Far From Land The Mysterious Lives of Seabirds

tied to home | 99

The annual cycle of the Emperor Penguin from laying at the start of the Antarctic winter

in June to the chicks’ departure in February.

Laying

Females

leave

after

laying

Females

return to

feed

and

brood

Males

return to

feed

chicks

Chicks

in

creches

Chicks

& adults

moult

Adults

& chicks

leave

on sea

ice

Males

incubate

for 64

days

Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar

Winter Summer

Hatching

Emperor Penguin

many species, the youngest chicks require constant brooding and so one

parent remains at the nest to provide the chick with warmth and atten-

tion whilst the other is at sea collecting food. After that so- called guard

stage, which lasts from a few days to some three weeks according to

species, the chicks are left alone while the parents are away at sea search-

ing for food to deliver to the nest.

Given that seabirds with chicks return to the colony every few hours

or every few days, it is relatively easy to place a tracking device on them

to establish where, for example, the Puffin has caught that beakful of

sand eels or the Lesser Black- backed Gull has obtained that mushy ball

of earthworms. Studies on numerous species have demonstrated that

birds with chicks, to which they must return more or less frequently,

feed closer to the colony than they do during incubation when, as we

have seen, the absences and journeys can be lengthy. To try to make

sense of the torrent of information that has accrued, I shall shirk a com-

prehensive account. It would be over- lengthy. Instead I will explore

some influences on parent seabirds foraging for their chicks.

A very obvious possible influence is the age of the chick. Many years

ago I studied Northern Wheatears, small territorial songbirds that enjoy

open country. I wondered if those adults with small chicks, needing