\9T72 io8 BREEDING times I observed ample urination of clear fluid The baby is obviously gaining weight and, after the mother had cleaned the perineal area barring unforseen events, I am confident that with her tongue, and on the fifth day I noticed a Mumbi will continue to care adequately for her yellow-coloured stool denoting passage of milk offspring, whom we have named Kumba. through the intestinal tract. Notes on the behaviour and breeding of pacaranas Dinomys branickii in captivity L. R. COLLINS & J. F. EISENBERG National Zoological Park, Washington, DC, USA INTRODUCTION tion. Although they were compatible and were The pacarana Dinomys branickii is a large cavio- maintained together in large quarters for four morph rodent inhabiting the valleys and lower months, no sexual behaviour was observed be- slopes of the Andes in Colombia, Ecuador, Peru, tween them. Female 1 died on 8 June 1968; male Brazil, and Bolivia (Walker, 1964). Little is known 1 lived until 23 August 1968. of the behaviour of free-living specimens (Tate, An additional female ($2) was acquired as an 1931; Sanborn, 1931), but a few accounts have immature animal on 1 March 1968. She was been published on their behaviour and main- housed with male 1 after the first female's death, tenance in captivity (Mohr, 1937; Crandall, but again no sexual activity was observed. 1964). Gravid females have been taken in Feb- Female 2 was then transferred to the Research ruary and May. Females have four mammae, and Division and an intended mate (<? 2), which had two young apparently constitute the average been acquired on 17 July 1968, was placed with litter. Dinomys are thought to be nocturnal and her. These two animals were housed in a metal- captive animals are primarily active after dark. lined enclosure measuring 3*6X i-oX 12 m (12X Although several zoos have maintained this 3^X4 ft). This was subdivided into four equal- species, its breeding in captivity has been re- sized compartments by the addition of metal corded only recently. C. Schmidt (pers. comm.) panels with sliding access doors. Each animal had reports two successful matings at Zurich Zoo. access to two compartments except during breed- The first gravid female died before parturition, ing encounters when both animals could get into but the most recently-mated female was still alive all four compartments. Stout branches were pro- on 10 January 1971. A female at San Antonio vided for climbing, and wood shavings were laid Zoo gave birth to two young on 8 January 1970 on the floor. after arriving gravid from the wild. Pacaranas Copulation was observed between female 2 and have been investigated since 12 February 1968 male 2 on 24 July 1968, but unfortunately the by personnel of the Research Division of the female died on 7 August 1968. An autopsy revealed National Zoological Park. myocarditis as the cause of death. It is interesting that, although the female was receptive to the BREEDING HISTORY AND MAINTENANCE OF male's mating attempts, the animals could not be COLLECTION housed together for extended periods without Five Dinomys branickii have been maintained in fighting. The same situation later prevailed our collection. The first pair of specimens, between male 2 and female 3. acquired on 7 February 1968, consisted of a large Since male 2 showed promise of being a poten- female (? 1) and a smaller male (<? 1). These ani- tial breeder, a third female (acquired on 7 May mals were kept together for a short period in an 1968, and subsequently placed on exhibit) was observation arena measuring 6-5x5m (2i|x transferred to the Research Division in an attempt 16% ft); they were subsequently placed on exhibi- to mate her with male 2. Copulation occurred BREEDING 109 between this pair of animals and several intro- hind foot of the opposite side. At a slow walk the missions were observed on 23 June 1969, but animal is plantigrade but as it increases speed, again the animals had to be separated at night to the heel of the hind foot is not brought into full prevent fighting. Female 3 did not become preg- contact with the floor; hence, the animal be- nant as a result of the recorded mating, and, on 6 comes semi-digitigrade during fast quadrupedal April 1970, both animals were placed in a rect- locomotion (Mohr, 1937). The animal can walk angular cage where they are at present housed. bipedally and very frequently does so during This enclosure measures 49X 1 zx 12m (i6x4 social encounters. This consists of moving the X4A). Subdivision of the run is possible by hind limbs alternately while maintaining an up- closing a central partition; however, this was not right posture. The animals are unable to jump at first necessary as the animals were compatible but they climb very well using the crossed exten- when placed in this larger arena. Fresh wood sion pattern. Descending a tree trunk is accom- shavings are provided daily as cover for the con- plished by reversing this pattern and descending crete floor. Shelving 45 cm (18 in) wide was rear end first. They are able climbers and their installed approximately 45 cm (18 in) above the long claws aid them in ascending trunks which are floor at both ends of this enclosure, to which too large to be easily clasped. Their climbing ramps provided access. Both animals seemed to ability is similar to that of the North American prefer these elevated shelves as resting places. porcupine Erethizon dorsatum. The latest and only productive mating took In the wild, the animals are said to den in a place in this enclosure on 13 April 1970. It is not burrow; apparently they use natural crevices by known whether fertilisation occurred on this date, enlarging them somewhat through digging (Tate, but no further mating behaviour was observed 1931). In captivity, the animals readily used nest until the animals were separated on 10 July boxes, although at times they prefer to sleep on a 1970. The interoestrous interval for Dinomys is raised shelf. This suggests that they may sleep in unknown but our experience with other large trees if opportunity affords. caviomorph rodents leads us to believe that it They may adopt a variety of postures when may be from four to six weeks. Hence, conception sleeping, including resting on the heels and the may have taken place one or two months later than base of the tail while sitting in an upright posi- 13 April. For this reason, gestation could not be tion with the head drooping slightly on the chest; determined exactly but it is certainly not more than lying on one side at full length; or lying on the 283 days nor less than 223. back with the ventrum fully exposed. Sleeping in Both animals receive a diet consisting of corn- the first position, that is, while sitting, is especially on-the-cob, kale, white and sweet potatoes, common when the animal rests in the crotch of a carrots, apples, oranges, bananas, grapes, a tree or utilises sleeping shelves. Nest-building variety of breads, a seed and grain mixture, behaviour by pregnant or parturient females was monkey biscuits and pelleted alfalfa. Fresh or never observed. fresh-frozen corn-on-the-cob is an excellent Typically the animals feed while upright, hold- dietary component when weight gain is desired. ing the food with the forepaws. They are quite This item is usually the first to be eaten when the selective in their feeding habits as has been noted daily feed is placed in the enclosure. It also serves in the previous section. No caching behaviour as an excellent medium for administering liquid could be detected on the part of our specimens. multi-vitamin drops or medication, and the speci- The animals have rather complicated self- mens receive one cob daily unless weight gain is grooming patterns. A specimen will alternatively desired. stroke the length of its face with the inner part of its wrists, first the right side, then the left. It BEHAVIOUR PATTERNS AND ASSOCIATION may pause to wipe the wrists on the inside of the VOCALISATIONS lips at the conclusion of the down stroke, repeat- ing the arm or wrist stroke on the face. After General maintenance behaviour: The animals several wipes on the face, the animal will begin move about by means of a crossed extension to brush down and backward along its flanks with pattern with a forefront in synchrony with the the wrists, pausing to scratch with its fore-claws BREEDING under an arm or between the legs. It appears that related to visual display functions but, rather, are the washing pattern involves wiping the wrists on movements accompanying the various positions the side of either cheeks, brushing down over taken up during combat. Olfactory signals are the face and flanks with the wrists, followed by probably involved in marking behaviour, naso- delicate scratching movements. The claws of the genital investigation, and naso-nasal contact. forepaws may be used to scratch around the eyes General odours emanating from a conspecific and ears. The hind foot is also used to scratch the are probably perceived during all close contact cheeks and face. interactions and, indeed, it is difficult to separate A pacarana will generally urinate and defaecate tactile communication from olfactory communica- at a single locus in its cage, urine and faeces gen- tion during such interaction. Hence, rather than erally being deposited on the same spot. When two separate these two forms, they will be con- animals are housed together, they will use a com- sidered together when we discuss the various mon toileting spot within the cage.