Behavioral Ecology

"This chapter discusses how models, combined with modern data sources and statistical methods, can be used to test different hypotheses about the causes of migration. Mathematical formalisms for migration are presented. The ecological mechanisms that could spontaneously have given rise to migration-like patterns of space use from the interaction within and between groups of animals and their environment are discussed, showing that migration is best seen as to lie on a continuum from sedentary to nomadic movement patterns and not as a clearly distinct movement behaviour. Given the multitude of potential processes leading to migration, and the constraints imposed by data collection methods, it may be difficult to observe and identify the original cause. With this caveat in mind, the use of inferential methods to detect, quantify and identify the underlying mechanisms of migration is discussed and the links between models, data and inference are illustrated using three case studies.
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Updates:
The book already sold out! A corrected reprint is available since Dec 2011."

Among studies of social species, it is common practice to rank individuals using dyadic social dominance relationships. The Elo-rating method for achieving this is powerful and increasingly popular, particularly among studies of nonhuman primates , but suffers from two deficiencies that hamper its usefulness: an initial burn-in period during which the model is unreliable and an assumption that all win–loss interactions are equivalent in their influence on rank trajectories. Here, I present R code that addresses these deficiencies by incorporating two modifications to a previously published function, testing this with data from a 9-mo observational study of social interactions among wild male chimpanzees (Pan troglodytes) in Uganda. I found that, unmodified, the R function failed to resolve a hierarchy, with the burn-in period spanning much of the study. Using the modified function, I incorporated both prior knowledge of dominance ranks and varying intensities of aggression. This effectively eliminated the burn-in period, generating rank trajectories that were consistent with the direction of pant-grunt vocalizations (an unambiguous demonstration of subordinacy) and field observations, as well as showing a clear relationship between rank and mating success. This function is likely to be particularly useful in studies that are short relative to the frequency of aggressive interactions, for longer-term data sets disrupted by periods of lower quality or missing data, and for projects investigating the relative importance of differing behaviors in driving changes in social dominance. This study highlights the need for caution when using Elo-ratings to model social dominance in nonhuman primates and other species.

... 24 h and then presented with 5 beetles on each of 2 consecutive days; half the beetles had their gland openings blocked with Duco | cement. ... rate (4.0 L/min), was tested at 5 temperatures from 30-50 C [body temperature of eutherian mammals = 38 • 2 C (Schmidt-Nielsen 1979 ...

Recent developments in ecological statistics have reached behavioral ecology, and an increasing number of studies now apply analytical tools that incorporate alternatives to the conventional null hypothesis testing based on significance levels. However, these approaches continue to receive mixed support in our field. Because our statistical choices can influence research design and the interpretation of data, there is a compelling

This study investigated the relative importance of pheromone trails and visual landmarks on the ability of Lasius niger foragers to relocate a previously used food source. Colonies formed foraging trails to a 1-M sucrose feeder. Sections of this trail were then presented back to the same colony after variable time intervals. Individual outgoing foragers were observed to determine if they walked for 15 cm in the direction of the feeder or not. On newly established pheromone trails formed by 500 ant passages, 77% of the foragers walked in the correct direction vs 31% for control foragers (no trail pheromone). Pheromone trails decayed to the control levels in 20–24 h. Trails formed with fewer ant passages (125 or 30) decayed quicker. The use of visual landmarks was investigated by using trails with outgoing foragers from the colony that established the trail, either in the same room or in a different room, with different visual landmarks, to that used during trail establishment. Approximately 20% more ants walked in the correct direction in the same room vs the different room. This difference decreased to around 10% 2 h after trail establishment, indicating that the ants in the different room were learning the new visual cues to navigate by. Our results show that visual landmarks and pheromone trails are approximately equally useful in initially guiding L. niger foragers to food locations and that these two information sources have a complementary function.

Despite its central place in animal ecology no general mechanistic movement model with an emergent home-range pattern has yet been proposed. Random walk models, which are commonly used to model animal movement, show diffusion instead of a bounded home range and therefore require special modifications. Current approaches for mechanistic modeling of home ranges apply only to a limited set of taxa, namely territorial animals and/or central place foragers. In this paper we present a more general mechanistic movement model based on a biased correlated random walk, which shows the potential for home-range behavior. The model is based on an animal tracking a dynamic resource landscape, using a biologically plausible two-part memory system, i.e. a reference- and a working-memory. Our results show that by adding these memory processes the random walker produces home-range behavior as it gains experience, which also leads to more efficient resource use. Interestingly, home-range patterns, which we assessed based on home-range overlap and increase in area covered with time, require the combined action of both memory components to emerge. Our model has the potential to predict home-range size and can be used for comparative analysis of the mechanisms shaping home-range patterns.

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Update:
Evaluated by Faculty of 1000 Biology (level 3 - Recommended) in 2009:
http://f1000biology.com/article/id/1161966/evaluation

Some species of the fungal genus Ophiocordyceps that parasitize ants have evolved some degree of behavioral manipulation to increase their own transmission. Carpenter ants (Camponotus spp.) infected by Ophiocordyceps unilateralis species climb vegetation and bite leaves or other plant parts before death, while other ants infected by other Ophiocordyceps species die buried within or on the leaf-litter, attached to stems and tree trunks. The microenvironment of the host's death location is important for fungal development and dispersal to new hosts, being an interesting example of an extended phenotype. This study investigated the effect of humidity variation in space (15 km 2) and time (14 months) on the occurrence and expression of the extended Ophiocordyceps phenotype parasitizing ants in Central Amazonia. We found O. unilateralis s.l., O. kniphofioides s.l. and O. australis s.l. parasitizing 30 ant species, but O. unilateralis s.l. was by far the most abundant fungus. Parasitized Camponotus atriceps and C. bispinosus were more abundant and died in higher places in periods with greater air humidity. Otherwise, the abundance and height of C. senex cadavers were higher in drier plots. These results provide insights on how the spatial and temporal variation in air humidity may shape the occurrence and behavioral manipulation of ants infected by entomopathogenic fungi at larger scales.

Many bird species have white spots in their tails or wing feathers, and such characters have been hypothesized to be either reliable signals (handicaps) or amplifiers that facilitate the message of a signal. In barn swallows,Hirundo rustica , the size of the white spots in the tail feathers is sexually dimorphic and positively correlated with feather length. We tested whether such spots act as handicaps or amplifiers. These white spots affect sexual selection in barn swallows, as shown by an experiment in which we randomly subjected males to (1) a considerable reduction of the size of all the spots by the use of a black permanent marker pen, (2) a small reduction of the size of the spots, or (3) no reduction. There was a positive association between spot size and the number of offspring produced per season. The white tail spots were preferred by feather-eating Mallophaga as a feeding site: holes made by Mallophaga were more abundant in the white spots than expected by chance. A habitat choice experiment with Mallophaga on barn swallow tail feathers revealed that they preferred white spots over black parts of the tail feathers. We therefore expected long-tailed male barn swallows to have more Mallophaga than short-tailed males. However, the opposite relationship was observed, indicating that long-tailed males may reliably signal their quality by the presence of large white tail spots without parasite damage. Thus white tail spots in barn swallows appear to be a reliable signal of phenotypic quality.

In mammals, adult behaviour patterns are often expressed by juveniles throughout ontogeny. In bats, many social behaviours develop before pups are weaned, but the ontogeny of social
behaviours in juvenile bats is largely unexplored. We studied bat pups’ social behaviour, specifically the solicitations for maternal care in the greater sac-winged bat, Saccopteryx bilineata. Solicitation periods were prolonged (up to 25 min) and consisted of conspicuous behavioural interactions between pups and their mothers. Since solicitation periods could be initiated by pups or mothers, their duration is probably not caused by a conflict over nursing alone. Solicitation periods were the second most prevalent use of activity time in pups. Some pup behaviours resembled the courtship behaviours of adult males and these incipient courtship behaviours occurred most often within solicitation periods. Both length and complexity of solicitation periods increased significantly during ontogeny but there was no significant difference between male and female pups. Also, the activity outside of solicitation periods was not significantly different between pups of both sexes, even though their activity differs remarkably as adults. Prolonged solicitation periods of S. bilineata pups might be comparable to mammalian play and potentially function as practice for adult courtship behaviours.

A comparison was made of the social and physical milieu of supermarkets and farmers' markets in ten California cities. On the semantic differential, the farmers' markets were perceived by their customers as more friendly, personal, rural, smaller, and happier settings than were the ...

We disagree with the idea of Roughgarden et al. that because sexual reproduction is cooperative it can only be understood in a cooperative framework that ignores conflict. In our view, it is conflict that has generated the array of sex-specific traits that we observe in nature.

Loggerhead sea turtles (Caretta caretta) are a species of endangered sea turtle, whose nesting and hatching success can be hindered by light pollution. We hypothesize that beaches with lower light pollution levels will have higher nesting success, i.e. higher number of nests, higher ratio of nests to false crawls, higher nest success, higher beach success, and lower nest relocation percentage. Using data from SeaTurtle.org and the 2015 VIIRS light data, we analyzed the effects of light pollution on loggerhead sea turtle nesting behavior. We performed a series on linear regressions to examine the relationship between light pollution and six sea turtle nesting success variables. We found a significant positive relationship between light pollution and the ratio of nests to false crawls, and a significant positive relationship between light pollution and the nest relocation percentage. The other four linear regressions were not statistically significant. However, low R 2 values indicate that light pollution does not explain much of the variation in these nesting success variables, and further studies should be conducted to investigate sea turtle nesting behavior.

This article is an attempt to alert sexuality educators and counsellors to the viability of peer association as machinery for propagating sexual ideals and mores. The study reported here examined the influence of peers on the sexuality of adolescents in public universities. The study utilised the ex post facto survey design; a randomised sample of 1,580 adolescent students; and the Tertiary Institution Students’ Sexuality Questionnaire to answer the question: How do peer groups influence the sexuality of adolescent students in public universities in Akwa Ibom State? Analysis of the data collected showed that peers have a persuasive influence on the sexuality of adolescent students in the public universities surveyed. Based on the dynamics of peer influence discussed from the findings, the researchers recommended among other things that peer counselling and peer education on sexuality should be designed and utilised in programmes of sexuality education. This will allow peers to positively influence peers to adopt healthy pro-social sexual mores and ideals and thus forestall sexual maladjustment among adolescents in public universities.

Fig trees are pollinated by fig wasps, which also oviposit in female flowers. The wasp larvae gall and eat developing seeds. Although fig trees benefit from allowing wasps to oviposit, because the wasp offspring disperse pollen, figs must prevent wasps from ovipositing in all flowers, or seed production would cease, and the mutualism would go extinct. In Ficus racemosa, we find that syconia (‘figs’) that have few foundresses (ovipositing wasps) are underexploited in the summer (few seeds, few galls, many empty ovules) and are overexploited in the winter (few seeds, many galls, few empty ovules). Conversely, syconia with many foundresses produce intermediate numbers of galls and seeds, regardless of season. We use experiments to explain these patterns, and thus, to explain how this mutualism is maintained. In the hot summer, wasps suffer short lifespans and therefore fail to oviposit in many flowers. In contrast, cooler temperatures in the winter permit longer wasp lifespans, which in turn allows most flowers to be exploited by the wasps. However, even in winter, only in syconia that happen to have few foundresses are most flowers turned into galls. In syconia with higher numbers of foundresses, interference competition reduces foundress lifespans, which reduces the proportion of flowers that are galled. We further show that syconia encourage the entry of multiple foundresses by delaying ostiole closure. Taken together, these factors allow fig trees to reduce galling in the wasp-benign winter and boost galling (and pollination) in the wasp- stressing summer. Interference competition has been shown to reduce virulence in pathogenic bacteria. Our results show that interference also maintains cooperation in a classic, cooperative symbiosis, thus linking theories of virulence and mutualism. More generally, our results reveal how frequency-dependent population regulation can occur in the fig-wasp mutualism, and how a host species can ‘set the rules of the game’ to ensure mutualistic behavior in its symbionts.

1. The North American signal crayfish Pacifastacus leniusculus has been widely introduced throughout Europe where it is expanding its range and in many areas replacing the native white-clawed crayfish Austropotamobius pallipes. There is concern with regards to the impact of this species replacement on benthic fish. Interspecific behavioural interactions and competition for shelter between the benthic fish, bullhead Cottus gobio and A. pallipes and P. leniusculus were measured to assess the comparative impact of native and non-native crayfish. 2. Both white-clawed crayfish and signal crayfish were dominant over bullhead. Bullheads moved away from approaches of crayfish, left shelters on entry of crayfish and rarely entered an occupied shelter. Signal crayfish made significantly more aggressive approaches towards bullheads than white-clawed crayfish. 3. Alone, bullheads spent most of their time by day under shelter (median 96%), reflecting a highly entrained behavioural response, which was relaxed by night (median 60%). Both crayfish species reduced shelter use by bullheads although the extent of shelter sharing by bullheads was higher in trials with white-clawed crayfish than with signal crayfish. 4. Sampling in the River Wharfe, northern England, where signal and white-clawed crayfish and bullhead currently exist, demonstrated a negative relationship between the densities of signal crayfish and bullhead, with high bullhead abundance where crayfish were absent or where white-clawed crayfish were present at low density. 5. Assuming that shelter is sometimes limited under natural conditions, crayfish are likely to displace bullheads from shelters, which may increase predation risk for bullheads. Although the effects of signal crayfish on bullhead shelter use were more intense, the pattern was highly evident for the native white-clawed crayfish. The higher fecundity and densities attained by signal crayfish may be more significant than differences in the behaviour of the two crayfish species in determining the impact of crayfish on bullheads.

Behavioral Insights in Peace Building and Development: Workshop on 29-30 August 2019

The Research Centre "Poverty, Equity and Growth in Developing Countries" at Göttingen University will host the workshop "Behavioral Insights in Peace Building and Development" between the 29th and 30th of August in Göttingen. It is organized by Prof. Marcela Ibañez Diaz, Ph.D., Professor for behavioral development economics at the Faculty of Business and Economics.

The objective of the workshop is to bring together academics working in the areas of behavioral economics, conflict and more general development economics to discuss the pathways to peacebuilding in conflict-affected areas.

The keynote speakers are Ana Maria Arjona, Associate Professor in the Department of Political Science at the Northwestern University (USA), and Chris Blattman, Professor in the Harris School of Public Policy at the University of Chicago (USA).

https://www.uni-goettingen.de/en/behavioral+insights+in+peace+building+and+development%3A+workshop+on+29-30+august+2019/611579.html

Radio-telemetry was used to study the late autumn and winter movements of twenty adult signal crayfish Pacifasta-cus leniusculus (32.9–63.8 mm carapace length) an introduced exotic crayfish species, in the upland River Wharfe, northern England. The distances moved during the study varied greatly between individuals (0–328 m). Movements were generally sporadic; crayfish would remain in one position for several weeks and make occasional movements to new locations. Total distances travelled, linear range and ranging area did not differ significantly between males and females. The distance travelled in upstream and downstream directions did not differ significantly and there was no correlation between distance travelled and crayfish size. Several high flow events occurred during the study, but these did not cause any mortality or apparent displacement of crayfish downstream, suggesting that this is not a significant factor in downstream dispersal or mortality of adults of this invasive crayfish species in winter. A marked reduction in large-scale movements occurred in mid-December which coincided with a decline in water temperature. There was a less distinct pattern in local activity which was strongly correlated with water temperature and varied before and after mid-December.

Social foraging strategies and their association with learning and innovation abilities have been studied extensively in flocking birds,
but their importance for cooperatively breeding birds has remained relatively unexplored. The high degree of sociality typical of cooperative
societies may indicate an important role of social foraging for learning and innovation. We studied 1) social foraging strategies
and 2) the acquisition of a novel foraging skill in 16 groups of wild, cooperatively breeding Arabian babblers (Turdoides squamiceps).
In Experiment 1, we provided a foraging grid of 96 feeding wells to each group, allowing them either to search for food individually
(producer) or to join other birds (scrounger). Subordinates scrounged significantly more than dominant individuals, spent longer on
the foraging grid, and had a higher proportion of their foraging steps rewarded (due to the effect of successful scrounging). However,
scrounging was not related to poor learning ability because almost all the individuals that learned the novel foraging skill in Experiment
2 (removing a rubber lid to reach food) were scroungers. These findings suggest that group members differ in their foraging strategies
and learning abilities according to their rank and that subordinate group members may be more opportunistic and flexible in their
behavior than dominants, making use of both scrounging and novel foraging opportunities.