THE BREEDING BEHAVIOUR OF THE WHITE BOOBY SULA DACTYLATRA*

The aim of this paper is to describe the form and interpret the motivation, function and derivation of breeding behaviour in the White Booby. Attention is paid to adaptive aspects and an effort made to correlate behaviour with environment? particularly colony density and associated degree of competitive behaviour. The absence, simplicity or complexity of certain displays can be correlated with the extent to which highly developed social and /or pair interaction are needed. Throughout I have tried to place White Booby behaviour in the framework of behaviour in the Sulidae as a group and particularly to compare it with Gannet behaviour, since the latter nest more densely than other sulids and show more extreme aggression and greater ritualization of behaviour patterns used in interpair and wider social communications. The White Booby provides an interesting contrast. After a brief account of morphology and voice the points are made that White Booby colonies are generally smaller and much less dense than those of the Gannet or Peruvian Booby and also that White Boobies breed in a wide variety of habitats. Site establishment, pair formation, later pair relations, social interactions, body maintenance behaviour, incubation and care of young are described and an account of behaviour in the young is given. The male establishes the site and shows yes /no headshaking as an aggressive, site-ownership display, often performed after landing. He attracts the female with a sky-pointing display which is homologous with sky-pointing in the Gannet, where, however, it subserves a different and, it is argued, phylogenetically older function, signalling that a bird is about to leave the site rather than serving as an advertizing display. In the White Booby it is thus a good example of a motivationally and functionally emancipated display. When the pair meet, mutual jabbing, a hostile-looking and relatively undifferentiated meeting ceremony, and bill-touching occur. Symbolic nest building plays an important part in White Booby pair behaviour, though the nest is structurally negligible. Nest building is associated with copulation, in which the female is not gripped. Bill-up-face-away is a bill-averting posture used when a booby moves away from its mate. It is probably an appeasement posture and, so far as the situation “I am about to move” is concerned, seems to have taken the place of Gannet sky-pointing, the latter having become the booby's advertizing. Wing rattle is a movement probably partly functional in preparing feathers for flight, but is also used as signal behaviour prior to take-off, particularly during the frequent flights around the breeding area that White Boobies show early in the season. Wing flapping, sometimes with rotary headshaking, is mainly feather maintenance behaviour. The forms of headshaking and head flinging are described. Reciprocal allo-preening occurs; it is suggested that it can do so without disadvantage since White Boobies possess mutual jabbing—an interaction which can accommodate any aggression engendered by the pair pointing bills at each other, as required for reciprocal allo-preening. The average incubation spell in the male is 30 hours and in the female 25 hours; all sulid males show this tendency to spend longer on the site. Seasonally, too, there is a marked sex-difference in site attendance and this is depicted in graphs for different categories of White Boobies. The young are left unguarded from about four weeks of age and move off the site. They are fed about 1.4 times per day. They respond to adult investigation or attack by beak-hiding—an effective appeasement posture. Soon, they perform aggressive territorial behaviour and dispel other young and adults. They return to the site to be fed for around 50 to 60 days after they become free-flying and show all forms of territorial behaviour. The discussion is mainly concerned with the correlation between nesting density, aggression and associated appeasement behaviour. It is concluded that, overall, the White Booby's ritualized postures and displays are less well differentiated than those of the Gannet, though individual behaviour patterns may be more complex. The pair relationship in the White Booby approximates more closely to that normally found in birds, where the male is not outstandingly aggressive to his mate.     

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.     

Is Preening Behaviour Sexually Selected? An Experimental Approach

Elaborate or colourful feathers are important traits in female mate choice in birds but little attention has been given to potential costs of maintaining these traits in good condition with preening behaviour. Recent studies indicate that the time and energy required to maintain ornamental plumage in good condition reinforces the honesty of plumage trait. It has been proposed that some behaviours, whose primary function is not to transfer information, can also evolve as signalling components. Here we investigate whether the preening behaviour intensity has a signalling component: we hypothesized that if only high quality males can invest a lot of time in preening, this behaviour may be used by females as a quality signal (attractive preening hypothesis). We tested this hypothesis by using female budgerigars in mate‐choice tests in captivity. We tried to experimentally manipulate the preening behaviour of two groups of budgerigar males (treatment and control group). The proportion of time in which treated males preened in front of females was statistically higher than for control males, however, females spent similar amounts of time with treated males and control males. Moreover, males did not show significant quantitative changes in preening (for both groups) when females were present, suggesting that male budgerigars did not use this behaviour to convey information. These results are inconsistent with the ‘attractive preening’ hypothesis which predicts that preening behaviour itself provides information on condition and is used in female choice.     

Bowing and allopreening of captive Jackdaws Corvus monedula

Allopreening interactions were observed in groups of captive, hand-reared Jackdaws Corvus monedula. Head fluff and Bowing, both resembling 'soliciting' postures described in the literature, are described. Head fluff seems to be associated with allopreening. Bowing was performed more frequently by socially top-ranking birds, performed and received equally frequently by females and by males, and directed at birds higher than and lower than the performer with equal frequency. Bowing was followed mostly by the recipient's moving away or by no apparent response, and only rarely by the allopreening of the actor. Allopreening was performed mostly by socially low-ranking towards high-ranking birds, and both when the actor was dominant to or submissive to the recipient. Bowing and allopreening seemed to be associated with situations of tension. It is suggested that Bowing here was used as intimidation rather than 'solicitation' or appeasement, and that allopreening and Bowing function in confirming relationships and in conveying information about relative status to other members of the group.     

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.     

Multiple ornaments correlate with aspects of condition and behaviour in female northern cardinals, Cardinalis cardinalis

Male ornamentation in socially monogamous birds has been shown to provide information to potential mates on aspects of condition and behaviour. We studied female ornamentation in the socially monogamous, biparental northern cardinal to determine whether expressions of multiple ornaments correlate with aspects of female condition and behaviour. Expressions of the ornamental red-orange bill, red underwing feathers, head crest and blackish face mask were compared to several measures of condition, parental behaviour and intrasexual aggression. Red-orange bill colour of females was correlated with both body size and an index of body condition. Redness of the underwing feathers was correlated with body size, body condition, date of first nest produced and reproductive success. Face mask expression was correlated with both nestling feeding rate and level of intrasexual aggression. The length of head crest feathers did not correlate with any measured aspect of condition or behaviour. These results are consistent with the hypothesis that ornaments in female cardinals provide redundant information to prospective mates on aspects of female condition and behaviour.     

BEHAVIOUR OF THE BLUE-CROWNED HANGING PARROT LORICULUS GALGULUS WITH COMPARATIVE NOTES ON THE VERNAL HANGING PARROT L. VERNALIS

The maintenance activities of Loriculus galgulus and L. vernalis are described and discussed, and compared with the behaviour of the parrots of the genus Agapornis. Maintenance activities reveal some adaptations to the genus-typical habit of resting and sleeping upside-down. A peculiar defaecation posture ensures that the plumage of hanging birds is not soiled. L. galgulus holds food either in the foot or in the bill, but L. vernalis seems not to use the foot in feeding:there is much regurgitation and remastication of food. Scratching is indirect, as in the Agapornis species, though the foot is brought directly to the bill to be preened. Loriculus is more ready to bathe in standing water than is Agapornis, actually entering the water, and not merely splashing from the edge. There is some evidence that L. galgulus rain-bathes hanging upside down, as does A. cana. Agonistic behaviour is highly ritualized in Loriculus:some actions are identical with those of the more primitive species of Agapornis. Threat displays are described: the so-called Super Threat Display combines all agonistic actions in one. There are three appeasement displays. Group upside-down pseudo-sleeping as a response to the appearance of potential predators is frequent in both species: it is not certain if this is a displacement reaction or a normal escape reaction to the safety of an inaccessible refuge. Little is known about reproductive behaviour in captivity and even less about behaviour in the wild. Pair formation appears to occur late in the period of attaining maturity, and to be initiated and maintained by courtship feeding: homosexual pairing is not unusual n flocks of captive birds. Of the courtship displays, one-Strutting-seems to be common to several Loriculus species. Cutting of nest material is an activity of both male and female Loriculus. A maturing or learning process is seen in the cutting of little “bits” by inexperienced and immature birds, and by the cutting of straight or arcuate strips by those more experienced. In Loriculus galgulus, females were seen to tuck strips of nesting material in the throat and breast feathers, though they have been reported to tuck material into the rump feathers also: L. oernalis females tucked arcuate strips among the rump feathers only. Both male and female L. galgulus and L. vernalis investi- gated nest boxes, but none actually nested. This study in general reinforces the ideas about the relationship of the genera Loriculus and Agapornis but more data on other Loriculus species are needed. At this stage of investigation it appears that both L. galgulus and L. oernalis are behaviourally closest to the more primitive species of Agapornis, namely, cana, tarantu and pullaria.     

Effect of restricted preen-gland access on maternal self maintenance and reproductive investment in mallards

Background

As egg production and offspring care are costly, females should invest resources adaptively into their eggs to optimize current offspring quality and their own lifetime reproductive success. Parasite infections can influence maternal investment decisions due to their multiple negative physiological effects. The act of preening – applying oils with anti-microbial properties to feathers – is thought to be a means by which birds combat pathogens and parasites, but little is known of how preening during the reproductive period (and its expected disease-protecting effects) influences maternal investment decisions at the level of the egg.

Methodology/Principal Findings

Here, we experimentally prevented female mallards (Anas platyrhynchos) from accessing their preen gland during breeding and monitored female immunoresponsiveness (e.g., plasma lysozyme concentration) as well as some egg traits linked to offspring quality (e.g., egg mass, yolk carotenoid content, and albumen lysozyme levels). Females with no access to their preen gland showed an increase in plasma lysozyme level compared to control, normally preening females. In addition, preen-gland-restricted females laid significantly lighter eggs and deposited higher carotenoid concentrations in the yolk compared to control females. Albumen lysozyme activity did not differ significantly between eggs laid by females with or without preen gland access.

Conclusion/Significance

Our results establish a new link between an important avian self-maintenance behaviour and aspects of maternal health and reproduction. We suggest that higher yolk carotenoid levels in eggs laid by preen-gland-restricted females may serve to boost health of offspring that would hatch in a comparatively microbe-rich environment.     

SIDEWAYS-THROWING AND SIDEWAYS-BUILDING IN BIRDS

Birds which build the simplest and scantiest nests use a single movement, sideways-throwing, in assembling material; and a modified form of it, sideways-building, in arranging material on the site. Sideways-throwing is usually performed by a standing or walking bird which picks up a small object in front of it, and throws it back, either to one side or beneath it, with a sharp sideways movement of the head. Sideways-building is normally performed by a sitting bird which takes material and deliberately places it to either side or in towards its breast. Sideways-throwing and sideways-building occur in the Struthionidae, Rheidae, Dromaiidae, Gaviformes, Procellariformes, Anseriformes, Meleagrididae, Phasianidae, Gruidae and Charadrüformes. Sideways-building only is recorded in the Sulidae ahd, for Platalea leucorodia, in the Threskiornithidae. There are no records of nest-building in the Apterigidae, Tinamidae, Otidae, and Pteroclididae. Sideways-throwing occurs within the vicinity of the nest-site, often in conjunction with conflict behaviour; and typically occurs at nest-relief, performed by the bird leaving the nest. This results in material accumulating at the nest-site, and this may be pulled in by the sitting bird during sideways-building, The amount and type of material depends on its availability around the nest-site. In species where only one sex incubates the sitting bird may leave the nest at intervals and perform sideways-throwing. Sideways-throwing appears to occur frequently as a form of irrelevant behaviour, usually in agonistic situations; sideways-building often occurs when a sitting bird is disturbed. Since sideways-throwing is a relatively ineffectual form of nest-building, the creation of a nest appears to depend on the extent to which the bird finds itself in a conflict situation and the amount of material near the nest. It seems possible that it may have evolved as Irrelevant Behaviour rather than true nest-building. It is suggested that the movements might be derived from false-feeding movements involving the picking up of inedible objects, and from the flick of the head, with which a bird removes an unwanted object adhering to its bill. Such behaviour performed by a bird walking repeatedly from the nest could result in the accumulation of material at a nest-scrape. Relatively little modification would be needed to create a form of nest-building suitable for very simple nests. Chance sideways-throwing seems to occur in many species. Nests in damp situations may be larger than those in dryer ones and, although this might be accidental, the behaviour of some species during floods suggests purposeful building. Some species appear to align their throwing in relation to the position of the nest. In some groups within the Charadrüformes sideways-throwing appears to have been replaced by the carrying of material to the nest. In such species relict sideways-throwing often occurs when material is deposited on the nest-site; and sideways-building is used in the arrangement of the material. It is possible that movements similar to sideways-building used in nest construction by birds in other groups might be homologous with it and represent the persistence of an earlier behaviour pattern.     

繁殖期高原鼠兔的攻击行为

通过室内配对实验对高原鼠兔（Ｏｃｈｏｔｏｎａ ｃｕｒｚｏｎｉａｅ）繁殖期的攻击行为进行了研究。结果表明,雌雄动物的攻击水平相同,同性个体间的攻击性明显高于异性个体间。雌雄动物具有不同的攻击模式。雌性个体遇到陌生个体首先以攻击中的进攻和追逐为主,然后通过相互接触确定个体的性别,若为同性个体,以防御为主,若为异性个体,则有防御和亲昵两种选择;雄性动物遇到陌生个体同样首先以攻击为主,相互接触后,若为异性     

Preparing for battle? Potential intergroup conflict promotes current intragroup affiliation

Groups of human soldiers increase their affiliative behaviour when moving into combat zones. Despite numerous other species also competing as groups, little is known about how potential intergroup conflict might influence current intragroup affiliative behaviour in non-human animals. Here, I show that allopreening (when one individual preens another) increases in groups of cooperatively breeding green woodhoopoes (Phoeniculus purpureus) when they enter areas where conflicts with neighbours are more likely. Self-preening, which is an indicator of stress in other species, did not increase in conflict areas, suggesting that the change in affiliative behaviour is not the simple consequence of greater stress. Instead, because it is the dominant breeding pair that increase their preening of subordinate helpers, it is possible that current affiliative behaviour is being exchanged for agonistic support in any intergroup conflicts that might ensue. These results are important for our understanding of group dynamics, cooperation and the evolution of sociality, but also bring to mind the intriguing possibilities of social contracts and future planning in birds.     

Sex and migratory strategy influence corticosterone levels in winter-grown feathers,with positive breeding effects in a migratory pelagic seabird

To overcome unpredictable stressful transitory events, animals trigger an allostatic response involving the hypothalamic–pituitary–adrenal cortex. This hormonal response, which involves the release of glucocorticoids which in turn mediate between the main physiological mechanisms that regulate the energetic demands and resource allocation trade-off with behavioural responses to environmental perturbations and may ultimately lead to variation in fitness. We have used the Cory’s shearwater Calonectris borealis, a sexually dimorphic pelagic seabird with a partial migratory strategy, as a model bird species to analyse a number of traits related to the stress response. We investigated whether the activation of a stressful response, mediated by corticosterone, during the wintering period (1) correlated with the previous breeding success, (2) was affected by the migratory behaviour of male birds and (3) had consequences in the fitness of the birds. Corticosterone levels in feathers grown overwinter were analysed in 61 adult birds during three consecutive migratory periods (2009–2012) and in 14 immature birds in the wintering period 2010–2011. Moreover, the levels of corticosterone were analysed in experimental birds which were freed from their reproductive duties and compared with control birds which raised fledglings to the end of the breeding period. The results show that the levels of corticosterone were sex dependent, differed between years and were affected by the migratory strategy performed by the birds. The activation of the stressful response over the wintering period generated residual carry-over effects that positively affected the reproductive output in the subsequent breeding stage, a phenomenon previously undescribed in a long-lived pelagic seabird. Our study provides evidence that the analysis of corticosterone from feathers is a useful tool to evaluate carry-over effects in birds far away from breeding sites, opening new possibilities for future studies in this field.     

Plumage maintenance affects ultraviolet colour and female preference in the budgerigar

Elaborate or colourful feathers are important traits in female-mate choice in birds but little attention has been given to the potential costs of maintaining these traits in good condition via preening behaviour. While preening is known to be an important component of plumage maintenance, it has received little attention with respect to colouration. We investigated whether preening can influence plumage reflectance and whether females show a preference for plumage cleanliness in captive-bred, wild-type budgerigars, Melopsittacus undulatus. To do this, we compared the spectral colour of birds that were allowed to preen their plumage and individuals that were prevented from preening. The plumage of birds that were prevented from preening showed a significant lower reflectance in the UV range (300-400 nm). Subsequently, we measured females’ preferences for preened and unpreened males using a two-choice test. In a second experiment we allowed females to choose between an unpreened male and a male smeared with UV-absorbing chemicals (UV-blocked male). The proportion of time that females stayed near preened males was statistically higher than for unpreened males, but females spent similar amounts of time with unpreened males and UV-blocked males. These results are consistent with the idea that female budgerigars are able to discriminate between preened and unpreened males, and that UV colours, mediated by preening, can convey information about a bird's current condition.     

The response to eye-like shapes by birds II. The importance of staring,pairedness and shape

Laboratory-reared 37-day-old white leghorn chicks were placed individually in an arena with one of a range of eight three-dimensional stimuli. The chick's behaviour was recorded over a 3-min period. Each bird was exposed to a stimulus which varied in three ways, being either circular concentric (eye-like) or rectangular, single or paired and which appeared to either persistently look at (track) or look away from (avoid) the chick. All three manipulations produced significant effects on how close the bird approached. The most avoided combination was two, tracking, eyelike shapes. The results are discussed in the context of the problems involved in isolating the effective components of stares and the head forwards threat posture.     

中国鸟类一新纪录种--黑背信天翁(鹱形目,信天翁科)

近期在福州江智明先生的鸟类标本收藏中发现1只1956年3月采自福建沿海的黑背信天翁Diomedea immutabilis标本,为中国鸟类新纪录.     

小型啮齿动物种群系统调节复合因子理论的野外实验研究：食物可利用性和捕食对根田鼠种群空间行为的作用模式及其对种群调节的探讨

本项研究在野外围栏条件下,采用析因实验设计,测定食物可利用性和捕食对根田鼠（Ｍｉｃｒｏｔｕｓｏｅｃｏｎｏｍｕｓ）种群空间行为的作用模式。检验的特定假设为,高质量食物较大的可利用性能降低田鼠的攻击行为和活动;捕食能减少田鼠的活动。研究结果表明,食物可利用性能间接地和直接地影响根田鼠的空间行为。附加食物种群具有较高的密度和较小的巢区,且在诱捕期间具有较少的长距离活动和较低的攻击水平。捕食者的存在不直接影响攻击行为,但能影响诱捕期间的长距离活动,此为根田鼠对捕食者存在作出的直接反应。在阐明田鼠种群动态时,应仔细考虑上述因子相互作用的效应。     

Coping behaviour as an adaptation to stress: post-disturbance preening in colonial seabirds

In humans, coping behaviour is an action taken to soothe oneself during or after a stressful or threatening situation. Some human behaviours with physiological functions also serve as coping behaviours, for example, comfort sucking in infants and comfort eating in adults. In birds, the behaviour of preening, which has important physiological functions, has been postulated to soothe individuals after stressful situations. We combine two existing modelling approaches - logistic regression and Darwinian dynamics - to explore theoretically how a behaviour with crucial physiological function might evolve into a coping behaviour. We apply the method to preening in colonial seabirds to investigate whether and how preening might be co-opted as a coping behaviour in the presence of predators. We conduct an in-depth study of the environmental correlates of preening in a large gull colony in Washington, USA, and we perform an independent field test for comfort preening by computing the change in frequency of preening in gulls that were alerted to a predator, but did not flee.     

"Conventional" Signals in Avian Agonistic Displays: Integrating Theory, Data and Different Levels of Analysis

We present an integration of communication theory and data, drawing on examples from titmice (Aves: Paridae). We suggest how display actions such as lifting the head, raising the nape feathers, crest erecting and spreading the wings, act in agonistic communication when physical contact between opponents is rare. We propose that such displays largely act as strategic choice handicap signals. By giving these displays the signaller is believed to incur costs which underwrite the reliability of the signals; it may strategically increase these costs (for example by display repetition or adding additional elements) to signal its condition, motivation and hence the subjective value of a resource. It is shown that linking these ideas with earlier theories on the causation of display components, leads to an explanation of why birds have a greater repertoire of signals associated with aggression/winning, than with submission/losing. It is suggested that modellers of communication systems and those interested in the theory of signal design should pay more attention to the evolutionary constraints imposed by signal origin. Copyright 1999 Academic Press.