Genomics

I am using whole genomes and population genomic data to understand the evolution of noncoding elements across palaeognath species. The aim of this project is to distinguish relaxed selection from adaptive evolution of noncoding elements.

I am investigating the shifts in tarsus size in birds and their correlation with acceleration in non coding elements through the genomes. For this project I located shifts in tarsus length among 5000 species of birds. I have also created a 79-way whole genome alignment to locate the parts of the genome that evolve convergently to the location of shifts.

I am using 3D scans of forelimb and hindlimb bones of large number of anseriform species to understand the variation in bone morphology in the group. Using this dataset of variation in bone morphology, I am looking to compare variation in bones to genomic differences.

I am looking into the genetic underpinnings of the color morphs, dark and light morphs, in herons (Aredeidae) using whole-genome sequencing, protein expression, and protein assays using the Great Blue Heron (Ardea herodias) as the study system.

The Black-headed Bulbul has two distinct morphs, yellow and gray, which are identical except that gray individuals lack yellow pigment. On mainland Southeast Asia and the Greater Sunda Islands, the yellow morph predominates. However, on Maratua Island, an oceanic island off the coast of NE Borneo, all individuals are gray. On Bawean Island, a continental island between Java and Borneo, both yellow and gray forms are common. Based on this heterogeneous dispersion of color morphs, I am looking into the potential genetic basis of the polymorphism by comparing whole genome sequences of yellow and gray birds from both the islands and mainland.

Horned Larks are widespread, granivorous songbirds found in open country from grassy savannas to stony mountain tops from Alaska to Mexico and Colombia, as well as from the Atlas Mountains to the Siberian Tundra. Using morphological, ecological, and genetic data, I aim to quantify associations among various aspects of biological variation among horned larks along an elevational transect on the eastern slope of the Sierra Mountains.

Phylogeography of SE Asia

What is the history behind the current distributions of birds on Borneo? This is the sort of question I am working on with several collaborators and my advisor Dr. Frederick H. Sheldon. Different species of birds have different distributions but certain patterns are seen over and over again. I am looking into some of these patterns using next-generation sequencing methods to understand the evolutionary history of these birds.

The Oriental Dwarf Kingfisher complex Ceyx erithaca/rufidorsa includes rufous-backed and blue-backed forms along with a host of intermediate forms. Using ddRAD data, I looked at the demographic history and phylogenetic history of the species to understand whether there is one or two species in this complex. We also attempted to look for the region of the genome that could potentially explain the variation in back coloration in this species.

Avian Phylogenetics

Woodpeckers are an interesting group of birds because they exhibit remarkable instances of convergence in plumage and behavior, and also intriguing biogeographic patterns, the group offers rich opportunities for research into associated evolutionary and ecological issues. They are of interest biogeographically as they thread Wallace's line but only a few species cross the barrier even though nearly 20 species occur on the other side of this zoogeographic split. There is also evidence of convergence, mimicry, and hybridization among several woodpecker taxa. I am looking into some of these patterns trying to get a better answer to why such patterns exist.

Bulbuls comprise a prominent group of passerines in the tropics and subtropics of the Old World. They are generalists, feeding on a wide variety of fruits and arthropods, and they play a particularly important ecological role as seed dispersersI used a supermatrix approach to reconstruct the phylogeny of bulbuls.

Natural History

A routine project involving population genetics and comparisons of Sundaic taxa lead to the discovery of a new species of bulbul. Characterized by a cream-colored iris as opposed to red iris in P. simplex, this species was the first new species discovered in Borneo in nearly a 100 years.

Two distinct populations of Eye-browed Wren-Babbler Napothera epilepidota to description of two new species and a new subspecies of bulbul from Meratus Mountains, Sundaland has yielded a lot of exciting discoveries

Part of my research involves field work in remote places in SE Asia. After each expedition, we publish the natural history details of the birds of the site.