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Mother–offspring relationships in donkeys
Applied Animal Behaviour Science 60 Ž1998. 253–258
Mother–offspring relationships in donkeys Jane M. French
)
Crofters Middle Dimson, Gunnislake, Cornwall PL18 9NQ, UK
Abstract The social relationship between female domestic donkeys Žjennies. and their offspring was explored by observation of their spatial relationship. The donkeys were kept together for life and the ages of the offspring at the beginning of the observation period ranged from a few hours to 13 yr. There was a gradual change in the jenny–foal spatial relationship in the foal’s first year reflecting the foal’s increasing independence. The offspring’s sex made no difference to this relationship. Jennies stayed very close to their newborn foals but thereafter approached them less frequently and had an overall tendency to move away. The foals responded by moving towards their mothers and so maintaining contact. Older foals were less persistent in following their mothers. In this study, jennies moved away most persistently from their 10-month-old foals. In unconfined conditions, this would begin the process of weaning. Since older foals are also often observed to be some distance away from their mothers, this also allows for the possibility that they can become separated by some external event. Under conditions of domestic management, e.g., unlimited resources, confinement and reproductive inactivity, jenny and offspring do not separate at weaning and their spatial relationship reverts to the close relationship seen between jennies and young foals. This is due mainly to a change in the jennies’ behaviour from leaving to approaching and, to a lesser extent, to an increased frequency of approach by the offspring. The result is a pair of adult donkeys that stay very close together and are equally active in maintaining contact. This close relationship may provide some benefits. One potential benefit is an immediately available and willing grooming partner. Another is the potential for the pair to develop a coalition for future support, for example, in accessing resources and mutual protection. q 1998 Elsevier Science B.V. All rights reserved. Keywords: Donkey; Social relationships; Weaning; Companion animal; Motherroffspring bond
1. Introduction Where animals are not closely confined, proximity is commonly used as a measure of affiliation between individuals. In equids, mares stay very close to their newborn foal for )
Tel.: q44-1822-832841
0168-1591r98r$ - see front matter q 1998 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 1 5 9 1 Ž 9 8 . 0 0 1 7 3 - 7
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J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
the foal’s first few days, and the foal suckles frequently. In horses Ž Equus caballus ., mares rarely move more than 5 m away during the foal’s first few weeks ŽTyler, 1972; Crowell-Davis, 1986.. Thereafter, mares gradually spend more time farther away, and suckling becomes less frequent. The time at which the foal becomes physically independent of its mother Ži.e., at weaning. often coincides with the time at which she has her next foal. Where the social organisation is based on the stable family group, there is the possibility for physically independent offspring to remain with their mothers and so continue their close psychological attachment. Nevertheless, colts are often ejected from their natal group by the stallion as they reach maturity ŽWells and von GoldschmidtRothschild, 1979.. Organisation into family groups is typical of the horse, mountain zebra Ž E. zebra., plains zebra Ž E. quagga. and onager Ž E. hemionus . ŽKlingel, 1974.. Within a social system in which animals are often solitary or transiently associated with others, the close association between mother and foal is rarely continued into adulthood. Such a social system is typical of the feral donkey Ž E. asinus . and Grevy’s zebra Ž E. greÕyi . ŽKlingel, 1974.. Observations of donkeys living in the wild have shown that the length of time foals remain with their mothers depends upon the carrying capacity of the local environment ŽMoehlman, 1974; Morgart, 1978; Woodward, 1979; McCort, 1980; Hoffmann, 1983.. In more hospitable habitats, colts leave their mothers to join bachelor groups at around 3 yr of age, whereas fillies may remain until they themselves foal ŽMcCort, 1980.. This paper explores the nature of the relationship between female domestic donkeys Žjennies. and their offspring under conditions where there is the potential for the relationship to be continued throughout life.
2. Materials and methods I observed 13 jennies and their offspring at the Donkey Sanctuary ŽSidmouth, UK.; seven offspring were female and six male. Male foals were castrated as soon as their testes descended. The ages of the offspring at the beginning of the observation period ranged from a few hours to 13 yr. Jennies and their offspring lived with other donkeys of similar ages in grass paddocks. The size of both the group and the paddock varied Žthe smallest being two jennies in a 0.2 ha paddock, and the largest being 60 donkeys in a 22 ha field.. The foals were allowed free access to their mothers at all times and were not separated nor forcibly weaned at a particular age. Every week from the beginning of May through September 1987, I observed each pair for 1 h in each of four time categories; 0600 to 1000 h, 1000 to 1400 h, 1400 to 1800 h and 1800 h to 2200, until I had observed each pair for about 50 h. During the observation I recorded the distance between the pair, the member of the pair responsible for changing this distance Žeither increasing the distance by moving away or decreasing the distance by moving towards., and the activity of both donkeys Žgrazing, walking, playing, etc... The data were recorded using the continuous Žor ‘all-occurrences’ recording. method which aims to produce an exact record of events ŽMartin and Bateson, 1986.. All the donkeys were accustomed to humans and I observed them from a distance of at least 10 m. Because
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
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the donkeys were restricted to paddocks, the actual distances moved are not relevant and cannot be compared with those recorded for free-ranging equids. The relative movement of mares and foals is therefore expressed in donkey lengths.
3. Results Jennies stayed close to their newborn foals and maintained almost continuous tactile contact. When their young foals rested, they either rested with them or grazed nearby. Most jennies with very young foals actively discouraged the approach of other donkeys by adopting threatening postures towards any donkey that came too close. The new foal fed frequently, about every 15–20 min Žwild ass foals suckle every 3–10 min for the first 5 days but by 10 days they suckle only every 20–30 min; Rashek, 1976.. Jennies were observed to ‘invite’ their young foals to suckle by standing still with one hind leg flexed back to expose their udders. After the first day, jennies approached their foals less frequently and had an overall tendency to move away ŽFig. 1a.. This tendency increased as the foals got older. Although jennies would regularly invite foals to suckle in the first few days, thereafter foals had to initiate most of the suckling bouts. Foals were observed to adopt a special approach when they wanted to suckle: they vocalised softly, laid back their ears and sometimes tossed their heads. If the jenny intended to permit the foal to suckle she would stand still; otherwise she would continue browsing or walk away. It was noticeable that foals nearly always attempted to suckle after periods of Žvoluntary.
Fig. 1. Spatial relationship between jennies and their offspring. The lines are composites of all the pairs and have been smoothed for clarity. They represent the number of approaches an animal made minus the number of times it left, and are plotted as a percentage of all movements the animal made during the hour’s observation. Points above the x-axis indicate a net movement towards the other member of the pair. Points below the x-axis indicate a net movement away. Ža. Jennies with young offspring, Žb. Jennies with adult offspring.
256
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
separation from their mothers Žafter 95% of separations., after some disturbance in the group Žafter 97% of disturbances., and when other foals began to suck Žafter 76% of occasions.. Jennies also no longer grazed nearby when their foals were resting, and they allowed their foals contact with other animals. This pattern continued as the foals aged, but any threatening events, such as the introduction of strange donkeys into the paddock, caused jennies to approach their foals more frequently. All foals followed their mothers Žtherefore foals’ movements tend to lie on or above the x-axis in Fig. 1a.. As foals aged they became less persistent in following their mothers and preferred to play and rest with other foals, but they would always return to their mothers if threatened. They were also sometimes observed to be grazing or resting close to their mothers and on other occasions at some distance from them: this is reflected in the large day to day variation in the data relating to older foals. The sex of the offspring made no difference to the spatial relationship with their mothers Žanalysis of variance, F s 1.3, df s 1169.. An analysis of the changes in distance of all pairs showed that the spatial relationship changed because jennies moved away from their foals to graze, etc. Žanalysis of variance, F s 3.879, df s 10,169..
4. Discussion The increasing independence of the foals is reflected in the gradual change in the jenny–foal spatial relationship in the first year. Rashek Ž1976. noted that wild ass foals are already beginning to drink water and graze by 4 weeks of age. Weaning represents a milestone in this relationship. The timing of weaning has been considered as a source of conflict between mother and offspring ŽTrivers, 1974.. It is in the mother’s interest to wean her foal as soon as it can survive on an adult diet, particularly when she may be pregnant again. McCort Ž1980. observed that jennies restricted suckling when food was scarce. The foal, conversely, gains by prolonging suckling. For desert-dwelling feral donkeys, lactation has additional risks. Lactating jennies must remain within range of water holes because they need to drink 2–3 = a day and therefore are more likely to meet predators ŽMoehlman, 1974.. As suckling is usually initiated by the foal and terminated by the jenny, weaning requires the jenny to aggressively discourage her foal’s approaches. In this study, jennies moved away most persistently from their 10-month-old foals Žas illustrated in Fig. 1a.. In unconfined conditions this would begin the process of weaning. Since older foals are often observed some distance away from their mothers, this also allows for the possibility that they can become separated from their mothers by some external event. In these data, the sex of the offspring made no difference to the spatial relationship with their mothers. Observations of domestic horses also suggest that both colts and fillies can have equally strong attachments to their mother ŽKiley-Worthington, 1987.. However, to be certain that the offspring’s sex had no effect, it would be necessary to observe individual jennies as they raised foals of both sexes. At the Sanctuary, offspring remain with their mothers for their lifetime Žusually within a group of approximately 60 other unrelated donkeys. and, as all the males are castrated, neither reproduce thereafter. The nature of the relationship between jenny and
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
257
offspring under these unusual circumstances is an interesting one: the mother behaves as she would to a newborn foal; she shows a predominance of approaches and movement that maintains contact ŽFig. 1b.. The adult offspring have also settled back into a foal’s pattern of approaching and maintaining contact with their mothers. Jennies changed the spatial relationship by moving away from their foals to graze, etc. The foals’ response was to move towards their mothers and so maintain contact. Older foals were less persistent in following their mothers, and in the wild this eventually results in separation of the jenny from her adult offspring. Under conditions of domestic management, where resources are not limited and the animals are confined together and are reproductively inactive, this separation does not occur and the spatial relationship between jennies and their adult offspring reverts to that seen between jennies and young foals. This is due mainly to a change in the jennies’ behaviour from leaving to approaching and, to a lesser extent, to an increased frequency of approach by the offspring. The result is a pair of adult donkeys that stay very close together and are equally active in maintaining contact. This close relationship may provide some benefits. One is an immediately available and willing grooming partner. Amongst the groups of Sanctuary donkeys, mutual grooming occurs most commonly between related donkeys Žusually mother and adult offspring. and their grooming sessions can last for half an hour or more Žpers. obs... Certainly, allogrooming has a hygienic and protective function by cleaning those areas that the individual cannot reach itself, and it does seem to be a pleasurable experience as both donkeys appear relaxed. It also cements the close relationship between the grooming partners, allowing a coalition to develop for future support. In a large group of donkeys, pairs act as a unit when accessing resources Žit seems to be harder for donkeys to displace pairs from feeders than singletons. and responding to unwelcome approaches Žpers. obs... It would be interesting to determine whether the benefits postulated for these pairs have any tangible effects in terms of better health or increased longevity but the information has not been explored. A similar spatially close relationship is also seen between donkeys that have been raised together in private homes Žpers. obs... It may not, therefore, be a response only to the particular conditions that the study group experienced but may also be applicable to donkeys kept as companion animals.
Acknowledgements The author acknowledges the support and funding of the Donkey Sanctuary, Sidmouth, UK.
References Crowell-Davis, S.L., 1986. Spatial relations between mares and foals of the Welsh pony, Equus caballus. Anim. Behav. 34, 1007–1015. Hoffmann, R., 1983. Social organisation patterns of several feral horse and feral ass populations in Central Australia. Z. Saugetierkunde 48, 124–126.
258
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
Kiley-Worthington, M., 1987. The Behaviour of Horses in Relation to Management and Training. J.A. Allen, London, p. 122. Klingel, H., 1974. A comparison of the social behaviour of the Equidae. In: Geist, V., Walther, F. ŽEds.., The Behaviour of Ungulates and its Relation to Management. New Ser. 24. I.U.C.N. Publ. Morges, Switzerland, pp. 124–132. Martin, P., Bateson, P., 1986. Measuring behaviour: An Introductory Guide. Cambridge Univ. Press, Cambridge, UK, pp. 51–54. McCort, W.D., 1980. The behaviour and social organization of feral asses, Equus asinus on Ossabaw Island, Georgia. PhD Thesis, Pennsylvania State University, University Park, PA. Moehlman, P.D.R., 1974. Behaviour and ecology of feral asses Equus asinus. PhD Thesis, University of Wisconsin, Madison, WI. Morgart, J.R., 1978. Burro behaviour and population dynamics, Bandelier National Monument, New Mexico. PhD Thesis, Arizona State University, Tucson, AZ. Rashek, V.A., 1976. Details of feeding and feeding behaviour in young wild asses on Barsa–Kelmes Island ŽAral Sea.. Zool. Zh. 55 Ž5., 784–786, Žin Russian.. Trivers, R.L., 1974. Parent–offspring conflict. Am. Zool. 14, 249–264. Tyler, S.J., 1972. The behaviour and social organisation of the New Forest ponies. Anim. Behav. Mongr. 5, 85–196. Wells, S.M., von Goldschmidt-Rothschild, B., 1979. Social behaviour and relationships in a herd of Camargue horses. Z. Tierpsychol. 49, 363–380. Woodward, S.L., 1979. The social system of feral asses Ž Equus asinus .. Z. Tierpsychol. 49, 304–316.
Mother–offspring relationships in donkeys Jane M. French
)
Crofters Middle Dimson, Gunnislake, Cornwall PL18 9NQ, UK
Abstract The social relationship between female domestic donkeys Žjennies. and their offspring was explored by observation of their spatial relationship. The donkeys were kept together for life and the ages of the offspring at the beginning of the observation period ranged from a few hours to 13 yr. There was a gradual change in the jenny–foal spatial relationship in the foal’s first year reflecting the foal’s increasing independence. The offspring’s sex made no difference to this relationship. Jennies stayed very close to their newborn foals but thereafter approached them less frequently and had an overall tendency to move away. The foals responded by moving towards their mothers and so maintaining contact. Older foals were less persistent in following their mothers. In this study, jennies moved away most persistently from their 10-month-old foals. In unconfined conditions, this would begin the process of weaning. Since older foals are also often observed to be some distance away from their mothers, this also allows for the possibility that they can become separated by some external event. Under conditions of domestic management, e.g., unlimited resources, confinement and reproductive inactivity, jenny and offspring do not separate at weaning and their spatial relationship reverts to the close relationship seen between jennies and young foals. This is due mainly to a change in the jennies’ behaviour from leaving to approaching and, to a lesser extent, to an increased frequency of approach by the offspring. The result is a pair of adult donkeys that stay very close together and are equally active in maintaining contact. This close relationship may provide some benefits. One potential benefit is an immediately available and willing grooming partner. Another is the potential for the pair to develop a coalition for future support, for example, in accessing resources and mutual protection. q 1998 Elsevier Science B.V. All rights reserved. Keywords: Donkey; Social relationships; Weaning; Companion animal; Motherroffspring bond
1. Introduction Where animals are not closely confined, proximity is commonly used as a measure of affiliation between individuals. In equids, mares stay very close to their newborn foal for )
Tel.: q44-1822-832841
0168-1591r98r$ - see front matter q 1998 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 1 5 9 1 Ž 9 8 . 0 0 1 7 3 - 7
254
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
the foal’s first few days, and the foal suckles frequently. In horses Ž Equus caballus ., mares rarely move more than 5 m away during the foal’s first few weeks ŽTyler, 1972; Crowell-Davis, 1986.. Thereafter, mares gradually spend more time farther away, and suckling becomes less frequent. The time at which the foal becomes physically independent of its mother Ži.e., at weaning. often coincides with the time at which she has her next foal. Where the social organisation is based on the stable family group, there is the possibility for physically independent offspring to remain with their mothers and so continue their close psychological attachment. Nevertheless, colts are often ejected from their natal group by the stallion as they reach maturity ŽWells and von GoldschmidtRothschild, 1979.. Organisation into family groups is typical of the horse, mountain zebra Ž E. zebra., plains zebra Ž E. quagga. and onager Ž E. hemionus . ŽKlingel, 1974.. Within a social system in which animals are often solitary or transiently associated with others, the close association between mother and foal is rarely continued into adulthood. Such a social system is typical of the feral donkey Ž E. asinus . and Grevy’s zebra Ž E. greÕyi . ŽKlingel, 1974.. Observations of donkeys living in the wild have shown that the length of time foals remain with their mothers depends upon the carrying capacity of the local environment ŽMoehlman, 1974; Morgart, 1978; Woodward, 1979; McCort, 1980; Hoffmann, 1983.. In more hospitable habitats, colts leave their mothers to join bachelor groups at around 3 yr of age, whereas fillies may remain until they themselves foal ŽMcCort, 1980.. This paper explores the nature of the relationship between female domestic donkeys Žjennies. and their offspring under conditions where there is the potential for the relationship to be continued throughout life.
2. Materials and methods I observed 13 jennies and their offspring at the Donkey Sanctuary ŽSidmouth, UK.; seven offspring were female and six male. Male foals were castrated as soon as their testes descended. The ages of the offspring at the beginning of the observation period ranged from a few hours to 13 yr. Jennies and their offspring lived with other donkeys of similar ages in grass paddocks. The size of both the group and the paddock varied Žthe smallest being two jennies in a 0.2 ha paddock, and the largest being 60 donkeys in a 22 ha field.. The foals were allowed free access to their mothers at all times and were not separated nor forcibly weaned at a particular age. Every week from the beginning of May through September 1987, I observed each pair for 1 h in each of four time categories; 0600 to 1000 h, 1000 to 1400 h, 1400 to 1800 h and 1800 h to 2200, until I had observed each pair for about 50 h. During the observation I recorded the distance between the pair, the member of the pair responsible for changing this distance Žeither increasing the distance by moving away or decreasing the distance by moving towards., and the activity of both donkeys Žgrazing, walking, playing, etc... The data were recorded using the continuous Žor ‘all-occurrences’ recording. method which aims to produce an exact record of events ŽMartin and Bateson, 1986.. All the donkeys were accustomed to humans and I observed them from a distance of at least 10 m. Because
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
255
the donkeys were restricted to paddocks, the actual distances moved are not relevant and cannot be compared with those recorded for free-ranging equids. The relative movement of mares and foals is therefore expressed in donkey lengths.
3. Results Jennies stayed close to their newborn foals and maintained almost continuous tactile contact. When their young foals rested, they either rested with them or grazed nearby. Most jennies with very young foals actively discouraged the approach of other donkeys by adopting threatening postures towards any donkey that came too close. The new foal fed frequently, about every 15–20 min Žwild ass foals suckle every 3–10 min for the first 5 days but by 10 days they suckle only every 20–30 min; Rashek, 1976.. Jennies were observed to ‘invite’ their young foals to suckle by standing still with one hind leg flexed back to expose their udders. After the first day, jennies approached their foals less frequently and had an overall tendency to move away ŽFig. 1a.. This tendency increased as the foals got older. Although jennies would regularly invite foals to suckle in the first few days, thereafter foals had to initiate most of the suckling bouts. Foals were observed to adopt a special approach when they wanted to suckle: they vocalised softly, laid back their ears and sometimes tossed their heads. If the jenny intended to permit the foal to suckle she would stand still; otherwise she would continue browsing or walk away. It was noticeable that foals nearly always attempted to suckle after periods of Žvoluntary.
Fig. 1. Spatial relationship between jennies and their offspring. The lines are composites of all the pairs and have been smoothed for clarity. They represent the number of approaches an animal made minus the number of times it left, and are plotted as a percentage of all movements the animal made during the hour’s observation. Points above the x-axis indicate a net movement towards the other member of the pair. Points below the x-axis indicate a net movement away. Ža. Jennies with young offspring, Žb. Jennies with adult offspring.
256
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
separation from their mothers Žafter 95% of separations., after some disturbance in the group Žafter 97% of disturbances., and when other foals began to suck Žafter 76% of occasions.. Jennies also no longer grazed nearby when their foals were resting, and they allowed their foals contact with other animals. This pattern continued as the foals aged, but any threatening events, such as the introduction of strange donkeys into the paddock, caused jennies to approach their foals more frequently. All foals followed their mothers Žtherefore foals’ movements tend to lie on or above the x-axis in Fig. 1a.. As foals aged they became less persistent in following their mothers and preferred to play and rest with other foals, but they would always return to their mothers if threatened. They were also sometimes observed to be grazing or resting close to their mothers and on other occasions at some distance from them: this is reflected in the large day to day variation in the data relating to older foals. The sex of the offspring made no difference to the spatial relationship with their mothers Žanalysis of variance, F s 1.3, df s 1169.. An analysis of the changes in distance of all pairs showed that the spatial relationship changed because jennies moved away from their foals to graze, etc. Žanalysis of variance, F s 3.879, df s 10,169..
4. Discussion The increasing independence of the foals is reflected in the gradual change in the jenny–foal spatial relationship in the first year. Rashek Ž1976. noted that wild ass foals are already beginning to drink water and graze by 4 weeks of age. Weaning represents a milestone in this relationship. The timing of weaning has been considered as a source of conflict between mother and offspring ŽTrivers, 1974.. It is in the mother’s interest to wean her foal as soon as it can survive on an adult diet, particularly when she may be pregnant again. McCort Ž1980. observed that jennies restricted suckling when food was scarce. The foal, conversely, gains by prolonging suckling. For desert-dwelling feral donkeys, lactation has additional risks. Lactating jennies must remain within range of water holes because they need to drink 2–3 = a day and therefore are more likely to meet predators ŽMoehlman, 1974.. As suckling is usually initiated by the foal and terminated by the jenny, weaning requires the jenny to aggressively discourage her foal’s approaches. In this study, jennies moved away most persistently from their 10-month-old foals Žas illustrated in Fig. 1a.. In unconfined conditions this would begin the process of weaning. Since older foals are often observed some distance away from their mothers, this also allows for the possibility that they can become separated from their mothers by some external event. In these data, the sex of the offspring made no difference to the spatial relationship with their mothers. Observations of domestic horses also suggest that both colts and fillies can have equally strong attachments to their mother ŽKiley-Worthington, 1987.. However, to be certain that the offspring’s sex had no effect, it would be necessary to observe individual jennies as they raised foals of both sexes. At the Sanctuary, offspring remain with their mothers for their lifetime Žusually within a group of approximately 60 other unrelated donkeys. and, as all the males are castrated, neither reproduce thereafter. The nature of the relationship between jenny and
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
257
offspring under these unusual circumstances is an interesting one: the mother behaves as she would to a newborn foal; she shows a predominance of approaches and movement that maintains contact ŽFig. 1b.. The adult offspring have also settled back into a foal’s pattern of approaching and maintaining contact with their mothers. Jennies changed the spatial relationship by moving away from their foals to graze, etc. The foals’ response was to move towards their mothers and so maintain contact. Older foals were less persistent in following their mothers, and in the wild this eventually results in separation of the jenny from her adult offspring. Under conditions of domestic management, where resources are not limited and the animals are confined together and are reproductively inactive, this separation does not occur and the spatial relationship between jennies and their adult offspring reverts to that seen between jennies and young foals. This is due mainly to a change in the jennies’ behaviour from leaving to approaching and, to a lesser extent, to an increased frequency of approach by the offspring. The result is a pair of adult donkeys that stay very close together and are equally active in maintaining contact. This close relationship may provide some benefits. One is an immediately available and willing grooming partner. Amongst the groups of Sanctuary donkeys, mutual grooming occurs most commonly between related donkeys Žusually mother and adult offspring. and their grooming sessions can last for half an hour or more Žpers. obs... Certainly, allogrooming has a hygienic and protective function by cleaning those areas that the individual cannot reach itself, and it does seem to be a pleasurable experience as both donkeys appear relaxed. It also cements the close relationship between the grooming partners, allowing a coalition to develop for future support. In a large group of donkeys, pairs act as a unit when accessing resources Žit seems to be harder for donkeys to displace pairs from feeders than singletons. and responding to unwelcome approaches Žpers. obs... It would be interesting to determine whether the benefits postulated for these pairs have any tangible effects in terms of better health or increased longevity but the information has not been explored. A similar spatially close relationship is also seen between donkeys that have been raised together in private homes Žpers. obs... It may not, therefore, be a response only to the particular conditions that the study group experienced but may also be applicable to donkeys kept as companion animals.
Acknowledgements The author acknowledges the support and funding of the Donkey Sanctuary, Sidmouth, UK.
References Crowell-Davis, S.L., 1986. Spatial relations between mares and foals of the Welsh pony, Equus caballus. Anim. Behav. 34, 1007–1015. Hoffmann, R., 1983. Social organisation patterns of several feral horse and feral ass populations in Central Australia. Z. Saugetierkunde 48, 124–126.
258
J.M. Frenchr Applied Animal BehaÕiour Science 60 (1998) 253–258
Kiley-Worthington, M., 1987. The Behaviour of Horses in Relation to Management and Training. J.A. Allen, London, p. 122. Klingel, H., 1974. A comparison of the social behaviour of the Equidae. In: Geist, V., Walther, F. ŽEds.., The Behaviour of Ungulates and its Relation to Management. New Ser. 24. I.U.C.N. Publ. Morges, Switzerland, pp. 124–132. Martin, P., Bateson, P., 1986. Measuring behaviour: An Introductory Guide. Cambridge Univ. Press, Cambridge, UK, pp. 51–54. McCort, W.D., 1980. The behaviour and social organization of feral asses, Equus asinus on Ossabaw Island, Georgia. PhD Thesis, Pennsylvania State University, University Park, PA. Moehlman, P.D.R., 1974. Behaviour and ecology of feral asses Equus asinus. PhD Thesis, University of Wisconsin, Madison, WI. Morgart, J.R., 1978. Burro behaviour and population dynamics, Bandelier National Monument, New Mexico. PhD Thesis, Arizona State University, Tucson, AZ. Rashek, V.A., 1976. Details of feeding and feeding behaviour in young wild asses on Barsa–Kelmes Island ŽAral Sea.. Zool. Zh. 55 Ž5., 784–786, Žin Russian.. Trivers, R.L., 1974. Parent–offspring conflict. Am. Zool. 14, 249–264. Tyler, S.J., 1972. The behaviour and social organisation of the New Forest ponies. Anim. Behav. Mongr. 5, 85–196. Wells, S.M., von Goldschmidt-Rothschild, B., 1979. Social behaviour and relationships in a herd of Camargue horses. Z. Tierpsychol. 49, 363–380. Woodward, S.L., 1979. The social system of feral asses Ž Equus asinus .. Z. Tierpsychol. 49, 304–316.