| This
        fortnightly feature was published on October 25
 
 
 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  
 
 |