Wednesday, December 23, 2015

Waterbird foods: Lesser Adjutant

Surprisingly little is known of many species of large waterbirds such as storks, ibis and spoonbills. The Lesser Adjutant is one such species. Until recently, it was thought to require tall trees in forests to nests. However, surveys in the lowlands of eastern and central Nepal during 2013-15 have found that practically all of the nesting in some of the rice-growing districts are on trees amid fields. Clearly, a lot is needed to be done in the field to understand this species better. Here is my bit.

With my colleagues, I observed Lesser Adjutants for many an hour in central lowland Nepal in the districts of Rupandehi and Kapilvastu. I restrict this blog post to some of the observations we had of the species feeding in the rice paddies.

As has been seen in eastern Nepal, and in Sri Lanka, Lesser Adjutants in Nepal frequent rice paddies during the monsoon. They steer clear of traffic on the roads, and keep at least 20-30 feet from farmers working on the fields.

One morning, we observed three stork feeding together - all three were exceedingly successful in finding earthworms in the flooded rice fields! We watched as each of them found and devoured 5-7 earthworms in just five minutes! The photo below shows one earthworm meeting its end between the massive beak of a Lesser Adjutant.

Another individual seemed an expert at finding insects in the rice fields. In the photo below, a Belastomatid (giant water bug) is swallowed with gusto.

Another individual, shown below, caught and devoured a freshwater crab that seemed too tiny to be of consequence, but clearly kept the stork's attention as it maneuvered the animal into its mouth.

With almost no time wasted the same stork also caught a fish, which nearly escaped. But,down the hatch it went!

Other colleagues and students have seen Lesser Adjutants in Nepal bring snakes to feed chicks at nests. Now, that must have been a treat for all!

(All photos from Rupandehi and Kapilvastu districts in lowland Nepal, Aug 2014.) 

Sunday, December 20, 2015

Bill Fence

Bird behaviour is fascinating to observe. It is no less fascinating to read about. Particularly since several behaviours have been given catchy names - some really spot-on.

Bill Fencing is one such phrase used for a behaviour that many storks exhibit. As the name suggests, they fence with their bills!

Fencing can start pretty small - appearing to be a friendly, even affectionate, touching and clicking of bills. Like the two Painted Storks below.

Quickly, it can escalate to an obvious joust that is not so friendly!

The point of bill fencing appears to be to grab hold of the beak of the opposition.

And then, if food or a prized foraging patch is involved, it can escalate to a full-on fight! Use of wings, beaks and even legs seem fair game. A stork below appears to be karate-chopping the other lunging stork!

Until the beak of the opponent is finally in hand. Or rather, in bill!

Then, the "vanquished" opponent either walks away, or, if feeling particularly adventurous, tries to disengage, and another bout of bill fencing ensues until the beak is in hand (or bill) again.

One bird, clearly tired of the forced bill-shutting (and perhaps finally alarmed at the dangerous jabs of the long bill so close to the face!), eventually flies away. And the winner, after some work, keeps the spoils!!


Better this I say than jabs to the body, bleeding wings, and gouged eyes. Maybe these happen too...

(All photos taken in 2015 from various locations in western Uttar Pradesh.)