Matthew Halley, Ph.D
Research Director & Curator, Bird Collection
mhalley@delmns.org
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. In January 2026, he was promoted to Research Director & Curator, Bird Collection. 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.
Education
- 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:
2025
Halley, M. R. In press. Ornithology in Peale’s Museum. Transactions of the American Philosophical Society. (Accepted 24 September 2025; expected early 2026)
Halley, M. R.. In press. Rediscovery and history of Alexander Wilson’s house in Philadelphia, the forgotten birthplace of American Ornithology (1808-14). Archives of Natural History. (Accepted 6 December 2024, expected November 2025)
Halley, M. R. In press. Plumage variation in White-eared Tailorbird Orthotomus cinereiceps (Cisticolidae) with a description of a new subspecies from Mindanao, Philippines. Journal of Asian Ornithology 41: 51–57. (Accepted 4 August 2025, expected October 2025)
Halley, M. R.. 2025. The ambiguous identity of Muscicapa trailli Audubon, and a neotype designation for Willow Flycatcher Empidonax traillii (Tyrannidae). Bulletin of the British Ornithologists’ Club 145(3): 181–192. LINK
Halley, M. R., Catanach, T. A., Klicka, J., Weckstein, J. D. 2025. Comparative phylogenetic analysis of functional morphology sheds light on the evolution of seasonal migration in nightingale-thrushes (Turdidae: Catharus). Scientific Reports 15: 25951. LINK
Halley, M. R. In press. Composite figures in the intaglio plates of Wilson’s American Ornithology (1808–1814). Bulletin of the British Ornithologists’ Club, accepted 27 March 2025, publication expected June 2025.
Halley, M. R. 2025. The status of Catharus fumosus Ridgway (Turdidae). Bulletin of the British Ornithologists’ Club 145: 24–34. LINK
2024
Halley, M. R. 2024. Comments on a Red-billed Tropicbird (Phaethon aethereus) specimen from New Jersey. Delaware Ornithologist 53: 14–16.
Halley, M. R. 2024. Slaty-backed Nightingale-Thrush (Catharus fuscater), version 1.1. In Birds of the World (T. S. Schulenberg, S. M. Billerman, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. [Note: This is an updated version of my 2020 article] LINK.
Areta, J. I., Halley, M. R., Kirwan, G. M., Norambuena, H. G., Krabbe, N. K., Piacentini, V. Q. 2024. The world’s largest hummingbird was described 131 years ago. Bulletin of the British Ornithologists’ Club 144: 328–332. LINK
Halley, M. R. 2024. Remarks on the Costa Rican expeditions of Ridgway and Zeledón in 1905 and 1908, with a focus on three type localities. Bulletin of the British Ornithologists’ Club 144: 121–131. LINK
Halley, M. R. 2024. Morphological review of the genus Eupherusa (Trochilidae) does not support recognition of the monotypic genus Dicranurania Sangster et al., 2023. Bulletin of the British Ornithologists’ Club 144: 103–108. LINK
Halley, M. R. 2024. “Ornithology in Peale’s Museum”. In America’s Earliest Museums: A Virtual Reconstruction of the Collections of Pierre Eugène Du Simitière and Charles Willson Peale (J. Van Horne, C.E. Soltis, C. King, M.R. Halley, Eds.). Forthcoming website hosted by the American Philosophical Society. DOI: 10.13140/RG.2.2.32727.07846 **This is a beta release (without images) of the dataset, while the website is under construction.**
Catanach, T. A., Halley, M. R., and S. Pirro. 2024. Enigmas no longer: using Ultraconserved Elements to place several unusual hawk taxa and address the non-monophyly of the genus Accipiter (Accipitriformes: Accipitridae). Biological Journal of the Linnaean Society, blae028. LINK
Halley, M. R. 2024. Geographic variation and taxonomy of the Tawny-crested Tanager Chrysocorypha delatrii (Passeriformes: Thraupidae). Proceedings of the Academy of Natural Sciences of Philadelphia 168: 197–209. LINK
Halley, M. R. 2024. Return to the ‘Great Pine Swamp’ of Alexander Wilson. Bulletin of the British Ornithologists’ Club 144(1): 48–72. LINK
2023
Halley, M. R. 2023. Comments on the first specimen of Western Tanager (Piranga ludoviciana) from Delaware. Delaware Ornithologist 52: 43–46. LINK
Halley, M. R. 2023. The forgotten history of Oreortyx pictus (mountain quail), discovered by the Lewis and Clark expedition, 1806. Archives of Natural History 50: 337–346. LINK
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
2022
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
2021
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. 10.1093/ornithology/ukab041
Halley, M. R. 2021. The correct scientific name of the Black Crake (Gruiformes: Rallidae). Bulletin of the British Ornithologists’ Club 141:211–215. https://doi.org/10.25226/bboc.v141i2.2021.a11
Halley, M. R. 2021. Neotypification of Catharus ustulatus (Nuttall). Bulletin of the British Ornithologists’ Club 141:109–112. https://doi.org/10.25226/bboc.v141i1.2021.a9
2020
Halley, M. R. 2020. Audubon’s Bird of Washington: unravelling the fraud that launched The Birds of America. Bulletin 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. 10.1676/1559-4491-132.1.206
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] https://doi.org/10.2173/bow.sbnthr1.01.
Halley, M. R. 2020. Book review: The Wonderful Mr Willughby: The First True Ornithologist. The Auk: Ornthological Advances, ukz075, 10.1093/auk/ukz075.
2019
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
2018
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
2017
Halley, M. R. 2017. Origin of the phrase “Indian Summer.” Notes & Queries 64(3): 503–505. doi.org/10.1093/notesj/gjx078
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
2016
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
2015
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 life. READ 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 Winnower.
2014
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
2013
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
2012
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.