Warming Antarctic brings changes to penguin breeding cycles

Three penguin species that share the Western Antarctic Peninsula for breeding grounds have been affected in different ways by the higher temperatures brought on by global warming, according to Stony Brook University Ecology and Evolution Assistant Professor Heather Lynch and colleagues. The work by Lynch and her team is contained in three papers that have been published online in Polar Biology, Ecology and Marine Ecology Progress Series (MEPS). 

Pictured are chinstrap penguins at Bailey Head, Deception Island in the Antarctic Peninsula [Credit: Ron Naveen ©2011]

Lynch and her colleagues used a combination of field work and, increasingly, satellite imagery to track colonies of three penguin species -- Adélie, chinstrap and gentoo. The Adélie and chinstrap migrate to the peninsula to breed, while the gentoo are year-round residents. 

The Antarctic is considered one of the world's most rapidly warming regions. Warmer temperatures move up the breeding cycle, causing the penguins to lay their eggs earlier. The resident gentoo population is able to adapt more quickly and advance their "clutch initiation" by almost twice as much as the other species. Lynch believes this may allow them to better compete for the best nesting space. The Adélie and chinstrap are unaware of the local conditions until they arrive to breed and have not been able to advance their breeding cycles as rapidly. 

A researcher counts the number of chinstrap penguins at Bailey Head, Deception Island in the Antarctic Peninsula [Credit: Ron Naveen ©2011]

In addition, the gentoo prefer areas with less sea ice, and have been able to migrate further south into the Antarctic as the sea ice shrinks. The chinstrap and Adélie species rely more heavily on the abundance of Antarctic krill, which require sea ice for their lifecycle. 

The result -- the gentoo numbers are increasing while the other two species have noticeably dwindling populations on the Antarctic Peninsula. 

Professor Lynch will speak about her research and advances in the use of satellite imagery to track penguin populations as part of "Polar Climate Change Research: A Workshop for Educators" at the Charles B. Wang Center at Stony Brook University on April 10-11, 2012. The workshop, sponsored by the joint BNL-SBU Center for Impacts of Regional Climate Change (CIRCC), is designed to give high school science teachers the tools they need to teach about climate change in the Polar regions. 

Source: Stony Brook University [March 21, 2012]