Environmental Unpredictability and the Value of Social Information for Foraging Starlings

Abstract

Environmental and behavioral cues are useful sources of information that allow group foraging individuals to improve their foraging success. Few studies to date, however, have examined how varying degrees of environmental unpredictability may affect when and how individuals use the social information they obtain in foraging groups. In this experiment, European starlings (Sturnus vulgaris) were tested to determine in which type of environment, predictable or unpredictable, social information would be the most valuable. Subjects were placed under one of four conditions: an unpredictable environment with either (1) an informing demonstrator bird or (2) an uninforming demonstrator; or a predictable environment with either (3) an informing demonstrator or (4) an uninforming demonstrator. Environmental predictability was manipulated by altering the meaning of available color cues. Subjects in the unpredictable environment that had an informing demonstrator performed significantly better than subjects in an unpredictable environment with an uninforming demonstrator, although only on the second day of testing. Subjects in both the predictable conditions performed similarly to each other. The results suggest that social information is more valuable to individuals in an unpredictable environment than it is in a predictable environment; however, there appears to be a time lag in the ability of the birds to recognize the value of this information.

How social network structure affects decision-making inDrosophila melanogaster

“…We used interaction data from 62 social learning experiments, of which 49 were presented in Battesti et al [9] and 13 new ones, to calculate and analyse social network measures, and to study their evolution over time. Each experiment was divided into three phases: (i) a conditioning phase, during which eight mated females (3-5 days old) were conditioned to prefer either a banana-or a strawberry-scented egg-laying medium (these were the informed females in the subsequent phases); (ii) an interaction phase during which we video-tracked the interactions among eight informed and four uninformed females, and later calculated network parameters; and (iii) a test phase during which the informed and uninformed females were tested separately for their oviposition site choice.…”

“…This discriminating decision-making process could accelerate the spread of adaptive behaviours by favouring those of individuals with higher fitness. Adult starlings (Sturnus vulgaris) exposed to unpredictable food availability copied the behaviour of informed demonstrators to make foraging decisions more than starlings in predictable environments did, and performed better when they could access social information than when they could not [9]. However, Japanese quails (Coturnix japonica) postnatally exposed to unpredictable food availability preferred to avoid the food source previously used by demonstrators [10].…”

Unfamiliar stopover sites and the value of social information during migration

“…A foraging individual, for example, may supplement personal sample information (i.e., private information gained on its own) with socially acquired cues provided inadvertently by other foraging individuals (inadvertent social information) (Danchin et al 2004;Valone and Templeton 2002). The combination of private information with social information obtained from observing the location and successful or unsuccessful sampling activities of others improves the speed and accuracy with which an individual assesses habitat quality (Rafacz and Templeton 2003;Smith et al, 1999;Templeton and Giraldeau 1996;Valone 1989). Social learning enables the individual to assess an unfamiliar environment more completely (Galef and Giraldeau 2001;Valone 1989), which may be particularly important for individuals under time and energy constraints.…”

Observation of Daytime Sleep-like Behavior in a Migratory Songbird during Stopover

“…For example, European Starlings (Sturnus vulgaris) cue on foraging conspecifics to determine whether to remain at or to leave a foraging patch when information about patch quality is difficult to acquire by personal sampling, thus using social information in a manner consistent with the ''copy when asocial learning is costly'' strategy (Templeton and Giraldeau 1996). If, however, the location of food is predictably associated with contextual cues in an environment, starlings are less likely to rely on social information than in environments where these cues are unpredictable, lending importance to the ''copy when uncertain'' strategy (Rafacz and Templeton 2003).…”