Sandgrouse
birds feed mainly on seeds, pecking frequently at the
ground and walking quite fast as they feed, observes Nutan
Shukla
They carry
water in a novel way
Seeds
contain very little water. So sandgrouse, pigeon-like
bird of the arid regions, has to drink water frequently
for which it often flies 20 or 30 km to its favourite
water holes. Young birds who are even grown up take
several months to become strong enough to accompany their
parents to the water source. In such a situation every
species of the arid region has to adopt some technique to
fulfil the needs of its offsprings. Namaqua
sandgrouse of the dry south-western Africa has devised a
novel way of carrying water to their young. When parents
visit any water hole to quench their thirst, fathers
crouch in the water and allow their breast feathers to
get fully soaked. After that they fly back to their nests
where chicks suck moisture from their fathers
breast. This also helps in keeping eggs or chicks cool in
high temperature.
In birds usually feathers
do not soak easily, but with sandgrouse it is different.
Their breast feathers have barbules which are not hooked
together like in other birds, and this causes loss of
water-shedding properties of the feathers and they act
like a sponge. These breast feathers soak so much of
water that despite long journeys, from water sources to
nests, enough water usually remains for the young to
drink by sucking. Females too adopt this technique, but
their feathers are not so absorbent.
These birds have short
legs and long pointed wings which enable them to fly fast
to get away from predators. They spend most of their time
on the ground where they are camouflaged by their soft
grey, brown or buff plumage. With their short legs and
crouching posture they cast little give-away shadow which
further enhances their camouflage. In these birds the
males are more brightly coloured than the females, often
having a contrasting breast band. Unlike pigeons, the
sandgrouse has no patch of bare skin at the base of the
bill.
They roost in hollows on
the ground, often in flocks of several hundreds, made up
of small family groups. Their soft, thick plumage
provides warmth during the cold desert nights. It also
protects them from the heat of the sun. Unlike other
birds, these birds have feathers covering the base of the
bill which help in keeping the sand out of their
nostrils. Their spreading toes enable them to walk on the
soft sand without any difficulty.
These birds feed mainly on
seeds, pecking frequently at the ground and walking quite
fast as they feed. They store the seeds in their crop, an
extension of the gut, and digest them later in a safer
place. Seeds have hard shells, and the sandgrouse often
swallows grit to help grind them down. The crop of these
birds is highly elastic and can hold around 9,000 seeds
at a time.
These birds, like pigeons,
are able to suck up water by dipping their bills in it,
whereas most birds have to raise their heads after
filling their beaks with water so that it can trickle
down the throat. While dipping their bills in the water,
the sandgrouse birds close their nostrils with the help
of small flaps which prevents the water from entering
inside.
Sandgrouse birds lay their
eggs on the bare soil, sometimes in a shallow unlined
scrape. The normal clutch is of three eggs, pale greyish
or yellowish stone in colour, spattered with numerous
specks and spots of brown. When chicks emerge from the
egg, they are already protectively covered and are able
to run about as soon as they hatch. This helps them
whenever danger threatens
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