Suckling and Allosuckling in Captive Fallow Deer (Dama dama, Cervidae)

Do human-wildlife interactions predict offspring hiding strategies in peri-urban fallow deer?

Human activities can induce significant behavioural changes in wildlife. Often explored through extractive interactions (e.g. hunting) that can favour certain behavioural traits, the implications of non-extractive ones, such as wildlife feeding, remain understudied. Research shows that people tend to favour bolder individuals within populations despite their dynamics and consequences being unclear. Using fallow deer in a peri-urban environment, we studied whether mothers that show reduced fear of humans and consistently approach them for food adopt weaker anti-predator strategies by selecting less concealed fawning bedsites closer to human hotspots. This would provide the advantage of additional feeding opportunities in comparison with shyer mothers while keeping their fawns close. Our dataset encompassed 281 capture events of 172 fawns from 110 mothers across 4 years. Surprisingly, mothers that regularly accepted food from humans selected more concealed bedsites farther from human hotspots, giving their offspring better protection while also benefitting from additional food during lactation. Our results show behavioural adaptations by a subset of females and, for the first time, link the tendency to approach humans and strategies to protect offspring. Given previous findings that these begging females also deliver heavier fawns at birth, our research further investigates human-wildlife feeding interactions and their behavioural implications.

Allonursing in Wild and Farm Animals: Biological and Physiological Foundations and Explanatory Hypotheses

The dams of gregarious animals must develop a close bond with their newborns to provide them with maternal care, including protection against predators, immunological transference, and nutrition. Even though lactation demands high energy expenditures, behaviors known as allonursing (the nursing of non-descendant infants) and allosuckling (suckling from any female other than the mother) have been reported in various species of wild or domestic, and terrestrial or aquatic animals. These behaviors seem to be elements of a multifactorial strategy, since reports suggest that they depend on the following: species, living conditions, social stability, and kinship relations, among other group factors. Despite their potential benefits, allonursing and allosuckling can place the health and welfare of both non-filial dams and alien offspring at risk, as it augments the probability of pathogen transmission. This review aims to analyze the biological and physiological foundations and bioenergetic costs of these behaviors, analyzing the individual and collective advantages and disadvantages for the dams' own offspring(s) and alien neonate(s). We also include information on the animal species in which these behaviors occur and their implications on animal welfare.

Interactions between fawns and does of farmed fallow deer Dama dama in the postnatal period

The aim of the present study was to describe the suckling behavior of the offspring of farmed European fallow deer Dama dama in the postnatal period. Video surveillance footage from the first 18 days postpartum was analyzed in detail to reveal that the duration of interactions between the mother and the offspring changed with the fawns' age. The duration of mother-offspring interactions was longest between postpartum days 12 and 18. The frequency of interactions at different times of the day varied in the analyzed periods. The results of the study could be used to increase the welfare of farmed deer.

Impact of allosucking on growth of farmed red deer calves (Cervus elaphus)

It is generally presumed that allosucking brings benefits to the allosucking infants. Nevertheless, the data supporting such a presumption are rare. The aim of the study was to determine whether allosucking has any impact on growth rates of the allosucking calves. Fifty pregnant hinds were observed between 28 May (1st day of calving) and 2 September (abrupt weaning of all calves) on a red deer farm at Vimperk, South Bohemia, the Czech Republic. Of the 50 calves born the growth curve was calculated for 39 calves. During their 1st month of life these calves were observed in 1015 sucking bouts. In 690 cases the calves sucked from maternal hinds and in 325 cases non-maternal hinds. Only 25·64% of calves sucked exclusively from maternal hinds. The prevailing type of sucking behaviour was a combination of sucking from maternal hinds and allosucking (74·36%). Calves sucking from maternal and non-maternal hinds showed 1·6-fold higher sucking frequency than did calves feeding from maternal hinds only. Our results indicate that to some extend allonursing behaviour of the hind may affect their calves’ feeding behaviour. The more non-filial calves the maternal hind nursed, the higher frequency of the sucking by their calves occurred. The groups of calves did not differ in birth weight. With increasing age, the relative body weight increased faster in calves sucking maternal hinds only than in calves sucking maternal and non-maternal hinds. This gain in body weight was not essentially influenced by the fact whether or not the calf’s maternal hind nursed non-filial or exclusively filial calves. However, at weaning (99 days), the lowest body weight occurred in allosucking calves whose maternal hinds were allonursing. The results suggest that allosucking does not mean an extra profit to the allosucker. Instead, in our subjects, allosucking was rather attributed to compensation of nutritional requirements based on a combination of various factors, such as discrete differences in body weight at birth and also later and allonursing of the maternal hind.

Adoption, allonursing and allosucking in farmed red deer (Cervus elaphus)

Following a pilot study, the aim of this study was to test the hypothesis whether occurrence of massaging the anogenital region of a calf by a non-maternal hind is a reliable indicator of adoption. The investigation was conducted between 28 May (1st day of calving) and 2 September (abrupt weaning of all calves) on a red deer farm at Vimperk, Czech Republic. Fifty hinds and their calves were observed but only complete data sets of sucking bouts were considered for evaluation. Massaging occurred mostly during the 1st month of the calf’s life. All filial calves were massaged repeatedly. Other calves received ano-genital massage at least twice (termed adopted), on a single occasion or not at all (termed non-filial). Filial and adopted calves behaved in a similar way but differently from non-filial calves. They sucked in an antiparallel standing position so that the hind could lick their ano-genital region more often than the non-filial calves. This occurred even when two calves were involved in the bout. When two calves were involved in the sucking bout, non-filial calves sucked from behind, between the hind’s hind legs. This position occurred more frequently with non-filial than among the filial and adopted calves. It was therefore concluded, that repeated allonursing accompanied with massaging of the ano-genital region of the sucking calf by the hind can be considered a signal of adoption. Hinds usually adopted calves older than their own progeny. The adopted calves were on average 2·5 days old. This suggests that it is most likely the calf’s activity which leads to bonding. No reciprocity was found in allosucking and/or allonursing. The fact that non-filial calves commonly initiated allosucking from a non-maternal hind during the day when she gave birth appeared crucial for establishing bonding which subsequently led to adoption. Hinds may be bonded with several calves including their own. Therefore, bonding with a non-filial calf did not principally mean failure in looking after their own progeny as shown in other studies.

Allosuckling in reindeer (Rangifer tarandus): milk-theft, mismothering or kin selection?

Allosuckling, the suckling of offspring from females other than their own mother, has been reported in a number of mammalian species, including reindeer. The causes and function of this behaviour are still being investigated. We monitored 25 doe-calf pairs of semi-domestic reindeer Rangifer tarandus over 10 weeks to test three allosuckling/allonursing hypotheses: (1) milk theft, calves opportunistically allosuckle; (2) mismothering, misdirected maternal care; and (3) kin-selected allonursing. A calf soliciting an allosuckling bout was categorized as non-filial (NF), and a calf soliciting a suckling bout from its mother was categorized as filial (F). We recorded 9757 solicitations, of which 5176 were successful F bouts and 1389 were successful NF bouts. The rejection rates were greater for NF than F calves. The proportions of antiparallel positions adopted were greater for F than NF calves. The odds of an allobout were lower for calves arriving 1st, 3rd, 4th, 5th or 6th than for those arriving 2nd, but the odds did not vary with position adopted and relatedness. Our results provided support to the milk-theft hypothesis, whereas limited support for the mismothering hypothesis was found. Our results did not support the hypothesized kin selection function of allosuckling in reindeer. This article is part of a Special Issue entitled: insert SI title.

Mother‐Young Recognition in an Ungulate Hider Species: A Unidirectional Process

Parent-offspring recognition is usually crucial for survival of young. In mammals, olfaction often only permits identification at short range, and vocalizations are important at longer distances. Following and hiding antipredator strategies found in newborn mammals may also affect parental recognition mechanisms. We investigated mother-offspring recognition in fallow deer, an ungulate hider species. We analyzed the structure of adult female and fawn contact calls to determine whether they are individually distinctive and tested for mother-offspring recognition. Only females (and not fawns) have individualized vocalizations, with the fundamental frequency as the most distinctive parameter. Playback experiments showed that fawns can distinguish the calls of their mothers from those of other females, but mothers could not discriminate their own and alien fawn calls. Thus, the vocal identification process is unidirectional. In followers, mother-offspring acoustic recognition is mutual, and therefore the different antipredator strategies of newborn mammals may have shaped the modalities of parent-offspring acoustic recognition.

Mother-offspring bonding in farmed red deer: accuracy of visual observation verified by DNA analysis

The accuracy of a maternity assessment based on visual observation was tested during the post parturient phase in farmed red deer. The mother of the calf was determined using visual observation of the hind's peri-parturient and early maternal behaviour during the first week of the calf's life. This assessment was compared with genetic analysis based on DNA microsatellite polymorphism. Data for 48 new-born calves and 50 hinds were compared. The visual assessment of maternity was correct in 43 of the 48 cases (89.58%). In the five remaining cases the mother was identified by DNA testing whereas adoptive mother was determined by visual observation. Altogether 14 cases of adoption were seen in this study and in 9 cases the biological mother was correctly determined by visual observation. Detailed observation of the hind-calf interactions during calving and the first week after the parturition allowed an accurate prediction of maternity. However, such observation is technically demanding.

Milk intake and production curves and allosuckling in captive Iberian red deer, Cervus elaphus hispanicus

In two experiments, we compared milk intake (assessed by weighing calves before and after suckling) and milk production (by hand milking hinds) in Iberian red deer both when calves sucked their mothers together (group-suckling experiment) and when mother and offspring were isolated (isolation-suckling experiment). In both experiments, the general lactation curve for calves increased to a peak and then decreased (type I, standard lactation curve in mammals), whereas the curve for hinds decreased from the start (type II). However, in the experiment on group suckling, calves ingested 17.2% more milk than that produced by their mothers from weeks 6 to 20. In both isolation- and group-suckling experiments, hinds showed an overproduction of milk decreasing from weeks 1 to 5. This decreasing overproduction coincides with a similar trend in calf mortality reported in the literature and might thus be aimed at ensuring calves have sufficient nutrients when mortality is highest. In addition, allosuckling observations in the group-suckling experiment showed an inverse relationship between milk production and percentage of allosucking attempts. Allosucking attempts were also more frequent after the milk overproduction period. Both findings suggest that allosuckling is a response to compensate for a reduced maternal milk supply. Copyright 2000 The Association for the Study of Animal Behaviour.