Sexual differences in risk-taking behaviour of the Southern house wren during the nestling rearing stage

FERNÁNDEZ, GUSTAVO J.; CORRAL, MARÍA GABRIELA; LLAMBIAS, PAULO

ACTA ETHOLOGICA

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2015 vol. 18 p. 11 - 18

0873-9749

When faced with a predator near the nest, breedingbirds faced a dilemma: to continue providing parental care totheir offspring exposing themselves to risk or to desert the nestfor a brief period of time, exposing their offspring to harm dueto the suspension of parental brooding and feeding. In thisstudy, we analysed the response of nesting Southern housewrens (Troglodytes aedon musculus) to a predator modelplaced near the nest. The experiment was performed in 56nests when nestling were 3?4 or 10?12 days old. The model (aplastic decoy of the Great Horned Owl Bubo virginianus) wasplaced at 3 m from the nest. Parent risk-taking was measuredas the time elapsed for males and females to resume parentalactivities during the exposition to the model. We found thatmales and females delayed parental visits when exposed to thepredator model, but females resumed them faster than males,irrespectively of the nesting stage. We also found that malesrefused to enter to the nest more frequently than females whenexposed to the predator model. No effect of breeding experienceor nesting stages was noted in the risk taking behaviourof adults. We suggest that sexual differences detected in thisspecies reflect the higher ability of females to cope with thenestling needs and its lower lifetime expectancy.