Biparentally deserted offspring are viable in a species with intense sexual conflict over care.
Desertion of clutch (or brood) by both parents often leads to breeding failure, since in vast majority of birds care by at least one parent is required for any young to fledge. Recent works in a highly polygamous passerine bird, the Eurasian penduline tit (Remiz pendulinus), suggest that biparental clutch desertion is due to intense sexual conflict over care. However, an alternative yet untested hypothesis for biparental desertion is low offspring viability so that the parents abandon the offspring that have poor prospect for survival. Here we test the latter hypothesis in a common garden experiment by comparing the viability of deserted and cared for eggs. We show that embryonic development does not differ between deserted and cared for eggs. Therefore, sexual conflict over care remains the best supported hypothesis for biparental clutch desertion in penduline tits. Our work points out that conflict over care is a potential - yet rarely considered - cause of biparental nest desertion, and a strong alternative for the traditional explanations of low offspring viability, human disturbance or deteriorating ambient environment. Apart from a handful of species, the intensity of sexual conflict has not been quantified, and we call for further studies to consider sexual conflict as a cause of nest desertion.
Department of Ethology, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary. Electronic address: akos.pogany@ttk.elte.hu.
Ákos
Á
Pogány
Department of Ecology, Szent István University, Rottenbiller utca 50, H-1077 Budapest, Hungary.
András
A
Kosztolányi
Department of Ethology, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.
Ádám
Á
Miklósi
Behavioural Ecology and Self-Organization, Centre for Ecological and Evolutionary Studies, University of Groningen, 9700 CC Groningen, The Netherlands.
Jan
J
Komdeur
Department of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY Bath, United Kingdom.
Tamás
T
Székely
D000818:Animals; D005260:Female; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D009425:Nesting Behavior / Q000502:physiology*; D010152:Pair Bond; D046109:Passeriformes / Q000502:physiology*; D010332:Paternal Behavior / Q000502:physiology*; D012726:Sexual Behavior, Animal
Biparental desertion; Cost of conflict; Offspring viability; Parental care; Penduline tit; Sexual conflict