Evolutionary biologist and ornithologist
My research intersects the fields of ornithology, systematics, and population and landscape genetics. Most of my recent work is based on birds of the Amazon Basin and Andes of South America, where bird diversity is at its highest in the world. I use genomic and phenotypic data to better understand the processes that generate and maintain this biodiversity. Here are some more details on several recent and current projects:
Avian systematics
How many bird species are there? And how are they related to each other? These are questions I seek to answer using cutting-edge molecular techniques, bioinformatics, fieldwork, and specimens found in natural history collections. In a recent study (Moncrieff et al., 2022), I used genomic sequencing of RADcap markers from modern and historical DNA samples to clarify our understanding of the evolutionary relationships across a genus of Neotropical birds, the Lepidothrix manakins. Among other findings, I identified a particularly divergent clade (in terms of genotype, plumage, and voice) that I formally proposed be elevated to the species level. The frequency of these taxonomic “splits” in birds is a testament to the large gap between currently recognized species-level diversity and the diversity that actually exists. I have also collaborated with a team of researchers (Zhao et al., 2022) to explore sources of phylogenetic conflicts obscuring relationships among certain species in the manakin (Pipridae) family.
Artwork by Subir Shakya
Role of rivers in shaping patterns of gene flow
A common and striking phylogeographic pattern for bird populations in the Amazon Basin is that genetic variation is structured by large river barriers, particularly in species of birds that inhabit the understory of upland forests. Our recent analysis of genomic variation in 706 individuals of one such species—the widespread Blue-capped Manakin (Lepidothrix coronata)—is aimed at better understanding the fine-scale influence of river barriers on patterns of gene flow across the Amazon Basin (Moncrieff et al., 2024). In general, our results support the hypothesis that gene flow increases between intraspecific populations of birds on opposite banks of rivers as one approaches the narrower headwater regions of these rivers.
Evolution of super-black plumage
Some bird species have phenomenally dark plumage, known as super-black plumage, that is due to specialized feather microstructure rather than or in addition to high melanin content as in other black-plumaged birds. This super-black plumage has been suggested to evolve through sexual selection due to the increased contrast it provides for brightly colored feather patches. I am collaborating with LSU researcher Roberta Canton and others to better understand the evolution of the shades of black plumage—both “standard” and super-black—found in the Lepidothrix manakins. We are using spectrophotometry and scanning electron microscopy of body feathers to characterize variation in feather reflectance and microstructure with the goal of integrating these data into the evolutionary framework provided by my recently completed phylogenetic study of Lepidothrix.
Inventories on the ornithological frontier
One of my passions in ornithology is working with local collaborators to explore remote sites in the tropics where our knowledge of avian communities is extremely poor. In these areas, potential for discovery is high as evidenced by our description of the Cordillera Azul Antbird (Myrmoderus eowilsoni; Moncrieff et al. 2018) and numerous findings with biogeographic and taxonomic implications (Moncrieff et al. 2019; Moncrieff et al. 2020). A key step for assessing the conservation priorities of a region is knowing what species make up its biodiversity, and I hope that these inventories will also promote excitement about the incredible species richness still present in the tropics.
Artwork by Daniel Lane