Cormorants: Hung Out to Dry

Cormorants must be amongst the easiest birds to spot and identify around a waterbody, be it a river, lake, jheel, tidal estuary, or pond. They are found anywhere and everywhere in India. Black and glossy as ravens, they are large- to medium-sized (between 50 and 100 cm long) waterbirds. We see them swimming in small (5-10) or medium-sized (20-50) flocks in the water, their bodies seemingly sunk below their Plimsoll line, heads slanting upwards, or else scissoring, with short, stiff wingbeats across the skies in the classic “V” formation or long wavy echelons. If they’re not in the water or the skies, they’ll probably be perched on branches or dead trees, gazing heavenwards (looking a bit foolish, it has to be said!), their glossy blue-black wings hung out on either side, as if they have been crucified.

Happily, it’s not that dire! But there is still plenty of debate raging over exactly why cormorants adopt this posture. Cormorants are all fisherfolk that must dive beneath the surface, chase their prey underwater, and emerge after catching them. It’s long been thought their feathers are not waterproof, so they must dry them out in between fishing forays, or they may sink and drown. They do have secretions from preen glands (beneath the tail), which provide some waterproofing, but evidently not enough. Some suggest that the cormorants’ feathers are water-permeable and not waterproof, meaning the pinions absorb water but do not allow it to permeate the layer of air that lies alongside the skin. Others suggest that the wings-held-out-to-dry posture regulates body temperature, helps the birds digest food, balances them while perched, or advertises that this is a good place to go fishing. A heavy-duty study of the large or great cormorant (Phalacrocorax carbo; 80-100 cm) has conclusively shown that it does so to dry its wings and nothing else.

Of the approximately 40 species of cormorants found worldwide, just three are found in India: large cormorant, Indian cormorant or Indian shag (Phalcrococorax fuscicollis; 63 cm) and the little cormorant (Phalcocorax niger; 51 cm).

The large cormorant is both a resident and winter migrant; local flocks are augmented by “made in China” birds, which fly down in winter. This somewhat heavily built bird has a slim hook-tipped bill and a stiff broomstick-like tail. It’s easiest to identify because of its size, and during the breeding season, it is glossy bronze-black, with white “decal” patches along its thighs. Its head, neck, and crest are streaked with silky white feathers, its cheeks and throat are white, and its gular patch (bag of loose skin under the chin) is bright yellow.

The Indian cormorant, also a glossy-bronze to jet black, wears elegant white tufts behind its ears, has a yellow gular patch, and a few white specks on its head during the breeding season. Its plumage looks scalloped, like beaten metal, and its eyes are china blue.

The little cormorant has a longer tail, no yellow gular patch and its upper portions and wing coverts are dark silver-grey, outlined with black. A short crest on the top of the head and a few silky white plumes on its fore-crown and sides of its face complete its breeding ensemble. It loses its white feathers in the non-breeding season and may be difficult to tell apart from the Indian cormorant. But if you can, look into its eyes — they are glittering black.

All three cormorant species build untidy twiggy nests that vary in size according to the size of the species. The large cormorants’ nests are around 50 cm across, lined with waterweeds and plants, and built-in colonies or heronries near waterbodies. They lay between 3 and 5 elongated blue-green eggs, overlaid with chalky white and both parents look after their broods. Incubation lasts for a little over three weeks. The babies are hideous when they hatch, bald and then covered with black fuzz, and appear to be extraordinarily greedy. When their parents return from a fishing expedition, the fledglings will grab hold of their parents’ yellow throat patches and shake them violently from side to side (euphemistically, this is called “tickling”), wheezing petulantly all the while (“give me, give me, give me!”). Of course, it makes the parents throw up, which is what the babies want.

Cormorants may fish in small groups or join larger congregations, even working together to corral shoals of fish against the shallows. They dive underwater with a small leap and chase the fish using their webbed feet and relatively small wings to propel them swiftly. Hooked fish are caught crosswise in the beak, straightened out, and swallowed headfirst.

Salim Ali has mentioned an interesting case of a large cormorant playing with its food in the way cats may do with mice. A 15 cm catfish was caught and brought to the shore, dropped, flipping and flopping on the ground; it was then picked up and taken back to the water where it was released and then caught again, the process was repeated several times before it was ultimately swallowed.

Large cormorants appear to be quite possessive of their “crucifix” perches. I have watched them play “King of the Castle” wherein a bird on the topmost end of a dead tree, repeatedly fights off the attempts of a rival to displace it. (Ultimately, the interloper flew off.)

In the 1300s, in many parts of Southeast Asia, China (and at some time even India), cormorants were used for fishing by fishermen. Large, tethered flocks would be let loose in the waters, with binding around their throats so they could not swallow what they caught. After diving down and “hooking” a fish, the birds would be brought back to or would swim back to the boats, where the fishermen removed the fish from their beaks and sat back pretty. Of course, the birds were ultimately allowed to eat after the day’s work had been done!

In Delhi, the Okhla Bird Sanctuary, Yamuna Biodiversity Park, and the Yamuna River are the haunts of large flocks of cormorants, and I occasionally see them winging their way across the skies towards the river as I drive home. Even on a tiny, scummy green pond on the Northern Ridge, I have on several occasions met a solitary little cormorant drying itself out on a dead tree, content in its solitude.