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Prospects for restoring river otters in Indiana.

ABSTRACT. Native populations of the North American North American

named after North America.

North American blastomycosis
see North American blastomycosis.

North American cattle tick
see boophilusannulatus.
 river otter otter, name for a number of aquatic, carnivorous mammals of the weasel family, found on all continents except Australia. The common river otters of Eurasia and the Americas are species of the genus Lutra. The North American river otter, L.  (Lontra canadensis) in Indiana declined sharply through the early 1900s due to unregulated harvest and habitat loss and were believed extirpated from the state by 1942. To restore otters to portions of their historic range, 303 otters (184 [male]: 1199) obtained from Louisiana were released at 12 sites in six watersheds (Muscatatuck, Patoka, southcentral Ohio, St. Joseph, Tippecanoe, upper Wabash) between 1995 and 1999. Fifty-nine (43 [male]:16 [female]) of these otters (19.5%) were known to have died through December 2005, most (81%) in traps set for other furbearers and from collisions with vehicles. Otter sign was found on 31 of 43 surveys (72%) at each of 11 release sites sampled 0-6 years ([bar.x] = 2.5) post-release. Overall detection rate was 20.6%. A total of 1328 post-release records, comprised of sightings (n = 884), accidental captures (n = 17), reports of otter sign (n = 170), and mortalities (n = 257) was compiled from 1995 through 2005. During this period, river otters were reported from 65 of 92 counties and 14 of 15 watersheds in Indiana. They are widely distributed Adj. 1. widely distributed - growing or occurring in many parts of the world; "a cosmopolitan herb"; "cosmopolitan in distribution"

bionomics, environmental science, ecology - the branch of biology concerned with the relations between organisms
 in northeast, northcentral, and southern Indiana Southern Indiana, in the United States, is notable because it is culturally distinct from the rest of the state. The area's geography has led to a blend of Northern and Southern culture that is not found in the rest of Indiana.  but are most common in 26 contiguous counties surrounding the 12 release sites. Otters are rare or were not reported from 57 counties in central Indiana. Reproduction was confirmed, either by recovery of untagged individuals and/or observations of family groups, each year after the initial release year and at 11 of 12 release sites. Size of family groups averaged 4.2 otters (range = 3-8). Ovulation ovulation /ovu·la·tion/ (ov?u-la´shun) the discharge of a secondary oocyte from a graafian follicle.ov´ulatory

The discharge of an ovum from the ovary.
 rates based on presence of corpora lutea corpora lu·te·a  
Plural of corpus luteum.
 were 88% and 50% for adults and yearlings, respectively; mean litter size was 3.25 (SD = 1.12). Source of mortality for 206 (111 [male]: 95 [female]) untagged otters killed in Indiana was incidental trapping (n = 131), collisions with vehicles (n = 68), drowning (n = 5), and unknown factors (n = 2); distribution by age class was 54 juveniles (27.3%), 64 yearlings (32.3%), and 80 adults (40.4%). Recommendations for otter management in Indiana include defining occupied range, collecting age-specific reproductive parameters, and developing management strategies to protect, maintain, and regulate restored populations.

Keywords: Distribution, furbearer fur·bear·er also fur-bear·er  
An animal whose skin is covered with fur, especially fur that is commercially valuable.

, Indiana, Lontra canadensis, population, reintroduction Noun 1. reintroduction - an act of renewed introduction
intro, introduction, presentation - formally making a person known to another or to the public
, river otter, survey


The historical distribution of the North American river otter (Lontra canadensis) was widespread and encompassed most major watersheds in the continental United States United States territory, including the adjacent territorial waters, located within North America between Canada and Mexico. Also called CONUS.  and Canada (Hall 1981). Indigenous populations, however, declined sharply through the early 1900s, primarily due to unregulated trapping, water pollution, and habitat losses associated with human encroachment An illegal intrusion in a highway or navigable river, with or without obstruction. An encroachment upon a street or highway is a fixture, such as a wall or fence, which illegally intrudes into or invades the highway or encloses a portion of it, diminishing its width or area, but  (Melquist & Dronkert 1987; Polechla 1990; Melquist et al. 2003). Such declines were especially severe in the central plains and midwestern regions of the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area.  (Hamilton & Fox 1987) where aquatic habitats were sparse and extensive agricultural activity had eliminated or degraded many wetland communities and ripar ian systems. In Indiana, native populations were also greatly reduced by the turn of the century (Lyon 1936). River otters were first protected in Indiana in 1921. Prospects for recovery, however, were unlikely; and they were believed to have been extirpated from the state by 1942 (Mumford 1969). Rangewide, otters were reported absent from five states, including Indiana, and protected in 17 others in 1976 (Deems & Pursley 1978).

During the 1970s, advances in furbearer management and broad environmental initiatives to improve water quality and protect or restore wetland and riparian riparian adj. referring to the banks of a river or stream. (See: riparian rights)  habitats improved conditions for river otters in North America North America, third largest continent (1990 est. pop. 365,000,000), c.9,400,000 sq mi (24,346,000 sq km), the northern of the two continents of the Western Hemisphere.  (Endangered Species endangered species, any plant or animal species whose ability to survive and reproduce has been jeopardized by human activities. In 1999 the U.S. government, in accordance with the U.S.  Scientific Authority 1978). As a result, several state agencies began reintroduction projects to restore or enhance diminished otter populations in portions of their historic range. These initial efforts proved an effective strategy for recovery, and by 1998, over 4000 otters had been released in 21 states (Raesly 2001). Several states reported initial successes shortly after releases (e.g., Serfass & Rymon 1985; Erickson & McCullough 1987; Erickson & Hamilton 1988; Bluett et al. 1999; Johnson & Berkley 1999). Most reintroductions were ultimately considered successful (Raesly 2001); and by 2004, several states (e.g., Missouri, Kentucky, Ohio) had initiated or proposed regulated harvests of restored otter populations.

Although most reintroduction projects began more than 15 years ago, there are few published accounts that assess their long-term status and efficacy in restoring viable otter populations. In Pennsylvania, Serfass et al. (1993) documented a self-sustaining otter population 6-8 years post-release, which subsequently contributed to a statewide range expansion (Serfass et al. 1999). Hamilton et al. (2000) described unanticipated otter-human conflicts and management challenges following a highly successful program in Missouri. Bluett et al. (2004) reported a statewide distribution of otters and recommended de-listing following releases in Illinois. Herein, we provide a comprehensive evaluation of otter restoration efforts in Indiana from its origin in 1995 through 2005. We document population stability and growth, range expansion, and reproductive success Reproductive success is defined as the passing of genes onto the next generation in a way that they too can pass those genes on. In practice, this is often a tally of the number of offspring produced by an individual.  during this 11-year period and discuss the species' legal status and impending im·pend  
intr.v. im·pend·ed, im·pend·ing, im·pends
1. To be about to occur: Her retirement is impending.

 issues concerning management of river otters in Indiana.


Otter releases.--Johnson & Madej (1994) delineated de·lin·e·ate  
tr.v. de·lin·e·at·ed, de·lin·e·at·ing, de·lin·e·ates
1. To draw or trace the outline of; sketch out.

2. To represent pictorially; depict.

 15 watersheds in Indiana, and based on habitat quality, identified the Muscatatuck, Patoka, southcentral Ohio, St. Joseph, Tippecanoe, and upper Wabash as most suitable for otter restoration. These six watersheds were located in northeast, northcentral, and southern Indiana (Fig. 1).

Wild-trapped otters were purchased from a private supplier in coastal Louisiana (L.R. Sevin, Bayou Otter Farm, Theriot, Louisiana) because they are of the same subspecies subspecies, also called race, a genetically distinct geographical subunit of a species. See also classification.  native to Indiana (Lontra canadensis laxitina) and were used successfully in other midwestern states (e.g., Illinois, Iowa, Ohio, Missouri; Raesly 2001). Otters were captured in Louisiana during open trapping seasons using modified foothold traps and restraint techniques to reduce injury (Shirley et al. 1983). They were held in captivity for up to ten weeks before being transported to Indiana in agency vehicles, typically in late January. Upon arrival, otters were examined at the School of Veterinary Medicine veterinary medicine, diagnosis and treatment of diseases of animals. An early interest in animal diseases is found in ancient Greek writings on medicine. Veterinary medicine began to achieve the stature of a science with the organization of the first school in the , Purdue University Purdue University (pərdy`, -d`), main campus at West Lafayette, Ind.  and treated for trap-related dental or foot injuries (e.g., broken canines, lacerations, fractured digits). Each otter was administered ivermectin ivermectin

an avermectin with broad activity against many helminths and arthropods. A broad-spectrum anthelmintic, acaricide and insecticide, used orally, subcutaneously and as a pour-on.
 for internal parasites and multivalent vaccine multivalent vaccine
See polyvalent vaccine.
 products (e.g., Eclipse[R] 4, Fel-O-Vax[R] PCT (Private Communications Technology) A protocol from Microsoft that provides secure transactions over the Web. See security protocol. , Vanguard[R] 5 CV-L) containing antigens for canine and feline feline

of, or pertaining to, members of the family Felidae. See also cat.

feline agranulocytosis
see feline panleukopenia (below).

feline actinic dermatitis
see solar dermatitis.
 diseases (i.e., distemper distemper, in veterinary medicine, highly contagious, catarrhal, often fatal disease of dogs. It also affects wolves, foxes, mink, raccoons, and ferrets. Distemper is caused by a filtrable virus that is airborne; it is also spread by infected utensils, brushes, and , rhinotracheitis, panleukopenia panleukopenia

1. abnormal depression in numbers of white blood cells.

2. the name of a disease caused by feline parvovirus; see feline panleukopenia.

feline panleukopenia virus
). A numbered Monel[R] fingerling fingerling

young fish.
 and No. 3 tag was placed in each ear and interdigital interdigital

between two digits.

interdigital cysts
see interdigital pyoderma, pododermatitis.

interdigital dermatitis
1. the early lesion in the development of infectious footrot in sheep; called also sheep scald.
 membrane of the hind foot, respectively. Unless held for observation or rehabilitation rehabilitation: see physical therapy. , otters were released 3-4 days after their arrival in Indiana.


We released otters at two sites within each of the six watersheds (Fig. 1). Overall, 303 otters (184 [male]:119 [female]) were released during five consecutive winters between January 1995 and February 1999 at 12 sites in 11 counties. An average of 25.3 otters (range = 23-31) was released per site at a mean sex ratio of 1.55 males per female (Table 1). Otters exhibit delayed implantation that can postpone parturition parturition
 or birth or childbirth or labour or delivery

Process of bringing forth a child from the uterus, ending pregnancy. It has three stages.
 for ca. 12 months after copulation copulation /cop·u·la·tion/ (kop?u-la´shun) sexual union; the transfer of the sperm from male to female; usually applied to the mating process in nonhuman animals.

 (Liers 1951; Hamilton & Eadie 1964). Therefore, otters were released in late January, before peak breeding season Breeding season is the most suitable season usually with favorable conditions and abundant food and water when wild animals and birds (wildlife) have naturally evolved to breed to achieve the best reproductive success. , to improve the prospect that females would mate and bear young in their second spring after release.

Post-release field surveys.--Field surveys for otter sign (i.e., tracks, slides, scats, latrines, prey remains) were conducted during six winters between February 1996 and January 2001. Survey routes were limited to release sites and surrounding drainages within the six targeted watersheds. On each survey, accessible points along waterways (e.g., bridges, boat ramps) were visited to record the presence of otter activity. No limits were set on the length of stream bank examined, number of points visited, their distribution in the survey area, or proximity to one another. Number of nights elapsed e·lapse  
intr.v. e·lapsed, e·laps·ing, e·laps·es
To slip by; pass: Weeks elapsed before we could start renovating.

 since the last measurable snowfall, percent ice cover, snow depth, and type of otter sign (if present) were recorded at each survey point.

Post-release records of otters.--A variety of approaches was used to increase public awareness of Indiana's river otter restoration program and encourage post-release reporting of otter activity. Most releases received substantial media coverage by local, regional, and statewide newspapers and television stations and were well attended by the public. To solicit reports, "River Otter Release Area" signs were posted at release sites, boat ramps, and bait shops, and notices encouraging the reporting of otter sightings were published in annual hunting and trapping regulation booklets. Periodic news releases and articles in popular magazines generated other reports. Date, location, number of otters, and type of observation (e.g., sighting, road-kill, tracks, slides) were recorded for each report. Observers lacking experience with otters were contacted directly to evaluate the validity of their account. Licensed trappers, anglers, and personnel from federal and state natural resource agencies also provided reliable reports of otter activity.

Carcass carcass, carcase

1. the body of an animal killed for meat. The head, the legs below the knees and hocks, the tail, the skin and most of the viscera are removed. The kidneys are left in and in most instances the body is split down the middle through the sternum and the vertebral
 examinations.--We attempted to recover the carcasses of all otters reported killed in Indiana between 1995 and 2005. Date, location, cause of death, sex, and physical condition were noted for each mortality. A lower canine was extracted and sent to a private facility (Matson's Laboratory, LLC (Logical Link Control) See "LANs" under data link protocol.

LLC - Logical Link Control
; Milltown, Montana) for age determination using cementum cementum /ce·men·tum/ (se-men´tum) the bonelike connective tissue covering the root of a tooth and assisting in tooth support.

A bonelike substance covering the root of a tooth.
 annuli an·nu·li  
A plural of annulus.
 analysis. A parturition date of 1 April was used to assign otters into three age classes: juveniles (< 12 months of age), yearlings (1-2 years), and adults (> 2 years). We examined each carcass for ear and/or web tags and also searched for intraperitoneal transmitters used to monitor 15 otters in our first release (Johnson & Berkley 1999). Reproductive characteristics of females were assessed by examining ovaries Ovaries
The female sex organs that make eggs and female hormones.

Mentioned in: Choriocarcinoma

ovaries (ō´v
 and uterine horns The uterine horns are the points where the uterus and the uterine tubes meet.

It is one of the points of attachment for the round ligament of uterus (the other being the mons pubis.

The Fallopian tubes often (but not always) attach to the uterine horns as well.
 for presence and number of corpora lutea, blastocysts, and embryos using methods described by Hamilton & Eadie (1964) and Gilbert (1987).


Fate of founder otters.--Fifty-nine (43 [male]: 16 [female]) of the 303 otters (19.5%) released in Indiana were known to have died between January 1995 and December 2005. Otters killed in traps legally set for other furbearers (n = 29), primarily beaver (Castor canadensis Castor canadensis

(syn. C. fiber) see beaver.
), and collisions with vehicles (n = 19) accounted for 81.4% of the known mortalities (Table 2). Two males released at Big Oaks National Wildlife Refuge Big Oaks National Wildlife Refuge is a 50,000 acre (202 km) nature preserve in Southern Indiana, USA. The nearest city is Madison, Indiana.  (NWR NWR National Wildlife Refuge
NWR NOAA Weather Radio
NWR National Wildlife Reserve
NWR North West Region
NWR Not Work Related
NWR Network Wavelength Requirement
NWR Not Worth Reporting
NWR Nuclear Weapons Report
) were found dead within one week during an extended period of exceptionally severe winter weather. Both were recovered near frozen intermittent drainages within 10 km from the release site and were deplete de·plete
1. To use up something, such as a nutrient.

2. To empty something out, as the body of electrolytes.
 of fat reserves; cause of death was presumed to be release-related stress and associated exposure. Two males drowned in commercial fishing nets, one was shot, and another died from an abdominal infection eight days after surgery to implant an intraperitoneal transmitter. Cause of death for five otters recovered post-mortem was unknown because of inconclusive evidence or advanced autolysis autolysis /au·tol·y·sis/ (aw-tol´i-sis)
1. spontaneous disintegration of cells or tissues by autologous enzymes, as occurs after death and in some pathologic conditions.


Time and point of release for eight otters (3 [male] :5 [female]) were unknown because they had lost their identification tags. They were killed 1.7-73.8 km ([bar.x] = 19.4) from the nearest release site and had distinctive split ear pinnea and punctured or torn interdigital membranes where tags had been affixed af·fix  
tr.v. af·fixed, af·fix·ing, af·fix·es
1. To secure to something; attach: affix a label to a package.

. The remaining 51 otters traveled an average of 42.0 km (SD = 67.6), but most (53%) were killed within 15 km from their release site. Eight otters (7 [male]:1 [female]) were recovered in Kentucky (n = 5), Illinois (n = 2), and Michigan (n = 1), but the greatest distance traveled was 370 km for a male from Salamonie Lake that drowned 14 months post-release in a commercial fishing net in the lower Wabash River Wabash River

River, flowing westward across Indiana, U.S. After crossing Indiana, the Wabash forms the 200-mi (320-km) southern section of the Indiana-Illinois boundary below Terre Haute, Ind.
. Seventeen (35%) deaths occurred within two months after release, and over half (51%) occurred within one year. Two males were struck by vehicles more than six years post-release 13.2 and 19.7 km from their respective release site, and a female released at Pigeon River The Pigeon River may refer to:
  • The Pigeon River (Minnesota-Ontario), between Minnesota, USA and Ontario, Canada in North America
  • One of four rivers named the Pigeon River (Michigan) in Michigan, USA
  • The Pigeon River (Tennessee - North Carolina) in the United States
 Fish & Wildlife Area (FWA (Fixed Wireless Access) See fixed wireless. ) was killed in a beaver trap 7.8 km away nearly six years later. Mean number of mortalities from each site was 4.3 [+ or -] 2.2, which comprised from 8-36% ([bar.x] = 16.7%) of the number of otters released per site.

Post-release field surveys. We conducted 43 surveys between February 1996 and January 2001 and located otter sign on 31 (72%) routes in the 11 release sites sampled (Table 3). An average of 25.9% of the points visited on these 31 surveys had otter sign (range = 6.3-60.0%). Pigeon River FWA was the only release site not sampled; mean number of surveys at the remaining 11 sites was 3.9 (range = 1-9). Surveys were run an average of 2.5 years (SD = 1.9) after otters had been released, but most (81%) were conducted within four years. Eight surveys (19%) at Big Oaks NWR, Tippecanoe River State Park Tippecanoe River is a state park in Pulaski County, Indiana, USA. It is located 58 miles south-southwest of South Bend, Indiana. Noted for a grove of old-growth white pine trees, the park also preserves more than 2 miles (3 km) of undisturbed wetland shoreline on the Tippecanoe  (SP), Etna Green, and Mallard mallard: see duck.

Abundant “wild duck” (Anas platyrhynchos, family Anatidae) of the Northern Hemisphere, ancestor of most domestic ducks. The mallard is a typical dabbling duck in its general habits and courtship display.
 Roost Wetland Conservation Area (WCA (Web Clipping Application) An application for a Palm PDA that accepts an abbreviated version of a Web page for efficient display on the PDA's limited screen size. ) were conducted only 11-23 days ([bar.x] = 17.1) after otters had been released. Sign was detected on seven (88%) of these surveys at 0-60% ([bar.x] = 28.3%) of the points. Otter sign, however, was also found at 0-45.7% ([bar.x] = 16.9%) of the points on five of eight surveys (63%) at three sites (Etna Green, Big Oaks NWR, Muscatatuck NWR) that were sampled at least five years post-release. Overall detection rate at all sites averaged 20.6% and ranged from 10.3% at Big Oaks NWR to 30.3% at Tippecanoe River The Tippecanoe River is a gentle, 225 mile (362 km) long river in northern Indiana that flows from Lake Tippecanoe in Kosciusko County to the Wabash River near Battle Ground, about twelve miles northeast of Lafayette.  SP and the Little Blue River (Table 3).

Reports of otters and their sign.--We received 1107 sightings from 62 of Indiana's 92 counties; 223 reports were omitted because they were suspect or lacked sufficient information to assess their validity. The remaining 884 sightings occurred in 14 of 15 watersheds, but 849 (96%) originated from the six targeted watersheds. Otter sightings were confirmed in 48 counties, but 17 counties surrounding the 12 release sites accounted for 799 (90%) observations. Number of otters sighted ranged from 1-9 ([bar.x] = 2.0), but sightings of single otters (n = 499, 56%) were most common.

Since December 1996, we documented 17 incidents from 13 counties in which otters were accidentally caught but released from snares or foothold traps set for other furbearers. Fifteen (88%) occurred an average of 9.7 km (range = 3.1-22.5) from a release site. The other two otters were trapped in the Kankakee and Whitewater watersheds, 32 and 47 km from the nearest release site, respectively.

Excluding post-release field surveys, 170 reports of otter sign were collected, mostly from licensed trappers or natural resources personnel, from 27 counties. Twelve counties, most of which surrounded the six release sites in northern Indiana Northern Indiana is the region of Indiana including 26 counties bordering parts of Illinois, Michigan, and Ohio. The area is generally sub-classified into other regions. The northwest is economically and culturally intertwined with Chicago, and is considered part of the Chicago , accounted for 138 (81%) reports.

Recovery of untagged otters.--A total of 206 (111[male]: 95 [female]) untagged otters (i.e., non-founder individuals) was reported killed in 47 Indiana counties through December 2005. Cause of death was incidental trapping (n = 131), collisions with vehicles (n = 68), drowning (n = 5), and unknown factors (n = 2). Age data were available for 198 otters (105 [male] :93 [female]); distribution by age class was 54 juveniles (27.3%; 20 [male] 3:34 [female]), 64 yearlings (32.3%; 38 [male]: 26 [female]), and 80 adults (40.4%; 47 [male]:33 [female]). The age of five additional males could not be distinguished between yearling yearling

an animal in its second year of age, e.g. yearling cattle, yearling filly, yearling colt.

yearling disease
rinderpest in wildebeeste in the Serengheti.
 and two-year-old due to indistinct in·dis·tinct  
1. Not clearly or sharply delineated: an indistinct pattern; indistinct shapes in the gloom.

2. Faint; dim: indistinct stars.

 or irregular cementum patterns.

Most untagged otters (n = 177; 86%) were killed in the Muscatatuck, Patoka, St. Joseph, Tippecanoe, and upper Wabash watersheds. Similarly, 14 counties near release sites (Cass, Dubois, Fulton, Gibson, Huntington, Jackson, Jennings, Noble, Orange, Pike, Pulaski, Scott, Wabash, White) each had more than five mortalities that comprised 67% (n = 138) of the total kill statewide.

Evidence of reproduction.--Fifty-two of 884 sightings (5.9%) were of otter family groups reported from 16 counties in eight watersheds. Thirty-seven reports (71%) originated from eight release sites including 20 at Muscatatuck NWR. Family groups were sighted each year except for the first release year (1995). Group size averaged 4.2 otters (range = 3-8) and was typically comprised of one or two adults and 2-5 juveniles ([bar.x] = 2.9).

Untagged juvenile and yearling otters, definitive proof of successful reproduction, were recovered in 36 counties and 12 of 15 watersheds statewide. Most (69%), however, were taken in three of the six targeted watersheds (Patoka, Tippecanoe, upper Wabash). Five counties (Dubois, Fulton, Huntington, Pike, Wabash) surrounding six release sites each had over nine recoveries that accounted for 39% of the total. Untagged otters less than two years of age were also killed in eight counties in six non-targeted watersheds: Kankakee (Laporte, Starke), lower West Fork West Fork may be:
  • The city of West Fork, Arkansas, USA
  • The West Fork River in West Virginia, USA
 of the White (Knox), Maumee (Allen), upper East Fork East Fork is the name of the following places in the United States of America:
  • East Fork, Arizona
  • East Fork, Pennsylvania
  • East Fork, California
  • East Fork State Park, Ohio
See also East Fork Township, a disambiguation page
 of the White (Decatur), Wabash--main stem (Parke), and Whitewater (Ohio, Switzerland). Lastly, we were encouraged by the high proportion of young otters recovered each year in Indiana. An average of 58% of the untagged, known-age otters killed each year were < 2 years old. Juveniles were recovered as early as March 1996 and comprised 0-100% ([bar.x] = 33%) of the annual total; yearlings consisted of 0-73% ([bar.x] = 25%).

We examined fresh, whole reproductive tracts from 64 non-juvenile females for presence and number of corpora lutea, blastocysts, and embryos. Placental placental

pertaining to or emanating from placenta.

placental barrier
the placental separation of maternal and fetal blood which varies in its structure and permeability between the species.
 scars were evident in four post-partum tracts collected between 15 March and 8 May. Of the remaining 60 tracts, corpora lutea were present in 13 of 26 (50.0%) yearlings and 30 of 34 (88.2%) adults (Table 4). The degraded condition of ten tracts precluded complete counts of the number of corpora lutea; thus, minimum number of corpora lutea per female averaged 2.62 (SD = 1.04) and 2.86 (SD = 0.99) for yearlings and adults, respectively. Blastocysts were recovered from six of 11 (54.5%) yearling and eight of 15 (53.3%) adult females that had ovulated and did not contain implanted embryos. Mean number of blastocysts per female, however, was only 2.21 (SD = 0.98). Litter size based on counts of implanted embryos (n = 16) and post-partum placental scars (n = 4) averaged 3.25 (SD = 1.12). Most females (63%) with implanted embryos were taken from mid-December through mid-January and had uterine uterine /uter·ine/ (u´ter-in) pertaining to the uterus.

Of, relating to, or in the region of the uterus.
 swellings to indicate embryonic development. Mean crown-rump length crown-rump length
The length of an embryo or fetus measured from the skull vertex to the midpoint between the apices of the buttocks.

crown-rump length,
 (CRL CRL - Carnegie Representation Language.

Carnegie Group, Inc. Frame language derived from SRL. Written in Common LISP. Used in the product Knowledge Craft.
) of 12 embryos from three females killed between 31 December and 24 January was 1.94 [+ or -] 0.83 cm (range = 1.10-3.21). Two adults killed on 13 January and 3 March each contained four embryos averaging 7.83 [+ or -] 0.30 cm (range = 7.45-8.27) in CRL. Four male fetuses near full term were recovered from an adult killed on 2 March; they averaged 12.27 cm in CRL and weighed 120-130 g ([bar.x] = 125.5). Another adult killed on 7 March contained three fetuses (1 [male]: 2 [female]) averaging 23.1 cm in total length and weighing 160-166 g ([bar.x] = 162.7).

Cumulative distribution and range expansion. We used field surveys, sightings, and information from mortalities to assess the distribution and post-release range expansion of river otters in Indiana. Using all data sources (n = 1328 post-release records), otters were reported from 65 of 92 counties during the 11-year period between January 1995 and December 2005 (Fig. 2). We also received, but later omitted, 15 unconfirmed reports from nine additional counties (Clinton, Dearborn, Floyd, Hamilton, Hancock, Monroe, Putnam, Rush, Wayne). Otters occurred in 14 of 15 watersheds, but 94% of the records originated from the Muscatatuck, Patoka, southcentral Ohio, St. Joseph, Tippecanoe, and upper Wabash River watersheds. The only watershed from which otters were not reported was Lake Michigan in extreme northwest Indiana Northwest Indiana, also known as The Calumet Region, or just The Region, is comprised of Lake, Porter, LaPorte, Newton, and Jasper counties in Indiana. This region neighbors Chicago, Illinois and Lake Michigan, and is also the Indiana component of the Chicago .

River otters are widely distributed throughout northeast, northcentral, and southern Indiana but are most prevalent in 15 counties surrounding the 12 release sites (Fig. 2). These top counties each had more than 20 records ([bar.x] = 71.9; range = 21-320) that accounted for 81% of all records and probably support the highest densities of otters in the state. Eleven adjacent counties (Cass, Crawford, Dubois, Gibson, Harrison, Jefferson, Miami, Posey A posey can be a flower bouquet. As a surname it is of French and English origins, originating and or derived from the greek word Desposyni. People whose surname is or was Posey include:
  • John Posey -an actor
  • Buford Posey - Civil rights worker
  • Francis B.
, Scott, Starke, White) had 10-19 records ([bar.x] = 13.3); they too have relatively high otter numbers, most likely due to dispersal from nearby core populations. Otters are present, but less common, in nine counties that had 4-9 records ([bar.x] = 6.0). Excluding Marion and Newton counties, most lie on the periphery of the six priority watersheds. We consider otters rare in 30 counties in which there were from 1-3 records. Most of these counties, as well as those from which otters were not reported (n = 27), are in central Indiana (Fig. 2) where land use is typified by human development, urbanization, and widespread agricultural activity. Johnson & Madej (1994) considered watersheds in central Indiana less suitable for restoration, and the few scattered records in this region probably represent transient otters rather than re-established populations. Nonetheless, several larger waterways (e.g., east and west forks of the White River) and their major tributaries had at least 12 records, which suggests some pioneering individuals had colonized Colonized
This occurs when a microorganism is found on or in a person without causing a disease.

Mentioned in: Isolation
 these lower priority systems.



Otter mortality.--As expected, human-induced factors were significant sources of mortality for river otters in Indiana. Incidental trapping and collisions with vehicles accounted for 61.1% (n = 157) and 32.3% (n = 83), respectively, of 257 mortalities reported in this study. These were also key factors in other state restoration programs (Erickson & Hamilton 1988; McDonald 1989; Bluett et al. 1999; Serfass et al. 1999).

Beavers often enhance conditions for otters because their impoundments create wetland habitats, foraging opportunities, and den sites (Tumlison et al. 1982; Melquist & Hornocker 1983; Dubuc et al. 1990). Otters are particularly vulnerable to beaver trapping (Lehman 1979), yet no special regulations or restrictions were enacted to protect them from accidental take in traps legally set for other furbearers. To minimize losses, however, trappers were encouraged to voluntarily employ methods less likely to take otters, and where possible, otters were released on public properties that already restrict trapping (e.g., Big Oaks NWR, Muscatatuck NWR, Tippecanoe River SP). Nonetheless, sets for beaver accounted for 78% (n = 123) of all trap-related mortalities. Otters were most often killed in body-gripping traps (n = 91) and foothold traps in submergent sets (n = 28) for beaver. Thirty otters (19%) were taken in traps targeting raccoon raccoon, nocturnal New World mammal of the genus Procyon. The common raccoon of North America, Procyon lotor, also called coon, is found from S Canada to South America, except in parts of the Rocky Mts. and in deserts.  (Procyon lotor Procyon lotor

see raccoon.
). Although incidental trapping was the leading source of mortality in nine of 11 years, losses in the first five years were few ([bar.x] = 4.4/year; range = 0-8) and did not hinder the eventual re-establishment of otters.

Drowning by entanglement in commercial fishing nets is another important source of otter mortality (Mowbray et al. 1979; Anderson & Woolf 1984; Erickson & Hamilton 1988; Bluett et al. 1999). Only four otters (less than 2% of all mortalities) drowned in nets set in Indiana waters, probably because these devices are restricted to the Ohio River Ohio River

Major river, eastern central U.S. Formed by the confluence of the Allegheny and Monongahela rivers, it flows northwest out of Pennsylvania, and west and southwest to form the state boundaries of Ohio–West Virginia, Ohio-Kentucky, Indiana-Kentucky, and
 and lower to middle reaches of the Wabash, Patoka, and East and West Forks of the White River. Sugar Ridge FWA was our only release site in waterways open to commercial fishing, and two males drowned in a 1.3-km reach of the Patoka River The Patoka River is a tributary of the Wabash River, approximately 138 mi (222 km) long, in southwestern Indiana in the United States. It drains a largely rural area of forested bottomland and agricultural lands among the hills north of Evansville.  ca. 7 km upstream of this site. The other two mortalities occurred in the middle (Vermillion County) and lower (Posey County) reaches of the Wabash River bordering Illinois.

We observed a significant increase (t = 5.82, P < 0.01) in the number of mortalities after releases concluded in 1999 (Fig. 3). Between 1995 and 1999, an average of 9.8 (SD = 3.3) otters was reported killed annually; this figure increased to 36.0 (SD = 9.5) in the following six years. Concurrently, the percentage of tagged otters recovered each year declined steadily from a high of 83% (5 of 6 mortalities) in 1995 to only 2% (1 of 41) by 2005. Both trends were considered further proof that otter populations in Indiana were growing and reproducing as anticipated.

Reproductive success.--Excluding 1995, reproduction was confirmed each year, either by recovery of untagged otters and/or observations of family groups. Successful reproduction was ultimately documented at 11 of 12 release sites, often in successive seasons, and other streams statewide. The Little Blue River in the southcentral Ohio River watershed was the only release site at which recruitment was not confirmed. It is a smaller (66 km total length), undisturbed stream in a relatively isolated, sparsely populated pop·u·late  
tr.v. pop·u·lat·ed, pop·u·lat·ing, pop·u·lates
1. To supply with inhabitants, as by colonization; people.

 region of southern Indiana. Human use is sporadic and mostly limited to occasional recreational pursuits (e.g., canoeing, sport fishing). We compiled only ten records in the Little Blue River since the 1999 release, eight of which were from field surveys. Otter sign, however, was still evident, including at the release site, in 2001 and 2004. Few sightings and lack of reproductive evidence were likely a result of little human presence rather than failure of otters to repopulate the Little Blue River.

Based on presence of corpora lutea, ovulation rates of 88% and 50% were obtained for adult and yearling otters, respectively. Comparable rates were reported for adults from Oregon (98%; Tabor & Wight 1977), Maryland (65%; Mowbray et al. 1979), Maine (77%; Docktor et al. 1987) and Missouri (84%; Hamilton 1998). The reproductive potential of yearling females, however, is less certain. Early studies (Liers 1951; Hamilton & Eadie 1964; Tabor & Wight 1977) concluded female otters do not breed until two years of age. Liers (1958)later reported conception by a 15-month-old female, and others have since reported pregnancy rates in yearlings of 7.1% (Mowbray et al. 1979), 33% (Docktor et al. 1987), and 43% (Hamilton 1998). Because otters exhibit delayed implantation, these females would have mated when they were ca. 12 months old and subsequently produced their first litter in the spring near the end of their second year. No corpora lutea were found in the ovaries of 27 juvenile females, but two killed between 2-13 March (i.e., ca. 11+ months old) each contained three Graafian follicles or vesicles, small cavities in which the ova are developed in the ovaries of mammals, and by the bursting of which they are discharged.

See also: Graafian
 indicating they had recently ovulated.


Regardless of age class, fewer blastocysts were often recovered from uteri than corpora lutea counted in matching ovaries. This difference is almost certainly due to blastocysts being lost during flushing or destroyed by autolysis, desiccation des·ic·ca·tion
The process of being desiccated.

, and/or poor preservation. Thus, productivity estimates based on blastocysts were biased low when compared to those obtained from corpora lutea and embryo counts (Table 4) as also reported by Chilelli et al. (1996). Although rates of intrauterine intrauterine /in·tra·uter·ine/ (-u´ter-in) within the uterus.

Within the uterus.

Situated or occuring in the uterus.
 mortality appear low in otters (Tabor & Wight 1977; Mowbray et al.

1979), embryo counts still provide the most reliable estimate of litter size (Chilelli et al. 1996). Our estimates, based on either embryo counts ([bar.X] = 3.06; SD = 1.12; n = 16) or post-partum placental scars ([bar.X] = 4.00; SD = 0.82; n = 4), compare favorably with those obtained elsewhere. For example, litter size averaged 2.68 in Alabama and Georgia (Hill & Lauhachinda 1981), 2.73 in Maryland (Mowbray et al. 1979), 2.75 in Oregon (Tabor & Wight 1977), and 3.44 for newly restored and increasing populations in Missouri (Hamilton 1998).

Swellings signifying implantation had occurred were noted in the uteri of nine females killed from 28 November to 1 February. The early date may be an anomaly because the tract was from an adult female transported from Louisiana 22 months earlier. Mean date for the eight remaining tracts was 3 January, which suggests parturition in Indiana otters, assuming a 61-63 day gestation period Gestation period

In mammals, the interval between fertilization and birth. It covers the total period of development of the offspring, which consists of a preimplantation phase (from fertilization to implantation in the mother's womb), an embryonic phase
 (Lariviere & Walton 1998), is well underway by early March and likely extends into April. The reproductive histories of several females further support this timeline. Three fetuses near full-term were recovered from an adult killed on 7 March, and placental scars were visible in the uteri of females killed on 15 March (n = 2) and 21 April (n = 1). Their reproductive tracts were distended distended Medtalk Enlarged, bloated. Cf Nondistended.  and their teats showed signs of lactation lactation

Production of milk by female mammals after giving birth. The milk is discharged by the mammary glands in the breasts. Hormones triggered by delivery of the placenta and by nursing stimulate milk production.
, suggesting they had recently given birth.

Monitoring restored otter populations.--River otters are inherently difficult to monitor because of their low population densities, high mobility, secretive nature, and use of poorly accessible habitats (Erickson & Hamilton 1988; Rails 1990). These factors are likely exacerbated in the initial stages of restoration when numbers are inevitably low before populations become re-established. Our post-release field surveys were intended only to document presence and distribution near release sites; and otter activity was detected in each watershed sampled, including three sites that were visited five and six years post-release. Although most sign was near release sites, we also found evidence otters used adjacent habitats and other waterways in the six priority watersheds. Therefore, other drainages were surveyed in subsequent winters to improve the prospects of detecting emerging populations elsewhere in the state. Since 2002, these surveys still found otter sign in the six priority watersheds as well as the upper East Fork of the White, upper West Fork of the White, lower West Fork of the White, and Whitewater river Whitewater River may refer to:
  • The occurrence of whitewater rapids in rivers
  • The Whitewater River (California) in the U.S. state of California
  • The Whitewater River (Keowee River) in the U.S.

Public interest and enthusiasm in otter restoration was keen during the release phase, which created a high profile atmosphere conducive to reporting of sightings, particularly near release sites where otters were visible. Bluett et al. (1999), however, cautioned frequency of observations depends on collection effort and changes in public sentiment as otters become established and less of a novelty. As anticipated, there was a steady decline in the number of observations reported annually after our releases concluded in 1999. Only 258 of 884 sightings (29%) were reported since 2000, including 26 in 2004 and 29 in 2005, the fewest during the 11-year study. We attribute this decline to waning public interest as otters became more commonplace and concur with Woolf et al. (1997) that sightings lose their utility as an effective tool to monitor otter populations over time.

Regional perspective.--River otters are highly mobile as demonstrated by eight individuals released in Indiana that were later recovered in adjacent states. Bluett et al. (1999, 2004) attributed immigration immigration, entrance of a person (an alien) into a new country for the purpose of establishing permanent residence. Motives for immigration, like those for migration generally, are often economic, although religious or political factors may be very important.  of otters from neighboring neigh·bor  
1. One who lives near or next to another.

2. A person, place, or thing adjacent to or located near another.

3. A fellow human.

4. Used as a form of familiar address.

 states of Iowa, Missouri, and Wisconsin contributed to population growth in Illinois. Dispersal of otters from Ohio and Maryland also facilitated range expansion in Pennsylvania (Serfass et al. 1999). Accordingly, we anticipate releases of over 700 otters in Illinois and Kentucky during the 1990s (Raesly 2001) to aid re-establishment in Indiana waterways bordering these states. In fact, otters possibly had already colonized the Kankakee River The Kankakee River is a tributary of the Illinois River, approximately 90 mi (144 km) long, in northwestern Indiana and northeastern Illinois in the United States. At one time the river drained one of the largest wetlands in North America and furnished a significant portage  prior to our first release in northern Indiana in 1996. A male was trapped on LaSalle FWA in 1994, and otter sign was reported on the Kankakee River in Lake and Newton counties in 1996 and 1997. Although we compiled 22 records in the Kankakee watershed, it's possible that early reports, all within 15 km from Illinois, were from transient otters immigrating into Indiana along the Kankakee River. Additionally, releases in southeast Illinois (Bluett et al. 1999) may bolster recovery in western and southwest Indiana while releases in northern Kentucky may contribute to colonization colonization, extension of political and economic control over an area by a state whose nationals have occupied the area and usually possess organizational or technological superiority over the native population.  of Ohio River tributaries in southern Indiana.

Legal status and considerations.--River otters were first given complete protection in Indiana in 1921 (Lehman 1982) and were subsequently listed as endangered by the Indiana Department of Natural Resources The Indiana Department of Natural Resources is the agency of the U.S. state of Indiana charged with maintaining natural areas such as state parks, state forests, recreation areas, etc.  (IDNR IDNR Illinois Department of Natural Resources
IDNR Iowa Department of Natural Resources
IDNR Indiana Department of Natural Resources
) in 1969. The species' status was changed to extirpated in 1986, however, because conclusive evidence CONCLUSIVE EVIDENCE. That which cannot be contradicted by any other evidence,; for example, a record, unless impeached for fraud, is conclusive evidence between the parties. 3 Bouv. Inst. n. 3061-62.  of a remnant population Remnant Population is a 1996 science fiction novel by American writer Elizabeth Moon. The story revolves around an old woman who decides to remain behind on a colony world after the company who sent her there pulls out.  in the state was lacking. In 1994, the IDNR reclassified the otter as endangered in anticipation of forthcoming restoration efforts.

Endangered species are defined by statute (IC 14-2-8.5-1) as any species or subspecies of wildlife whose prospects for survival or recruitment within the state are in jeopardy or are likely to become so within the foreseeable future. The goal of Indiana's river otter restoration program was to re-establish otter populations in six priority watersheds. Although quantitative delisting criteria were not developed at the onset of the program, restoration efforts to date have met, and in some cases exceeded, the stated program goal. The six targeted watersheds accounted for 94% of the post-release records documented in this study. Multiple lines of evidence indicate otters are consistently reproducing in these watersheds, and core populations surrounding release sites are self-sustaining and secure. Further, otters have expanded to adjacent habitats, colonized watersheds not initially targeted for restoration, and were documented in > 70% of Indiana's counties in the 11 years following the program's inception. These data indicate long-term prospects for maintaining healthy populations were favorable, and in 2005, the IDNR removed the river otter from endangered status in the state.

The rapid and widespread return of river otters to portions of Indiana was not unexpected. Strategies that were successful in the initial release at Muscatatuck NWR (Johnson & Berkley 1999) were used throughout the program. By 1995, releases in adjoining states had concluded or were nearing completion, and many programs were already reporting stable or growing otter populations (Raesley 2001). Such successes, however, may also generate unexpected social conflicts such as those experienced in Missouri with local sport-fishing interests, private pond owners, and aquaculture aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasing share of world fisheries production.  facilities (Hamilton et al. 2000). Few complaints have been received from anglers on the impacts, real or perceived, of otters on native sport fish populations in Indiana waterways. Reports of otter depredation DEPREDATION, French law. The pillage which is made of the goods of a decedent. Ferr. Mod. h.t.  from pond owners, however, are a more common and recent phenomenon (10 of 18 complaints since 2004). These ponds are typically small (ca. 1 ha) and often close to release sites where otter densities are likely highest. As restored populations continue to grow and expand, nuisance complaints at private ponds and aquaculture facilities in Indiana are likely to become more widespread and numerous.

Melquist & Dronkert (1987) described a comprehensive management program for river otters that included elements of conservation (e.g., reintroductions, habitat preservation, identification and control of limiting factors, regulation of mortality) and population regulation (e.g., sustained yield sus·tained yield
1. The continuing yield of a biological resource, such as timber from a forest, by controlled periodic harvesting.

2. The quantity of a resource harvested in this manner.
 harvest, damage control). Thus far, otter management in Indiana has focused on the initial components of conservation, primarily reintroductions and protecting and monitoring restored populations. As otter numbers continue to increase as expected, management strategies should explore opportunities to regulate populations and alleviate legitimate depredation complaints where appropriate. Most midwestern U.S. states that reintroduced otters before Indiana (i.e., Missouri, Kentucky, Iowa, Ohio) have already enacted or proposed regulated harvests of restored populations. An average of 27.2 otters (range = 21-37) was reported accidentally trapped during the last five fur harvest seasons in Indiana, but the extent of unreported, trap-related mortalities is unknown. Key population monitoring activities, however, should continue to better define otter distribution and identify age-specific reproductive parameters. These data will become increasingly important as management strategies progress toward a more holistic approach holistic approach A term used in alternative health for a philosophical approach to health care, in which the entire Pt is evaluated and treated. See Alternative medicine, Holistic medicine.  of protection, maintenance, and regulation of restored otter populations.


We thank W.B. Morrison and the School of Veterinary Medicine, Purdue University for providing medical care to otters prior to release. We appreciate the assistance and logistical support given by the managers, staff, and landowners of the 12 properties at which otters were released. Personnel from the IDNR, Division of Fish and Wildlife assisted with the transport, processing, and post-treatment care of the otters and also conducted post-release field surveys. Fish to feed captive otters prior to release was purchased by the Indiana State Trappers Association. K. Ehrenberger, K. Gremillion-Smith, and B. Plowman reviewed earlier versions of this manuscript. R. Walker produced figures. River otter restoration in Indiana was funded by federal aid through the Wildlife Conservation and Restoration Program, State Wildlife Grant Program, and public contributions to the Indiana Nongame Wildlife Fund.

Manuscript received 24 January 2007, revised 16 April 2007.


Anderson, E.A. & A. Woolf. 1984. River otter (Lutra canadensis) habitat utilization in northwestern Illinois Northwestern Illinois is a geographic region of the state of Illinois within the USA.

Northwestern Illinois is generally considered to consist of the following area: Jo Daviess County, Carroll County, Whiteside County, Stephenson County, Winnebago County, Ogle County, and
. Final report, Illinois Department of Conservation. 90 pp.

Bluett, R.D., E.A. Anderson, G.E Hubert, Jr., G.W. Kruse & S.E. Lauzon. 1999. Reintroduction and status of the fiver otter (Lutra canadensis) in Illinois. Transactions of the Illinois State Academy of Science 92:69-78.

Bluett, R.D., C.K. Nielsen, R.W. Gottfried, C.A. Miller & A. Woolf. 2004. Status of the river otter (Lontra canadensis) in Illinois, 1998-2004. Transactions of the Illinois State Academy of Science 97:209-217.

Chilelli, M.E., B. Griffith & D.J. Harrison. 1996. Interstate comparisons of river otter harvest data. Wildlife Society Bulletin 24:238-246.

Deems, E.E, Jr. & D. Pursley. 1978. North American Furbearers: Their Management, Research, and Harvest Status in 1976. International Association of Fish and Wildlife Agencies and University of Maryland University of Maryland can refer to:
  • University of Maryland, College Park, a research-extensive and flagship university; when the term "University of Maryland" is used without any qualification, it generally refers to this school
. 171 pp.

Docktor, C.M., R.T. Bowyer bow·yer  
1. One who makes or sells bows for archery.

2. Archaic An archer.
 & A.G. Clark. 1987. Number of corpora lutea as related to age and distribution of river otter in Maine. Journal of Mammalogy The Journal of Mammalogy is the flagship publication of the American Society of Mammalogists. Both the society and the journal were founded in 1919. The peer-reviewed journal publishes papers about mammals throughout the world and their conservation.  68:182-185.

Dubuc, L.J., W.B. Krohn & R.B. Owen, Jr. 1990. Predicting occurrence of river otters by habitat on Mount Desert Island Mount Desert Island (dĭzûrt`), c.100 sq mi (260 sq km), largest island off the coast of Maine; separated from the mainland by Frenchman Bay, Mt. Desert Narrows, and Western Bay. The island's rugged topography is a result of glacial action. , Maine. Journal of Wildlife Management 54:594-599.

Endangered Species Scientific Authority. 1978. Export of bobcat bobcat: see lynx.

Bobtailed, long-legged North American cat (Lynx rufus) found in forests and deserts from southern Canada to southern Mexico. It is a close relative of the lynx and caracal.
, lynx, river otter, and American ginseng ginseng (jĭn`sĕng), common name for the Araliaceae, a family of tropical herbs, shrubs, and trees that are often prickly and sometimes grow as climbing forms. . Federal Register 43:11082-11093.

Erickson, D.W. & D.A. Hamilton. 1988. Approaches to river otter restoration in Missouri. Transactions of the 53rd North American Wildlife and Natural Resources Conference 53:404-413.

Erickson, D.W. & C.R. McCullough. 1987. Fates of translocated river otters in Missouri. Wildlife Society Bulletin 15:511-517.

Gilbert, EE 1987. Methods for assessing reproductive characteristics of furbearers. Pp. 180-190, In Wild Furbearer Management and Conservation in North America. (M. Novak, J.A. Baker, M.E. Obbard & B. Malloch, eds.). Ontario Ministry of Natural Resources.

Hall, E.R. 1981. The Mammals of North America. 2nd ed. John Wiley John Wiley may refer to:
  • John Wiley & Sons, publishing company
  • John C. Wiley, American ambassador
  • John D. Wiley, Chancellor of the University of Wisconsin-Madison
  • John M. Wiley (1846–1912), U.S.
 and Sons, New York New York, state, United States
New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of
, New York.

Hamilton, D.A. 1998. Missouri river Missouri River

River, central U.S. The longest tributary of the Mississippi River, it rises in the Rocky Mountains of southwestern Montana. It flows east to central North Dakota and south across South Dakota, forming sections of the South Dakota–Nebraska boundary, the
 otter population assessment: 1996-97 and 1997-98 trapping seasons and petition for multi-year export authority. Final report, Missouri Department of Conservation. 24 pp.

Hamilton, D.A. & L.B. Fox. 1987. Wild furbearer management in the midwestern United States. Pp. 1100-1115, In Wild Furbearer Management and Conservation in North America. (M. Novak, J.A. Baker, M.E. Obbard & B. Malloch, eds.). Ontario Ministry of Natural Resources.

Hamilton, D., D.J. Witter witter

Chiefly Brit informal to chatter or babble pointlessly or at unnecessary length [origin unknown]

verb chatter, chat, rabbit (on)
 & T.L. Goedeke. 2000. Balancing public opinion in managing river otters in Missouri. Transactions of the 65th North American Wildlife and Natural Resources Conference 65:292-299.

Hamilton, W.J., Jr. & W.R. Eadie. 1964. Reproduction in the otter, Lutra canadensis. Journal of Mammalogy 45:242-252.

Hill, E.P. & V. Lauhachinda. 1981. Reproduction in river otters from Alabama and Georgia. Pp. 478-486, In Worldwide Furbearer Conference Proceedings. (J.A. Chapman & D. Pursley, eds.). Worldwide Furbearer Conference, Inc.

Johnson, S.A. & K.A. Berkley. 1999. Restoring river otters in Indiana. Wildlife Society Bulletin 27:419-427.

Johnson, S.A. & R.E Madej. 1994. Reintroduction of the river otter in Indiana: Feasibility study The analysis of a problem to determine if it can be solved effectively. The operational (will it work?), economical (costs and benefits) and technical (can it be built?) aspects are part of the study. Results of the study determine whether the solution should be implemented. . Final report, Indiana Department of Natural Resources. 30 pp.

Lariviere, S. & L.R. Walton. 1998. Lontra canadensis. Mammalian Species No. 587. 8 pp.

Lehman, L.E. 1979. The feasibility of river otter reintroduction in Indiana. Final report, Indiana Department of Natural Resources. 19 pp.

Lehman, L.E. 1982. Indiana fur harvests, 1700-1980. Pittman-Robertson Bulletin No. 13, Indiana Department of Natural Resources. 40 pp.

Liers, E.E. 1951. Notes on the river otter (Lutra canadensis). Journal of Mammalogy 32:1-9.

Liers, E.E. 1958. Early breeding in the river otter. Journal of Mammalogy 39:438-439.

Lyon, M.W., Jr. 1936. Mammals of Indiana. American Midland Naturalist 17:1-384.

McDonald, K.P. 1989. Survival, home range, movements, habitat use, and feeding habits of reintroduced river otters in Ohio. M.S. thesis, Ohio State University Ohio State University, main campus at Columbus; land-grant and state supported; coeducational; chartered 1870, opened 1873 as Ohio Agricultural and Mechanical College, renamed 1878. There are also campuses at Lima, Mansfield, Marion, and Newark. , Columbus, Ohio Columbus is the capital and the largest city of the American state of Ohio. Named for explorer Christopher Columbus, the city was founded in 1812 at the confluence of the Scioto and Olentangy rivers, and assumed the functions of state capital in 1816. .

Melquist, W.E. & A.E. Dronkert. 1987. River otter. Pp. 625-641, In Wild Furbearer Management and Conservation in North America. (M. Novak, J.A. Baker, M.E. Obbard & B. Malloch, eds.). Ontario Ministry of Natural Resources.

Melquist, W.E. & M.G. Hornocker. 1983. Ecology of river otters in west central Idaho. Wildlife Monographs 83:1-60.

Melquist, W.E., P.J. Polechla, Jr. & D. Toweill. 2003. River otter. Pp. 708-734, In Wild Mammals of North America: Biology, Management, and Conservation. 2nd. (G.A. Feldhamer, B.C. Thompson & J.A. Chapman, eds.). John Hopkins University Press, Baltimore, Maryland "Baltimore" redirects here. For the surrounding county, see Baltimore County, Maryland. For other uses, see Baltimore (disambiguation).
Baltimore is an independent city located in the state of Maryland in the United States.

Mowbray, E.E., D. Pursley & J.A. Chapman. 1979. The status, population characteristics and harvest of the river otter in Maryland. Publications in Wildlife Ecology. No. 2, Maryland Department of Natural Resources The Maryland Department of Natural Resources is a Government agency in the state of Maryland charged with maintaining natural resources such as state parks, public lands, state forests, and recreation areas. . 16 pp.

Mumford, R.E. 1969. Distribution of the Mammals of Indiana. Indiana Academy of Science. Monograph No. 1, Indianapolis. 114 pp.

Polechla, P. 1990. Action plan for North American otters. Pp. 74-79, In Otters: An Action Plan for their Conservation. (P. Foster-Turley, S. Macdonald & C. Mason, eds.). Kelvyn Press, Inc., Broadview, Illinois Broadview is a village in Cook County, Illinois 13 miles west of Chicago. The population was 8,264 at the 2000 census. About Broadview
Broadview was incorporated as a village in 1914. It is located in Proviso Township along the western edge of Cook County.

Raesly, E.J. 2001. Progress and status of river otter reintroduction projects in the United States. Wildlife Society Bulletin 29:856--862.

Ralls, K. 1990. Reintroductions. Pp. 20-21, In Otters: An Action Plan for their Conservation. (P. Foster-Turley, S. Macdonald & C. Mason, eds.). Kelvyn Press, Inc., Broadview, Illinois.

Serfass, T.L., R.P. Brooks & L.M. Rymon. 1993. Evidence of long-term survival and reproduction by translocated fiver otters, Lutra canadensis. Canadian Field-Naturalist 107:59-63.

Serfass, T.L., M.J. Lovallo, R.P. Brooks, A.H. Hayden & D.H. Mitcheltree. 1999. Status and distribution of river otters in Pennsylvania following a reintroduction project. Journal of the Pennsylvania Academy of Science 73:10-14.

Serfass, T.L. & L.M. Rymon. 1985. Success of river otters reintroduced into Pine Creek Pine Creek may refer to:
  • In Colorado, USA
  • Pine Creek High School
  • Pine Creek Golf Course (Colorado Springs)
  • In Illinois, USA
 drainage in northcentral Pennsylvania. Transactions of the Northeast Section of the Wildlife Society 41: 138-149.

Shirley, M.G., R.G. Linscombe & L.R. Sevin. 1983. A live trapping and handling technique for river otter. Proceedings of the Annual Conference of Southeastern Association of Fish and Wildlife Agencies 37:182-189.

Tabor, J.E. & H.M. Wight. 1977. Population status of fiver otter in western Oregon This article is about the region of Western Oregon. For the University, see Western Oregon University.
Western Oregon is a geographical term that is generally taken to apply to the portion of the state of Oregon that is west of the Cascade Range.
. Journal of Wildlife Management 41:692-699.

Tumlison, R., M. Karnes & A.W. King. 1982. The river otter in Arkansas: II. Indications of a beaver-facilitated commensal commensal /com·men·sal/ (kom-men´sil)
1. living on or within another organism, and deriving benefit without harming or benefiting the host.

2. a parasite that causes no harm to the host.
 relationship. Proceedings of the Arkansas Academy of Science 36:73-75.

Woolf, A., R.S. Halbrook, D.T. Farrand, C. Schieler & T. Weber. 1997. Survey of habitat and otter population status. Federal Aid Project W-122-R-3, Illinois Department of Natural Resources The Illinois Department of Natural Resources (IDNR) is a cabinet-level department of the state government of Illinois. It is headquartered in the state capital of Springfield. . 163 PP.

Scott A. Johnson, Heather D. Walker and Cassie M. Hudson: Indiana Department of Natural Resources, 553 East Miller Drive, Bloomington, Indiana Bloomington is a city in south central Indiana. Located about 50 miles southwest of Indianapolis, it is the seat of Monroe County. As of the 2000 U.S. Census, Bloomington had a total population of 69,291, making it the 7th largest city in Indiana.  47401 USA

Thomas R. Hewitt: Indiana Department of Natural Resources, 1124 North Mexico Road, Peru, Indiana Peru is a city in Miami County, Indiana, United States. The population was 12,994 at the 2000 census. The city is the county seat of Miami CountyGR6. Geography
Peru is located at  (40.757690, -86.
 46970 USA

Jeff S. Thompson: Sugar Ridge Fish & Wildlife Area, 2310 East State Road 364, Winslow, Indiana Winslow is a town in Pike County, Indiana, United States. The population was 881 at the 2000 census. Geography
Winslow is located at  (38.382302, -87.213849)GR1.
 47598 USA
Table 1.--Summary of river otter releases in Indiana, 1995-1999.
Number in brackets denotes location of release site in Figure 1. Big
Oaks National Wildlife Refuge was Jefferson Proving Ground at time of

Watershed/release site                        County       period(s)

Muscatatuck River watershed
  [1]--Muscatatuck National Wildlife        Jackson      Jim 1995
  [2]--Big Oaks National Wildlife Refuge    Ripley       Jan 1996;
                                                           Jan 1999
Tippecanoe River watershed
  [3]--Tippecanoe River State Park          Pulaski      Jan, Feb 1996
  [4]--Etna Green (Tippecanoe River)        Kosciusko    Jan 1996
Patoka River watershed
  [5]--Patoka Lake                          Orange       Jan 1997
  [6]--Sugar Ridge Fish & Wildlife Area     Pike         Jan 1997
    (Patoka River)
St. Joseph River watershed
  [7]--Mallard Roost WCA (South Branch      Noble        Jan, Feb 1997:
    Elkhart River)                                         Jan 1998
  [8]--Pigeon River Fish & Wildlife Area    Lagrange     Jan 1998
    (Pigeon River)
Upper Wabash River watershed
  [9]--Salamonie Lake                       Huntington   Jan 1998
  [10]--Eel River                           Wabash       Jan 1998
Southcentral Ohio River watershed
  [11]--Blue River                          Crawford     Feb 1999
  [12]--Little Blue River                   Crawford     Feb 1999

                                            No. otters        Sex
Watershed/release site                       released        (M: F)

Muscatatuck River watershed
  [1]--Muscatatuck National Wildlife            25           15:10
  [2]--Big Oaks National Wildlife Refuge        31           19:12
Tippecanoe River watershed
  [3]--Tippecanoe River State Park              26           16:10
  [4]--Etna Green (Tippecanoe River)            24           14:10
Patoka River watershed
  [5]--Patoka Lake                              24           14:10
  [6]--Sugar Ridge Fish & Wildlife Area         25            16:9
    (Patoka River)
St. Joseph River watershed
  [7]--Mallard Roost WCA (South Branch          27           17:10
    Elkhart River)
  [8]--Pigeon River Fish & Wildlife Area        25           15:10
    (Pigeon River)
Upper Wabash River watershed
  [9]--Salamonie Lake                           25           15:10
  [10]--Eel River                               25           15:10
Southcentral Ohio River watershed
  [11]--Blue River                              23            14:9
  [12]--Little Blue River                       23            14:9

Table 2.--Source of mortality for river otters released in Indiana,
1995-1999. Distance expressed as linear distance to release site.

                                                Both sexes

                         n                     Distance (km)

Source             Males   Females    Mean    SD       Range

Trapping            20        9       50.0    61.5    1.7-239.0
Road-kills          13        5       29.3    36.5    3.1-152.3
Unknown              3        2       18.2    27.1    2.1-65.6
Drowning             2        0      191.0   253.6   11.7-370.4
Stress/exposure      2        0        8.2     2.6    6.3-10.0
Research-related     1        0        3.1     --        --
Shooting             l        0        2.5     --        --
All sources         42       16       42.0    67.6    1.7-370.4

                        Both sexes

                    Days since release

Source             Mean   SD     Range

Trapping            888   548    41-2149
Road-kills          478   761     4-2234
Unknown             130   146    44-298
Drowning            972   774   425-1519
Stress/exposure       6     l     5-6
Research-related      5    --      --
Shooting              2    --      --
All sources         630   661     2-2234

Table 3.--Summary of post-release field surveys for river otter
activity near 11 release sites in Indiana, February 1996-January 2001.
Overall detection rate is expressed as percent of points on all
surveys conducted at a release site at which otter sign was confirmed.

                                   Mean years       Mean [+ or -] SD
                        No.      (range) elapsed       points per
Release site          surveys     since release          survey

Muscatatuck NWR          7      5.0 (4-6)          11.7 [+ or -] 10.5
Big Oaks NWR             9      2.8 (0-5)          15.1 [+ or -] 7.8
Tippecanoe River SP      2      0                  16.5 [+ or -] 2.1
Etna Green               3      1.7 (0-5)          22.7 [+ or -] 19.3
Patoka Lake              2      2.0 (1-3)          27.0 [+ or -] 4.2
Sugar Ridge FWA          9      2.4(1-4)           11.2 [+ or -] 3.6
Mallard Roost WCA        4      0.8 (0-2)          10.3 [+ or -] 1.3
Salamonie Lake           2      2.5 (2-3)          17.5 [+ or -] 0.7
Eel River                1      2.00               46.0
Blue River               2      1.5 (1-2)          15.0 [+ or -] 7.1
Little Blue River        2      1.5 (1-2)          16.5 [+ or -] 3.5
All sites               43      2.5 (0-6)          15.3 [+ or -] 9.5

                       Surveys with otter sign    surveys

                               Mean percent       Overall
                             (range) of points   detection
Release site             n    with otter sign       rate

Muscatatuck NWR          4   25.0 (12.5-45.7)       25.6
Big Oaks NWR             5   18.4 (7.7-37.5)        10.3
Tippecanoe River SP      2   32.2 (11.1-53.3)       30.3
Etna Green               3   29.8 (27.3-33.3)       29.4
Patoka Lake              2   20.8 (16.7-25.0)       20.4
Sugar Ridge FWA          5   27.7 (6.3-57.1)        17.8
Mallard Roost WCA        3   36.7 (16.7-60.0)       26.8
Salamonie Lake           2   20.3 (11.1-29.4)       20.0
Eel River                1   15.20                  15.2
Blue River               2   25.0 (20.0-30.0)       23.3
Little Blue River        2   31.0 (26.3-35.7)       30.3
All sites               31   25.9 (6.3-60.0)        20.6

Table 4.--Reproductive characteristics of yearling (1-2 y) and adult
(>2 y) female river otters (n = 60) collected in Indiana. February
1998 to March 2006. Corpora lutea counts are minimum number that was
detected in ovaries. Corpora lutea were present but not counted in one

                               Corpora lutea
Age class   examined    n     Mean [+ or -] SD    Range

Yearling       26       13   2.62 [+ or -] 1.04    1-5
Adult          34       29   2.86 [+ or -] 0.99    1-4
Combined       60       42   2.79 [+ or -] 1.00    1-5

Age class   examined    n     Mean [+ or -] SD    Range

Yearling       26       6    1.83 [+ or -] 0.75    1-3
Adult          34       8    2.50 [+ or -] 1.07    1-4
Combined       60       14   2.21 [+ or -] 0.98    1-4

                             Implanted embryos
Age class   examined    n     Mean [+ or -] SD    Range

Yearling       26       2    4.00 [+ or -] 1.41    3-5
Adult          34       14   2.93 [+ or -] 1.07    1-4
Combined       60       16   3.06 [+ or -] 1.12    1-5
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Author:Johnson, Scott A.; Walker, Heather D.; Hudson, Cassie M.; Hewitt, Thomas R.; Thompson, Jeff S.
Publication:Proceedings of the Indiana Academy of Science
Article Type:Report
Geographic Code:1U3IN
Date:Aug 9, 2007
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