Tuesday, January 24, 2012

Continued Work on Leach's Storm Petrels

Sandy Camilleri is a graduate student of Dr. Heather Koopman at the University of North Carolina, Wilmington.  She has been studying Leach's Storm Petrels for her Masters thesis on Kent Island, part of the Bowdoin Scientific Station, in the Grand Manan archipelago.  Sandy hopes to defend her thesis this spring.

Most seabirds provision their chicks with whole or partially digested prey items whereas tube-nosed seabirds (albatrosses, shearwaters, fulmars and petrels) concentrate their prey into a lipid rich oil, called stomach oil. For her master’s thesis research she is investigating this unique strategy used by tube-nosed seabirds by comparing the lipid composition, energy content, and the contaminant levels of the stomach oil to prey items that would be fed to other species.

Leach's Storm Petrel chick.  Note the tube-nose on the bill.

The tube-nosed species chosen for this study was the Leach’s storm-petrel, which has a large population that nests on Kent Island and has been studied since the 1930s by Bowdoin College. I spent a couple of weeks learning how to properly handle petrels and how to collect stomach oil in 2009, then developing the laboratory analyses of the stomach oil. In the summer of 2010, I spent a total of 8 weeks on Kent Island monitoring and collecting stomach oil samples from petrels. A total of 83 samples were collected in 2010, 49 from adults and 34 from chicks.
Sandy Camilleri with a Leach's Storm Petrel adult on Kent Island.

In the summer of 2011, Ispent a total of 8 weeks on Kent Island, again monitoring and collecting stomach oil samples from petrels. The field season was split into two parts, the first was 2 weeks in June which was used to set up the field site, called the Ditch, monitor the burrows and collect adult stomach oil samples. The second part started in mid-July and lasted for 6 weeks. During this time, I finished sampling adults and monitored the nests daily waiting for chicks to hatch. The first chick to hatch for the summer was found in the Ditch on July 14! Once the chicks hatched, they were weighed daily and measurements of wing length and tarsus (foot bone) length were recorded as growth indicators. Once chicks were 2 weeks old, those that gained more than 10g overnight were sampled, indicating that mom and/or dad had fed it that night. A second sample from the chicks was collected at least one week after the first.
Some of the buildings on Kent Island, part of the Bowdoin Scientific Station

A total of 147 samples were collected in 2011, 72 from adults, 45 from chicks sampled once, and 30 from chicks sampled twice. All samples were brought back to UNCW where lipid analysis and energy content will take place in Dr. Heather Koopman’s lab. Contaminant analysis will be completed in Dr. John Kucklick’s lab at the National Institute of Standards and Technology in Charleston, SC.

This project will provide insights to the costs and benefits to the unique provisioning strategy used by tube-nosed seabirds. Leach’s storm-petrels are ideal for monitoring environmental health and can be used as a model for other tube-nosed seabirds that have more remote nesting locations, those that are experiencing population declines, and those that live in known contaminated areas.

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