Inter-annual patterns of aggression and pair bonding in captive American flamingos (Phoenicopterus ruber)

Short-Term Changes in Food Spatial Distribution by Zoo Husbandry Practices Increase Agonism and Affect Feeding Behavior in Chilean Flamingos (Phoenicopterus chilensis): A Case Study

Short-term modifications to animals' enclosures, stemming from zoo husbandry practices, can significantly impact animal behavior and, consequently, their welfare. In this case study, we examined a captive-bred population of 23 adult Chilean flamingos (Phoenicopterus chilensis) during a non-breeding season to evaluate whether short-term alterations in the spatial distribution of feeders would affect the birds' feeding and agonistic behaviors. Initially, we developed an ethogram to establish baseline behavioral data. Subsequently, we assessed individual (latency to approach the feeders) and group (feeding and agonism) responses to feeder changes using an ABA-type experimental design (A1 and A2 feeders at the original location; B feeder location changed). Latency to approach feeders was also correlated with the birds' sex and body weight. The results revealed that during and immediately after the alterations, agonistic behaviors at the most frequently used feeding site by the flamingos increased, while the use of alternative food sources decreased significantly. Latency was not influenced by the birds' sex or body weight. These findings emphasize the importance of closely monitoring even seemingly minor changes in food spatial distribution to prevent negative impacts on the behavior, and presumably, the welfare of flamingos.

The consistency of individual centrality across time and networks in wild vervet monkeys

Previous primate social network studies largely limited their focus to grooming and/or aggression networks, particularly among adult females. In addition, the consistency of individuals' network centrality across time and/or different networks has received little attention, despite this being critical for a global understanding of dynamic social structure. Here, we analyzed the grooming, aggression, and play social networks of a group of 26-28 wild vervet monkeys (Chlorocebus pygerythrus), including adults and juveniles, over two periods of 6 months. We collected data on grooming, play, and aggression using focal animal sampling with instantaneous recording and ad libitum sampling. We examined whether individuals' network centralities were consistent over the two periods and across networks, as well as the effect of age, sex, and dominance rank on three individual centrality metrics in each network and within each study period. We found that individuals were quite consistent in their network position from 1 year to the next despite changes in group composition. However, their network centralities were not correlated across networks, except for Strength and weighted Eigenvector centrality between grooming and aggression networks. We also found that in the aggression network, high-rankers showed the highest centrality in most network metrics (e.g., Degree, Strength, and Eigenvector centrality) and compared to males, females were most central in 2017 but not in 2018. In the grooming network, high-ranking females had the highest Eigenvector centrality, whereas in the play network, juvenile males had the highest Eigenvector centrality. Our findings corroborate previous findings on vervet monkeys. In addition, they show that individuals' network centralities may vary among networks and over time; thus highlighting the effect of sociodemographics and behaviors' functions on the group level dynamics of social behavior.

Social network position experiences more variable selection than weaponry in wild subpopulations of forked fungus beetles

The phenotypic expression and fitness consequences of behaviours that are exhibited during social interactions are especially sensitive to their local social context. This context-dependence is expected to generate more variation in the sign and magnitude of selection on social behaviour than that experienced by static characters like morphology. Relatively few studies, however, have examined selection on behavioural traits in multiple populations. We estimated sexual selection in the wild to determine if the strength and form of selection on social phenotypes is more variable than that on morphology. We compared selection gradients on social network position, body size, and weaponry of male forked fungus beetles Bolitotherus cornutus as they influenced mating success across nine natural subpopulations. Male horn length consistently experienced positive sexual selection. However, the sign and magnitude of selection on individual measures of network centrality (strength and betweenness) differed significantly among subpopulations. Moreover, selection on social behaviours occurred at a local scale ('soft selection'), whereas selection on horn length occurred at the metapopulation scale ('hard selection'). These results indicate that an individual with a given social phenotype could experience different fitness consequences depending on the network it occupies. While individuals seem to be unable to escape the fitness effects of their morphology, they may have the potential to mediate the pressures of selection on behavioural phenotypes by moving among subpopulations or altering social connections within a network.

Vocal networks remain stable after a disturbance in Emei music frogs

Social network analysis has been widely used to investigate the dynamics of social interactions and the evolution of social complexity across a range of taxa. Anuran species are highly dependent on vocal communication in mate choice; however, these species have rarely been the subject of social network analysis. The present study used social network analysis to investigate whether vocal network structures are consistent in Emei music frog (Babina daunchina) after the introduction of a simulated exotic rival of varying competitiveness into the social group. We broadcasted six categories of artificial calls (either highly sexually attractive calls produced from inside male nests or calls of low sexual attractiveness produced outside nests with three, five or seven notes, respectively) to simulate an intruder with different levels of competitiveness. We then constructed vocal networks for two time periods (before and after the disturbance) and quantified three network metrics (strength, closeness, and betweenness) that measure different aspects of individual-level position. We used the mean values of these network metrics to evaluate group-level changes in network structure. We found that the mean strength, mean closeness and mean betweenness were consistent between two time periods in all ponds, despite the fact that the positions of some individuals had changed markedly after disturbance. In addition, there was no significant interaction effect between period and numbers of notes on the three network metrics. These finding suggest that the structure of vocal networks in Emei music frogs remain stable at the group level after a conspecific disturbance, regardless of the intruder's competitiveness.

Patterns of nocturnal activity in captive greater flamingos

Wild flamingos are known to forage overnight, but little is known of their nocturnal activity patterns in captivity. Captive flamingos can show daytime inactivity, reflecting natural periods of resting and loafing documented in wild birds. Assessment of behavior outside of normal zoo opening hours can provide more detailed information on how animals use the space provided to them, and highlights how enclosure areas not commonly occupied during the day may still be important for inhabitants at other times. We examine whether captive flamingos at WWT Slimbridge Wetland Centre change their enclosure usage and behavior overnight compared to that observed during daylight. Using three night-vision remote cameras, the behavior and enclosure usage of a flock of over 270 greater flamingos was recorded from March to July 2016. Results show that these flamingos had higher rates of foraging at certain points during the night, and had a more even enclosure usage when compared to daylight hours. Change in pool use is apparent throughout the course of the day and night, suggesting that different areas of water depth are used by these flamingos at different times. Flamingos increased nocturnal foraging in their pool during the breeding season. The large enclosure size and range of different land and water areas may have enabled these flamingos to follow daily activity patterns similar to those observed in wild birds. Captive flamingos clearly show a difference between daytime and nocturnal behavior patterns and this should be considered when designing enclosures and general management routines for these birds.

Investigating parental care behaviour in same-sex pairing of zoo greater flamingo (Phoenicopterus roseus)

Same-sex pair bonds have been documented in several animal species and they are widespread in birds. However, little is known about the evolutionary origin and the adaptive value of such behaviour. The aim of this study was to investigate the parental behaviour of four zoo female greater flamingos involved in two breeding pairs, housed in a flock at Parco Natura Viva, Italy. Further, the behaviour of the study females was compared with that of male and female flamingos in heterosexual pairs described in a previous published work on this same flock. For each pair, the behaviour of both birds during the incubation period was recorded and twenty 10-minute sessions were run within the incubation period. A continuous focal animal sampling method was used to collect data on location (on the nest or not on the nest) and the parental care behaviour (e.g.: agonistic behaviours toward disturbing conspecifics, egg-care, nest-building, self-comfort behaviour, sleeping) of the two pairs. Data of the current study females were compared with those of females and males involved in heterosexual pairs of this same flock. Results showed that within each pair the egg-layer female stayed away from the nest more than the other female. In addition, the female that did not lay an egg was more involved in agonistic behaviour compared to other females, particularly when in specific locations. In heterosexual pairs, male flamingos were more involved in the incubation and in nest protection. Moreover, no significant differences in the time spent on the nest and away from the nest between the heterosexual male and the non-layer females of same-sex pairs were found. The same findings were reported when comparing heterosexual females and the egg-layer females of the same-sex pairs. Therefore, our findings suggest that in greater flamingos the behaviour of the female–female pairs seems to be equivalent to that of male-female bonds. Such research provides more insight into flamingo social behaviour, and their reproductive cycle, and provides information on why pair bonds may form and how these affect the wider breeding behaviour of the flock.