RT Journal Article SR Electronic T1 Flexible parental care: Uniparental incubation in biparentally incubating shorebirds JF bioRxiv FD Cold Spring Harbor Laboratory SP 117028 DO 10.1101/117028 A1 Martin Bulla A1 Hanna Prüter A1 Hana Vitnerová A1 Wim Tijsen A1 Martin Sládeček A1 José A. Alves A1 Olivier Gilg A1 Bart Kempenaers YR 2017 UL http://biorxiv.org/content/early/2017/04/19/117028.abstract AB Recent findings suggest that relative investment of females and males into parental care depends on the population’s adult sex-ratio. For example, all else being equal, males should be the more caring sex if the sex ratio is male biased. Whether such outcomes are evolutionary fixed (i.e. related to the species’ typical sex-ratio) or whether they arise through flexible responses of individuals to the current population sex-ratio remains unclear. Nevertheless, a flexible response might be limited by evolutionary history when one sex loses the ability to care or when a single parent cannot successfully care. Here, we demonstrate that after the disappearance of one parent, individuals from 8 out of 15 biparentally incubating shorebird species were able to incubate uniparentally for 1-19 days (median = 3, N = 69). Such uniparental phases often resembled the incubation rhythm of species with obligatory uniparental incubation. Although it has been suggested that females of some shorebirds desert their brood after hatching, our findings indicate that either sex may desert prior to hatching. Strikingly, in 27% of uniparentally incubated clutches - from 5 species - we document successful hatching. Our data thus reveal the potential for a flexible switch from biparental to uniparental care.