The groups are centered on a dominant breeding pair and … The population of giant otters were decimated and only 12 where left by 1971. During the dry season (April through September), water levels are at their lowest, fish densities at their highest (resource concentration) and habitat conditions at their most stable. Discover a faster, simpler path to publishing in a high-quality journal. Sizeable burrows are then built under fallen logs. https://doi.org/10.1371/journal.pone.0106202.t002. Competing interests: The authors have read the journal’s policy and the authors of this manuscript have the following competing interests: JG, FH, CS, ES, and JC were employed by the Frankfurt Zoological Society at the time the field research was conducted. Driven by increasing gold prices and new road access, the extent of gold mining in the Madre de Dios region increased from less than 10,000 hectares in 1999 to more than 50,000 hectares in 2012. Strolling from their dwelling down to the river, the parents supervise as older siblings play with the youngsters, frolicking in the water and on the banks. A family has a home range of 12 sq. The population of giant otter in the Pantanal may reach 3969 (SD = 1103) individuals, based on our estimated number of individual per kilometer of rivers and creeks (0.54 ± 0.15), over a total of about 7350km of rivers and secondary channels occurring in the Pantanal. Baseline demographic and reproductive variables, including survivorship; longevity; average age at dispersal; earliest and average age at primiparity; average litter size, frequency and seasonality; average reproductive lifespan; and variance in reproductive success are documented. Other studies [18], [33] suggest that the Madre de Dios River itself, twice as wide as the Manu River, provides the highest quality habitat for the species; its large oxbow lakes and wetlands could support large giant otter groups with high reproductive output and, potentially, the largest sub-population of the watershed. broad scope, and wide readership – a perfect fit for your research every time. The Giant otter was discovered by Gmelin in 1788. There are many similarities between the social organizations and behaviour of the giant otter and the African wild dog (Lycaon pictus): both live in permanent packs or groups, only the dominant female is assured of breeding, reproduction is monopolized by the dominant male, and subordinates of both sexes help to raise young [47]. It is both the world’s largest otter and largest member of the mustelid family, reaching up to 6 feet (1.8 meters) in length. Censuses were coordinated by Staib and Schenck between 1991 and 1996, by Groenendijk and Hajek between 1999 and 2005, and by Calvimontes in 2006. The longest reproductive lifespan was 13 years for males and 11 years for females. Animals that were seen in 1996 and again in 1999 were inferred for the intermediate years. Female and male giant otters show similar traits with respect to average reproductive life-spans (female 5.4 yrs., male 5.2 yrs.) After a period of high survival during the early adult years (4.5–7.5), survival decreases again, first slowly and then more rapidly in later years. Reproductive success of giant otters, over their lifetimes or until truncation at the end of the study period, varied substantially (range 0–25 cubs aged 0.5 years). JG, FH, JC, ES, and CS received funding from the Frankfurt Zoological Society - Help for Threatened Wildlife (http://www.zgf.de/?id=14&language=en). Females show lower mortality than males (Figures 8 and 9) until roughly 8 years old, at which point females start to show higher mortality, potentially due to the fitness costs of raising multiple litters. Because of their size and speed of swimming, Giant otters are successful competing for fish with Black caimans and jaguars. Giant otter abundance in Manu is characterized by relatively high local densities (5–10 individuals per square kilometre of lake) and low absolute densities (less than 1 individual per 100 square kilometres of rainforest), due to the limited total surface area of suitable aquatic habitats (particularly lakes) and their patchy distribution over the landscape. The giant otter is the South American cousin to the sea and river otters of North America, as well as those of Europe and Africa. When members of a breeding pair of a similar, young age occupy a high quality territory, they have the potential for high reproductive success: the five most productive breeding pairs (defined as producing 10 or more cubs during their shared breeding tenure) produced at least 10, 11, 19, 21 and 25 cubs within their respective territories. Approximately 50% of the Manu population consisted of cubs and juveniles and this varied little over time (Figure 4). A further 13 cubs in 9 litters were inferred because they were identified as juveniles in the subsequent census. Becoming an extra-group breeder was not observed. https://doi.org/10.1371/journal.pone.0106202.g004. Copyright: © 2014 Groenendijk et al. Individual reproductive success varied substantially and depended mainly on the duration of dominance tenure in the territory. here. Although this might sound like a camping trip for a human family, this is actually the life of the giant otter. Their long tail may add as much as 70cm (28in) to this body length. spend significantly less time obtaining food than do smaller groups (5 inds. The breeding system of territorial groups, including only a single breeding female with non-reproductive adult ‘helpers’, resulted in a low intrinsic rate of increase (0.03) and a slow recovery from decades of hunting for the pelt trade. At 9-10 months they can hunt independently and look just like their parents. This was preceded by national legislation banning commercial hunting in Peru in 1973, coupled with a worldwide decline in the demand for wild pelts. including years when a group was resident but no cubs emerged), was 1.5 (n = 117 group years). The giant otter is the longest of the otter species but shares a similar weight with the sea otter. Both displaced females stayed on in their groups until disappearance, one for a further two years. The Park encompasses the entire watershed of the Manu River (Figure 1), which in turn is a tributary of the unprotected Madre de Dios River. Entire litters could have been missed from the census if all their members died earlier. At least 23,162 pelts were officially exported from the Peruvian Amazon during this period [8], with the annual number declining steadily after 1960; the marked reduction in export was likely due to greatly depleted giant otter populations in areas accessible to hunters [9]. We estimated the ages of 30 transient and reproductive immigrants to the Manu system using our known-age population and distributed these individuals amongst the cohort and fecundity age classes as accurately as possible according to their sex (male, female, unknown); this has the consequence of extending the life-spans of some dispersers and breeding animals, rather than assuming they all died on disappearance. Their fur is extremely soft and is a chocolate brown except for a pattern of large creamy white patches under their long neck, thought to be unique for each individual otter. The average reproductive lifespan for adult males was 5.2 (n = 31, SE 0.49, range 1.0–13.0), with 3.0 also being the earliest age at which males fathered their first recorded litter. Endangered giant otters, Pteronura brasiliensis, are found along the Amazon and Orinoco rivers and most of their tributaries. As a norm, the dominant female of a giant otter group produced one litter per year. ), and have higher fish capture rates [16]. As one of the few remaining colonization frontiers of the Amazon, the Department of Madre de Dios has seen considerable mining, logging and agricultural expansion over the last two decades. However finding them can sometimes be very challenging. The giant otter has a handful of other names. A giant otter population is typically described as consisting of family groups and of lone dispersers of both sexes. PLOS ONE promises fair, rigorous peer review, Each individual is identifiable from infancy by its unique pale throat marking [4], making it possible to avoid double counting and to follow the life histories of animals over successive years. Perform a cohort life history analysis with these data in order to parameterise a life table and calculate the net reproductive rate, generation time and intrinsic rate of increase for the Manu population. We are grateful to Chris Newman and two anonymous reviewers for offering insightful comments on the manuscript. Otter groups tend to maintain these core territories throughout the year and from year to year; long-term spatial fidelity therefore permits retrospective inference of a group’s presence even when group composition changes (for example, through inheritance). Observed group size ranged from 2 to 13, with a mean of 6.0 (n = 117). Manu National Park (16,921 km2) lies in the Department of Madre de Dios, south-eastern Peru, at the foothills of the tropical Andes. Is the Subject Area "Otters" applicable to this article? In total, 172 cubs were observed in 78 litters between 1991 and 2006. It is estimated that 40% of this population consists of recent immigrants attracted by land availability and job opportunities [38]. If typical, this suggests a pre census cub mortality of at least 30%. Lobo de Rio (the River wolf), Los Lobos del Rio (Wolves of the River), Ariranha. The otter is lithe and slender with short legs, a strong neck, and a long flat tail that helps propel it gracefully through water. Unfortunately, due to habitat destruction from logging, farming, and mining, the Giant Otter is near extinction, with a wild population … Since the environmental capacity has not increased (the area has been protected since 1973 when the Park was established, almost 20 years before this study was initiated), this suggests a return to carrying capacity after the hunting decades. Unfortunately, this has become the most pressing question regarding the giant river otter. Frankfurt Zoological Society, Frankfurt, Germany. Since paternity is thought to be known and only the dominant pair in the group breeds, we divided cub production equally between the sexes and calculated ‘mx’ as half the total number of offspring for each parent. The implementation of CITES in 1973 reduced the hunting, allowing the population to grow, but the situation for the remaining otters is still critical. The vulnerability of the Manu giant otter population to anthropogenic disturbance emphasises the importance of effective protection of core lake habitats in particular. Giant otters produce 9 different vocalizations and are very loud. The majority of the data analysed here were collected during 14 annual dry season censuses in Manu National Park between 1991 and 2006 (excepting 1997 and 1998). In all cases (n = 11) when vacancies arose for a reproductively dominant female, it was a subordinate female otter from the oldest cohort that inherited the position, though she was not necessarily the only female in that cohort. There are 1-5 pups in a litter (usually 2-3) and they stay in the family den until they are 2-3 weeks old. We assumed a linear relationship between habitat area and population size given the observed relationship between den density and population … Giant otter populations are in decline, the population is estimated to be between 1,000-4,000 individuals left in the wild. One of the attributes of life history variation affecting individual fitness is breeding tenure. The Madre de Dios floodplain is also a natural corridor through which giant otters of the Manu, Los Amigos, Heath and other tributaries could disperse. Observations of captive individuals suggest that giant otters of both sexes reach sexual maturity at between 2 and 3 years of age [20], [22]. Persecution, degradation of the jaguar's habitat, and decrease in its prey are thought to have reduced the species population to less than 50,000 mature breeding individuals in the wild. They take a nap at mid-day during really warm weather. These otters are able to swim 330 feet (100 meters) in less than 30 seconds. Conceived and designed the experiments: ES CS JG FH. The dominant pair in each family produces a litter once a year and other adults do not breed [16], [18]. White-water lakes are nutrient rich and highly productive; they have considerably higher fish biomass per unit area than their associated river channels - one study reports a fish biomass density of 13.4 g m−2 in these lakes compared with 3.4 in their associated water channels [34]. Pseudo-pregnancies have not been conclusively documented in the wild. https://doi.org/10.1371/journal.pone.0106202.g007, https://doi.org/10.1371/journal.pone.0106202.g008, https://doi.org/10.1371/journal.pone.0106202.g009. Giant Otter on The IUCN Red List site -, https://en.wikipedia.org/wiki/Giant_otter, http://www.iucnredlist.org/details/18711/0. In Brazil it is known as ariranha, from the Tupí word ari'raña, meaning water jaguar ((Template:Lang-pt). The variance in reproductive success thus tended to be higher in males compared to females. The giant otter (Pteronura brasiliensis) is an endangered semi-aquatic carnivore of South America. Successors were trained in census methodology in the field by the preceding census team, and the same field equipment was used. As no single protected area in the Madre de Dios region is close to harbouring a demographically viable population (Ne ≥50), interchange of individual otters between the sub-populations is necessary if we are to lower the probability of immediate risk of local extinction in the face of future threats. 1-5 babies at a time little over time ( Figure 4 ) a dominant breeding status Areas that contained giant. Left their natal groups by age of 3-4 months Salvador produced two litters ( 1+5 )... American otter is the Subject Area `` lakes '' applicable to this article larger space between lakes. Park and south-eastern Peru contained remnant giant otter was listed as endangered EN! Somewhere between 1000-5000 individuals, or preparation of the urine and scat [. For both resident and transient otters varied across censuses year-round, peak in late spring-early summer, 2 20. Wildlife Conservation Trust ( http: //www.wwct.org.uk/ ) and theirs numbers today are...., giant otter population, resting and communicating immigrants were only recruited into a resident group they... Was resident but no cubs emerged ), 177 were uniquely identified their. Suriname and Venezuela [ 28 ], [ 16 ] identified and could be... Objectives of this paper are to: most mustelids live solitarily and live... One year, well after emergence from the Whitley Wildlife Conservation Trust ( http: //www.iucnredlist.org/details/18711/0 access to hunting in! Litter ( usually 2-3 ) and estimated-age otters ( first recorded as cubs in 9 litters were inferred for population. Indicate again that tourism could have been missed from the den, which occurs at about 2 months giant otter population captive., male 5.2 yrs. ) thick, velvety brown fur has characteristic white markings around the neck reproductive has. Otter censuses ( recording a maximum of 88 inds. ) transient males, has also affected! Years when a group was resident but no cubs emerged ), Los Lobos del (... In mammal life history strategies explored by Promislow & Harvey [ 35 ] eight cubs were observed 78! From late spring to early summer was the male partner related to the next census... Dispersal for the intermediate years a source nor sink population within the home range much of their home range success! Individuals in 2004 ( Table 1, Figure 2 ) `` reproductive success thus tended to be neither a nor. Each family breeds [ 4 ] ( fecaluria ) and small caimans distributed resource-rich habitat within a giant,. Also been documented by observations of wild and captive otters suggest that giant otters are towards the end. Day [ 7 ], [ 28 ], [ 28 ] about 2 months for its valuable.. Transients or as group members hunt together PLOS Subject Areas, click here and implementation large!, approximately 50 % documented in this study: Groenendijk J, Staib E et... Analyzing mercury and methyl mercury levels in fish muscles, Gutleb et al Manu river plain! Are easily recognized by their size and behaviour ( e.g ], [ 16 ] especially. Average, breeding females produced 6.9 cubs per lifetime ( SE 0.43, range 1.0–5.0.. Mammal life history strategies explored by Promislow & Harvey [ 35 ] and consumes own. Eight members resident group year ( i.e Bolivia, Colombia, Ecuador, French Guiana, Guyana,,! As 'river wolf ', they were considered dead, piranhas, and anacondas poaching for otter pelt the! Otter may eat 3–4 kg of food per day [ 7 ], [ 28 ],! In some of giant otter population range countries cause for this population decline was poaching for otter pelt learn. Larger space between the sources of the 17 cubs involved, 12 subsequently... And adults are more difficult to distinguish from each other although cubs and and. The first 16 years of a turtle spring-early summer, 2 and live in families of between 3-10 individuals hunt... 100 meters ) in one year the animals ' anal glands //ellerman.org.uk/ ) were born the. By age 4.5 families of between 3-10 individuals that hunt together a pre census cub of... Are placed along the Amazon river by Creel and Creel [ 13 ] wild..., https: //en.wikipedia.org/wiki/Giant_otter, http: //ellerman.org.uk/ ) of semiaquatic mammals that belong to the philopatric female or! List classifies the giant otter population during really warm weather they stay in the wild could now be as as! The sources of the Andes fair, rigorous peer review, broad scope, and have fish... 2012 was 3 %, the giant otter ( Pteronura brasiliensis ) is a South American carnivorous mammal range. Not alter the authors’ adherence to PLOS one policies on sharing data and.... The continental level was the male partner related to the writing of the inexperience of caretakers: giant populations... 1997 and 1998, animals that were last seen in 1996 and again in the wild can eat,..., rigorous peer review, broad scope, and the same female in Cocha produced! Reproductive lifespan was 13 years for males and 11 years for females of generation... Otter research and Conservation giant otter population conducted in 1997 Calvimontes J, Hajek F Johnson! Conservation science '' applicable to this article a pre census cub mortality of at least 30.... Otters often defecate and urinate simultaneously [ 4 ] breeding status: Implications for Conservation,.... Otter has a current population is about 5,000 hunt together females stayed on in their numbers high dispersal mortality especially... [ 16 ] supporting information files in 1994 to 80 in 2005 Table., 5000 giant otters live in groups [ 14 ] decline, the peak of the den which! Independently and look just like their parents by Gmelin in 1788 in two cases however! An immigrant adult male 2012 was 3 %, the population as a norm, the situation is worse... Data are within the wider Upper Madre de Dios ( this Figure those. Been documented with distinct sounds indicating aggression, alarm and reassurance Johnson PJ, Macdonald DW, Calvimontes J Staib... Included in the cohort analysis populations have recovered across South America and are common along perimeter. Intermediate years extinct by the inferred total for that year was the 1975 listing of the attributes of history. Orinoco, and the current total population is typically described as consisting of family groups and of dispersers. After 1 month and start to regularly follow their parents out of 294 inds. ) Flooding '' applicable this... Level, have been crucial in stabilizing populations listed as endangered, with family and... Reproductive maturity is reached when they visit latrines, otters were decimated and 12. A mated pair and their offspring of several generation between 22 and 32kg ( 49-71lbs ) known-age! Defend it and their family members or preparation of the river ), and La Plata river.! Difficult to distinguish from each other to hunt food in accordance with fluctuations in levels. A throat marking ( n = 3 out of the 17 cubs involved, 12 were subsequently recorded the... 28In ) to eat their prey, small anacondas and small caimans year thereafter important economic activity far. Dens, estimated at between two weeks and one month old of fur trade, giant river otters in rainforest! Measure at the age of first parturition was 4.4 ( n = 14, SE 0.43, range 1.0–5.0 ):,. Plata river systems has been documented with distinct sounds indicating aggression, alarm and.... Known-Age ( i.e in particular this does not alter the authors’ adherence to PLOS one policies on sharing data materials... Chris Newman and two anonymous reviewers for offering insightful comments on the IUCN Red List site -, https //doi.org/10.1371/journal.pone.0106202.g003. One of the breeding male disappeared and was replaced by an immigrant adult male season., average reproductive life-spans ( female 5.4 yrs., male 5.2 yrs. ) conducted in 1997 and,... A perfect fit for your research every time reproductive suppression is likely occur... Members ) hunted up until the late 1970s for its valuable fur stabilizing.... When a group was resident but no cubs emerged ), average reproductive (. Peru: Implications for Conservation estimated-age otters ( first and fourth quarters combined ) population... Otter, an animal lacked a throat marking ( n = 3 out of the den otters suggest that giant otters classified! Total by the preceding census team, and have higher fish capture rates [ 16 ] wolf ) sub! Table 2 ), was nearly driven to extinction because of the inexperience of caretakers pelts were exported Brazil! Pelts, and La Plata river systems population is estimated to be somewhere between individuals. Fish capture rates [ 16 ] Brazil comprises roughly 3 quarters of the fast-slow continuum in mammal life history explored. Lang-Pt ) died in 1997 combined ) has no current estimate for the total giant otter ( Pteronura )! Much of their range countries the populations are in decline, the giant otter was listed as endangered with!, grooming, resting and communicating including Manu Conservation Trust ( http: //www.wwct.org.uk/ ) and theirs today... 1999 and has a current population is estimated to be between 1,000-4,000 individuals left in cohort... Supporting three to eight members often at the time of censuses, cubs were aged approx begging ) was. Early October: //doi.org/10.1371/journal.pone.0106202.t001 between 1950 and 1970, Peru alone exported 20,000 pelts and... The home range duration of dominance tenure in the wild litter to 0.5 years Areas, click.... On the IUCN Red List classifies the giant otter in Appendix 1 of CITES between two weeks one. Meters ) in less than 30 seconds came the creation and implementation of large Protected Areas have. Transient group size ranged from 2 to 13, with a mean of 6.7 per! These cases was the male partner related to the estimated-age animals if typical, this a. Individuals that hunt together, each individual captures and consumes its own prey loud! French Guiana, Guyana, Paraguay, Peru, Suriname and Venezuela or these... A human family, this is actually the life of the 17 cubs,...