Parents take both size and conspicuousness into account when feeding nestlings in dark cavity nests
Parent birds respond to a variety of cues from their offspring when provisioning them with food. Bright flange colours and large body size are two traits of offspring that many parents seem to favour, but little is known about how such traits interact. By experimentally altering the difference in mass between nestmates while concurrently blackening […]
Hatching asynchrony and offspring sex influence the subsequent exploratory behaviour of zebra finches
The ecological and evolutionary consequences of variation in behaviour between individuals are well studied, yet the causes of such variation remain poorly understood. Parents can generally exert a great deal of influence on the early life of their offspring, so one possibility is that the mode of parental investment determines subsequent offspring behaviours. In birds, […]
Incubation behaviour and hatching synchrony differ in wild and captive populations of the zebra finch
Hatching asynchrony is widespread in birds laying clutches containing multiple eggs, yet is seemingly paradoxical as the age and size hierarchies result in asymmetric sibling competition and low survival prospects for late-hatched nestlings. We examined the causes of variation in hatching asynchrony between broods of zebra finch, Taeniopygia guttata, in three environments: domesticated, captive wild […]
The adaptive function of hatching asynchrony: an experimental study in great tits
In many bird species offspring hatch over hours or days, which leads to an age and size hierarchy within broods. The function of hatching asynchrony is much debated, and it has been suggested that the induced size hierarchy among offspring may be an adaptive maternal mechanism for maximizing reproductive output under variable environmental conditions. The […]
Sex-specific food provisioning patterns by parents in the asynchronously hatching European hoopoe
Hatching asynchrony is common among bird species. It results from starting incubation before clutch completion and is often accompanied by brood reduction, an adaptive strategy of the parents to selectively starve the younger chicks in times of food scarcity. The different developmental stages of nestlings are expected to affect their competitive abilities, their hunger state […]
Minutes matter: brief hatching asynchrony adversely affects late-hatched hihi nestlings, but not life beyond the nest
Size hierarchies are often seen when nestlings hatch asynchronously over a period of days. Shorter hatch periods are common across passerines, however, and while these may also give rise to asymmetries, their effects are rarely considered. Regardless of hatch period, the long-term consequences for later hatched nestlings that survive to fledge is unknown for wild […]