Birds do It–and Scientists are Watching

Nazca Booby

Creative Commons http://creativecommons.org/licenses/by-sa/3.0/

Nazca Booby

The mating habits of Galápagos birds are being closely watched by scientists these days and some of those researchers were eager to share their findings at the annual meeting of the Pacific Division of the American Association for the Advancement of Science (AAAS), meeting in San Francisco, California.

In what sounds like an avian version of TV’s “The Bachelorette,” Dr. Terri Maness of Louisiana Tech University described the mating behavior of the Nazca boobies on Española Island.  She said because males outnumber females, the female boobies sometimes swap their mates for more vital ones. 

Maness described scenarios where the females either abandon their previous mates and nest sites or gang up with new male partners to drive the former mates from their nests.  The term for this latter practice is “coercive divorce.”

Dr. Terri Maness, biologist

Louisiana Tech University

Dr. Terri Maness, biologist

Maness said the females who trade in their mates for a newer model usually have higher reproductive rates than those who engage in other mating practices.

Her talk was received enthusiastically by her audience which reinforces the notion that “sex sells.”  But on a more serious level, successful reproductive behavior is crucial to some Galápagos birds nearing extinction. That includes the critically endangered Galapagos Waved Albatross.

Dr. Kathryn P. Huyvaert, Dept of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO, gave an update on the ecology and conservation of the birds. Early research conducted in 1973 showed that the waved albatross were monogamous and had a high survival rate.

A pair of Waved Albatross on Española Island

D. Gordon E. Robertson / http://creativecommons.org/licenses/by-sa/3.0

A pair of Waved Albatross on Española Island

In the early 2000’s an “intense study of banded birds on Española ” revealed that females were no longer monogamous. In some cases this could be because males were not returning from their long distance fishing expeditions. Male albatross fly all the way to the Peruvian coast in search of sustenance. Many are unintentionally killed when caught in fishing nets or on fishing hooks. This has resulted in declines of adult survival and population size.

Another presenter, Jill A. Awkeman, of Wake Forest University, Department of Biology, Winston-Salem, NC, presented a paper postulating that during severe El Niño events, the albatross suffers reproductive failure because the warmer waters do not have its preferred seafood.

If these situations continue over a period of several years, the waved albatross, one of the most magnificent Galápagos birds, could become extinct.

Here’s a link to the Galápagos presentations at the meeting in San Francisco.