Matthew Halley, Ph.D

Assistant Curator of Birds
302-658-9111, ext. 315

Matthew R. Halley, Ph.D joined the Collections and Research Division as Collections Manager of Birds in June 2021 and served as Interim Curator of Birds from December 2021 to October 2022, when he was promoted to Assistant Curator of Birds. Dr. Halley received his doctorate in environmental science from Drexel University and the Academy of Natural Sciences of Drexel University, where he primarily studied the systematics of the nightingale-thrushes (genus Catharus) and the evolution of seasonal migration. His field research spans a wide range of countries including Panama, Venezuela, Nicaragua, India, Israel, Canada, and the United States.

Dr. Halley’s interdisciplinary research focuses primarily on the systematics and social evolution of American birds, as well as analysis and reinterpretation of the work of historical American scientists from the 18th and 19th centuries. His research utilizes many different technologies including genetics, video cameras, tracking devices, and analysis of audio recordings and museum specimens. In addition to being a historian and scientist, Dr. Halley is also a lifelong musician and featured on numerous albums, including his own self-titled album Matthew Halley (2020). His broad expertise in history, science, and art allows him to continually contribute to the research of a wide multitude of subjects.

Visit his website to learn more. 

Twitter: @MatthewHalley


  • Ph.D. Drexel University, The Academy of Natural Sciences of Drexel University 2021
  • M.S. Delaware State University 2014
  • B.A. Pennsylvania State University 2004

Recent Publications:


Halley, M. R. (In press). The forgotten history of Oreortyx pictus (mountain quail), discovered by the Lewis and Clark expedition, 1806. Archives of Natural History (Accepted 26 May 2023).

Catanach, T. A., Halley, M. R., and S. Pirro. (In revision). Enigmas no longer: using Ultraconserved Elements to place several unusual hawk taxa and address the non-monophyly of the genus Accipiter (Accipitriformes: Accipitridae). bioRxiv PREPRINT [16 Sept 2023: Accepted pending minor revisions, Biological Journal of the Linnaean Society]

Halley, M. R., Catanach, T. A., Klicka, J., and J. D. Weckstein. 2023. Integrative taxonomy reveals hidden diversity in the Catharus fuscater (Passeriformes: Turdidae) complex in Central and South America. Zoological Journal of the Linnean Society zlad031. LINK

Halley, M. R. 2023. The composite identity of Muscicapa virens Linnaeus, and a neotype designation for Eastern Wood Pewee Contopus virens (Tyrannidae). Bulletin of the British Ornithologists’ Club 143: 196–211.  LINK

Halley, M. R. 2023. Why was John James Audubon denied membership at the Academy of Natural Sciences of Philadelphia in 1824? Proceedings of the Academy of Natural Sciences of Philadelphia 168: 97-108 (2023).  LINK

Halley, M. R. 2023. The Philadelphia Breeding Bird Census of 2020. Cassinia 78: 14–45.  LINK

Halley, M. R. 2023. Some primary sources relating to the oölogical collection of J. Hoopes Matlack (1832–1916). Cassinia 78: 75–82. LINK

Halley, M. R. 2023. The “self-portrait” of John James Audubon is a copy. Cassinia 78: 55–59. LINK


Halley, M. R. 2022. A new subspecies of Black-headed Tailorbird Orthotomus nigriceps (Cisticolidae) and clarification of age-related plumage sequences. Journal of Asian Ornithology 38: 129–134  DOWNLOAD PDF

Halley, M. R. 2022. Comments on the first specimen of Masked Booby (Sula dactylatra) from the northeastern United States: a Delaware state record. Delaware Ornithologist 51: 9–11.  DOWNLOAD PDF

Halley, M. R. 2022. Audubon’s diary transcripts were doctored to support his false claim of personally discovering Lincoln’s Sparrow Melospiza lincolnii (Audubon, 1834). Bulletin of the British Ornithologists’ Club LINK

Halley, M. R. 2022. Historical records of Canada Jay (Perisoreus canadensis) in Pennsylvania. Pennsylvania Birds 35(3): 157. DOWNLOAD PDF 

Halley, M. R. 2022. Rediscovery of the holotype of the American Goshawk, Accipiter gentilis atricapillus (Wilson, 1812), and a commentary about Alexander Wilson’s contributions to the Peale Museum. Proceedings of the Academy of Natural Sciences of Philadelphia 167: 171–178  DOWNLOAD PDF

Halley, M. R. 2022. Comments on the first specimen of Cave Swallow (Petrochelidon fulva) from Delaware. Delaware Ornithologist 50: 5–6.  DOWNLOAD PDF


Halley, M. R. 2021. Lectotypes resolve the taxonomic entanglement of the Acacia Pied Barbet Tricholaema leucomelas (Piciformes: Lybiidae) and Pied Puffbird Notharchus tectus (Piciformes: Bucconidae). Zootaxa 5071 (3): 447–450.  LINK

Halley, M. R. 2021. Integrative systematics and evolution of seasonal migration in the nightingale-thrushes (Aves: Turdidae: Catharus). Ph.D. dissertation, Drexel University. 293 pp.  LINK

Catanach, T. A., Halley, M. R., Allen, J. M., Johnson, J. A., Thorstrom, R., Palhano, S., Thunder, C. P., Gallardo, J. C., and J. D. Weckstein. 2021. Systematics and conservation of an endemic radiation of Accipiter hawks in the Caribbean islands. Ornithology 138: 1–23.

Halley, M. R. 2021. The correct scientific name of the Black Crake (Gruiformes: Rallidae). Bulletin of the British Ornithologists’ Club 141:211–215.

Halley, M. R. 2021. Neotypification of Catharus ustulatus (Nuttall). Bulletin of the British Ornithologists’ Club 141:109–112.


Halley, M. R. 2020. Audubon’s Bird of Washington: unravelling the fraud that launched The Birds of AmericaBulletin of the British Ornithologists’ Club 140:110–141. DOWNLOAD PDF

Halley, M. R. 2020. Rediscovery of a lost type specimen of Alexander Wilson. Wilson Journal of Ornithology 132:206–213.

Halley, M. R. [editor]. 2020. Cassinia volume 77. Delaware Valley Ornithological Club, 107 pp. DOWNLOAD PDF

Halley, M. R. 2020. The theft of Morton’s Hawk, now known as Harris’s Hawk. Cassinia 77: 26–33. DOWNLOAD PDF

Halley, M. R. 2020. Slaty-backed Nightingale-Thrush (Catharus fuscater), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. [Note: This is a rebranded version of my 2014 article in Neotropical Birds Online]

Halley, M. R. 2020. Book review: The Wonderful Mr Willughby: The First True Ornithologist. The Auk: Ornthological Advances, ukz075,  


Halley, M. R. 2019. The misidentification of Turdus ustulatus Nuttall, and the names of the nightingale-thrushes (Turdidae: Catharus). Bulletin of the British Ornithologists’ Club 139(3): 248–69.DOWNLOAD PDF

Halley, M. R. 2019. Rediscovery of the holotype of the extinct cephalopod Baculites ovatus Say, 1820 after nearly two centuries. Proceedings of the Academy of Natural Sciences of Philadelphia 167: 1–9. DOWNLOAD PDF


Halley, M. R. 2018. Jefferson’s ornithology reconsidered. Proceedings of the American Philosophical Society 162(3): 231–258. DOWNLOAD PDF

Halley, M. R. 2018. The ambiguous identity of Turdus mustelinus Wilson, and a neotype designation for the Veery Catharus fuscescens (Stephens). Bulletin of the British Ornithologists’ Club 138(2): 78–91. DOWNLOAD PDF  

Halley, M. R. 2018. Audubon’s famous banding experiment: Fact or fiction? Archives of Natural History 45(1): 118–121. LINK  

Halley, M. R. [editor]. 2018. Cassinia volume 76. Delaware Valley Ornithological Club, 116 pp. LINK  

Halley, M. R. 2018. Lost tales of American ornithology: Reuben Haines and the Canada Geese of Wyck (1818–1828). Cassinia 76: 52–63. DOWNLOAD PDF  

Halley, M. R., and A. W. Croasdale. 2018. The Philadelphia Breeding Bird Census of 2016. Cassinia 76: 5–26. DOWNLOAD PDF  


Halley, M. R. 2017. Origin of the phrase “Indian Summer.” Notes & Queries 64(3): 503–505.  

Halley, M. R., Klicka, J., Sesink Clee, P., and J. D. Weckstein. 2017. Restoring the species status of Catharus maculatus (Aves: Turdidae), a secretive Andean thrush, with a critique of the yardstick approach to species delimitation. Zootaxa 4276(3): 387–404. DOWNLOAD PDF 


Halley, M. R. 2016. Neglected type specimens of Western Meadowlark Sturnella neglecta from Audubon’s last expedition. Bulletin of the British Ornithologists’ Club 136(4): 287–290. DOWNLOAD PDF  

Halley, M. R., Heckscher, C. M., and V. Kalavacharla. 2016. Multi-generational kinship, multiple mating, and flexible modes of parental care in a breeding population of the Veery (Catharus fuscescens), a trans-hemispheric migratory songbird. PLoS ONE 11(6): e0157051. doi:10.1371/journal.pone.0157051  


Halley, M. R. 2015. The Heart of Audubon: Five unpublished letters (1825–1830) reveal the ornithologist’s dream and how he (almost) achieved it. Commonplace: the journal of early American lifeREAD ONLINE  

Halley, M. R., Holmes, A. L., and W. D. Robinson. 2015. Biparental incubation and allofeeding at nests of Sagebrush Brewer’s Sparrows. Journal of Field Ornithology 86(2): 153–162. DOWNLOAD PDF  

Halley, M. R. 2015. Sexual behavior of Tufted Titmice in the Mid-Atlantic Piedmont and southern New Jersey. Cassinia 74-75: 66–70. DOWNLOAD PDF  

Heckscher, C. M., Halley, M. R., and P. Stampul. 2015. Intratropical migration of a Nearctic-Neotropical migratory songbird (Catharus fuscescens) in South America with implications for migration theory. Journal of Tropical Ecology 31: 285–289. DOWNLOAD PDF  

Halley, M. R. 2015. Melvin’s Sandhill Cranes (Grus canadensis): An iconic migratory species returns to the Atlantic Seaboard. The WinnowerREAD ONLINE  


Halley, M. R. 2014. Use of light-level geolocators in the study of avian migration: ethics and opportunities. Science 345(6192): 24–27, online edition. DOI: 10.1126/science.345.6192.24 READ ONLINE  

Halley, M. R. 2014. Slaty-backed Nightingale-Thrush (Catharus fuscater), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology. READ ONLINE  

Halley, M. R. 2014. Kin structure and mating system of the Veery (Catharus fuscescens) in the Mid-Atlantic Piedmont. MS Thesis, Delaware State University  READ ONLINE  


Halley, M. R., and C. M. Heckscher. 2013. Interspecific parental care by a Wood Thrush (Hylocichla mustelina) at a nest of the Veery (Catharus fuscescens). Wilson Journal of Ornithology125(4): 823–828. DOWNLOAD PDF  

Kneidel, A. K., and M. R. Halley. 2013. Notes on berry foraging and vocal behavior of a male Pileated Woodpecker (Dryocopus pileatus). Delmarva Ornithologist 42: 28–31. DOWNLOAD PDF  

Halley, M. R., and C. M. Heckscher. 2012. Multiple male feeders at nests of the Veery. Wilson Journal of Ornithology 124(2): 396–399. DOWNLOAD PDF  


Halley, M. R. 2012. Direct evidence of Kentucky Warbler (Geothlypis formosus) breeding success from a disturbed Mid-Atlantic Piedmont forest in Delaware. Delmarva Ornithologist 41: 7–9.  DOWNLOAD PDF  

Halley, M. R., and A. Goel. 2012. A novel color morph and additional population of Raorchestes akroparallagi (Anura: Rhacophoridae) and a second R. chromasynchysi population in Karnataka, India. Herpetological Review 43(2): 233–235.  DOWNLOAD PDF  

Visit here for a complete list of Dr. Halley’s publications.