Current Objectives

1. Characterization of a Local Population of Black-capped Chickadees (P. carolinensis), Carolina Chickadees (P. atricapillus), and their hybrids – a preliminary genetic analysis. Eric Zluhan, Corbin Salthouse & Gabriel Colbeck Introduction Methods • We set out bird feeders to attract chickadees • 22 Chickadees were captured 1. in mistnetsat bird feeders and 2. using song playback • 50 microliter blood samples were taken from the brachial vein • Measurements were taken of the birds’ wings, nares, and legs • The birds were each tagged with a unique plastic color band combination and a unique Fish & Wildlife aluminum band • Mitochondrial DNA was extracted from the chickadee blood samples • PCR protocol was ran using forward primer HBCCHCR (50-AATAGCGCGGTTTAACG-30) and reverse primer LBCCHCR (50-CATGCTTTAYAGGGTATGC-30) • Sequencing of the mtDNA is forthcoming • Song characterization of marked individuals is forthcoming Black-capped Chickadees and Carolina Chickadees come into contact and ‘hybridize’ within a narrow zone in the eastern region of the United States. Hybrids can possess physical traits of either purebred species, making identification of the chickadees in the zone difficult for field observations. Our project sought to establish a marked population of chickadees around the Maryville campus. We sought to use 1. mtDNA genetic analysis; and 2. song attributes to identify potential hybrids and potential pure breeds. Here, we outline our preliminary field and lab work, and discuss the long term goals of the project. Discussion/Further Research Map of eastern United States illustrating the hybrid zone (green) of the Chickadee species. • Previous studies (in Pennsylvania) have shown that the Black-capped/Carolina hybrid zone is moving northward. The dynamics of the local hybrid zone remain unstudied. After characterizing the local population via song and mtDNA, we would like to study the causes and consequences of hybridization in the local population. Our long term project would like to: • Analyze nuclear DNA of the local population • Establish ~40 bird houses and a marked population of breeding individuals • Determine mating patterns, and infer if hybrids have lower fitness • Look for correlations between song characteristics and reproductive success (e.g. do males who sing Carolina songs have higher reproductive success?) • Compare our current results with historical records to infer if the hybrid zone is moving http://goo.gl/27IfN Current Objectives • Catch and color-mark ~40 individual chickadees breeding on the Maryville campus • Record and measure song characteristics from all marked males • Analyze DNA samples from captured individuals – determine if their mtDNA is ‘Black-capped’ or ‘Carolina’ • Look for mismatches between song and mtDNA that could indicate potential hybrids • Determine ratio of Black-capped/Carolina/potential hybrids in local population. A recently banded chickadee Setting up a mistnet to catch chickadees Corbin Salthouse taking morphological measurements of a chickadee Eric Zluhan working with chickadee DNA A gel showing preliminary mtDNA PCR product Reference: Reudink*, M. W., S. G. Mech, S. P. Mullen*, and R. L. Curry. 2007. Structure and dynamics of the Black-capped Chickadee (Poecileatricapillus) and Carolina Chickadee (P. carolinensis) hybrid zone in southeastern Pennsylvania. Auk 124:463-478