Characterization of a Local Population of Black-capped Chickadees (P. carolinensis), Carolina Chickadees (P.

atricapillus), and their hybrids – a preliminary genetic analysis.

Current Objectives

Eric Zluhan, Corbin Salthouse & Gabriel Colbeck

We set out bird feeders to attract chickadees

22 Chickadees were captured 1. in mistnets at 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

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.

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.

Reference: Reudink*, M. W., S. G. Mech, S. P. Mullen*, and R. L. Curry. 2007. Structure and dynamics of the Black-capped Chickadee (Poecile atricapillus) and Carolina Chickadee (P. carolinensis) hybrid zone in southeastern Pennsylvania. Auk 124:463-478

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

Discussion/Further Research

http://goo.gl/27IfN

Methods

Map of eastern United States illustrating the hybrid zone (green) of the Chickadee species.

Introduction

A. A recently banded chickadee

B. Setting up a mistnet to catch chickadees

C. Corbin Salthouse taking morphological measurements of a chickadee

D. Eric Zluhan working with chickadee DNA

E. A gel showing preliminary mtDNA PCR product