ON THE ROLE OF ALLOPREENING INVITATION BEHAVIOUR IN REDUCING AGGRESSION AMONG RED AVADAVATS, WITH COMMENTS ON ITS EVOLUTION IN THE SPERMESTIDAE

This paper discusses the occurence of allopreening and allopreening invitation behaviour in red avadavats, and analyses tho factors which cause these birds to groom partners. It was found that allopreening tended to be temporally linked with aggression and autopreening beaviour in the actor, but that on many occasions, no signs of aggression preceded the act of allopreening. Allopreening invitation behaviour with the head feathers fully raised occurred in situations when the inviting individual was attacked and in response to being pecked or allopreened.
Alloprcening bouts which are tomporally correlated with autopreening behaviour may be a response by the groomer to the feathers of the clumping partner whon the preening tendency of the former bird is alroady activated.
From tho evidence submitted, it seems as though the allopreening invitation posture elicits non-aggressive preening in a bird which is likely to attack. It thus appears to act as an appeasement gesture; head ruffling changes the motivation of a bird tending to be aggressive. It was also found, however, that allopreening invitation behaviour may occur independently of appeasement.
The evolution of the Spermestid allopreening invitation posture from a "fluffed" body posture is also discussed.     

Different patterns of allopreening in the same-sex and opposite-sex interactions of juvenile large-billed crows (Corvus macrorhynchos)

Allogrooming, where an individual grooms another, has been extensively studied in various social animals to understand its role in the evolution of cooperation/prosociality. In existing studies in mammals, allogrooming has been suggested to exhibit not only a hygiene but also a social function. Allopreening, a topic of increasing interest in mammals but recently also in birds, has been studied mostly with mature animals. However, in some species immature individuals also show allopreening and its function remains poorly understood. Crows, Corvus spp., are an ideal model to study this phenomenon, because juveniles form year-round aggregates during their long juvenile stage (e.g., throughout 3–4 years). Here, we investigated the function of allopreening in juvenile groups of wild-caught large-billed crows (C. macrorhynchos). Allopreening frequency and duration for three groups of wild-caught juveniles were analysed to determine whether there was a symmetrical (i.e., reciprocal) or asymmetrical allopreening pattern, and if sex composition of the dyad and/or relative dominance of donor and recipient had an effect. We found that both the frequency and duration of male allopreening correlated with frequency of aggression. Allopreening between both males and females occurred unidirectionally from dominants to subordinates but not in the opposite direction. On the contrary, allopreening between a male and a female was found to be reciprocated, though the absolute frequency and duration were both greater in males than in females. These results suggest that the social function of allopreening in juvenile crows differs depending on the sex composition of the dyad, functioning as a dominance signal for same-sex dyads, and serving a social bonding function for opposite-sex dyads. These findings may reflect the potentially crucial roles of allopreening in within-sex competition and opposite-sex attraction during the 3 year-long juvenile stage affecting future mate choice in lifelong monogamy.     

Social interactions among breeding Brünnich's Guillemots Uria lomvia suggest constraints in relation to offspring vulnerability

Brünnich's Guillemots Uria lomvia are adapted to high-density breeding in large colonies on steep cliffs. Because they breed on narrow ledges, egg loss through dislodgement is an important cause of breeding failure. Fighting among breeders presumably raises the risk of accidental dislodgement. In this study, we investigated whether social behaviour among Brünnich's Guillemots shows any adaptations to reduce accidental egg loss by modifying behaviour during incubation. We found that the amount of aggression increased significantly at the time of hatching, perhaps in response to the reduced risk of breeding failure through dislodgement of a chick, compared with an egg. Allopreening followed an inverse trend, falling significantly after the day of hatch. This supports the hypothesis that allopreening is used to reduce aggressive interactions. At the same time, the frequency of allopreening was greatly increased on days when mosquitoes affected the birds, consistent with the hypothesis that allopreening is part of a defence strategy against ectoparasites.     

Fitness increases with partner and neighbour allopreening

Altruism and selfishness are fundamental characteristics of human and animal societies. Among colonial biparental species, breeding outcome depends on interactions between mates and neighbours. However, the relationships between cooperation within and among partnerships and fitness have not been fully investigated. We show that in the highly colonial common guillemot (Uria aalge), altruistic behaviour (allopreening) towards a mate was positively related to long-term fitness, whereas allopreening a neighbour was related to current fitness. Turnover is much lower within than between pairs, so our results suggest that allopreening within pairs generates fitness returns at longer timescales than between pairs. Allopreening not only removes ectoparasites and maintains plumage condition, but may also have important social functions. We found a negative relationship between fight rate and allopreen rate between breeding neighbours, with nests exhibiting low breeding success having a higher frequency of fights with neighbours. We also found evidence for reciprocity in allopreening. Thus, allopreening may function as a reciprocal stress reducer, to decrease the likelihood of fights and associated breeding failure. We suggest that altruistic behaviour has long-term benefits for the survival of the offspring when living in a crowded neighbourhood.     

Why preen others? Predictors of allopreening in parrots and corvids and comparisons to grooming in great apes

Allogrooming in primates serves not only a hygienic function, but also plays a crucial role in maintaining strong affiliative bonds between group members, which in turn, underpin the emergence of cooperative behavior. In contrast, although allopreening occurs in many avian species, we know little about its social functions. Our study addresses this issue by investigating allopreening in a broad comparative data set including six corvid and nine parrot species. We assessed whether rates of allopreening initiations, proportion of time spent allopreening, and the number of grooming partners in captive group-housed birds were comparable to patterns observed in captive chimpanzees and bonobos. While parrots and corvids were found to have similar rates of social grooming to bonobos and chimpanzees, Pan species dedicated significantly more time to social grooming. Animals in larger groups had more grooming partners, but when controlling for the number of potential partners, birds tended to have fewer grooming interaction partners than Pan species. We then investigated whether allopreening in parrots and corvids was predicted by behavioral markers of affiliative social bonds (close physical proximity, active feeding, and low levels of agonistic behavior). Results revealed that providing allopreening to a partner was significantly predicted by often being in close proximity, but not engagement in active feeding or agonistic behavior. We examined the region allopreened in a subset of species and found that preening a partner's head was predicted by both close physical proximity and active feeding, while body allopreening was only predicted by close physical proximity. Head preening may confer more hygienic benefits to recipients, and thus, may be more selectively provided to valued partners. Results support the hypothesis that allopreening in corvids and parrots helps maintain social bonds with an individual's most important social partners, showing some similarities to allogrooming in primates.     

Effect of kinship on the allopreening among juvenile Bengalese finches

Kin-directed affiliative behavior is widespread in social animals and kin selection theory suggests that such behavior increases fitness of the performer and is thus adaptive. Allopreening in birds is an altruistic behavior as it involves cleaning body parts that cannot be cleaned by self-preening. In this study, we investigated the effects of genetic relatedness on allopreening behavior among juveniles of the Bengalese finch Lonchura striata domestica shortly after the cessation of parental care. Nestlings were cross-fostered in order to distinguish the effects of genetic relatedness (sharing genetic parents) from the effects of familiarity (sharing rearing environment). Preening bouts toward siblings were more frequent and of longer duration than toward non-siblings. The frequency and duration of physical contact within a preening bout did not differ between siblings and non-siblings. In addition, the frequency and duration of preening bouts did not differ between the juveniles that were reared by the same foster parents and between those that were not. Our results suggest that Bengalese finch juveniles recognized siblings and performed affiliative behavior based on genetic similarity rather than familiarity.     

Effects of early rearing experience on adult behavior and nesting in captive Hawaiian crows (Corvus hawaiiensis)

Behavioral data were collected during the breeding season on eight pairs of Hawaiian crows (Corvus hawaiiensis) housed at two facilities on different islands. All data were collected from videocamera time‐lapse recordings of the nesting platforms. Behaviors included frequency of nest cup manipulation, percent of time spent on nest, allopreening, play, and stereotypy. The number of breeding pairs increased from four in 1996 to six in 1997, to seven in 1998, and to eight in 1999. Five of the older birds (three males and two females) were solitary‐reared for most if not all of their first year, while the remaining 12 birds were all socially reared. Significant differences were found between isolate‐ and socially‐reared birds, with isolate‐reared birds having higher rates of solo play (P = 0.0041) and stereotypies (P = 0.0090). Pairs that were comprised of at least one isolate‐reared bird engaged in significantly less allopreening (P = <0.0001) than pairs in which both birds were socially reared. From 1996 to 1999, 87 eggs were laid, with a mean of 1.88 ± 0.24 SEM eggs per clutch. Only three females produced clutches every year, and they were responsible for 85.1% of the eggs laid. Although not significant, the mean number of clutches produced per pair decreased from 2.50 ± 0.65 in 1996 to 0.87 ± 0.99 in 1999. Age of females does not appear to be a critical factor in the decrease in clutch production. New pairing combinations are under way in an effort to improve propagation in this highly endangered species. Zoo Biol 21:59–75, 2002. © 2002 Wiley‐Liss, Inc.     

Gender effects on aggression, dominance rank, and affiliative behaviors in a flock of captive adult cockatiels (Nymphicus hollandicus)

Agonistic and affiliative behaviors and spatial positioning were studied in a small psittacine species, Nymphicus hollandicus. Subjects studied were flock-housed breeders including five hens and seven cocks. Fifteen-minute focal animal samples were collected for the entire flock in a randomly distributed order during mate selection and the onset of the breeding season. All agonistic behaviors were recorded, including the winner and loser of each interaction, along with allopreening and copulation behavior. Point samples were recorded every 60s to determine social spacing. Rates of aggression were significantly higher for male cockatiels than female cockatiels. Results based on dyadic agonistic interactions showed males to rank significantly higher in the social hierarchy than females. Associations within the flock were not random. Individual birds associated more with specific birds than would be predicted by chance. Analysis of spatial data revealed that there were both same-sex and opposite-sex preferred associations within the flock. Male cockatiels engaged in allopreening behavior with females significantly more than with other males. Observations of breeding and nesting behaviors revealed pairs, a triad, and extra-pair mating.     

Corticosterone excretion patterns and affiliative behavior over development in ravens (Corvus corax)

Averse effects of social stress may be buffered by the presence of social allies, which mainly has been demonstrated in mammals and recently also in birds. However, effects of socio-positive behavior prior to fledging in relation to corticosterone excretion in altricial birds have not been investigated yet. We here monitored corticosterone excretion patterns in three groups of hand raised juvenile ravens (n=5, 6 and 11) in the nest, post-fledging (May-July) and when ravens would be independent from their parents (September-November). We related these corticosterone excretion patterns to socio-positive behavior. Behavioral data were collected via focal sampling in each developmental period considered. We analyzed amounts of excreted immunoreactive corticosterone metabolites (CM) using enzyme immuno assays. We collected fecal samples in each developmental period considered and evaluated the most appropriate assay via an isolation stress experiment. Basal CM was significantly higher during the nestling period than post-fledging or when birds were independent. The time nestlings spent allopreening correlated negatively with mean CM. Post-fledging, individuals with higher CM levels sat close to (distance <50 cm) conspecifics more frequently and tended to preen them longer. When birds were independent and a stable rank hierarchy was established, dominant individuals were preened significantly longer than subordinates. These patterns observed in ravens parallel those described for primates, which could indicate that animal species living in a complex social environment may deal with social problems in a similar way that is not restricted to mammals or primates.     

Food sharing and affiliation: An experimental and longitudinal study in cockatiels (Nymphicus hollandicus)

Food sharing has attracted much attention because of its apparently altruistic nature and its link to prosociality. However, food sharing has been mostly studied in a reproductive context, during courtship and parental care, where the fitness benefits are obvious. We still lack a clear understanding of the functions of food sharing outside any reproductive context and within social groups of same‐aged peers. Previous studies suggest that cofeeding, the action to let another animal feed from the same monopolizable food source, may be used to build and strengthen bonds between individuals. This may be particularly crucial in social birds forming long‐term associations between mates or siblings such as psittacids and corvids. Here, we investigated food sharing and affiliative behaviors such as allopreening in a psittacine species, namely in a group of captive juvenile cockatiels (Nymphicus hollandicus) consisting of five siblings and five unrelated birds. Our main objective was to study the developmental pattern of food sharing over time and its implication in social bonding depending on kinship, affiliation, and sex. Studying cockatiels in this context is providing many new information since most of the studies on food sharing in birds focused on corvids. We found that, contrary to jackdaws, cockatiels continued to share food with multiple individuals, although the frequency of cofeeding as well as the number of cofeeding partners decreased over time. Cockatiels shared more food with their siblings than with other conspecifics but they were not more likely to do cofeeding with birds of the opposite sex. We also found evidence that young cockatiels exchanged more food with those from whom they received food (reciprocity) and, to a lesser extent, allopreening (interchange), than from other cockatiels. Our findings suggest that in cockatiels, food sharing within social groups serves the formation (and maintenance) of affiliative bonds, especially between siblings, rather than pair bonds, but might additionally be explained by reciprocity, interchange, and harassment avoidance.     

Oxytocin-like receptors mediate pair bonding in a socially monogamous songbird

Although many species form socially monogamous pair bonds, relevant neural mechanisms have been described for only a single species, the prairie vole (Microtus ochrogaster). In this species, pair bonding is strongly dependent upon the nonapeptides oxytocin (OT) and vasopressin, in females and males, respectively. Because monogamy has evolved many times in multiple lineages, data from additional species are required to determine whether similar peptide mechanisms modulate bonding when monogamy evolves independently. Here we test the hypothesis that OT-like receptor activation is required for pair bond formation in the socially monogamous zebra finch (Taeniopygia guttata). Males and females were administered chronic intracerebroventricular infusions of saline or an OT receptor antagonist and were observed twice daily for 3 days in a colony environment. A variety of affiliative, aggressive and other behaviours were quantified. The antagonist produced significant and selective effects on pair bonding (latency to pair; number of sessions paired; stable pairing) and the associated behaviour of allopreening. Importantly, findings for males follow the trends of females; this yields main effects of treatment in two-way ANOVAs, although within-sex analyses are significant only for females. These data provide evidence for both convergent evolution and species diversity in the neuroendocrine mechanisms of pair bonding.     

Social behaviour within groups of jungle babblers (Turdoides striatus)

Five aspects of intra-group behaviour among wild jungle babblers were analysed in relation to the age, sex and breeding status of the participants. The amount of participation in allopreening, sentinel behaviour, and movement initiation were found to be closely correlated with age and breeding status, resulting in a rough concordance between rankings based on these three activities. There was some difference between the sexes in the degree of participation in allopreening and sentinel behaviour and this may be explained by differences in their strategies for breeding. Changes in play and roosting behaviour with age are related to the establishment of dominance relations among birds of the year and possible connections between other aspects of behaviour and social status are also discussed.     

Duration and outcome of intergroup conflict influences intragroup affiliative behaviour

Theoreticians have long suggested that the amount of intergroup conflict in which a group is involved could influence the level of cooperation or affiliation displayed by its members. Despite the prevalence of intergroup conflicts in many social animal species, however, few empirical studies have investigated this potential link. Here, I show that intragroup allopreening rates are highest in green woodhoopoe (Phoeniculus purpureus) groups that have the greatest involvement in intergroup conflict. One reason for this relationship is a post-conflict increase in allopreening, and I demonstrate for the first time that both conflict duration and outcome influence subsequent allopreening rates: group members allopreened more following long conflicts and those they lost compared with short conflicts and those they won, perhaps because the former are more stressful. The increase in affiliative behaviour was the result of more allopreening of subordinate helpers by the dominant breeding pair, which may be because the breeders are trying to encourage helpers to participate in future conflicts; relative group size influences conflict outcome and helpers contribute more to conflicts than do the breeding pair. These results emphasize that our understanding of cooperation and group dynamics can be enhanced by investigations of how intergroup interactions affect intragroup processes.     

Breeding and management of the common trumpeter (Psophia crepitans)

The breeding biology and management of three wild-caught adult Common trumpeters (one male and two females) was documented at the Woodland Park Zoological Gardens, Seattle, from April, 1984 to August, 1986. A total of 27 eggs were laid, and eight young survived to fledging. Both sexes exhibited crane-like dances during courtship, but the male appeared to perform these behaviors more frequently and with greater intensity than the females. Courtship feeding and allo-preening also occurred. Nests consisted of simple scrapes on the ground, but the birds had no opportunity to rest in trees or other elevated sites. Clutches contained two or three eggs, and the incubation period was aproximately 28 days. Although the breeding pair was generally aggressive toward the second female, all three adults participated in incubation and in caring for the young. Parental behavior consisted of brooding, allopreening, and feeding. The male preened and fed one chick significantly more often than either of the females. Trumpeter chicks were highly precocial, but grew relatively slowly, reaching 50% of adult weight by 45 to 50 days of age. Trumpeters are difficult to maintain and breed in captivity and appear to be susceptible to mycotic diseases, such as aspergillosis. Changes in the social composition of captive groups may result in improved breeding.     

The relative contributions of termites and microarthropods to fluff grass litter disappearance in the Chihuahuan Desert

Summary We tested the hypotheses that both subterranean termites and soil microarthropods are important in the disappearance of fluff grass (Erioneuron pulchellum) litter on the soil surface by an experiment designed to separate termite and microarthropod effects. Subterranean termites (Gnathamitermes tubiformans) removed more than 50% of the fluff grass litter in one year.Since there was no difference in mass loss of fluff grass with microarthropods present or excluded, they had no effect on decomposition of fluff grass litter. Microarthropod densities increased during the first 3 months then slowly decreased. The densities of microarthropods in fluff grass litter were too low to have a measurable effect on decomposition even if we assumed that the microarthropods consumed litter equivalent to their body weight each day.     

THE EVOLUTION OF PLUMAGE BRIGHTNESS IN BIRDS IS RELATED TO EXTRAPAIR PATERNITY

A positive association between plumage brightness of male birds and the degree of polygyny may be the result of sexual selection. Although most birds have a socially monogamous mating system, recent paternity analyses show that many offspring are fathered by nonmates. Extrapair paternity arises from extrapair copulations which are frequently initiated by females. Not all females will be able to mate with a male of the preferred phenotype, because of the mating decisions of earlier paired females; extrapair copulations may be a means for females to adjust their precopulation mate choice. We use two comparative analyses (standardized linear contrasts and pairwise comparisons between closely related taxa) to test the idea that male plumage brightness is related to extrapair paternity. Brightness of male plumage and sexual dimorphism in brightness were positively associated with high levels of extrapair paternity, even when potentially confounding variables were controlled statistically. This association between male brightness and extrapair paternity was considerably stronger than the association between male brightness and the degree of polygyny. Cuckoldry thus forms an important component of sexual selection in birds.     

Lack of evidence for vertical transmission of Campylobacter spp. in chickens

Campylobacter jejuni is a major cause of bacterial food-borne infection in the industrial world. There is evidence that C. jejuni is present in eggs and hatchery fluff, opening the possibility for vertical transmission from hens to progeny. Poultry operations in Iceland provide an excellent opportunity to study this possibility, since breeding flocks are established solely from eggs imported from grandparent flocks in Sweden. This leaves limited opportunity for grandparents and their progeny to share isolates through horizontal transmission. While Campylobacter was not detected in all grandparent flocks, 13 of the 16 egg import lots consisted of eggs gathered from one or more Campylobacter-positive grandparent flocks. No evidence of Campylobacter was found by PCR in any of the 10 relevant quarantine hatchery fluff samples examined, and no Campylobacter was isolated from the parent birds through 8 weeks, while they were still in quarantine rearing facilities. After the birds were moved to less biosecure rearing facilities, Campylobacter was isolated, and 29 alleles were observed among the 224 isolates studied. While three alleles were found in both Sweden and Iceland, in no case was the same allele found both in a particular grandparent flock and in its progeny. We could find no evidence for vertical transmission of Campylobacter to the approximately 60,000 progeny parent breeders that were hatched from eggs coming from Campylobacter-positive grandparent flocks. If vertical transmission is occurring, it is not a significant source for the contamination of chicken flocks with Campylobacter spp.     

The culture of bird conservation: Australian stakeholder values regarding iconic,flagship and rare birds

Iconic, flagship and rare threatened bird taxa attract disproportionate amounts of public attention, and are often used to enable broader conservation strategies. Yet, little is known about why certain taxa achieve iconic or flagship status. Also unclear is whether the perception of rarity among those acting to conserve threatened birds is sufficient to influence attitudes and behaviour that lead to effective conservation action and, if so, which characteristics of rare birds are important to their conservation. We interviewed 74 threatened bird conservation stakeholders to explore perceptions about iconic, flagship and rare threatened birds and classified their attitudes using a new typology of avifaunal attitudes. There was a relationship between societal interest and conservation effort for threatened species characterised as iconic, flagship and rare. Iconic species tended to arouse interest or emotion in people due to being appealing and readily encountered, thereby attracting conservation interest that can benefit other biodiversity. Flagships tended to have distinguishing physical or cultural characteristics and were used to convey conservation messages about associated biodiversity. Attitudes about rarity mostly related to a taxon’s threatened status and small population size. Rarity was important for threatened bird conservation but not always associated with attitudes and behaviour that lead to effective conservation action. We conclude that conservation action for individual threatened bird taxa is biased and directly influenced by the ways taxa are socially constructed by stakeholders, which is specific to prevailing culture and stakeholder knowledge.     

Mating strategies in dominant meerkats: evidence for extra‐pair paternity in relation to genetic relatedness between pair mates

Rates of extra‐pair paternity (EPP) have frequently been associated with genetic relatedness between social mates in socially monogamous birds. However, evidence is limited in mammals. Here, we investigate whether dominant females use divorce or extra‐pair paternity as a strategy to avoid the negative effects of inbreeding when paired with a related male in meerkats Suricata suricatta, a species where inbreeding depression is evident for several traits. We show that dominant breeding pairs seldom divorce, but that rates of EPP are associated with genetic similarity between mates. Although extra‐pair males are no more distantly related to the female than social males, they are more heterozygous. Nevertheless, extra‐pair pups are not more heterozygous than within‐pair pups. Whether females benefit from EPP in terms of increased fitness of the offspring, such as enhanced survival or growth, requires further investigations.