Palmer Station Antarctica LTER

Structural size measurements and isotopic signatures - Gentoo Penguins

Title
Structural size measurements and isotopic signatures of foraging among adult male and female gentoo penguins (Pygoscelis papua) nesting along the Palmer Archipelago near Palmer Station, 2007-2009

Abstract
Sexual segregation in vertebrate foraging niche is often associated with sexual size dimorphism (SSD), i.e., ecological sexual dimorphism. We examined ecological sexual dimorphism among sympatric nesting Pygoscelis penguins near Palmer Station, Antarctica, asking whether environmental variability in the form of winter sea ice is associated with differences in male and female pre-breeding foraging niche. Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. Molecular analyses were conducted at Simon Fraser University following standard PCR protocols, and stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

Keywords
birds, biology, isotopes, egg production

LTER Data System Record
http://dx.doi.org/10.6073/pasta/9fc8f9b5a2fa28bdca96516649b6599b
Projects
Palmer Station Antarctica LTER

Creators
Gorman, Kristen (kgorman@sfu.ca)

Contact
PAL LTER Information Manager (pallter.im@gmail.com)

Data

table StructuralsizemeasurementsandisotopicsignaturesGentooPenguins
Main data table for dataset
Rows: 124
Columns: 16
View / Download

Methods


General Methods
Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein using a sterile 3 ml syringe and heparinized infusion needle. Collected blood was stored in 1.5 ml micro-centrifuge tubes that were kept cool. In the field, a small amount of whole blood was smeared on clean filter paper stored in a 1.5 ml micro-centrifuge tube for molecular sexing. Measurements of culmen length and depth (using dial calipers ± 0.1 mm), right flipper (using a ruler ± 1 mm), and body mass (using 5 kg ± 25 g or 10 kg ± 50 g Pesola spring scales and a weigh bag) were obtained to quantify body size variation. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. Molecular analyses were conducted at Simon Fraser University following standard PCR protocols, and stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

Files


Sea ice area and duration in PAL LTER regional grid (0.00B)
Monthly averaged sea ice area and annual sea ice season duration for PAL LTER regional grid