Horial
lthough green pigeons (horial/treron phoenicoptera) are common in Bangladesh, I saw my first one only recently. I was watching some small birds feeding on the fruits of a banyan tree at the Mirpur Botanical Garden, when, through the leaves, the shadow of larger birds loomed from the overhead canopy. They stayed out of sight at the topmost branches but then, for a short while, my patience was rewarded as one of them descended to a lower branch while searching for fruit.
The bird's pigeon-like shape, green body and yellow feet identified it as a yellow-footed green pigeon - a member of the pigeon family's treron branch which includes 23 species, all green to various degrees. This bird also had patches of grey and yellow. It walked on a branch and tried to grab a fruit from a red cluster. The fruit was too large to fit in its opened beak, and after several attempts, it moved to another fruit of a more suitable size, swallowing it whole without pecking.
Reading about the horial led me to the world of pigeons.
The pigeon family (kobutor/columbidae) is one of the most successful families of birds, having adapted extremely well, some might say too well, to humans. There are 310 species of pigeons which are dispersed around the world, just about everywhere except parts of the Sahara, Antarctica and the Arctic. They are familiar to us because of the ubiquitous rock pigeon which inhabits many cities.
Some members of the pigeon family have become extinct. These include the Dodo, which evolved in isolation – in an island - from predators and lost its predator-avoiding behaviour. It was hunted to extinction once humans moved in.
Pigeons exhibit common traits. For example, they are strong fliers and make a loud flapping sound with their wings when taking off. Their heads bob back and forth when they are walking. This head-bobbing arouses our curiosity. A scientist observed that a pigeon walking on a treadmill does not bob its head and concluded that the bird bobs its head to maintain a steady view of the world around it. Doves – known in as ghughu – are also members of the pigeon family, but smaller in size. The spotted dove is the most common dove here.
Some species of the pigeon family are frugivorous - they live on fruit and help disperse seeds. Others are granivorous, living on grains and seeds. In general, the frugivores have brighter plumage. There are also physical differences – for example, frugivorous pigeons have shorter intestines and are able to cling to branches and even hang upside down to reach fruit.
The largest pigeon is the Crown Pigeon of New Guinea, nearly turkey-sized at four kilograms. The smallest is the Ground Dove of the Americas which is the size of a house sparrow (22 grams.)
Pigeons have a long association with humans. They served historically as messengers during wars. Many hobbyists race pigeons, taking them to a place far from home and setting them free; the first pigeon returning home wins. In Sylhet, the Rock Pigeons called “Jalali kobutor” were prolific during my childhood and can still be seen. They are believed to have descended from a pair owned by the sufi saint Hajrat Shahjalal in the 13th century.
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