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Copulation Call Coordinates Timing of Head-Tossing and Mounting Behaviors In Neighboring Glaucous-Winged Gulls ( Larus glaucescens )
Abstract
Reproductive behaviors such as mounting and copulation calls spread through gull breeding colonies via social facilitation. We showed that broadcasts of model copulation calls to breeding Glaucous-winged Gulls (Larus glaucescens) did not increase the overall numbers of bouts of head tossing or mounts, but they did coordinate the timing of subsequent head-tossing and mounting behaviors. By contrast, silent controls and non-gull sounds with similar spectral features and duty cycles did not coordinate the timing of either head tossing or mounts. Disturbances by humans, such as those occurring during an egg census, caused increases in head tossing in the short term but did not affect the number or timing of mounts. Eagle disturbances reduced the frequency of head tossing and mounting overall, and coordinated the timing of head tossing but on a longer time scale compared to the effect of a human disturbance. Our data demonstrate that the copulation call, without associated wing-flagging, is sufficient to cause the socially facilitated coordination of these reproductive behaviors in gulls, whereas other stimuli do not.
... Environmental factors trigger and control coordinated behaviors in birds. For example, seasonal changes in day length determine the timing of migration (Gwinner 1990, Berthold 1996 and breeding (Sharp 2005); tides and time of day influence the timing of group feeding, loafing, and other behaviors (Henson et al. 2004(Henson et al. , 2007aDamania et al. 2005;Hayward et al. 2009); changes in food availability due to reduced marine productivity alter feeding behaviors when water temperatures are high (Hipfner 2008, Hayward et al. 2014, Smith et al. 2017); social facilitation triggered by neighbor vocalizations leads to the coordination of courtship and breeding (Atkins et al. 2017, McWilliams et al. 2018; and predator activity may tighten and coordinate breeding seasons in temperate regions (Darling 1938, Burger andGochfeld 1991). ...
... Using audio playback of model copulation calls, Atkins et al. (2017) showed a significant effect on the temporal coordination of mounts among neighboring Glaucous-winged Gulls, even though there was no change in the number of mounts compared to silent controls. This effect was not observed when non-gull sounds were used or when other disturbances were evaluated. ...
... Before a socially coherent neighborhood becomes synchronized, females that lay earliest engage in less mounting the day an egg is laid. Fewer mounts by these gulls slightly reduce the overall socially facilitated spread of mounting and copulations for that day (see Atkins et al. 2017, McWilliams et al. 2018. The day following oviposition by these early nesters would exhibit a rebound of mounting levels that would spread through the socially coherent neighborhood. ...
Increased sea-surface temperatures lead to increased egg cannibalism in Glaucous-winged Gulls (Larus glaucescens). Under these conditions, female gulls, which lay an egg approximately every 2 d, can synchronize egg laying with other females on an every-other-day schedule. Eggs that are laid synchronously are less likely to be cannibalized. The mechanism for synchronization has remained unknown. We studied the relationship between egg laying and mounting in a colony of Glaucous-winged Gulls on Protection Island, Washington, for clues to a synchronizing mechanism. We found that for an individual female an oviposition event reduced the likelihood of mounts for that day as compared to the day before, and that for sampled areas of the colony, total numbers of mounts and eggs laid occurred in an out-of-phase rhythm. These findings support the following conceptual model: early in the breeding season, individual females that have begun laying exhibit a daily alternation of higher and lower mounting activity caused by their natural 2 d oviposition oscillation. By social facilitation, these mounting oscillations of early layers synchronize mounting across the colony, including mounting events involving females that are not yet laying. Mount synchronization eventually leads to every-other-day egg laying synchronization.
... Just before mounting, the male begins to utter a high amplitude, rhythmic copulation call, which may last for most of the interaction (McWilliams et al. 2018). This call socially facilitates reproductive behavior among other members of the breeding colony (Atkins et al. 2017). Copulation frequency increases gradually during the mating season, followed by a more rapid decline once egg-laying is complete (McWilliams et al. 2018). ...
... This appears to be case with many seabirds, especially the smaller species (Brooke & Prince 1991, McNeil et al. 1993. Bald Eagles Haliaeetus leucocephalus frequently prey on Glaucous-winged Gull chicks and adults at Protection Island (Galusha & Hayward 2002, Hayward et al. 2010, and their disturbances cause immediate bouts of preening (Henson et al. 2012) and suppress copulation (Atkins et al. 2017). However, only four diurnal disturbances, most likely caused by Bald Eagles, occurred during the study period, in contrast to 13 nocturnal disturbances. ...
Gulls (Laridae) are primarily diurnal, although many species forage opportunistically at night, and several species copulate at night. We used trail cameras to study time-of-day variation in the rate of copulation by Glaucous-winged Gulls Larus glaucescens in a breeding colony (1500+ pairs) at Protection Island, Washington, USA, from 31 May to 07 June 2018. Copulations (n = 353) occurred at a significantly higher rate during the day (0.82/camera-h) than at night (0.51/camera-h), with 76.3 % of copulations during the day and 23.7 % at night (daylight comprised 66.1 % and darkness comprised 33.9 % of the study period). The copulation rate peaked shortly before and after dawn, with a second peak before sunset. Copulation rate was lowest during the middle of the day and middle of the night. Glaucous-winged Gulls sleep intermittently during both day and night and have sufficient energy to sustain sporadic copulations during the night, which appears to be a normal part of their reproductive behavior. The most likely advantage of this pattern is an increased opportunity for fertilization with a mate.
... The male copulation call is emitted at high decibel levels and is readily distinguishable from the cacophony of other colony sounds. The fact that this boisterous behavior persists in this group, despite its obvious capacity to attract predators, suggests it has functionality (Atkins et al. 2017). Moreover, understanding how environmental variability influences the reproductive activities of these and other seabirds is particularly important given their sensitivity to the environment and their status as sentinels of marine environmental change (Blight 2011, Kershner et al. 2011, Hayward et al. 2014, Sydeman et al. 2015. ...
... When examined on a daily timescale, the rises and falls of courtship beg and copulation frequencies found in Glaucous-winged Gulls (Fig. 1) resemble the every-other-day egg-laying synchrony demonstrated for both this species (Henson et al. 2010) and for Ring-billed Gulls (Sandler et al. 2016). Moreover, Atkins et al. (2017) demonstrated that broadcast of a simulated copulation call coordinated the timing of subsequent headtossing and mounting behaviors among Glaucous-winged Gulls such that these behaviors tended to directly follow broadcast of the call; frequencies of head toss and mount gradually declined. These experiments provided further evidence that the copulation call is an important communicative signal and that social facilitation plays a role in synchronizing reproductive behavior. ...
Courtship and copulation constitute crucial elements of avian reproduction and fitness. Despite the potential impact of environmental perturbations and long-term climate change on avian reproduction, few studies provide quantitative information on courtship and copulation behaviors and their responses to proximate environmental factors. We provide the first quantitative description of courtship and copulation behavior in Glaucous-winged Gulls (Larus glaucescens), an important indicator species of marine environmental quality in North America's Pacific Northwest. Male and female Glaucous-winged Gulls exhibited similar frequencies of most pre- and post-mount behaviors, which closely resemble those used by other larids. Mounts were more frequent than expected during the pre-egg-laying and egg-laying stages of the breeding season and less frequent than expected during the incubation stage. In 2008, numbers of successful copulations vs. unsuccessful copulations, numbers of cloacal contacts per successful copulation, and copulation duration did not differ by reproductive stage. In 2012, copulation duration increased with day of the year and decreased with wind speed, and the number of cloacal contacts per copulation decreased with wind speed. The odds of paired head toss increased with tide height and decreased with solar elevation. The odds of female courtship beg increased with the number of days from its peak occurrence, and also with solar elevation, tide height, and Bald Eagle (Haliaeetus leucocephalus) disturbances. Mount interval, the time from the start of one mount in the study area to that of another, was positively related to time of day, barometric pressure, and solar elevation but was negatively related to solar radiation and colony occupancy. Both the temporal and spatial occurrence of copulation were socially facilitated by the behavior of neighboring birds in the colony. Our results suggest that changes in environmental variables due to climate change could affect reproductive behaviors and reproductive success in this species.
Cannibalism occurs regularly across a broad range of taxa with a variety of ecological and evolutionary consequences. Rises in sea surface temperature (SST) have been linked to increased cannibalism in some species, including polar bears (Ursus maritimus), Peruvian anchovy (Engraulis ringens), and Peruvian hake (Merluccius gayi peruanus), and might be expected in birds that depend on marine food webs for sustenance. Increased SSTs are associated with lowered ocean thermoclines and weakened upwellings. These changes, in turn, lead to decreased productivity in surface water and movement of surviving forage fish to deeper water, thereby food-stressing surface feeders such as gulls, diminishing energy intake and lengthening foraging bouts. While controlling for a suite of other environmental factors,
we tested whether egg cannibalism and hatching success were independent of rises in local SST at a colony of Glaucous-winged Gulls (Larus glaucescens) and Glaucous-winged3Western Gull (L. glaucescens occidentalis) hybrids during 2006–2011 on Protection Island, Washington, USA. Cannibalism increased and hatching success decreased with rises in SST. It is unclear if rises in SST impact overall population trends. Gulls are multiyear breeders; if they experience reproductive failure during one or several El Ni ˜ no-Southern Oscillation–related events, they typically have other opportunities to breed. With rising SSTs associated with climate change, however, increasing levels of cannibalism could lead to declining populations in the absence of compensatory adaptive modifications or range shifts.
Spontaneous oscillator synchrony is a form of self-organization in which populations of interacting oscillators ultimately cycle together. This phenomenon occurs in a wide range of physical and biological systems. In rats and humans, oestrous/menstrual cycles synchronize through social stimulation with pheromones acting as synchronizing signals. In previous work, we showed that glaucous-winged gulls (Larus glaucescens) can lay eggs synchronously on an every-other-day schedule, and that synchrony increases with colony density. We posed a discrete-time mathematical model for reproduction during the breeding season based on the hypothesis that pre-ovulatory luteinizing hormone surges synchronize by means of visual, auditory and/or olfactory cues. Here, we extend the seasonal model in order to investigate the effect of ovulation synchrony on population dynamics across reproductive seasons. We show that socially stimulated ovulation synchrony can enhance total population size and allow the population to persist at lower birth rates than would otherwise be possible.
Spontaneous oscillator synchrony has been documented in a wide variety of electrical, mechanical, chemical, and biological systems, including the menstrual cycles of women and estrous cycles of Norway Rats (Rattus norvegicus). In temperate regions, many colonial birds breed seasonally in a time window set by photoperiod; some studies have suggested that heightened social stimulation in denser colonies can lead to a tightened annual reproductive pulse. It has been unknown, however, whether the analog of
menstrual synchrony occurs in birds—that is, whether avian ovulation cycles can synchronize on a daily timescale within the annual breeding pulse. We report every-other-day clutch-initiation and egg-laying synchrony in a breeding colony of Glaucous-winged Gulls (Larus glaucescens) and show that the level of synchrony declined with decreasing colony density. We also pose a mathematical model based on the hypothesis that preovulatory luteinizing hormone surges synchronize through social stimulation. Model predictions are consistent with observations. Finally, we suggest a procedure for identifying synchronous egg laying in other colonies and species.
Behavioral contagion is defined operationally and is contrasted with conformity, imitation, social pressures, and social facilitation. Experiments dealing with contagion are reviewed and theoretical statements derived from this review. The basic theoretical argument is that the lowering of the avoidance gradient in an approach-avoidance conflict is essential to the occurrence of contagion. (2 p. ref.) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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.
We constructed differential equation models for the diurnal abundance and distribution of breeding glaucous-winged gulls (Larus glaucescens) as they moved among nesting and non-nesting habitat patches. We used time scale techniques to reduce the differential equations to algebraic equations and connected the models to field data. The models explained the data as a function of abiotic environmental variables with R(2 )=0.57. A primary goal of this study is to demonstrate the utility of a methodology that can be used by ecologists and wildlife managers to understand and predict daily activity patterns in breeding seabirds.
This study recorded sexual behavior within a captive herd of 8 Asian elephants for approximately 230 hr on 50 days over a period of 10 months. The study observed a single adult and a single juvenile bull mounting cows more than 160 times. When the juvenile bull was between 4 years, 2 months and 4 years, 8 months old, he exhibited mounting behavior only on days when adult mounting occurred. Adult mounting always occurred first. Beyond the age of 4 years, 8 months, the juvenile bull exhibited spontaneous mounting behavior in the absence of adult mounting. This suggests that mounting behavior may develop because of social facilitation. Determining the significance of the presence of sexually active adults in the normal development of sexual behavior in juveniles will require further studies. Encouraging the establishment of larger captive herds containing adults and calves of both sexes-if their presence is important-would improve the welfare of elephants in zoos and increase their potential conservation value.
The status of many Gyps vulture populations are of acute conservation concern as several show marked and rapid decline. Vultures rely heavily on cues from conspecifics to locate carcasses via local enhancement. A simulation model is developed to explore the roles vulture and carcass densities play in this system, where information transfer plays a key role in locating food. We find a sigmoid relationship describing the probability of vultures finding food as a function of vulture density in the habitat. This relationship suggests a threshold density below which the foraging efficiency of the vulture population will drop rapidly towards zero. Management strategies should closely study this foraging system in order to maintain effective foraging densities.
A solution is suggested for an old unresolved social psychological problem.
As a consequence of the anti-predator functions of flocking it is predicted that as flock size increases individual birds will (i) spend less time vigilant for predators and more time feeding, and (2) show fewer escape responses. These predictions are corroborated here in experiments with captive flocks of the red-billed weaverbird Quelea quelea varying in size from I to 32 individuals. In Experiment i the presence of companions reduced feeding latency and increased the rate of pecking. Feeding behaviour by the companion(s) was not necessary to produce these effects and did not produce additional facilitation of the rate of pecking, but feeding companions were more potent facilitators of the onset of pecking than non-feeding companions. The number of companions influenced different measures of feeding in different ways but facilitation reached a ceiling with three companions. These and other findings in the social facilitation literature are interpreted in the light of various propositions concerning the functions of flocking behaviour. In Experiment 2 undisturbed birds with companions made less frequent head-turns (possibly vigilant responses), wing-flicks (flight intention movements), hops and flights than birds on their own but the number of companions had no effect on the frequency of these responses. All responses correlated significantly and positively across individuals. Solitary individuals were more often perched, and less often on the ground, than those in flocks, a finding compatible with greater safety in flocks in the normal feeding habitat of the species. These (undisturbed) birds, in flocks of 1, 2 and 4, had lower rates of head-turning than those in another experiment (LAZARUS, 1979), which had been subjected to 10 alarm stimuli; in larger flocks there was no difference in the rate of head-turning. An alternative interpretation of the experimental results is evaluated and a possible reason for the weak effect of flock size considered.
The playback of vocalizations associated with visual courtship displays of ring-billed gulls (Larus delawarensis) stimulated courtship behaviors. Males and females responded more strongly to playback calls of their own sex than to playback calls of the opposite sex. This sex-specific response may be related to the reduction of interference with copulation.
This paper describes a number of displays of various gulls (Laridae) with special reference to the Herring Gull group, the hooded gulls, and the Kittiwake, and discusses their functions, causation, evolutionary origin and further evolution as signals. After a sketch of the rationale of comparative behaviour studies (chapter II), the most common single displays and display sequences are described (chapter III). They are rather similar through the family, though many species-specific differences exist. The behaviour similarities strengthen the conclusion that the gulls are a monophyletic group. Evidence is presented in chapter IV to show that the displays have signal function. A distinction is made between distance-increasing and distance-reducing displays. The reasons for the occurence of more than one, yet no more than about six distance- increasing postures are discussed ; it is argued that each display may well be adapted to deal with a distinct category of opponent : accidental trespassers require another repellent than intentional persistent intruders; and within each category actual trespassers are met in another way than potential trespassers. In addition, one particularly loud call is a typical long-distance threat. This call usually acts as advertisement in a double sense: it repels competitors and attracts unmated females. Some of the distance-reducing (or appeasement) postures are used in agonistic situations, and still more regularly at the end of the pair formation or meeting ceremony. The need for and the possibility of more systematic studies of the precise functions of displays is stressed. Chapter V discusses aims and methods of analysis of the motivation of the displays. The value of
A study of the social behavior of breeding flocks of sea birds, as observed on Priest Island (off Wester Ross in the Northwest Highlands). (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Male chickens produce characteristic pulsatile calls upon discovering food and are more likely to call in the presence of a hen. Calling thus appears to be dependent upon food and to be modulated by social context. An alternative explanation is that food calls are in fact components of a complex courtship display. The relationships between food calling, food availability and courtship were examined in a laboratory setting. Subjects interacted with an unfamiliar hen and were then given access to food, using an instrumental conditioning procedure. In some control conditions, the males were tested alone, while in others food was unavailable. Food calling, sexual display and the rate at which males performed an operant response were measured. Call production increased dramatically when food first became available, both when a hen was present and when males were alone. This change in call rate did not occur during control trials without food. Sexual display was maximal when males were first placed in the test chamber with a hen present and declined exponentially thereafter. The presence of a hen had no effect on food calling during this period. Food calling was thus principally elicited by food stimuli and was not reliably associated with courtship behaviour. When a hen was present, males called at a higher rate following food presentations. In contrast the rate at which males worked to obtain food was unaffected by social context. The 'audience' effect therefore acts specifically to potentiate calling and is distinct from social facilitation.
Cited By (since 1996): 10, Export Date: 18 November 2011, Source: Scopus
Spotted hyenas (Crocuta crocuta) are social carnivores, living in multifemale, multimale “clans. “ 1,2 With female philopatry and male dispersal, separate female and male dominance hierarchies, and female matrilines that constitute the fundamental social core of the clan, the social organization of spotted hyenas approximates that of many common old world monkeys in the broad outline of their sociality. 3,4 Membership in the clan enables hyenas to hunt prey as large as zebra and is essential to defense of kills against lions and of hunting territories against other groups of hyenas. Spotted hyenas also display some rather unique characteristics. Adult females and their juvenile, or subadult, offspring dominate adult immigrant males in virtually all social interactions. 4-6 In addition, h yenas often spend their days alone at solitary dens, typically reassembling in the late afternoon and socializing at the communal den before forming smaller hunting parties. For many hyenas there is a daily transition from a solitary existence to the intense, highly differentiated social interactions of life within the clan. 1 All social carnivores display a delicate balance between cooperation and competition.
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