IUCN <strong>Otter</strong> Spec. Group Bull. 28(1) 2011Table 1. Anecdotal rep<strong>or</strong>ts <strong>of</strong> otter attacks (time and geographical locations)Time n <strong>of</strong> cases Locations Rabies (% <strong>of</strong> cases)Pre-1980(1875 – 1979)4 2 Ontario1 Alabama1 Washington1980-1989 3 2 Fl<strong>or</strong>ida1 Vermont1990 – 1999 13 6 Fl<strong>or</strong>ida1 each in Calif<strong>or</strong>nia, Iowa, Montana, NewHampshire, Oregon, Virginia, Washington2000 – 2009 17 5 Fl<strong>or</strong>ida3 British Columbia2 Calif<strong>or</strong>nia1 each in Ge<strong>or</strong>gia, Massachusetts, Montana,New Hampshire, New Y<strong>or</strong>k, Virginia,Wisconsin1 Ontario(25%)2 Fl<strong>or</strong>ida(66%)5 Fl<strong>or</strong>ida1 Virginia(46%)2 Fl<strong>or</strong>ida1 Massachusetts1 New Y<strong>or</strong>k(24%)2010 2 2 Fl<strong>or</strong>ida 1 Fl<strong>or</strong>ida(50%)TOTALS 39 15 in Fl<strong>or</strong>ida 14 (36%)Table 2. Summary <strong>of</strong> scientific publications rep<strong>or</strong>ting otter attacks (n <strong>of</strong> people involved andgeographical location)Time n <strong>of</strong> people involved Locations1985- 2002 1 (attack) Guyana, South America1992 1 (death) Tungabhadra, India2004 1 rep<strong>or</strong>t (3 individuals) Calif<strong>or</strong>nia2002-2007 Unknown from various U.S. ZoosDISCUSSIONAnimal attacks take place w<strong>or</strong>ldwide with the maj<strong>or</strong>ity <strong>of</strong> victims never seekingany medical attention (Griego et al., 1995). Theref<strong>or</strong>e, it is not unexpected that since1875, there have been only 39 news articles and 4 scientific studies published thatfocused on otter attacks suggesting that there seems to be a lack <strong>of</strong> research in thisarea <strong>of</strong> animal bites <strong>or</strong> attacks on humans. Looking at the topic <strong>of</strong> otter attacksgeographically the vast maj<strong>or</strong>ity <strong>of</strong> cases rep<strong>or</strong>ted in this paper have occurred withinN<strong>or</strong>th America (Canada and the United States) and thus may be due to underrep<strong>or</strong>ting from other countries <strong>of</strong> these attacks.Aggression in otters has been documented towards humans and other species aswell. When accompanied by pups, female otters tend to avoid male otters, but displayaggressive behavi<strong>or</strong> and may fight when confronted (Chapman and Feldhamer, 1982;Shannon, 1989; Kruuk, 2006). Protection <strong>of</strong> the pups is necessary, as infanticide hasbeen documented (Simpson and Coxon, 2000; Mourão and Carvalho, 2001).Territ<strong>or</strong>iality was suggested as a reason f<strong>or</strong> attacks in a number <strong>of</strong> newspaper articles,as well as the attack upon a human as rep<strong>or</strong>ted by Potter et al. (2007).After suffering from population decline, otters have been at the center <strong>of</strong> severalreintroduction eff<strong>or</strong>ts (Baitchman and Kollias, 2000). This has led to an increasing <strong>or</strong>stabilization <strong>of</strong> otter populations in the maj<strong>or</strong>ity <strong>of</strong> American states and mostCanadian provinces (except f<strong>or</strong> Prince Edward Island) (Kimber and Kollias, 2000). At- 14 -
IUCN <strong>Otter</strong> Spec. Group Bull. 28(1) 2011the same time, human populations in several <strong>of</strong> the above mentioned regions havebeen rising dramatically. This can lead to the encroachment <strong>of</strong> humans onto otterterrit<strong>or</strong>y, which may <strong>of</strong>fer one possible reason f<strong>or</strong> increased attacks. This may beparticularly imp<strong>or</strong>tant in Fl<strong>or</strong>ida where human populations have grown 16% from2000 to 2009, compared to the average increase <strong>of</strong> only 9.1% f<strong>or</strong> the United States ingeneral (Fl<strong>or</strong>ida QuickFacts, 2010). This may be one possible reason why themaj<strong>or</strong>ity <strong>of</strong> attacks found in this paper have occurred in Fl<strong>or</strong>ida.In general otters avoid areas <strong>of</strong> human activity (Potter et al., 2007). Howeverwhen they do come in contact with humans, the result is not always violent. If leftalone, even when living in close proximity to humans, otters have shown indifferenceto people (Shannon, 1989; Lacomba et al., 2001). Encroachment <strong>of</strong> humanpopulations into otter territ<strong>or</strong>y, as well as the preferred avoidance <strong>of</strong> humans, shouldbe taken into consideration f<strong>or</strong> future studies on otter habitat requirements,reintroduction programs <strong>of</strong> otters and any closer human-otter interactions.ReferencesBaitchman, E.J., Kollias, G.V. (2000). Clinical anatomy <strong>of</strong> the N<strong>or</strong>th American river otter (Lontracanadensis). J. Zoo and Wildlife Med., 31(4): 473-483.Chapman, J.A., Feldhamer, G.A. (1982). Wild mammals <strong>of</strong> N<strong>or</strong>th America: biology, management,and economics. Baltim<strong>or</strong>e: Johns Hopkins University Press.Fl<strong>or</strong>ida QuickFacts [Internet]. U.S. Census Bureau; [updated 2010 Aug 16; cited 2010 Dec 21].Available from: http://quickfacts.census.gov/qfd/states/12000.html.Freer, L. (2004). N<strong>or</strong>th American wild mammalian injuries. Emerg. Med. Clin. N. Am., 22: 445-473.Goldstein, E.J.C. 1992. Bite wounds and infection. Clin. Infec. Dis., 14(3): 633-638.Griego, R.D. Rosen, T., Orengo, I.F., Wolf. J.E. (1995). Dog, cat and human bites: A review. J. Am.Acad. 33: 1019-1029.Kimber, K.R., Kollias, G.V. (2000). Infectious and parasitic diseases and contaminant-relatedproblems <strong>of</strong> N<strong>or</strong>th American river otters (Lontra canadensis): a review. J. Zoo and Wildlife Med.31(4): 452-472.Kruuk, H. (1995). Wild otters: predation and populations. Oxf<strong>or</strong>d: Oxf<strong>or</strong>d University Press.Kruuk, H. (2006). <strong>Otter</strong>s: ecology, behaviour, and conservation. Oxf<strong>or</strong>d: Oxf<strong>or</strong>d University Press.Lacomba, I., Soutullo, A., Prigioni, C.M. (2001). Observations on the distribution and conservationstatus <strong>of</strong> the Neotropical river otter (Lontra longicaudis) in the coastal lagoons <strong>of</strong> the UruguayanAtlantic basin and their main tributaries IUCN <strong>Otter</strong> Spec. Group Bull. 18(1): 20-27.McTurk, D., Spelman, L. (2005). Hand-rearing and rehabilitation <strong>of</strong> <strong>or</strong>phaned wild giant otters,Pteronura brasilienis, on the Rupununi river, Guyana, South America. Zoo Biol. 24: 153-167.Mourão, G., Carvalho, L. (2001). Cannibalism among giant otters (Pteronura brasiliensis).Mammalia. 65: 225-227.Nagulu, V. (1992). News from India. IUCN <strong>Otter</strong> Spec. Group Bull. 7: 41-42.Potter, T.M., Hanna, J.A., Freer, L. (2007). Human N<strong>or</strong>th American river otter (Lontra canadensis)attack. Wild. Environ. Med. 18: 41-44.Simpson, V.R., Coxon K.E. (2000). Intraspecific aggression, cannibalism and suspected infanticide inotters. British Wildl. 11: 423-426.Shannon, J.S. (1989). Social Organization and Behavioural Ontogeny <strong>of</strong> <strong>Otter</strong>s (Lutra canadensis) ina coastal habitat in N<strong>or</strong>thern Calif<strong>or</strong>nia. IUCN <strong>Otter</strong> Spec.Group Bull. 4: 8-13.Zelepsky, J., Harrison, T.M. (2010). Surveillance <strong>of</strong> rabies prevalence and bite protocols in captiveanimals in American zoos. J. Zoo and Wildlife Med. 41(3): 474-479.- 15 -