‘Adoption’ by Maternal Siblings in Wild Chimpanzees

The adoption of unrelated orphaned infants is something chimpanzees and humans have in common. Providing parental care has fitness implications for both the adopter and orphan, and cases of adoption have thus been cited as evidence for a shared origin of an altruistic behaviour. We provide new data on adoptions in the free-living Sonso chimpanzee community in Uganda, together with an analysis of published data from other long-term field sites. As a default pattern, we find that orphan chimpanzees do not become adopted by adult group members but wherever possible associate with each other, usually as maternal sibling pairs. This occurs even if both partners are still immature, with older individuals effectively becoming ‘child household heads’. Adoption of orphans by unrelated individuals does occur but usually only if no maternal siblings or other relatives are present and only after significant delays. In conclusion, following the loss of their mother, orphaned chimpanzees preferentially associate along pre-existing social bonds, which are typically strongest amongst maternal siblings.     

The effects of residential locality on parental and alloparental investment among the Aka foragers of the central African Republic

In this paper I examine the intracultural variability of parental and alloparental caregiving among the Aka foragers of the Central African Republic. It has been suggested that maternal kin offer higher frequencies of allocare than paternal kin and that maternal investment in infants will decrease when alloparental assistance is provided. Behavioral observations were conducted on 15 eight- to twelve-monthold infants. The practice of brideservice and the flexibility of Aka residence patterns offered a means to test the effect of maternal residence on parental and alloparental investment. There was significant variation in the frequency of investment and who supplied care to infants depending on whether mothers resided with their kin or their husbands’ kin. However, in spite of the variation in allocare, when all categories of caregivers were examined collectively, infants received similar overall levels of care. Courtney L. Meehan is a Ph.D. student in cultural anthropology at Washington State University. Her research interests include parenting, alloparenting, female social networks, and female-female cooperation and competition.     

Adoption of infant orphan chacma baboons

During a study of chacma baboons, Papio ursinus, in the Moremi Wildlife Reserve, Botswana, the mothers of 10 infants disappeared. Pre-reproductive males and females, all 4 to 5 years old, adopted nine natural orphans, and one older orphan was not adopted. Compared with other troop members, 4- and 5-year-old caregivers would incur the lowest costs of adoption in terms of interference with their direct reproductive potential. In the five instances in which relatedness of natural orphans could be assessed, caregivers were probably close relatives of orphans they cared for. By comparison, 5-year-old males immediately adopted two experimentally introduced orphans.     

Adoption in Eastern Grey Kangaroos: A Consequence of Misdirected Care?

Adoption is rare in animals and is usually attributed to kin selection. In a 6-year study of eastern grey kangaroos (Macropus giganteus), 11 of 326 juveniles were adopted. We detected eight adoptions by observing behavioural associations and nursing between marked mothers and young and three more by analysing the relatedness of mothers and young using microsatellite DNA. Four adoptions involved reciprocal switches and three were by mothers whose own pouch young were known to subsequently disappear. Adoptive mothers were not closely related to each other or to adoptees but adoptive mothers and young associated as closely as did biological pairs, as measured by half-weight indices. Switch mothers did not associate closely. Maternal age and body condition did not influence the likelihood of adoption but females were more likely to adopt in years with high densities of females with large pouch young. Adoption did not improve juvenile survival. We conclude that adoptions in this wild population were potentially costly and likely caused by misdirected care, suggesting that eastern grey kangaroos may have poorly developed mother-offspring recognition mechanisms.     

Alloparental behavior in a captive group of spider monkeys (Ateles geoffroyi) at the Auckland zoo

I studied alloparental behavior in a captive group of spider monkeys at the Auckland Zoo using seven infants as focal subjects and assessed the effects of age, sex, and reproductive status of alloparents on patterns of infant-other interaction. Adult males initiated interactions with infants most often, followed by adult females. Immature individuals interacted with infants infrequently. Infants themselves initiated contact with adult males more often than with other members of the group. Alloparental behavior in spider monkeys differs from that in most other species in that the infant is an active rather than a passive participant in alloparental interactions. I discuss the patterns of infant-other interaction in relation to the social structure and dispersal patterns of Ateles.     

Grooming relationships of adolescent orphans in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama: a comparison among orphans with sisters, orphans without sisters, and females with a surviving mother

The present study examined grooming relationships of adolescent females in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama. To assess whether the loss of the mother influenced the grooming relationships of adolescent females (5–7 years old), we compared the time spent in grooming interactions and the number of grooming partners among the following three groups: 6 adolescent orphans with sisters, 9 adolescent orphans without sisters, and 11 adolescent non-orphans with surviving mothers. In Japanese macaques, grooming most frequently occurs between mothers and their daughters. Therefore, it is expected that if the mother is lost, orphans will devote less time to grooming interactions than non-orphans. However, the time spent in overall grooming interactions did not differ among the three groups. While non-orphans maintained grooming relationships with their mothers, orphans acquired alternative grooming relationships with other group members. Orphans adopted two kinds of tactics to compensate for the loss of the mother. First, adolescent orphans with sisters developed more affiliative grooming relationships with their sisters than non-orphans with sisters. Secondly, adolescent orphans without sisters spent more time in grooming interactions with same-aged females and non-related adult females. Moreover, regarding grooming interactions with same-aged females and non-related adult females, orphans without sisters had a larger number of grooming partners than non-orphans. These results indicate that adolescent females have enough flexibility to develop their grooming network after the loss of their mothers, and that the lack of mother and sisters might accelerate socialization of adolescent females and enable them to be integrated in reciprocal adult grooming relationships.     

Grandmothers care for orphans in a provisioned troop of Japanese macaques (<Emphasis Type="Italic">Macaca fuscata</Emphasis>)

This study reports cases in which grandmothers and other closely related adult females cared for orphans in the Arashiyama E-troop, a provisioned troop of Japanese macaques (Macaca fuscata). I observed the behavioral patterns of three orphans (aged 1, 2, and 3 years, respectively). The grandmothers cared for two orphans, while three other closely related adult females cared for the rest of the orphans whose grandmothers were absent. These observations differ from those of previous studies that reported that grandmothers were indifferent towards orphans. This intraspecific variation may be attributed to the demographic conditions of the troop in this study, which had only a few related nulliparous adult females, as a result of artificial birth control. In this group, adult females showed decreased fecundity and an increased interbirth interval as they received birth control treatment; thus, in the absence of their own dependent infants, these females may have invested time in the care of related orphans. Although caregiving by grandmothers is believed to be rare or insignificant in primates, this study suggests that grandmothers and other closely related adult females play an important role for orphans in troops with few related adult females.     

Integration of a hand-reared chimpanzee (Pan troglodytes) infant into a social group of conspecifics

Rejections of infants among non-human primates occasionally occur in the wild as well as in captive settings. Controlled adoptions of orphans and introductions of individuals into new groups are therefore sometimes necessary in captivity. Consequently, behavioral research on integration procedures and on the acceptance of infants by adoptive mothers is much needed. In this study, the introduction and subsequent adoption were examined in an 18-month-old hand-reared chimpanzee (Pan troglodytes). The infant was introduced into an age/sex-diversified social group of conspecifics at Furuvik Zoo, Gävle, Sweden, and continuous focal data was collected during the final stage of integration, including infant care exhibited by the group members and the infant’s secure base behavior. The infant was successfully integrated into the group and engaged in positive social interactions with all group members. An adult primiparous female chimpanzee formed a bond resembling a mother–infant relationship with the infant, which continues to be maintained at publication. However, the female initially showed very limited interest in the infant. It was, in fact, two other younger female group members that exhibited most infant care. The infant’s secure base behavior patterns indicate that she adapted well to the new circumstances in the chimpanzee group as the integration progressed. This provides evidence that a final adopter does not necessarily initially show maternal interest and that there can be flexibility in maternal behavior in adult chimpanzee females. Moreover, the methods applied employing gradual familiarization with all the group members and the use of an integration enclosure, may have contributed to a successful result. These findings extend our knowledge of introduction procedures in captivity as well as provide information on foster mother–infant attachment in chimpanzees.     

Why do goose parents adopt unrelated goslings? A review of hypotheses and empirical evidence,and new research questions

Adoption of unrelated offspring by successful breeders is one form of brood mixing and alloparental care that is widespread among geese and other waterfowl. Biparental care and long-lasting family bonds in geese are likely to affect the costs and benefits of adoption. Most hypotheses that have been proposed to explain this behaviour assume that the separation of the gosling from its original family is accidental, and that adoption forms the 'best of a bad job' solution. For the gosling, adoption is therefore thought to be the only, and thus adaptive, option. For parents, some hypotheses assume that there are costs of adoption (intergeneration conflict), while others assume that there are benefits (mutually beneficial). The few studies of adoption in wild goose populations indicate cost-neutrality or that there are small benefits to parents of adopting young. This agrees with studies of brood size, which suggest that large families provide benefits for goslings and parents alike. By contrast, most observed adoption attempts involve parental aggression against the lone gosling. However, incidental observations are likely to be biased towards adoptions that involve conspicuous behaviour, such as aggression, and might overlook inconspicuous adoptions. Studies of individually marked goslings are needed to identify the background of the adoption goslings in order to identify whether in geese, as in some larids and altricial species, adoption might be an active strategy of offspring to improve their fitness prospects. In addition, more experimental studies are needed to test predictions about the costs and benefits of large families in geese.     

Natal Attraction in Adult Female Baboons (Papio cynocephalus ursinus) in the Moremi Reserve, Botswana

Mammalian females are strongly attracted to infants and interact regularly with them. Female baboons make persistent attempts to touch, nuzzle, smell and inspect other females’ infants, but do not hold them for long periods, carry them, or provide other kinds of care for them. Mothers generally tolerate these interactions, but never initiate them. The function of these brief alloparental interactions is not well understood. Infant handling might be a form of reproductive competition if females’ interest in infants causes distress to mothers or harm to their infants. Alternatively, infant handling might be the product of selection for appropriate maternal care if females who are highly responsive to infants are the most successful mothers. We test several predictions derived from these hypotheses with data collected in a free‐ranging group of baboons (Papio cynocephalus ursinus) in the Moremi Reserve of Botswana. Infants were most attractive when they were very young. Mothers of young infants were approached by other adult females on average once every 6 min, and other females attempted to handle their infants approximately once every 9 min. By the time infants were a year old, their mothers were being approached only once every 30 min and infants were being handled only once every 5 h. Females were more strongly attracted to other females’ infants when they had young infants of their own, and their interest in other females’ infants declined as their own infants matured. Females seemed to be equally attracted to all infants, but had greater access to offspring of their relatives and subordinate females. Females nearly always grunted as they handled infants. As in other contexts grunts are a reliable predictive signal that non‐aggressive behavior will follow, the use of grunts before handling suggests that these interactions were not a form of deliberate harassment.     

Early agonistic experience and rank acquisition among free-ranging infant rhesus monkeys

Several aspects of agonistic experience are described for freeranging infant rhesus monkeys (Macaca mulatta)on Cayo Santiago. Even before infants are fully integrated with peers in rank dominance based on maternal ranks,infants of highranking mothers tend to be threatened less frequently by other members of the group and are less likely to be threatened by unfamiliar individuals than are infants of lowranking mothers. There is no evidence that fearful interactions between pairs of infants are related to their mother’s ranks before 22 weeks of age. However, an imperfect hierarchy can be constructed for infants between 27 and 30 weeks of age. At this age,infants of higherranking mothers are also more likely to receive protection when threatened than are infants of lowerranking mothers. When protected, their protectors are less likely to emit fearful gestures to the infants’ threatener. Close female relatives appear to play a large role in the protection of infants and may be more directly responsible for the differences described above than the mother, other relatives, or other highranking members of the group. It is suggested that more than one mechanism, including intervention by the mother and by close female relatives,may be important in rank acquisition among peers.     

Investigating Some of the Factors that Affect the Selection of Shelter Cats by Adopters in the Czech Republic

Records on cat adoptions were collected from three cat shelters situated in different regions of the Czech Republic. Originally, 2,170 cats were admitted to the monitored shelters; of which 1,407 (65%) cats were adopted in the period from 2011 to 2015. Significantly (p < 0.001) greater numbers of cats were adopted in autumn and winter than in spring and summer. The differences in the numbers of adopted cats of different sex, age, or coat color corresponded with the differences in proportions of these characteristics in cats admitted to the monitored shelters. No effect of sex on time to adoption was found. However, age and coat color affected the length of stay (LOS). Geriatric cats had the greatest and adult cats the shortest LOS. Kittens, juveniles, and young adults did not differ in LOS but they all stayed in shelters longer (p < 0.05) than adult cats. The median length of the stay of dark-colored cats was significantly greater (p < 0.001) than that of cats with a light or medium shade of coat color. Significantly (p < 0.001) more cats were adopted by women (748; 76.2%) than by men (233; 23.8%). Understanding seasonal fluctuations in cat adoptions and potential adopter? preferences is crucial for shelter personnel to establish effective procedures for rehoming shelter cats. Considering the relatively long time to adoption (median LOS = 69 days, mean LOS = 139 days, range = 0–1,600 days) more efforts should be put into seeking strategies for reducing this.     

Discrimination of mother by infant among Japanese Macaques (Macaca fuscata)

Experiments on five mother-infant pairs of Japanese monkeys (Macaca fuscata)living together in a captive group were conducted during the first 12 weeks after birth in order to assess the time at which infants begin to discriminate their own mothers from other adult females. After removal from their social group, infants exposed to their mothers and three unfamiliar adult females at a distance of 150 cm failed to orient visually toward their mothers. However, when the infants were allowed to approach the four females, they responded preferentially to their mothers during the third month of life. We concluded that by 8–12 weeks of age, infant Japanese macaques are able to discriminate between their mothers and other adult females.     

Alloparental feeding in Adélie penguins: why is it uncommon?

We investigated alloparental interactions and conditions which could facilitate or prevent the expression of alloparental behaviours in Adélie penguins (Pygoscelis adeliae), a long-lived seabird which nests in high-density colonies around Antarctica. Observation sessions were carried out during the crèche stage on 48 identified pairs and 50 identified chicks in a 217-nest subcolony. As the season progressed, young were fed less often by their own parents because these were increasingly absent from the breeding site and less responsive to their offspring’s solicitations. As a consequence, young and particularly those with a low body mass, coming from a two-chick brood, opted for gradually soliciting more from other adults to obtain food, preferentially those nesting in their direct vicinity. Unsuccessful breeders represented a low and constant part of the adult population and were not specifically solicited by unrelated young. Despite the increasing chick demand, only 4.1% (3 out of 73) of alloparental solicitations resulted in feeding, which is negligible compared to parental feeding. To investigate factors that could trigger the appearance of alloparental care, we carried out comparisons with king (Aptenodytes patagonicus) and emperor penguins (Aptenodytes forsteri) which represent the closest species for which data on alloparental behaviour were available. Our results show different trends to those observed in these species and three factors may explain the low occurrence of alloparental behaviour in Adélie penguins: (1) the low and constant proportion of unsuccessful breeders, (2) the absence of chick selectivity towards unsuccessful breeders, and (3) the late period of chick accessibility for potential alloparents.     

Corticosterone Levels Correlate With Alloparental Care in a Sex‐Dependent Manner in African Striped Mice,Rhabdomys pumilio

Alloparental care of non‐breeders is the main characteristic of cooperatively breeding species. While many studies have contributed to the understanding of the evolutionary reasons why individuals provide care to young that are not their own offspring, the variables influencing and causing alloparental care are less understood. We tested in African striped mice (Rhabdomys pumilio) whether age, sex, testosterone and corticosterone were correlated with alloparental care of non‐breeding helpers. We studied 11 family groups under controlled conditions in the laboratory, each with two juvenile and two adult helpers, one being male and one being female in each age category. We predicted male helpers to show more alloparental care than female helpers, as males are the dispersing sex and might thus have to pay for staying. We also expected adult helpers to show more alloparental care than juvenile helpers and both corticosterone and testosterone to correlate negatively with alloparental care. We found high levels of alloparental care in non‐breeding striped mice, which spent a significant amount of time in the nest, huddling and licking pups. There was neither a difference between the sexes nor between age categories (although both factors were significant in interaction terms), indicating either low costs and/or high benefits of alloparental care. Mothers showed significantly more care than helpers, and fathers showed similar levels of parental care as mothers but not significantly more than helpers. Although testosterone levels differed significantly between helpers of different age and sex, with adult male helpers showing the highest levels, we did not find any relationships between testosterone and the amount of alloparental care. Corticosterone levels were negatively correlated with alloparental care, and these effects were modulated by the sex and the age of helpers. In females, less alloparental care was shown with increasing corticosterone levels, while in males, the relationship was positive. Also, younger individuals with lower corticosterone levels showed more alloparental care than older individuals with low corticosterone levels. In sum, alloparental care is well developed in male and female non‐breeding helpers of striped mice, both in adult and juvenile helpers, but independently of testosterone, with corticosterone showing an age‐ and sex‐specific relationship with alloparental care.     

Cross‐genus adoptions in delphinids: One example with taxonomic discussion

Although relatively rare, adoptions have been reported in a number of mammals, involving almost exclusively individuals of the same species, and hardly ever between species or across genera. Adoption remains poorly documented and its proximate causes are controversial. Here, we describe a unique case of a cross‐genus adoption within a small community of common bottlenose dolphins (Tursiops truncatus) at Rangiroa Atoll in French Polynesia. It involves a foster female adopting a presumed melon‐headed whale (Peponocephala electra) calf while already mothering its presumed biological offspring. While the inclusive fitness hypothesis can be rejected for this adult female mother, acquisition of parental skills is also unlikely to have driven adoption in parallel to natural motherhood. We argue that the primiparous foster mother’s inexperience and personality may have contributed to factors driving such non‐adaptive behavior. We also propose that the adoptee’s persistence in initiating and maintaining an association with the adult female bottlenose dolphin could have played a major role in the adoption’s ultimate success, as well as the persistence of this cross‐genus adoption after the disappearance of the biological offspring. A brief discussion of adoption and hybridization within the Delphinidae taxon is included to identify how this cross‐genus adoption fits into context of marine mammal parental care.     

What is new in adoption

Adoptions arranged through adoption agencies are on the increase because there are more agencies. The Citizens Committee on Adoption of Children in California has concluded that there are very few adoptable children under care in orphanages. Fifty per cent of physicians would prefer agency adoptions, but only 24 per cent actually refer both expectant mothers needing such services and couples wishing to adopt infants to such agencies. The program in this field of social welfare should be child-centered and physicians should seek and give cooperation to such agencies.     

WHAT IS NEW IN ADOPTION

Adoptions arranged through adoption agencies are on the increase because there are more agencies. The Citizens Committee on Adoption of Children in California has concluded that there are very few adoptable children under care in orphanages. Fifty per cent of physicians would prefer agency adoptions, but only 24 per cent actually refer both expectant mothers needing such services and couples wishing to adopt infants to such agencies. The program in this field of social welfare should be child-centered and physicians should seek and give cooperation to such agencies.     

Adoption success under single-cage conditions by cynomolgus macaque mothers (Macaca fascicularis)

Retrospective data were studied to determine the success of experimental adoption by 122 cynomolgus macaques kept in individual cages at the Tsukuba Primate Center. The four types of adoption procedures included (1) singletons adopted after weaning (SAW)—21 cases; (2) singletons adopted after stillbirth (SAS)—20 cases; (3) singletons adopted after forced separation of the biological infant during the nursing period (SAF)—4 cases; and (4) adoption of a second “twin” while still nursing a biological infant (TA)—77 cases. Adoption was defined as successful if the mother nursed the foster infants for at least 7 days. Success rates (percent) were 47.6 for SAW, 75 for SAS, 100 for SAF, and 74 for TA. Success was affected by the postbirth stage of foster mothers at adoption but not by foster infant age or sex.     

Speed of Dog Adoption: Impact of Online Photo Traits

The Internet has radically changed how dogs are advertised for adoption in the United States. This study was used to investigate how different characteristics in dogs' photos presented online affected the speed of their adoptions, as a proof of concept to encourage more research in this field. The study analyzed the 1st images of 468 adopted young and adult black dogs identified as Labrador Retriever mixed breeds across the United States. A subjective global measure of photo quality had the largest impact on time to adoption. Other photo traits that positively impacted adoption speed included direct canine eye contact with the camera, the dog standing up, the photo being appropriately sized, an outdoor photo location, and a nonblurry image. Photos taken in a cage, dogs wearing a bandana, dogs having a visible tongue, and some other traits had no effect on how fast the dogs were adopted. Improving the quality of online photos of dogs presented for adoption may speed up and possibly increase the number of adoptions, thereby providing a cheap and easy way to help fight the homeless companion animal population problem.