Page 18 - Complete Birds of Britain and Europe (DK - RSPB)

INTRODUCTION

NESTS AND EGGS

bird’s life, behaviour, and appearance revolves around
Afinding a mate and producing eggs in order to ensure
the survival of its genes.The nest is a safe place to lay those
eggs, incubate them, and raise the resulting brood, so
individuals will spend time locating and building the
perfect nest for their situation.
COLLECTING
MATERIAL
BUILDING A NEST Puffins line their
The birds within a species will create nests that are burrows with
grass and scraps
remarkably constant in terms of size, shape, structure, of vegetation from
and the materials from which they are made; building nearby slopes.
such nests seems to be instinctive. However, different
birds use an extraordinary variety of techniques to DUPING
create a whole range of structures.Some of these
are little more than scrapes in the ground with a few Some species habitually lay their eggs in other birds’
pebbles or shells as lining.Others are hugely complex, nests and leave them to rear their young. Not all of
and some are masterpieces these birds remain parasites at all times. Many ducks,
of construction and and even Swallows and Starlings, lay eggs in other
effective camouflage. nests while still incubating a clutch in their own.
CUP NEST CUCKOO
Most small birds make an open, The Cuckoo never makes its
cup-shaped nest that has a rough own nest. Once hatched in a
base, a neat superstructure, and a foster-parent’s nest, its chick
fine, soft, warm lining for the eggs throws all other eggs out to
and chicks. This kind of nest can gain their sole attention.
take a week or more to build.

EGGS AND HATCHING
TYPES OF EGGS
While most eggs are oval
and have a camouflage
pattern, there are variations
(some examples pictured).
Eggs laid out of sight in dark
holes, for example, are white.
Gamebirds and owls lay
spherical eggs, while wading ELLIPTICAL LONGITUDINAL
birds lay pear-shaped eggs. PEAR SHAPED NEAT ARRANGEMENT
Aerial species such as Swifts Waders lay four eggs that fit
have narrow bodies so they neatly under the sitting bird’s
lay longitudinal eggs.The pear body. The pointed ends also
shape of the Guillemot’s egg accommodate the long, folded
prevents it from rolling off the legs of chicks that can run
narrow cliff ledge it is laid on. OVAL SPHERICAL CONICAL within hours of hatching.

THE HATCHING PROCESS
Chicks call to each other and to CRACKING FORCING BREAKING OUT
their parents from within the
egg, helping to co-ordinate
their hatching. They use
a tiny “egg tooth” on the
bill tip to break the shell
and then struggle until they
push the two ends apart.

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