Heather R.L. Lerner, M.S.,  Ph.D. candidate
University of Michigan Department of Ecology and Evolutionary Biology

Email:  hlerner@umich.edu

Lab Phone:  734-763-0310

Address:  Museum of Zoology

               1109 Geddes Road

               Ann Arbor MI 48109-1079

Research Interests          Projects          Publications        C.V.

Systematics of Accipitridae

My research began with the reconstruction of a phylogenetic hypothesis for raptor relationships among the ~230 species of birds in family Accipitridae using mitochondrial and nuclear DNA.  Historically, phylogeny for Accipitridae was based on morphological traits and was difficult to resolve, due at least in part to extensive convergence in traits related to shared predatory lifestyles and high morphological plasticity in this group.  I assessed phylogenetic relationships for the Accipitridae using Bayesian inference, likelihood and parsimony methods based on molecular sequence from two mitochondrial genes (1047 bases ND2 and 1041 bases cyt-b) and one nuclear intron (1074 bases Beta-fibrinogen intron 7).  I sampled representatives of all 14 Accipitridae subfamilies, all but two genera and nearly all known species represented (>85%). 

Multiple well-supported relationships among accipitrids identified with this dataset differ from those traditionally recognized based on morphology or life history traits.  For example, harpy eagles (Harpiinae), snake eagles (Circaetinae), kites, accipiters andOld World vultures were all found to be non-monophyletic groupings.  Two species with highly specialized limb morphology enabling predation on cavity-nesting species (the gymnogene, Polyboroides typus; and the Crane Hawk, Geranospiza caerulescens) were found not to be close relatives, an example of convergent evolution that also highlights the morphological plasticity in the Accipitridae.  The inclusion of multiple samples at the subspecies level identified several species that are non-monophyletic or contain high levels of genetic diversity forming two or more reciprocally monophyletic groups (e.g. Hieraaetus fasciatus, H. morphnoides and Leucopternis albicollis).  In several cases these findings have important conservation implications as one or more taxa are threatened with extinction.

Harpy Eagle Phylogeography

The harpy eagle is a large predatory bird of lowland forests historically ranging from southern Mexico to Argentina and Brazil.  Wild harpy eagle populations have been in decline for some time and have been extirpated from much of their historic range, particularly in Central America. Geographic patterns of genetic relatedness in extant and historic populations can provide critical data to conservation efforts that aim to maximize genetic diversity for the health of captive and wild populations.  Furthermore, the broad distribution of harpy eagles on opposite sites of the Andean cordillera make it an appropriate candidate for studying the effects of vicariance events such as habitat fragmentation due to Andean orogeny, aridity during glacial maxima, and sea level rises during the Cenozoic.  Using both mitochondrial and nuclear data analyzed with phylogenetic and coalescent-based approaches, this component of my dissertation research addresses three main questions:

(1)    Is there phylogeographic structure between harpy eagle populations and, if so, does the pattern and estimated date of population divergence correspond to known barriers such as the Andean cordillera and its orogeny or the Panamanian land bridge?

(2)    Do mitochondrial (control region sequence) and nuclear (microsatellite frequencies) data show corresponding levels and patterns of genetic differentiation?

(3)    Is gene flow between South America and Central America symmetric or asymmetric and have levels of gene flow changed over time?

(4)    Is there evidence of recent or historic population bottleneck or expansion in harpy eagle populations and, if so, does the evidence correspond to known climate or habitat history (e.g. population bottleneck corresponding to tropical forest contraction during glacial maxima or recent habitat fragmentation)?