Social foraging and individual consistency in following behaviour: testing the information centre hypothesis in free-ranging vultures

Abstract

One contribution of 17 to a theme issue 'Moving in a moving medium: new perspectives on flight'. Natural selection theory suggests that mobile animals trade off time, energy and risk costs with food, safety and other pay-offs obtained by movement. We examined how birds make movement decisions by integrating aspects of flight biomechanics, movement ecology and behaviour in a hierarchical framework investigating flight track variation across several spatio-temporal scales. Using extensive global positioning system and accelerometer data from Eurasian griffon vultures (Gyps fulvus) in Israel and France, we examined soaring-gliding decision-making by comparing inbound versus outbound flights (to or from a central roost, respectively), and these (and other) homerange foraging movements (up to 300 km) versus long-range movements (longer than 300 km). We found that long-range movements and inbound flights have similar features compared with their counterparts: individuals reduced journey time by performing more efficient soaring -gliding flight, reduced energy expenditure by flapping less and were more risk-prone by gliding more steeply between thermals. Age, breeding status, wind conditions and flight altitude (but not sex) affected time and energy prioritization during flights. We therefore suggest that individuals facing time, energy and risk trade-offs during movements make similar decisions across a broad range of ecological contexts and spatial scales, presumably owing to similarity in the uncertainty about movement outcomes.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

Short‐term prey field lability constrains individual specialisation in resource selection and foraging site fidelity in a marine predator

“…In colonial species, this is promoted by the breeding site functioning as an information centre (Harel et al . ). Previous studies showed predator specialisation on resources that are temporally dynamic but predictable in space and/or time.…”

“…Individuals may overcome low spatio-temporal prey predictability by diversifying their diet, either through generalist foraging tactics (no selection) or by alternating foraging tactics targeting specific prey items (narrow short-term resource selection). In colonial species, this is promoted by the breeding site functioning as an information centre (Harel et al 2017). Previous studies showed predator specialisation on resources that are temporally dynamic but predictable in space and/or time.…”

Social Information Links Individual Behavior to Population and Community Dynamics

“…Furthermore, investigation of dependencies among species, where one species acts as a scout that produces information used by individuals of another species (e.g., lappet-faced and African white-backed vultures [70], eagles and Gyps vultures [58] or avian and mammalian scavengers [100]) illustrate how changes in community structure (e.g., local extinctions) can impact the fate of community members. A positive feedback loop, in which decreasing densities reduce the ability of the remaining individuals to find and/or access resources, can explain frequent population collapses in this guild [14,21,100]. Overall, this integration of approaches (observational, experimental, and modeling) provides insight into the role of social information in driving correlated behaviors in scavenger communities, offering tools to mitigate the detrimental effects of environmental change on the populations and communities of these sanitation providers.…”

“…Here, we show that social information-mediated positive density dependence can readily extend beyond populations to communities, when information is shared across species. Positive density dependence can not only lead to rapid population growth, but [ 2 8 9 _ T D $ D I F F ] can also create critical thresholds, below which the population or community is prone to sudden collapse [14,27,33,35]. The latter consequence arises because the loss of individuals is increasingly detrimental to the survival or reproductive rate of those that remain, a phenomenon that has been shown experimentally to cause collapse in laboratory-based yeast populations [37,38] ( Figure 2).…”

“…Behavioral ecologists have long studied how social information shared among conspecifics can influence habitat selection and trophic interactions [6][7][8]. Animals often use social information to acquire resources (e.g., individuals or groups feeding in a location alert others to food) [2,[9][10][11][12][13][14] and to detect and avoid predators [1,2,6,[15][16][17].…”