections will be examined under a dissecting microscope for the presence of corpora lutea. To determine age-specific fecundity, a lower canine tooth will be removed from each carcass and analyzed using cementum annuli examination. Contents of stomachs from carcasses will be analyzed. Fish scales will be identified to genus where possible using lateral line scales. Presence of other prey items will be recorded from both stomachs and scat samples. The percent frequency of occurrence and percent volume will be determined for each prey item by sex and age class of otters. Predictive models for habitat of river otters will be constructed using logistic regressions based on riparian and landscape measurements and otter presence/absence data from field surveys. Because of widely varying riparian habitats and topographic conditions, analyses will be made separately on data from the eastern, central, and western portions of the state using state ecoregions. A population model for otters in Kentucky will be constructed using Missouri otter population models as a template. The Kentucky model will be based on reproductive measurements taken from carcasses of river otters, and will include pregnancy rates, average litter sizes, mortality rates calculated from statewide harvest databases, and information gathered from trapper surveys and diaries such as capture per unit effort.

Progress 11/01/08 to 09/30/13

Outputs
Target Audience: The primary target audience was the Kentucky Department of Fish and Wildlife Resources (KDFWR). The KDFWR contributed external funding for the project and the final results were provided to them in the form of a Doctoral Dissertation, final report to the sponsor, and scientific publications. Information on the project findings also was disseminated tothe general public by KDFWR staff, as the results had significant implications for existing harvest regulations for river otters in Kentucky. Changes/Problems: The only change made was a 1-yearextension of the project deadline to permit population growth models to be revised and improved,to allow data analyses to be completed, and to provide time for development and submission offinal manuscripts for publication. What opportunities for training and professional development has the project provided? The principal investigator, a post-doctoral scholar, and graduate students were supported by the project for travel to multiple state, regional, national, and international scientific meetings and conferences. A total of 33 presentationswere delivered at meetings during the period covered by the project. How have the results been disseminated to communities of interest? Results have been provided to the scientific community via several refereed publications. Information was provided to the primary funding sponsor (KDFWR) through a final report and a doctoral dissertation. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The project achieved success withthe objectives and goals as specified in the proposal.Among the accomplishments include: a review of the historical staus of river otters in Kentucky, a detailed description of the winter diet of river otters in Kentucky, an assessment of parasite infestation of river otters in Kentucky, a detailed description of reproductive and demographic characteristics of river otter populations in Kentucky, and development of robust population growth models for river otters in Kentucky. Key findings include (1) limited impact on sport fish populations from river otters as evidenced in diet analyses, (2) a successful statewide recolonization of river otters, as evidenced byottersreoccupyingall major river drainages in the state, and (3) demographic and reproductive characteristics of river otters in the state that result in population growth models which project continued future growth, supporting statewide harvesting of river otters across Kentucky, with harvesting limits recommended for the eastern counties where river otter abundance remains low.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Lacki, M.J., J.S. Johnson, and M.D. Baker. 2013. Temperatures beneath bark of dead trees used as roosts by Myotis volans in forests of the Pacific Northwest, USA. Acta Chiropterologica 15:143-151. (in press).
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Johnson, J.S., and M.J. Lacki. 2013. Habitat associations of Rafinesques big-eared bats (Corynorhinus rafinesquii) and their lepidopteran prey in bottomland hardwood forests. Canadian Journal of Zoology 91: 94-101.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Johnson, J.S., J.N. Kropczynski, and M.J. Lacki. 2013. Social network analysis and the study of sociality in bats. Acta Chiropterologica 15: 1-17.
  • Type: Journal Articles Status: Accepted Year Published: 2013 Citation: Johnson, J.S., and M.J. Lacki. 2013. Effects of reproductive condition, roost microclimate, and weather patterns on summer torpor use by a vespertilionid bat. Ecology and Evolution doi:10.1002/ece3.913.
  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Johnson, J.S., and M.J. Lacki. 2013. Summer heterothermy in Rafinesques big-eared bats (Corynorhinus rafinesquii) roosting in tree cavities in bottomland hardwood forests. Journal of Comparative Physiology B (doi: 10.1007/s00360-012-0728).
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Johnson, J.S., M.J. Lacki, S.C. Thomas, and J.F. Grider. 2012. Frequent arousals from winter torpor in Rafinesques big-eared bat (Corynorhinus rafinesquii). PLoS ONE 7(11): e49754. doi: 10.1371/journal.pone.0049754.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Johnson, J.S., J.N. Kropczynski, M.J. Lacki, and G.D. Langlois. 2012. Social networks of Rafinesques big-eared bats (Corynorhinus rafinesquii) in bottomland hardwood forests. Journal of Mammalogy 93: 1545-1558.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Barding, E.E., and M.J. Lacki. 2012. Winter diet of river otters in Kentucky. Northeastern Naturalist 19: 157-164.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Lacki, M.J., M.D. Baker, and J.S. Johnson. 2012. Temporal dynamics of roost snags of long-legged myotis in the Pacific Northwest, USA. Journal of Wildlife Management 76: 1310-1316.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Dodd, L.E., E.G. Chapman, J.D. Harwood, M.J. Lacki, and L.K. Rieske. 2012. Identification of prey of Myotis septentrionalis using DNA-based techniques. Journal of Mammalogy 93: 1119-1128.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Kroll, A.J., M.J. Lacki, and E.B. Arnett. 2012. Research needs to support management and conservation of cavity dependant birds and bats on forested landscapes in the Pacific Northwest. Western Journal of Applied Forestry 27: 128-136.
  • Type: Journal Articles Status: Published Year Published: 2012 Citation: Dodd, L.E., M.J. Lacki, E.R. Britzke, D.A. Buehler, P.D. Keyser, J.L. Larkin, A.D. Rodewald, T.B. Wigley, P.B. Wood, and L.K. Rieske. 2012. Forest structure affects trophic linkages: how silvicultural disturbance impacts bats and their insect prey. Forest Ecology and Management 267: 262-270.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2013 Citation: Barding, E.E., and M.J. Lacki. 2013. Demographic and reproductive characteristics of reintroduced river otters in Kentucky: implications for population growth. American Midland Naturalist (in press).
  • Type: Journal Articles Status: Under Review Year Published: 2014 Citation: Barding, E.E., and M.J. Lacki. 2014. Occurrence of nematodes (Dracunculus spp.) in reintroduced river otters in Kentucky. Journal of the Kentucky Academy of Science (under review).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Dodd, L.E., N.S. Skowronski, M.B. Dickinson, M.J. Lacki, and L.K. Rieske. 2013. Using LiDAR to link forest canopy structure with bat activity and insect occurrence: preliminary findings. Pp. 50-57 in Mammoth Cave National Parks 10th Research Symposium: Celebrating the Diversity of Research in the Mammoth Cave Region. Mammoth Cave, Kentucky.


Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Further analyses of data from otter necropsies indicate that 35.7% of female otters in the yearling age class showed evidence of reproductive activity (i.e., placental scars, embryoes, or blastocysts). The population age ratio was skewed left demonstrating higher numbers in the younger age classes. The sex ratio of juvenile otters (1.58:1.0) was significantly higher for males than females, but the sex ratio of adult otters did not differ (0.84:1.0). Otter necropsies demonstrated a low level of endoparasite infection, with nematodes (Dracunculus sp.) occurring in 2.94% of otter carcasses examined. These finding are the first record of nematode parasites occurring in river otters in Kentucky. Population models of otters were refitted with a 5% additive mortality factor, based on input from biologists of the Kentucky Department of Fish and Wildlife Resources (KDFWR), due to current levels of trapping success of otters across Kentucky, especially western Kentucky. Results of these analyses indicate that significant population declines are possible if Kentucky otters exhibit annual survivorship rates below 0.73; the lowest survival rates reported in the literature for river otters elsewhere in the species' distribution. Results of the findings from this project are already published in three peer-reviewed papers, a final report to KDFWR, and a Doctoral dissertation; two more papers are in preparation and will be submitted for publication in 2013. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The refitting of population models with an additive mortality factor resulted in less variation in model outputs across a range of state-reported survivorship rates than previous iterations of the models; however, the likelihood of long-term population extiction remained high at low population survivorship rates (< 0.73). Based on these findings, and a lack of adequate data on known survivorship rates for river otters in Kentucky, we remain cautious with our recommendations to the KDFWR regarding the use of a statewide trapping season for river otters. Subsequent discussions with their biologists have resulted in modifications to their harvest protocols and strategy, with the state of Kentucky now partitioned into subsections where more conservative harvest levels are in place for the central and eastern regions starting with the 2012-13 harvest season. More liberal rates remain in the western region, where river otters appear to be far more abundant. A large number of residents in Kentucky use trapping of furbearing animals as part of their income, so these constraints do affect a significant number of state residents. However, the long-term benefits to the Kentucky river otter population, and the statewide trapping community, of instituting restrictions on river otter harvests at this time, outweigh overharvest and possible declines in this reestablished population.

Publications

  • Loeb, S.C., M.J. Lacki, and D.A. Miller. 2011. Conservation and management of eastern big-eared bats: an introduction. Pp. 1-11 in Conservation and management of eastern big-eared bats: a symposium (Loeb, S.C., M.J. Lacki, and D.A. Miller, eds.), Southern Research Station, USDA Gen. Tech. Report, SRS-145, Asheville, North Carolina.
  • Lacki, M.J., and L.E. Dodd. 2011. Diet and foraging behavior of Corynorhinus in eastern North America. Pp. 39-52 in Conservation and management of eastern big-eared bats: a symposium (Loeb, S.C., M.J. Lacki, and D.A. Miller, eds.), Southern Research Station, USDA Gen. Tech. Report, SRS-145, Asheville, North Carolina.
  • Johnson, J.S, and M.J. Lacki. 2011. Foraging and roosting ecology of Rafinesques big-eared bat at the northern edge of the range. Pp. 129-137 in Conservation and management of eastern big-eared bats: a symposium (Loeb, S.C., M.J. Lacki, and D.A. Miller, eds.), Southern Research Station, USDA Gen. Tech. Report, SRS-145, Asheville, North Carolina.
  • Johnson, J.S., and M.J. Lacki. 2012. Summer heterothermy in Rafinesques big-eared bats (Corynorhinus rafinesquii) roosting in tree cavities in bottomland hardwood forests. Journal of Comparative Physiology B (In press).
  • Johnson, J.S., M.J. Lacki, S.C. Thomas, and J.F. Grider. 2012. Frequent arousals from winter torpor in Rafinesques big-eared bat (Corynorhinus rafinesquii). PLOS ONE (In press).
  • Johnson, J.S., J.N. Kropczynski, M.J. Lacki, and G.D. Langlois. 2012. Social networks of Rafinesques big-eared bats (Corynorhinus rafinesquii) in bottomland hardwood forests. Journal of Mammalogy (In press).
  • Lacki, M.J., M.D. Baker, and J.S. Johnson. 2012. Temporal dynamics of roost snags of long-legged myotis in the Pacific Northwest, USA. Journal of Wildlife Management 76:1310-1316.
  • Lacki, M.J., and E.E. Barding. 2012. Research on North American river otters in Kentucky: recovery, ecological impacts, and population dynamics. Kentucky Woodlands Magazine 6:16-17.
  • Barding, E.E., and M.J. Lacki. 2012. Status, distribution, diet, and reproductive characteristics of river otters in Kentucky. Final Report. Annual Research Highlights 2011: Kentucky Department of Fish and Wildlife Resources. 5: 26-35.
  • Loeb, S.C., M.J. Lacki, and D.A. Miller, editors. 2011. Conservation and management of eastern big-eared bats: a symposium. Southern Research Station, USDA Gen. Tech. Report, SRS-145, Asheville, North Carolina. 157 pp.


Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Necropsies of adult female river otters were completed. Data for pregnancy rate (0.72) and average litter size (3.14) of adult females for the statewide population were used in modeling future population growth of river otters in Kentucky. Values for reproductive parameters recorded for Kentucky fell within the range of values published for populations in adjacent states. Population growth projections were evaluated using survivorship rates for Kentucky, as well as surrounding states where otter populations are recovering. Portions of the results of this research have been published or accepted for publication in two journals. A completed Doctoral Dissertation (Erin Barding) has been submitted to the Kentucky Department of Fish and Wildlife Resources for use with management of the river otter population in Kentucky. Changes to harvesting protocols, especially in western and north-central portions of the state where otters are more abundant, are being considered based upon the finding presented in the dissertation. PARTICIPANTS: This project was associated with the Doctoral program of Ms Erin Barding. Associated agencies include the Kentucky Department of Fish and Wildlife Resources (KDFWR). Mr. Steven Dobey and Ms Laura Patton continue to serve as the primary contacts for KDFWR with this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Projected results from population modeling of river otters suggest a wide range of growth trajectories ranging from extirpation (using West Virginia survivorship rates) to exponential growth (using Tennessee survivorship rates). Based on survivorship rates for Kentucky, which are only from populations in the Jackson Purchase physiographic region, projected growth predicts approximately 2000 river otters statewide by 2015. We believe this estimate to be conservative based upon trapper success over the past 3 years, and we recommend a need for improved data on survivorship of river otters in Kentucky. Changes to harvesting protocols, especially in western and north-central portions of the state where otters are more abundant, are being considered by the Kentucky Department of Fish and Wildlife Resources based upon the finding presented in the completed dissertation of Erin Barding.

Publications

  • Barding, E.E., and M.J. Lacki. 2011. Winter diet of river otters in Kentucky. Northeastern Naturalist. In press.
  • Dodd, L.E., E.G. Chapman, J.D. Harwood, M.J. Lacki, and L.K. Rieske. 2012. Identification of prey of Myotis septentrionalis using DNA-based techniques. Journal of Mammalogy. In press.
  • Dodd, L.E., M.J. Lacki, E.R. Britzke, D.A. Buehler, P.D. Keyser, J.L. Larkin, A.D. Rodewald, T.B. Wigley, P.B. Wood, and L.K. Rieske. 2011. Forest structure affects trophic linkages: how silvicultural disturbance impacts bats and their insect prey. Forest Ecology and Management. In press.
  • Dodd, L.E., M.J. Lacki, and L.K. Rieske. 2011. Habitat associations of Lepidoptera in the Ozark Mountains of Arkansas. Journal of the Kansas Entomological Society. In press.
  • Johnson, J.S., K.S. Watrous, G.J. Giumarro, T.S. Peterson, S.A. Boyden, and M.J. Lacki. 2011. Seasonal and geographic trends in acoustic detection of tree-roosting bats. Acta Chiropterologica 13: 157-168.
  • Barding, E.E., M.J. Lacki, and L.L. Patton. 2010. Recovery of the river otter to Kentucky. Proceedings of the Southeastern Association of Fish and Wildlife Agencies 64: 112-117.


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Data bases on distribution of river otters in Kentucky were accumulated using sign surveys at bridge crossings, and damage reports and harvest data provided by the Kentucky Department of Fish and Wildlife Resources (KDFWR). The pooled information indicated that river otters exist in all 12 major watersheds in Kentucky. Otter presence was highest in the Jackson Purchase physiographic region in west Kentucky and in the reintroduction zone in central Kentucky. Otters were most scarce in the Cumberland Plateau and mountain regions of eastern Kentucky. The number of otters harvested was highest in 2006-07, but has since leveled off in subsequent harvests. Several predictive models of otter population growth are being evaluated for their applicability to the Kentucky otter population and results of those analyses are pending. PARTICIPANTS: This project is associated with the Doctoral program of Ms Erin Barding. Associated agencies include the Kentucky Department of Fish and Wildlife Resources. Mr. Steven Dobey and Ms Laura Patton have served as the primary contacts for KDFWR with this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results of survey efforts suggest that river otters have been successfully reintroduced into Kentucky. The remnant population in the far western end of the state appears to be linked to the increasing number of otters in the central reintroduction zone, with the lowest populations of otters in eastern Kentucky; the latter likely a function of lower habitat quality in mountain regions and greater distances to source populations in the Jackson Purchase and the central reintroduction zone. Results suggest that otters should be able to be harvested on an annual basis, although refinement of harvest schedules is needed to ensure that populations are not overharvested and pushed to far below carrying capacity. The development of a predictive model for the state of Kentucky is intended to address this concern. The success of this reintroduction program adds to the biodiversity of Kentucky, the economy of the state through added opportunities and income for trappers, and to the health of aquatic ecosystems in forested environments. A more comprehensive understanding of the role that otters play in these ecosystems needs further study.

Publications

  • Dickinson, M.B., J.C. Norris, A.S. Bova, R.L. Kremens, V. Young, and M. J. Lacki. 2010. Effects of wildland fire smoke on a tree-roosting bat: integrating a plume model, field measurements, and mammalian-dose response relationships. Canadian Journal of Forest Research 40: 2187-2203.
  • Kroll, A.J., M.J. Lacki, and E.B. Arnett. 2010. Managing snags for birds and bats on forested landscapes in the Pacific Northwest, USA. Western Journal of Applied Forestry. (In press).
  • Barding, E.E., M.J. Lacki, and L.L. Patton. 2010. Recovery of the river otter (Lontra canadensis) to Kentucky. Proceedings of the Southeastern Association of Fish and Wildlife Agencies 64: in press.
  • Lacki, M.J., M.D. Baker, and J.S. Johnson. 2010. Geographic variation in roost-site selection of long-legged myotis in the Pacific Northwest. Journal of Wildlife Management 74: 1218-1228.


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: The initial phases of the project are underway. A total of 170 river otter carcasses was obtained from across the state with the help of the Kentucky Department of Fish and Wildlife Resources through experimental harvests. Acquisition of additional carcasses is planned and targeted for watersheds where insufficient carcasses were obtained in the initial harvests. Necropsies have been performed on all carcasses, with emphasis in year one placed on analysis of stomach contents. All other organs and tissues were extracted, preserved and stored for future analysis. Stomach were removed and the contents extracted, sorted and identified to the lowest taxonomic level discernible. Fish (86% of stomachs), crayfish (27%), and amphibians (5%) comprised the majority of the diet of otters. Among families of fishes, the Centrarchidae (66 % of stomachs with fish scales) was eaten most frequently followed by Catostomidae (21%), Cyprinidae (21%), Clupeidae (13%), Percichthyidae (6%), Esocidae (4%), Percidae (1%), and Amiidae (1%). There was no difference in composition of fish in the diet of male versus female otters, or between otters from eastern versus western Kentucky. Data for the Centrarchidae were further categorized as Group A (sunfish and crappie species) and Group B (black bass species). Results demonstrated most cetrarchids eaten were of Group A, with scales of species in Group B occurring in only 9% of stomachs with centrarchid remains. Of the remaining items found in otter stomachs, over 50 % of stomachs with crayfish remains were of species in the genus Orconectes and all amphibians remains were of species in the family Ranidae. Some evidence of consumption of snakes, turtles, and birds (mallard duck, Anas platyrhyncos) was also found in otter stomachs. PARTICIPANTS: This project is associated with the Doctoral program of Ms Erin Barding. Associated agencies include the Kentucky Department of Fish and Wildlife Resources. Mr. Steven Dobey and Ms Laura Patton have served as the primary contacts for KDFWR with this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Preliminary results from the experimental harvests and the stomach content analyses suggest three principle findings. First, river otters were harvested from all major drainages throughout Kentucky indicating the restoration effort of the mid-1990s has been successful in returning this once extirpated species back to the state. Second, the success of the experimental harvests also suggests that a sustained annual harvest may be possible, although numbers of otters remain low in the far eastern portions of the state (Cumberland Plateau region) and data on reproductive potential and population modeling projections have yet to be completed. Third, diet analyses demonstrated that sportfishes (black bass species, Group B) are uncommon in the diet of river otters in Kentucky. Therefore, maintaining a viable river otter population long-term is not likely to be in conflict with the sportfish industry in Kentucky, and the perceived decline in black bass in the state is not likely due to increasing otter numbers; this has been the misconception of the public in recent years (KDFWR, pers. commun.).

Publications

  • Dickinson, M.B, M.J. Lacki, and D.R. Cox. 2009. Fire and the endangered Indiana bat. Pp. 51-75 in Proceedings of the 3rd fire in eastern oak forests conference (Hutchinson, T.F., ed.), Northern Research Station, USDA Gen. Tech. Report, GTR-NRS-P-46.
  • Lacki, M.J., D.R. Cox, L.E. Dodd, and M.B. Dickinson. 2009. Response of northern bats (Myotis septentrionalis) to prescribed fires in eastern Kentucky forests. Journal of Mammalogy 90: 1165-1175.
  • Dzialak, M.R., K.M. Carter, M.J. Lacki, D.F. Westneat, and K. Anderson. 2009. Activity of post-fledging peregrine falcons in different rearing and habitat conditions. Southeastern Naturalist 8: 93-106.
  • Lacki, M.J., D.R. Cox, and M.B. Dickinson. 2009. Meta-analysis of summer roosting characteristics of two species of Myotis bats. American Midland Naturalist 161: 321-329.