Behavioural plasticity is an important evolutionary trait, enabling individuals to respond to environmental variability, or the behaviour of conspecifics. When the interests of family members differ, how do the conflicting interests between family members affect behavioural plasticity? Here I show that great tit parents (Parus major) are very flexible in their response to changes in partner work rate. The extent and even direction of this response varies in relation to factors including habitat quality, age and lay date. This fits a theoretical model, which predicts that parents should vary responsiveness to their partner depending on chick quality. Conversely, parents showed a fixed response to changes in chick begging. This may be explained by experiments with canaries, where maternal plasticity occurred pre-hatching via testosterone, which effectively ‘set’ mother and chick behaviour. Chicks benefited from begging at the same level that mothers prescribed for their own (cross fostered) chicks. Chicks that begged higher grew slowly, since parental responsiveness was not enough to offset costly begging. Mothers therefore do exhibit plasticity in response to chick begging, but only at the prenatal stage. Mothers reduce susceptibility to exploitation from chicks, since they will not be ‘fooled’ into excessive provisioning from manipulative chicks. By ‘setting’ begging levels before hatching in response to environmental conditions mothers prevent exploitation by their chicks. However the family presumably pays a cost in being less able to respond to rapid fluctuations in environmental quality.
|Title of host publication||Proceedings of the Netherlands Annual Ecology Meeting (NAEM), Lunteren, 5-6 February 2013|
|Place of Publication||Lunteren, The Netherlands|
|Publication status||Published - 2013|
|Event||Netherlands Annual Ecology Meeting 2013 - Lunteren, Netherlands|
Duration: 5 Feb 2013 → 6 Feb 2013
|Conference||Netherlands Annual Ecology Meeting 2013|
|Period||5/02/13 → 6/02/13|