Draft Terms of Reference – Brazilian Agouti
- Provide information on the taxonomy of the species
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Suborder: Hystricomorpha
Family: Dasyproctidae
Genus: Dasyprocta
Species:leporina
Common name: Brazilian Agouti
The species was first described as Musleporinusby Linnaeus in 1758 (later modified to Dasyproctaleporina), but until 1978 was known by the junior synonym Dasyproctaaguti (Linnaeus, 1766).1,2 Other synonyms which have been used in the past include Dasyproctacayana (Lacepede, 1802) and Dasyproctarubrata (Thomas, 1898). 3There are a number of named subspecies (at least eight).4,5Captive populations are not generally assigned to subspecies as the origins of the founders are usually unknown. The species is also commonly known as the Golden-rumped Agouti, Red-rumped Agouti, Orange-rumped Agouti, and Golden Agouti.
1 Wilson, D.E. and Reeder, D.M. (eds) (2005) “Mammal Species Of The World: a taxonomic and geographic reference” (3rd edition) John Hopkins University Press
2Husson, A.M. (1978) “The Mammals Of Suriname” Leiden, the Netherlands
3Husson (1978), op. cit.
4 Wilson (2005), op. cit.
5Husson (1978), op. cit.
- Provide information on the status of the species under CITES
CITES Listing:no status
IUCN Red List Status:Least Concern (LC)
The Brazilian Agouti is not listed on the CITES appendices,6, and is listed as Least Concern (LC) on the IUCN Red List due to the species’ wide distribution and presumed large overall population.7
The Brazilian Agouti has a distribution covering a large part of north-eastern South America, including Venezuela, Guyana, Surinam, French Guiana, Brazil, and Trinidad and Tobago.8,9,10 Insular populations in the Lesser Antilles are largely derived from prehistoric introductions by man and have been isolated long enough to have evolved into distinct subspecies.11
Population figures are unknown but the species is considered common and non-threatened throughout its range.12,13,14,15
6
7
8 Eisenberg, J.F. (1989) “Mammals Of The Neotropics: vol. 1 the northern Neotropics” University of Chicago Press
9 Eisenberg, J.F. and Redford, K.H. (1999)“Mammals Of The Neotropics: vol. 3 the central Neotropics” University of Chicago Press
10 Emmons, L.H. and Feer, F. (1997) ”Neotropical Rainforest Mammals: a field guide” (2nd edition) University of Chicago Press
11Wilson, D.E. and Reeder, D.M. (eds) (2005) “Mammal Species Of The World: a taxonomic and geographic reference” (3rd edition) John Hopkins University Press
12
13 Eisenberg (1989), op. cit.
14 Eisenberg and Redford (1999), op. cit.
15 Emmons and Feer (1997), op. cit.
- Provide information about the ecology of the species.
Like most large-bodied rodents, agoutis are quite long-lived animals. Little is known of the life spans of wild animals, but the oldest captive record for the Brazilian Agouti is 17.8 years.16 Most agouti species are of a roughly similar size, with the Brazilian Agouti specifically having a body-length range of 45-69cm and weight of 3-6kg.17,18 Females average larger than males but the difference is not great.19
All agouti species are similar in general appearance, being relatively large (about the size of a cat) but slender-bodied, with long thin legs, hoof-like claws, coarse but glossy pelage, small ears, and almost no tail.20,21 The gross differences between species are determined partly by distribution and partly by colouration. The Brazilian Agouti is very easily distinguished from all other agouti species by its distinctive coloration: dark brownish on the forebody becoming obviously orange or reddish on the rear part of the body (hence the alternative names of Orange-rumped Agouti, etc).22,23
Brazilian Agoutis have a large natural distribution covering most of north-eastern South America, including Venezuela, Guyana, Surinam, French Guiana, Brazil, and Trinidad and Tobago.24,25,26 Their distribution is entirely tropical and while their primary habitat is rainforest they also inhabit less vegetated areas including farmland, so long as there is some dense cover in the area.27,28,29 They live entirely terrestrially and are active by day, year-round (i.e. there is no hibernation period).30,31,32
The primary diet of all agouti species is fallen fruit and seeds, collected opportunistically from the forest floor.33,34 Agoutis are what are known as “scatter-hoarders”: they routinely cache food items (i.e. burying seeds and nuts) in separate locations when food is plentiful, which they return to when food becomes scarce.35,36 Because they do not retrieve all cached items they play a valuable role in their native forests as seed dispersers for the forest trees.37,38
Brazilian Agoutis occupy home ranges of between 3 and 10 hectares.39,40,41 Population densities may be between 1 and 63 animals per square kilometre.42 Males are territorial towards other males.43 Young may remain with the parents for a certain period, forming family groups.44
16Weigl, R. (2005) “Longevity Of Mammals In Captivity; from the living collections of the world” E. Schweizerbart’sche: Stuttgart
17Husson, A.M. (1978) “The Mammals Of Suriname” Leiden, the Netherlands
18Emmons, L.H. and Feer, F. (1997) ”Neotropical Rainforest Mammals: a field guide” (2nd edition) University of Chicago Press
19 Mendes-Oliveira, A.C.; de Maria, S.L.S.; de Lima, R.C.S.; Fernandes, A.S.; de Alameida, P.R.C.; Montag, L.F.A.; and de Carvalho Jr., O. (2012) “Testing simple criteria for the age estimation of six hunted mammal species in Brazilian Amazon” MastozoologicaNeotropical, vol. 19:1
20 Nowak, R.M. (1999) “Walker’s Mammals Of The World” (5th edition), John Hopkins University Press: Baltimore
21 Emmons and Feer (1997), op. cit.
22 Emmons and Feer (1997), op. cit.
23Eisenberg, J.F. and Redford, K.H. (1999)“Mammals Of The Neotropics: vol. 3 the central Neotropics” University of Chicago Press
24 Emmons and Feer (1997), op. cit.
25 Eisenberg and Redford (1999), op. cit.
26Eisenberg, J.F. (1989) “Mammals Of The Neotropics: vol. 1 the northern Neotropics” University of Chicago Press
27 Emmons and Feer (1997), op. cit.
28 Eisenberg and Redford (1999), op. cit.
29 Eisenberg (1989), op. cit.
30 Emmons and Feer (1997), op. cit.
31 Eisenberg and Redford (1999), op. cit.
32 Eisenberg (1989), op. cit.
33 Henry, O. (1999) “Frugivory and the importance of seeds in the diet of the orange-rumped agouti (Dasyproctaleporina)” Journal of Tropical Ecology, vol. 15: pp. 291-300
34Dubost, G. and Henry, O. (2006) “Comparison of diets of the acouchy, agouti and paca, the three largest terrestrial rodents of the French Guianan forests” Journal of Tropical Ecology, vol. 22: pp. 641-651
35 Henry (1999), op. cit..
36Dubost and Henry (2006), op. cit.
37 Henry (1999), op. cit.
38Dubost and Henry (2006), op. cit.
39 Emmons and Feer (1997), op. cit.
40Silvius, K.M. and Fragoso, J.M.V. (2003) “Red-rumped agouti (Dasyproctaleporina) home range use in an Amazonian forest: implications for the aggregated distribution of forest trees” Biotropica, vol. 35: pp. 74-83
41 Jorge, M.S.P. and Peres, C.A. (2005) “Population density and home range use of red-rumped agouti (Dasyproctaleporina) within and outside a natural Brazil nut stand in south-eastern Amazonia” Biotropica, vol. 37 (2): pp. 317-321
42Silvius and Fragoso (2003), op. cit.
43 Eisenberg and Redford (1999), op. cit.
44 Emmons and Feer (1997), op. cit.
- Provide information on the reproductive biology of the species
Compared to most rodents agoutis are slow breeders, producing few but well-developed young and investing a lot of time in raising them successfully.45 Brazilian Agoutis form monogamous pairs which remain together long-term, although young often remain with the parents for extended periods to form small family groups.46,47Females are larger than males but not to anygreat degree.48
Litter sizes are of just one to three young, born after a gestation of 104-120 days.49,50The young are fully-developed and are active within an hour of birth.51The young are not weaned until about twenty weeks of age and they often remain with the parents for much longer, although male offspring are less tolerated than females.52Sexual maturity is reached at about nine months but this does appear to be affected by the presence or absence of males/adult females: studies have shown that female agoutis raised in captivity without males do not seem to reach puberty at all but young females raised in the presence of a male reach maturity at nine months ; however a male placed with adult non-cycling females results in the onset of the oestrus cycle within ten to sixty days. Furthermore the presence of an adult female delays or prevents the onset of sexual maturity in the female offspring.53
There is no set season for breeding. Studies of wild Brazilian Agoutis show they may breed at any time of year, although most births occur between November to April.54
45 Weir, B.J. (1974) “Reproductive characteristics of hystricomorph rodents” Symposium of the Zoological Society of London, vol. 34: pp. 437-446
46Weir (1974), op. cit.
47 Eisenberg, J.F. and Redford, K.H. (1999)“Mammals Of The Neotropics: vol. 3 the central Neotropics” University of Chicago Press
48 Mendes-Oliveira, A.C.; de Maria, S.L.S.; de Lima, R.C.S.; Fernandes, A.S.; de Alameida, P.R.C.; Montag, L.F.A.; and de Carvalho Jr., O. (2012) “Testing simple criteria for the age estimation of six hunted mammal species in Brazilian Amazon” MastozoologicaNeotropical, vol. 19:1
49 Eisenberg and Redford (1999), op. cit.
50 Weir, B.J. (1971) “Some observations on reproduction in the female agouti, Dasyproctaaguti” Journal of Reproduction and Fertility, vol. 24: pp. 203-211
51Weir (1974), op. cit.
52Weir (1971), op. cit.
53Guimaraes, D.A.; Ramos, R.S.L.; Garcia, G.W.; and Ohashi, O.M. (2009) “The stimulatory effect of male agouti (Dasyproctaprymnolopha) on the onset of female puberty” ActaAmazonica, vol. 39:4
54Dubost, G.; Henry, O.; and Comizzoli, P. (2005) “Seasonality of reproduction in the three largest terrestrial rodents of French Guianan forest” Mammalian Biology, vol. 70:2, pp. 93-109
- Provide information on whether the species has established feral populations
There are eleven species of agouti in the genus Dasyprocta.55 Of these only three have been introduced to the wild in countries or territories outside their natural ranges.56
The Mexican Black Agouti Dasyproctamexicana was introduced to Cuba from Mexico in the 1930s and became established in the western parts of the island.57
The Central American Agouti Dasyproctapunctata was likewise introduced to Cuba from Mexico in the 1930s and became established in the western parts of the island.58This species has also been established as an introduced species on the Cayman Islands, probably since the late 1800s.59
The Brazilian Agouti Dasyproctaleporina has a series of populations in the Lesser Antilles island group which are believed to be the result of introductions by Amerindians in pre-Columbus times.60 These populations have been isolated long enough to have developed into distinct subspecies.61 The Brazilian Agouti was also introduced to St. Thomas in the U.S. Virgin Islands in historical times, probably in the late 1800s but the population did not establish and was probably gone by the early 1900s.62
None of the three species have caused any problems, environmentally or agriculturally, in their introduced ranges. Long describes all three species as “Damage: none known”.63 In SimberloffRejmanek it is stated “neither agouti [punctata and leporina] is reported to cause ecological damage.”64 The only potentially negative impact is noted in Borroto-Paez where it is suggested that in Cuba there may be ecological competition with an endemic large-bodied terrestrial rodent, the Demarest’s hutia (Capromyspilorides), although this in unproven.65
55 Nowak, R.M. (1999) “Walker’s Mammals Of The World” (5th edition), John Hopkins University Press: Baltimore
56 Long, J.L. (2003) “Introduced Mammals Of The World: their history, distribution and influence” CABI Publishing: Wallingford, UK
57 Long (2003), op. cit.
58 Long (2003), op. cit.
59 Long (2003), op. cit.
60 Long (2003), op. cit.
61Wilson, D.E. and Reeder, D.M. (eds) (2005) “Mammal Species Of The World: a taxonomic and geographic reference” (3rd edition) John Hopkins University Press
62 Long (2003), op. cit.
63 Long (2003), op. cit.
64Simberloff, D. and Rejmanek, M. (2011) “Encyclopedia Of Biological Invasions” University of California Press: Berkeley and L.A., USA
65Borroto-Paez, R. (2009) “Invasive mammals in Cuba: an overview” Biological Invasions, vol. 11: pp. 2279-2290
- Environmental risk assessments of the species
The Brazilian Agouti is included in the Vertebrate Pests Committee’s 2007 “List Of Exotic Vertebrate Animals In Australia” where they assign it a threat rating of “Extreme” but with no data on how or why they arrived at this conclusion. Their previous rating was “2” (i.e. “limited to statutory zoos or endorsed special collections”). The two hystricomorph rodents currently granted importation into Australia are also on this list with threat assessments of “Extreme” (Capybara) and “Serious” (Patagonian Mara).
The Brazilian Agouti was considered for inclusion into the Zoo Rodent Import Policy by the Department of Agriculture, Fisheries and Forestry (DAFF), along with Capybara, Patagonian Mara and Cape Porcupine, but was (along with the Cape Porcupine) removed from consideration because the species was not yet represented on the Live Import List of the Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) and could therefore not be issued with an import permit. The Zoo Rodent Import Policy covers two species of hystricomorph rodents (Capybara and Patagonian Mara) and states that importation of other species of hystricomorph rodents may be considered on a case by case basis.
Quarantine requirements for hystricomorph rodents have been established for Capybara and Patagonian Mara, and would cover Brazilian Agoutis if these were to be imported.
- Assess the likelihood that the species could establish a breeding population in Australia
Brazilian Agoutis have been held in Australian and New Zealand zoos for very many decades with no instances of escaped animals forming wild populations. In Australia they are currently held at the Taronga (Sydney) and Melbourne Zoos; in New Zealand they are currently held at the Auckland, Hamilton and Wellington Zoos.
The likelihood of Brazilian Agoutis establishing a breeding population in Australia outside effective human control is very low. The only established introduced populations of agoutis are all on tropical Central American islands and are all derived from direct transplantation of wild animals.66
The wild distribution of agoutis is entirely tropical and they are not likely to survive in the wild anywhere that falls outside this climate.67Their primary habitat is rainforest and although in their native range they can adapt to disturbed habitats near to appropriate forests, they are unlikely to be able to establish long-term populations in less vegetated regions.68Being diurnal and primarily non-burrowing they are also quite obvious animals and could easily be recaptured if individuals should escape.69
They have a fairly narrow dietary niche, feeding largely on fallen fruits and large seeds and so their theoretical survival as a wild population would be completely restricted to rainforest where such items are abundant year-round.70
Brazilian Agoutis are slow-breeding animals, producing only one to three offspring per litter and breeding just once or twice a year.71,72Sexual maturity is reached at about nine months of age.73,74They are not rapid breeders as is common in rodents (e.g. mice and rats), and hence control of an established wild population would be easily achieved.
In the wild state in Australia it is unlikely a population could establish in the presence of mammalian predators (foxes and dingoes), avian predators (hawks, eagles, etc), and reptilian predators (pythons and large goannas).
66 Long, J.L. (2003) “Introduced Mammals Of The World: their history, distribution and influence” CABI Publishing: Wallingford, UK
67 Nowak, R.M. (1999) “Walker’s Mammals Of The World” (5th edition), John Hopkins University Press: Baltimore
68 Nowak (1999), op. cit.
69 Emmons, L.H. and Feer, F. (1997) ”Neotropical Rainforest Mammals: a field guide” (2nd edition) University of Chicago Press
70 Emmons and Feer (1997), op. cit.
71 Weir, B.J. (1974) “Reproductive characteristics of hystricomorph rodents” Symposium of the Zoological Society of London, vol. 34: pp. 437-446
72 Weir, B.J. (1971) “Some observations on reproduction in the female agouti, Dasyproctaaguti” Journal of Reproduction and Fertility, vol. 24: pp. 203-211
73Weir (1974), op. cit.
74Weir (1971), op. cit.
- Provide a comprehensive assessment of the potential impact of the species should it become established in Australia
Brazilian Agoutis are large-bodied diurnal rodents which feed primarily on fallen fruits and large seeds (nuts). [75,76] They are entirely terrestrial and cannot climb trees at all.77,78They do not burrow, instead simply utilizing natural thickets, hollow logs, etc for shelter.79,80There are almost no native Australian mammals which fill a similar role because there is no year-round supply of suitable food in most habitats of the country. The habitat exception is the Wet Tropics of Far North Queensland. The Musky Rat Kangaroo (Hypsiprymnodonmoschatus), which is found there, is a similar-sized ground-dwelling diurnal fruit-eater and hence competition may be a factor but their distribution range falls well outside the location of most zoos in the country.81The Double-wattled Cassowary (Casuariuscasuarius) of Far North Queensland also feeds to a large extent on fallen fruits, but direct competition would be unlikely.82
If a wild population should become established there would be little to no impact on the environment. Agoutis do not usually dig burrows,83,84they do not interfere with other animals in any respect (e.g. by attacking or preying on them),85,86and even in the human-introduced populations in the Caribbean there have been no recorded detrimental effects on the local environments or other animal species.87Agoutis cache food supplies (i.e. nuts and large seeds) and hence act as distribution agents for those tree species which produce such fruit and nuts, but they do not usually feed on or cache small seeds and so cannot be an agent of distribution for smaller pest plants.88Agoutis are commonly found near waterways (streams etc) but they do not actively enter water or use it for obtaining food.89
A feral population of Brazilian Agoutis would have little to no impact on primary industries such as farming or agriculture. In their native ranges they may inhabit disturbed habitats (e.g. farms) if they are near forest, but they do no damage.90,91Their primary diet is fallen fruits and nuts; they cannot climb to obtain fruit from the tree itself.92,93They do not damage trees or compete in any way with livestock.94,95,96Because they are a low-density forest-dwelling animal, living alone or in pairs, they do not cause any nuisances in human-dominated surroundings.97,98,99
Brazilian Agoutis can be carriers of several external parasites such as ticks and fleas, and internal parasites such as nematodes, all of which can be treated effectively before/during quarantine.100They can also be carriers of host-specific Eimeria species.101Wild and wild-caught Brazilian Agoutis have been known to be carriers of Echinococcusoligarthrushydatid cyst disease, which is found only in Central/South America and is spread between large felids (e.g. pumas and jaguars) and rodents.102This is not an issue with captive-bred agoutis from zoos outside the disease’s distribution. As with many mammal species, including Capybaras (Hydrochoerushydrochoeris) and other hystricomorph rodents,103 agoutis can be carriers of Foot-and-Mouth Disease but this has only been recorded in laboratory situations through deliberate infection.104