Bird cannibalism sparks fears for Gulf's fish stocks
It was on December 6 last year. A young cormorant sneaked into a nest, watched a chick for a full 60 seconds then grabbed it, jerked his head back and swallowed it.
It was the first time in the world anyone had seen the normally laid-back fish-eating cormorant turn on one of its own.
Scientists snapping photos from nearby were astonished. The next day, another young cormorant came by, stole another chick and swallowed it whole.
Over 10 days, researchers from UAE University in Al Ain spotted nine cases of young fledgling cormorants devouring helpless young nesting chicks.
The question was, why?
Cormorants live in coastal countries all over the world and have been watched by humans for hundreds of years.
The reasons for this bizarre behaviour are unclear, although the UAE University scientists’ research paper published this week suggests it may be that chronic food shortages are driving parents to leave their nests and starving young adults have learned to eat chicks as a way to survive.
“Parents may also have abandoned their chicks earlier than usual due to food shortages, which a possible cause of cannibalistic behaviour,” the authors warned.
If the theory is correct, it could spell big trouble for the waters off the UAE, already suffering from pollution from development and overfishing.
Leading researcher Sabir Bin Muzaffar, from UAE University’s biology department, said: “It could be starvation... We are very excited to have seen this but will need to study it more to find out for sure.”
The expedition was to Siniya Island in Umm Quwain, the largest cormorant colony in the UAE. Muzaffar said: “The species is in decline, so we went out there to learn more about them - their breeding patterns and so on, we never expected to see this.”
Cormorants have always left their older young to starve for a few days to force them to fend for themselves. What’s different is that the cormorants are turning on their own while the young chicks are being left unattended as parents spend longer away from the nest looking for food.
If overfishing is part of the problem, help may be coming. Government-funded scientists at Umm Al Quwain Research Centre are working hard to replenish Umm Al Quwain waters, with ambitious programmes to restock zooplankton, on which so many fish species depend. Dr Ebrahim Al Jamali, director of the Umm Al Quwain Marine Centre, also has a government-funded programme to release 10 million fish a year back into the sea, as a way to compensate for overfishing in the area.
Jamali said several species, such as yellow fin seabeam, are no longer plentiful and will need careful restocking before the wildlife and fishermen can both rely on local stocks.
“It has been a success but it may take years to see full results,” he said. “The fish are the basis on which all the life in the area depends.”