Hierarchical analysis of avian re-nesting behavior: mean, across-individual, and intra-individual responses

Abstract

Anti-predator behavior is a key aspect of life history evolution, usually studied at the population (mean), or across-individual levels. However individuals can also differ in their intra-individual (residual) variation, but to our knowledge, this has only been studied once before in free-living animals. Here we studied the distances moved and changes in nest height and concealment between successive nesting attempts of marked pairs of grey fantails (Rhipidura albiscapa) in relation to nest fate, across the breeding season. We predicted that females (gender that decides where the nest is placed) should on average show adaptive behavioral responses to the experience of prior predation risk such that after an unsuccessful nesting attempt, replacement nests should be further away, higher from the ground, and more concealed compared with replacement nests after successful nesting attempts. We found that, on average, females moved greater distances to re-nest after unsuccessful nesting attempts (abandoned or depredated) in contrast to after a successful attempt, suggesting that re-nesting decisions are sensitive to risk. We found no consistent across-individual differences in distances moved, heights, or concealment. However, females differed by 53-fold (or more) in their intra-individual variability (i.e., predictability) with respect to distances moved and changes in nest height between nesting attempts, indicating that either some systematic variation went unexplained and/or females have inherently different predictability. Ignoring these individual differences in residual variance in our models obscured the effect of nest fate on re-nesting decisions that were evident at the mean level.

Towards powerful experimental and statistical approaches to study intraindividual variability in labile traits

“…Ideally, such data need to also be measured in controlled conditions to negate the effect of unquantified contextual environmental variation that could affect some individuals more than others [8,9]. However, that is not to say we should not study rIIV in the field, but individual differences in rIIV will probably be hard to distinguish from responsiveness to unobserved sources of temporal or contextual variation [14,17,18]. …”

“…More generally, the presence of individual variation in rIIV indicates a violation of model assumptions that can potentially affect our inferences from any data of a labile trait. Indeed, a recent study demonstrated how ignoring this level of behavioural variation altered the biological conclusions drawn from the data, severely reducing the power of the study [18]. …”

Behavioral Plasticity in Response to Perceived Predation Risk in Breeding House Wrens

“…Birds change their incubation patterns (Ghalambor and Martin 2002; Kovařík and Pavel 2011; Zanette et al 2011; LaManna and Martin 2016), provisioning behaviors (Ghalambor and Martin 2001; Fontaine and Martin 2006; Tilgar et al 2011; Zanette et al 2011; LaManna and Martin 2016), vigilance behavior (Morosinotto et al 2013), and nest-site selection behavior (Forstmeier and Weiss 2004; Eggers et al 2006; Peluc et al 2008; Beckmann et al 2015) in response to a change in the level of perceived risk. These studies also demonstrate that there are species-specific differences in plasticity.…”

Testing hypotheses about the function of repeated nest abandonment as a life history strategy in a passerine bird

“…, Munro , Beckmann et al . ). Fantail pairs will build up to seven nests in one breeding season, and abandon up to 71% of their nests before egg‐laying (Beckmann et al .…”

“…Fantail pairs will build up to seven nests in one breeding season, and abandon up to 71% of their nests before egg‐laying (Beckmann et al . ). At the population level, 40–47% of all nests are abandoned prior to laying (Munro , C. Beckmann pers.…”