by * Adriana G. Consorte-McCrea
This article is a brief account of a six month study
related to the breeding of maned wolves in captivity, conducted
at the São Paulo Zoological Park Foundation, Brazil.
The maned wolf (Chrysocyon brachyurus) is the largest South American canid and is easily identified by its long dark legs, orangy brown coat and dark mane (see illustration below [coming soon]). In addition to its distinctive appearance, it has some interesting habits, including a solitary lifestyle and largely frugivorous diet.
The maned wolfµs survival in the wild is threatened by a number of factors, including hunting, superstition and habitat loss to farms (Encke, 1970). Some local rural people attribute mystical qualities to several parts of the wolfµs anatomy (eyes, skin, tail), which are used as "talisman" or for medicinal remedies. They also consider the wolf a threat to domestic poultry. Meanwhile, as its habitat is encroached upon by ever-expanding farms, the wolf is forced into increasing proximity with people. The species is classified as "Vulnerable" in the IUCN Red Data Book.
The situation regarding environmental protection and the creation and maintenance of ecological reserves is still precarious in the areas where wild maned wolves remain, so it is important that zoological institutions around the world take responsibility to protect and breed animals in captivity. Unfortunately captive breeding has not proved to be easy.
At the São Paulo Zoological Park Foundation (São Paulo state, Brazil) attempts to breed maned wolves repeatedly met with problems; females did not seem able to rear their litters. Other zoos have also experienced difficulties, with the female maned wolf eating, burying or abandoning her newborn pups. The work reported here, which was undertaken as part of the authorµs apprenticeship to the Mammals Section of the Zoo, aimed to remedy these breeding difficulties.
Maned wolves inhabit cerrado vegetation and swampy areas from central and south eastern Brazil to north eastern Argentina and eastern Paraguay and Bolivia (IUCN, 1982) (see map, page 41).
Forming stable monogamous pairs, maned wolves are not abundant anywhere (Coimbra-Filho, 1972). Each pair occupies a territory of about 25-30 km² encompassing a variety of vegetation types (Red Data Book, 1982). The pair shares the territory and frequently the same resting, foraging, urinating and defecating sites, but they generally travel independently outside the whelping season (Carvalho, 1988). Although the female does not appear to depend upon her partnerµs help in caring for the pups, the fact that male maned wolves show a high rate of vocalization, scent marking and territorial defence may make an important indirect contribution to the female and pups (Dietz, 1984). Certainly, paternal care is the general rule amongst canids (e.g. reviews in Macdonald, 1992) so it might be expected in the maned wolf.
Maned wolves are highly territorial in the wild (Carvalho, 1976; Dietz, 1984). They inhabit relatively open regions with long vegetation cover, making it difficult for them to see other wolves, so they rely on long distance communication. Kleiman (1972) describes barking, a highly visible threat display, and scent marking with faeces and urine. Maned wolves are opportunistic generalists, small animals (rodents, insects) comprising about 30% of their diet and fruits 70%, including "fruta-do-lobo"- wolf's fruit (Dietz, 1984; Gomes da Silva, 1988). Foraging begins just after sunset and ends after sunrise.
Females in captivity in the southern hemisphere show only one oestrus per annum, between March and April. Following a gestation period of approximately 66 days, births occur between June and August. The problem of neonatal infanticide in captivity must be solved if captive breeding is to be more successful. Neonatal infanticide amongst primaparous females is recognized as a general phenomenon amongst many mammals, especially felids, and is reviewed by Guittin (1982). The persistent neonatal cannibalism shown by the São Paulo maned wolves may be caused by stressful conditions.
At the time of the study, the collection at São Paulo comprised 3 pairs of wild-caught adults which had never bred successfully at the Zoo. The facilities for the maned wolves consisted of a large (200 m²), well vegetated island enclosure, surrounded by a ditch and open to public view, and three adjacent fenced areas with dens which were not visible to the public (enclosure 126). Each fenced enclosure contained a 4x12m concrete floor, a 3x4m covered den, and a tunnel giving access to the island (see Figures 1, 6 & 7).
Only one pair of wolves was allowed onto the island each day, so the 3 pairs were subject to a daily rotation scheme, each spending one day on the island (from 8.30a.m. to 5p.m.) followed by two days in their fenced enclosure. Enclosure 126 was cleaned on a daily basis at 10.30a.m. and food trays were introduced at 4.30p.m.
A total of 127 hours of direct observation was recorded between August 1987 and January 1988 (i.e. 6 months of the females' anoestrous period). Each observation of a pair lasted 30-60 minutes, and took place between 8 a.m. and 6 p.m. Of the total, 39 hours were devoted to wolves on the island enclosure, the remaining 88 at enclosure 126. During this time the wolves were subject to varying amounts of privacy. In October pair A was removed from the island-sharing rota, followed by pair C from 17th November. For the latter part of the study pair B thus had exclusive access to the island territory. We hoped to test the hypothesis that privacy plays an important role in the maned wolf's reproductive behaviour in captivity.
From faecal analysis, Gomes da Silva (1988) reported the wild maned wolf diet to consist of the following:
Carvalho (1988) recommended that a suitable daily diet for maned wolves in captivity might consist of the following (depending on availability): 900 g seasonally available fruits (e.g. avocado, pineapple, peeled orange, caqui, banana, cerrado fruits), and 400 g animal matter (e.g. egg, 1/2 chicken, chicken's head and neck, cow's stomach and cartilage, 1 or 2 chicks).
At São Paulo the maned wolves' daily diet comprised 1100 g of animal food and 200 g of vegetable matter. Their diet would thus appear to be too rich in meat but the animals eat all the meat provided. It is likely that this is a common fault in captive maned wolf diets, and the Maned Wolf SSP Propagation Group (at Front Royal, USA) is currently studying the effects and potential health hazards of an excess of meat in the speciesµ diet.
Whilst in the island enclosure the wolves are disturbed very little by humans, other than by the presence of zoo visitors, and the dens and good vegetation cover provide tolerable privacy from audiences. In enclosure 126, however, where the wolves spend most of their time, they are disturbed by keepers at least twice a day. To a species which in the wild roams alone over large distances the regular presence of humans in a confined space could play a significant part in increasing stress.
Maned wolves are territorial, but their low density in the wild means that aggressive intraspecific encounters are probably infrequent. At São Paulo, however, the three pairs are kept in close proximity, leading to potentially stressful levels of territorial aggression. The pair on the island is separated from the other wolves in enclosure 126 by about 20m, so vocalizations are the main form of communication available. The pairs in the fenced enclosures are in continual auditory, olfactory and visual contact through the bars, which in combination with the restricted space available provides highly unnatural conditions. Moreover, each pair appears to treat the island enclosure as its own territory, and the timetabled sharing brings each pair into contact with the territorial scent markings of the previous occupants.
The graphs in Figure 2 illustrate differences in the vocalizations shown by pair B while in enclosure 126 and on the island during the study. The "bark" is a long-range communication (often preceded by amicable intra-pair interactions), and is used most often on the island, when other wolves are more distant. In the enclosure barking is much rarer than growling, a short-distance aggressive vocalization. The trends in frequency of the types of vocalization are probably due to the change in management. After mid-November only pair B had access to the island enclosure. From November to January there was an increase in barking by the male on the island and an increase in growling whilst in enclosure 126. This could be a result of more "natural" territorial behaviour due to the visual and olfactory isolation of the island couple from the other maned wolves. We also suggest that restricting contact between pairs to just vocalizations results in more amicable inter-pair interactions.
Contrary to expectation (Dietz, 1984), males urinated more frequently than females during the anoestrous period, both in enclosure 126 and on the island. Stress due to the constant close proximity of other maned wolves may intensify the male's territorial behaviour, resulting in unnatural levels of scent marking. There are no clear trends in behavioural changes in scent marking between November and January.
Females spent more time than males lying down, out of sight of observers and neighbouring maned wolves. Males were less timid, spending more time than females moving around, perhaps linked to a greater role in territorial defence. Both males and females spent nearly twice as long standing still on the island as in enclosure 126, probably in response to the greater degree of isolation from the other wolves and the more natural surroundings of the former environment.
Inside the enclosure, most movements serve to increase the distance between male and female, in stark contrast to behaviour on the island, where movements towards each other were more common. The rise in voluntary movements towards the partner increased considerably in the last 2 months of the study, after the other pairs ceased to be allowed access to the island. This might indicate that pair B felt more relaxed in their territory in the absence of other wolves' scent marks. The almost complete lack of distance-decreasing behaviour in enclosure 126 is not very surprising, given that members of a maned wolf pair tend to forage alone in the wild.
Based on knowledge of the ecology of the species, analyses of the material collected from behavioural observations, and on data from captivity we suggest that the wolves we observed had been subject to stress, caused mainly by the uninterrupted presence of other pairs of maned wolves. This social stress appeared to affect several aspects of their behaviour, and could be the cause of the captive breeding problems. Measures to increase privacy, particularly by allowing only one pair access to the island territory, resulted in an increase in amicable behaviour within the pair and a decrease in intra-pair alarm and aggressive behaviour.
The long term use of the island by one pair would appear to fulfil three important privacy requirements:
To avoid stress it would therefore seem important to attempt to isolate neighbouring pairs as far as possible. It would also be advisable to provide several potential dens in each enclosure, allowing the female to choose one that suits her and her pups, and giving more space to the male. Provided that they can den separately, male and female can be kept together after parturition. Privacy could also be enhanced by reducing interference from zookeepers.
An enclosure equipped with vegetation offers natural options of denning and facilitates other natural wolf behaviour (such as digging, chewing plants and walking). A diet closer to the composition found in the wild, with an extra supplement of fibre for those who do not have access to vegetation could also be considered.
Currently the maned wolf's natural environment is not receiving sufficient protection to make reintroduction feasible in the near future. In the meantime, it is important that knowledge of the species' ecology is applied to its requirements in captivity in order to maximize the potential of the captive population.
On a practical front some progress has been made in a number of zoos. Manipulation of factors such as security for the female have improved captive breeding results. Following the success achieved by Frankfurt Zoo in 1968 (Faust & Scherpner, 1968), other zoos have achieved good results in the rearing of pups by their own mothers (in Brazil, successes are recorded at Curitiba Zoo, Sorocaba Zoo, and most recently, São Paulo Zoo). Hand-rearing still remains a useful option, but it is not problem-free (Acosta, 1972; Diniz & Deutsh, 1980; Rodden & Blakely, 1987).
Since our study, the breeding situation at São Paulo Zoo has improved. On 5th June 1988 female B gave birth on the island, but the pups were never seen. Unfortunately, the additional privacy that had been afforded the pair before the birth was replaced by considerable management interference after the birth of the pups. The male was removed from the island and isolated in enclosure 126, the zookeepers went into the island enclosure to attempt to see the pups, and the grass inside the enclosure was cut. When, on 26th June 1989, female B gave birth to a litter of three female pups, the zoo management decided to hand rear them.
In the following year several wolves died from disease, after which male C and a new female occupied the island enclosure. On 10th June 1992 two male pups were born. On this occasion the male was not removed and no attempt was made to touch the pups. The two pups were successfully reared by the female and have now attained maturity. In 1993 the management introduced a new routine involving some sharing of the island enclosure by more than one pair of wolves. It remains to be seen what effect this will have on future breeding success.
Acknowledgements. I am grateful to Dr. D. Macdonald and Laura Handoca for their invaluable participation; to Dr. J.Gipps, Dr. D.Waugh, Dr. H.Lucker, Dr.W.Encke and Dr. B.Matern for receiving me at their zoos; Dr.J.Dietz, Melissa Rodden, Dr.Lilian M.Diniz and Dr. C.Carvalho for all the information and Dr. F.Simon and the São Paulo Zoological Park Foundation for making this work possible.
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* Adriana G. Consorte-McCrea graduated in Biological Sciences at the Federal University of São Carlos, SP, Brazil, and has been studying the relationships between privacy and performance of the maned wolf in captivity since 1987, when she undertook her apprenticeship at São Paulo Zoo. Since 1993 she has been coordinating the Alta Floresta Centre for Environmental Studies at the Cristalino Ecological Institute, a Brazilian NGO which aims to help researchers study the meridional Amazon.
© 1994 International Union for the Conservation of Nature and Natural Resources
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