The Mission of the River Otters of South Florida website is: To aid our understanding and interest in the biology, behavior, ecology, and the conservation issues impacting the river otter in Florida, in particular south Florida, and to help educate ourselves, our children, and others about otters worldwide. www.riverotterssouthfl.com

                            Table of Contents

I. Introduction…………………………………….……………………...........................................2-3
II. Some River Otter Life History Facts…………………………………….......…..3-5
       A. River Otter Habitat……………………………………….………………………….......…3-4
       B. The River Otter Diet…………………………………….……………………………............4
       C. The River Otter Family and Social Groups………….……………............5
       D. River Otter Reproduction……………………………………………….………….........5
III. Otter Roadway Mortalities …………………………………….……………….......…..5-6
IV. River Otter Attacks on People ………………………….……………………..........6-7
       A. Otter attacks on people in Florida (1875-2019)………………..........6-7
                  1. Known Historical Attacks from 1875-December 2010
                  2. Recent Attacks in Florida from 2011-mid 2019
       B. Some Thoughts on Why Otters May Attack……………………….......…7
       C. Photos of Injuries Sustained by Victims of Otter Attacks....7-8
       D. What You Need to Do and Know to Insure Your Health Is
       Not Compromised Should You be Attacked by a River Otter
       and Sustain Injuries…………………………...................................................................8
       E. Reporting an Attack on a Person or a Pet to the River Otters
       of South Florida website (ROSF) ……………………………………….....……………..8 
V. The Do’s and Don’ts (as mentioned in the Introduction, the
Don’ts are listed first)
       A. The Don’ts……..……………..........................................................................................9
       B. The Do’s…………………………………………………………………………….……………………9-11

     II. Some River Otter Life History Facts

A. River Otter Habitat: The typical environment inhabited by the North America river otter is the Riparian Zone. The Riparian Zone is where woodlands and the flowing waters of streams and rivers meet.

In addition to river otters inhabiting the riparian zones of south Florida they are also found in various other habitat types throughout south Florida. These habitats either contain impounded water or are located close to other habitats that are close to flowing waters, canals, or drainage ditches. These non-riparian habitats include rural areas of grasslands, woodlands, swamps, marshes, and bogs. The river otter of Florida may live within or routinely visit residential communities that are gated and fenced or unfenced. River otter sightings in gated communities that have been recorded by this author are extensive and suggest some biological and physical characteristics of design of the gated community must enhance otter presence in these communities. River otters spend time in streams and rivers and, in south Florida at least, in and around the ponds and lakes in your residential community and are frequently seen in or near the water hazards on golf courses and crossing fairways to get to another nearby water hazards. They are seen walking between homes or catching and eating a fish or turtle-sometimes right on the edge of the pond behind your residence. B. The River Otter Diet: The North American river otter’s diet varies with the seasons and availability of prey. Fish are the most prevalent prey of the river otter followed by crayfish. Slow moving, bottom-dwelling fish species are the most prevalent types of fish eaten by the river otter. These include the suckers, carp, and bullheads and catfish. Sunfishes are common fish species eaten in various regions while gamefish, such as largemouth bass, seldom appear in the diet of the North American river otter.

The river otter also eats a wide variety of other vertebrate prey species and some invertebrate species. These include amphibians, reptiles, birds, insects, snails and clams and even some mammal species.
C. The River Otter Family and Social Groups: The first social group is composed of the female and her pups and is the predominant social group. The male is not an integral part of the family unit and is only with the female when she is reproductively receptive. A second social group that occurs is the female and a “helper” and the pups and possibly a “helper” alone with one or more pups. The helper may be one of the female’s immature male or female offspring from the previous litter or the litter before that. A third social group would contain the adult female and her pups and an adult male. In this latter group a helper may also be present. A fourth social group would be the bachelor group. Bachelor groups have been observed in coastal marine otter populations of western and northwestern North America as well as freshwater of North America.
D. River Otter Reproduction: 1. Sexual Maturity: Both the female and the male North American river otter are sexually mature at approximately 2 years of age. Females may not breed when they are first mature and may not breed every year. It has been noted that even though a male is sexually mature at two years of age they may not successfully breed until they are five to seven years of age. 2. Breeding Period and Activity: The North American river otter is polygamous which means they will mate with several other partners. Females are in “heat” for 42-46 days. Unless the female has been bred they will be receptive every six to seven days during the heat period. In southern Florida, this author suspects otters breed in late fall shortly after the end of the rainy season. The National Weather Service in Miami has designated May 15th to October 15th as the rainy season for south Florida. It is being suggested that breeding occurs from mid or late November through December. This suggestion requires confirmation from several observers rather than a single individual having observed otters breeding in late November through early December. Breeding has been observed to occur in the water as well as on land. The male grasps the back of the female’s neck when breeding and loud vocalizations have been heard by some observers. Copulation may last from 15 or so minutes to near 75 minutes and may be interrupted by periods rest. The female may caterwaul during or shortly after copulation.

              IV. River Otter Attacks on People

A. Otter attacks on people in Florida (1875-2019): 1. Known Historical Attacks from 1875-December 2010 (Belanger, M. et al, 2010): In 1980-1989 two out of the three (66%) river otter attacks on people that occurred in North America (NA) occurred in Florida, of the 13 river otter attacks in 1990-1999 six occurred in Florida (46%), in 2000-2009 five (29.4 %) of the 17 attacks occurred in Florida, and in 2010 only two (100%) known river otter attacks occurred in NA and they both occurred in Florida. 2. Recent Attacks in Florida from 2011-mid 2019: An internet search for river otter attacks on people in Florida, by this author and based on news media reports, revealed two attacks occurred in 2011, three occurred in 2018, and three occurred in Florida as of mid 2011.
3. Literature Cited: Belanger, M., N. Clough, N. Askin, L. Tan, and C. Wittnich. (2011). A review of violent and fatal otter attacks. IUCN Otter Specialist Group Bulletin, 28(10): 11-16.
B. Some Thoughts on Why Otters May Attack: No direct evidence exists to specifically state why river otters attack humans. The mostly likely reason, particularly in south Florida, is the potential for human-otter contact where otters are frequently present in areas of highly concentrated human populations. The human population in Florida has significantly increased over the past half century (no population statistics were examined). In southwest Florida one need only consult aerial photographs, of residential community development, to realize how much area has actually been created for human habitation. This author has been recording river otter presence in southwest Florida since early 2011. The majority of the sightings reported have been within residential communities-particularly communities designed to include artificial lakes and ponds. Other potential reasons for otters attack on humans could include human encroachment into river otter territories. Territorial defense by the North American river otter, against other otters, has been suggested not to exist. The thought is, the otters’ scent marking behavior of specific areas “signals” unrelated otters that the area they have entered is that of another otter, more specifically a female, and “they” are not welcome. Consequently, no “strange” otter entry, no necessity for physical conflict. However, what about humans entering the females’ territories? When the female is reproductively receptive, i.e. “in heat”, a male is invariably present or nearby. He’s going to defend his access to this female. When the female is with her pups and a human gets too close she may choose to move away from the presence of humans. This is probably the most likely choice of the mother otter. However, if the human presence occurs suddenly, which could occur with boaters or kayakers, the female would probably defend her pups immediately. In summary, high human density and activity, in man-made or natural environments + extensive otter distribution in these environments = river otter attacks on humans as well as pets.
C. Photos of Injuries Sustained by Victims of Otter Attacks: Humans attacked by otters can receive minor injuries or severe, life-threatening injuries. Otters have been documented as attacking humans on land but, attacks in the water are far more prevalent. 

D. What You Need to Do and Know to Insure Your Health Is Not Compromised Should You be Attacked by a River Otter and Sustain Injuries: Whenever a person sustains a bite wound from any animal they should see a doctor as quickly as possible. This would normally require the victim go to the emergency room of the nearest hospital. It is extremely important that the victim advise the attending physician if they have an allergy to antibiotics, such as penicillin. It is also important for the victim to know that rabies has been diagnosed in some river otters in North America. The information, stated below, is quoted directly from the following publication: Cheng, M.P., L.O. Parkes, K. Paquette, and C.P. Yansouni. (2016). River otter bite in a 52-year-old woman: managing animal bites. Canadian Medical Association Journal, 188: 17-8. “Antibiotic prophylaxis after an animal bite is indicated for clinically significant wounds and for patients who are immunocompromised. Primary wound closure is routinely indicated only for facial wounds. Tetanus prophylaxis should be administered for any bite wound that breaks the skin if the patient has not received previous doses of the tetanus toxoid, if the vaccination history is unknown, if the most recent dose was administered more than 10 years ago, or if the most recent dose was administered more than 5 years ago and the wound is severe. Rabies prophylaxis must be considered for all patients with mammal bites, particularly if there was unusually aggressive behaviour. If rabies immune globulin is given, it should be instilled around the bite wounds (if anatomically possible), with the vaccine being administered at a remote sight.”
E. Reporting an Attack on a Person or a Pet to the River Otters of South Florida website (ROSF): To report an otter attack on a human or pet you will need to visit the River Otters of South Florida(ROSF) website at www.riverotterssouthfl.com. On the Home Page go to the black box at the bottom of the page and click the tab entitled Otters &People. When the page opens scroll down to Form to Report an Otter Attack on People and click to open, complete, and submit. Follow the same procedure  should you wish to report an otter attack on a pet by clicking on Form to to Report on Otter Attack on Pets.