Using stable isotopes to assess climate-change impacts on migrations of prions (Aves: Procellariiformes)

Furness, Grecian

The primary aim of this project is to measure carbon isotopes in feathers of broad-billed prions and a range of control species sampled from their breeding colonies in the South Atlantic, Indian Ocean and Pacific Ocean/Tasman Sea, to infer the main wintering areas. Most importantly, stable isotope analysis of historical samples will permit wintering latitudes used by these species in the past to be inferred in a similar way, having accounted for the Suess effect (Quillfeldt et al. 2010).

The study will compare wintering latitudes of birds sampled in contemporary austral winters (2009-10, 2010-11, 2011-12) with wintering latitudes of birds sampled in the recent past (previous decades) and up to 150 years ago. It will also deploy small data loggers (<1.5g) on adult broad-billed prions and other species at our principal study sites (see below) to determine wintering areas using light level geolocation and foraging activity levels (from proportions of time spent flying rather than resting on the sea) (see Phillips et al. 2004 for methodological details). Stable isotopes from these individuals with known winter movements will be measured in order to validate the use of stable isotope signature to infer wintering region. Hypotheses can be tested by determining whether carbon isotope signatures in feathers grown during winter have altered over this time period from isotopic signatures reflecting low latitude marine ecosystems to isotopic signatures reflecting high latitude marine ecosystems (Quillfeldt et al., 2010).