Applied Animal Ethology, 7 (1981) 293-299 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands

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Case .Report

SUCKLING BEHAVIOR OF LLAMA (LAMA GLAMA GLAMA) AND CHAPMAN’S ZEBRA (EQUUS BURCHELLI ANTIQUORUM) IN CAPTIVITY

JACQUES PRESCOTT

Jardin zoologique de Qukbec, 8191, avenue du Zoo, Charlesbourg, Qutfbec Gl G 4G4 (Canada)

(Accepted for publication 17 March 1980)

ABSTRACT

Prescott, J., 1981. Suckling behavior of Llama (Lama glama glama) and Chapman’s Zebra (Equus burchelli antiquorum) in captivity. Appl. Anim. Ethol., 7: 293-299.

Suckling behavior of one Llama foal and one Chapman’s Zebra foal born in captivity is presented. Both animals suckled less frequently and spent more time grazing as they grew older. The suckling frequency of the Zebra foal was twice that of the Llama but on the average each Llama-suckle lasted twice as long. These differences are analyzed and evidence for a dual function of suckling behavior is discussed.

INTRODUCTION

Although well documented in some ungulate species (see Lent, 1974, for a review), nursing behavior is still poorly known in Zebras and Llamas. Some information on the mother-infant relationships in the Zebra (Equus burchelli ssp.) can be found in Wackernagel(1965), Klingel and Klingel (1966), Klingel(1974) and Smuts (1976), and the mother-infant bond of zoo-living Llamas (Lama gluma) has been studied by Pilters (1954). However, the suckling behavior of foals of the two species concerned has never been studied.

This study presents an account of the frequency and duration of suckling as observed in one Chapman’s Zebra foal (Equus burchelli antiquorum) and one Llama foal (Lama grama gluma) born in captivity.

The results have practical implications in giving some insights in the way one could best bottle-feed orphaned or rejected wild or captivity-born Zebras and Llamas.

0304-3762/81/0000-0000/$02.50 0 1981 Elsevier Scientific Publishing Company

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ANIMALS AND METHODS

Animals

Llama The subject of the study is a female Llama foal (Lama glama glama) born

at the Jardin zoologique de Quebec on 22 July 1977. Her mother is a primi- parous 2-year-old female born at the zoo on 15 September 1975.

At the time of study, these animals were kept in a large (1600 m’) outdoor enclosure along with two other captivity-born animals: a 4-year-old male and a 4-year-old female. Animals were fed each morning with hay and hoofstock feed pellet ration. Natural grass growing in the paddock was actively grazed by the animals.

Zebra The animal studied is a female Zebra foal (Equus burchelli antiquorum)

born at the zoo on 21 June 1977, from a 6-year-old primiparous mare also born at our zoo on 26 June 1971.

The foal and its mother were kept in a large (1500 m’) paddock with a 23-year-old stallion and a 23-year-old mare. Feeding conditions were similar to those of the Llamas.

Methods of study

Suckling behavior of both Llama and Zebra was studied during two con- secutive periods: from 3 to 12 and from 17 to 27 days of age for the Llama, and from 28 to 44 and from 55 to 68 days of age for the Zebra. All the suckling bouts that occurred during the 118 hours of observation (from 19 July to 28 August 1977) were recorded and timed to the nearest 5-s interval.

The observed animals were always within 30 m from the observer. How- ever, it was often difficult to ascertain whether each mouth-udder contact led to successful suckling, especially when this contact lasted only a few seconds. Sometimes, the foal would only lick the udder of the mare without actually suckling. For this reason, only the mouth- -udder contacts lasting 5 s or more were considered to be suckling events. Two consecutive suckling bouts were considered as distinct when separated by more than 5 s. How- ever, intervals between successive suckles were seldom shorter than 10 s; only 2.92% of all intervals recorded in the Zebra and 6.11% in the Llama were between 5 and 10 s.

RESULTS

Suckling behavior of Llama

A foal born on 26 July 1978, and observed non-stop for several hours

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from the time of birth, was first seen to contact the mother’s udder with its muzzle 62 min after birth and 71 min before the first successful suckling. The latter lasted about 3 min. The second successful suckling bout lasted about 3.5 min and occurred half an hour later, that is 2 h 43 min after birth.

On 5 October 1977 and 10 October 1978, the first mouth-udder contacts of two other newborn Llamas were recorded around 50 min after birth. Whether suckling actually took place or not in these instances, however, is WlkIlOWn.

All 157 suckles observed in the Llama were performed in the reverse parallel suckling posture commonly seen in ungulates (Lent, 1974). Even if most of the suckles were directed toward the mother, suckling was occa- sionally tolerated by other lactating females.

Suckling frequency decreased with age (Table I). Also, the foal spent more time grazing and less time suckling as it grew older (Fig. 1).

The mean duration of a single suckle was 55.4 s (n = 157). As can be seen in Fig. 2, the distribution of the suckling events according to their duration shows three peaks: a main peak at 15-20 s, a second one at 45-50 s and a third one at 105-110 s.

The longest recorded suckling event lasted 210 s, and 41.4% (n = 157) of the suckles were shorter than 20 s.

, Grazing

Fig. 1. Feeding activity of a captivity-born Llama foal expressed as percentage of observation time. The foal was first seen grazing when 10 days old.

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TABLE I

Suckling frequency

Age (days) Number of Suckling frequency hours of per hour observation

Llama 3-l 2 28 3.4 17-27 30 2.1

Zebra 28-44 30 5.6 55-68 30 3.8

45

Age of young -

Duration of suckle (seconds)

Fig. 2. Duration of suckling bouts in a captivity-born Llama foal.

Suckling behavior of Zebra

As in the Llama, the reverse parallel suckling posture was commonly used by the Zebra foal. On only a few occasions did the foal try to suckle from behind, but it never succeeded.

Suckling frequency decreased markedly from the second to the third month after birth (Table I).

Feeding activity varied greatly with age, the foal spending more time grazing and less time suckling as it grew older (Fig. 3).

The mean duration of the 283 suckling events recorded was 30.8 s. The distribution of these suckling events according to their duration reveals two peaks; a main one at 5-10 s and a secondary one at 75-80 s (Fig. 4).

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28-44

Fig. 3. Feeding activity of observation time.

of a captivity-born Chapman’s Zebra foal expressed as a percentage

Age of young

0 28-44days (n=l69)

??55_6* days (n=,,4)

Duratm of suckle (seconds)

Fig. 4. Duration of suckling bouts in a captivity-born Chapman’s Zebra foal.

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The longest recorded suckle lasted 135 s and 56.9% of the bouts (n = 283) were below 20 s in duration.

DISCUSSION

However limited the number of animals involved in the observations, and despite the age difference between them, the author feels that the best possible experimentation was carried out and that interesting conclusions may be drawn from the data. Nevertheless, some of the interpretations of interspe- cific comparisons suggested here should be considered with these experimental limitations well in mind.

As is the case with many ungulate (Lent, 1974), the two animals studied suckled less frequently as they grew older. However, the frequency and dura- tion of suckling varied greatly from one species to the other.

Even if at the time of study the Zebra foal was older than the Llama, his suckling frequency was almost twice that of the Llama. On the other hand, the mean suckling bout was approximately twice as long in the Llama as in the Zebra. Finally, the proportion of short suckles (less than 20 s) was con- siderably larger in the Zebra than in the Llama. Interestingly, these differ- ences cancel out, resulting in both animals spending about the same propor- tion of their time suckling (4.2% in the first month of life).

From our data, we expect that orphaned or rejected Zebra foals would be successfully raised if bottle-fed 3 times per hour during the day, each feeding session being shorter than one minute. In the same conditions, a Llama foal should be fed twice per hour with each feed lasting at least one minute. This remains to be tested.

Even though our data is limited, there seems nonetheless to be a clear difference in the nursing behavior of Llama and Zebra. The difference can be correlated to specific differences in mother-infant relationships. From the naturalistic observations of Klingel (1974) and Smuts (1976), we know that Zebra foals show a strong tendency to follow any moving object when only a few days old. The high frequency-low duration suckles exhibited by our Zebra foal may be correlated to that follower-type mother-infant relation- ship. The survival value of a high suckling frequency may be in helping to establish and maintain a close mother--infant bond (see later).

Llamas are less typical followers. In captivity, the foal did not always follow its mare around the paddock as did the young Zebra, and was often seen resting far from her. The low frequency-long duration suckles recorded in the Llama can be correlated to this looser mother-infant bond, and in fact can constitute a measure of this type of bond.

Neither of the two distributions of suckling durations presented in Fig. 2 and 4 exhibit the normal distribution pattern that one might expect. In the Zebra, the distribution clearly shows two peaks and seems to correspond to the superposition of a Poisson distribution (having its mode around 5-10 s) and a normal distribution (having its mode around 75-80 s). In the Llama,

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the same tendency is shown, although less clearly. In that case, the peak of the Poisson distribution is around lo-20 s and the peak of the normal distri- bution pattern would be around 105-110 s.

These dual distributions suggest the existence of two types of suckling: long and short duration. Since the main function of suckling is feeding, one would expect a long suckling bout to be more effective than a shorter one in that respect. On the other hand, short duration suckling may constitute a particularly effective way to promote mother-infant cohesion. Although the foal probably gains some milk from short suckling bouts, their main function would be to strengthen the mother--infant bond through an in- crease in the frequency of olfactory, tactile, visual and auditory contacts.

This hypothesis is supported by the fact that in the two species studied, high frequency-short duration suckling bouts are much more common in the Zebra, i.e. in the species exhibiting the closest mother-infant relation- ship and the one that expectedly needs it most as an adaptation to its high mobility and gregariousness.

Although this hypothesis still has to be substantiated, it may be viewed as further evidence for the dual function of suckling “satisfying both nutri- tive and non-nutritive emotional needs of the young animal” (Lent, 1974, p. 33).

ACKNOWLEDGEMENTS

The author is particularly indebted to B. Aubin who recorded most of the observations, and to Dr. C. Barrette who reviewed the manuscript. Dr. R. Patenaude, R. Joly and P. Richard helpfully commented on early drafts of the text. J. Gag& typed the manuscript and R. Ouellet prepared the figures.

REFERENCES

Klingel, H., 1974. A comparison of the social behaviour of the equidae. In: V. Geist and F. Walther (Editors), The Behaviour of Ungulates and its Relation to Management. Vol. 1. Morges, Switzerland, IUCN Publ. No. 24, pp. 124-132.

Klingel, H. and Klingel, U., 1966. Die Geburt eines Zebras (Equus guugga bahmi Matschie). Z. Tierpsychol., 23: 72-76.

Lent, P.C., 1974. Mother-infant relationships in ungulates. In: V. Geist and F. Walther (Editors), The Behaviour of Ungulates and its Relation to Management. Vol. 1. Morges, Switzerland, IUCN Publ. No. 24, pp. 14-55.

Pilters, H., 1954. Untersuchungen llber angeborene verbaltensweisen bei Tylopoden, unter besonderer Beriicksichtigung der neuweltlichen Formen. Z. Tierpsychol., 11: 213-303.

Smuts, G.L., 1976. Reproduction in the Zebra mare Equus burchelli antiquorum from the Kruger National Park. Koedoe, 19: 89-132.

Wackernagel, H., 1965. Grant’s Zebra, Equus burchelli boehmi, at Basle Zoo -a contribu- tion to breeding biology. Int. Zoo Yearb., 5: 38-41.