Is HARLAN’S HAWK a subspecies of Red-tailed Hawk? Why published taxonomic justifications are not convincing

British Columbia Washington

harlani B. j. calurus William S. (Bill) Clark I AM NOT A TAXONOMIST I work on raptor ID, but I have published papers on raptor . My taxonomy papers are based on similarities or differences in raptor plumages, morphology, and behaviors.

I’m both a lumper & a splitter My taxonomy papers: 1992. Taxonomic status of the White-tailed . Wilson Bulletin 1992. The taxonomy of Steppe and Tawny , with criteria for separation of museum specimens and live eagles. Bull. BOC 1996. The validity of Archer's as a . J. Afr. Raptor Biol. 1999. Plumage differences and taxonomic status of three similar Circaetus -eagles. Bull. BOC 2002. On the taxonomic status of the Indian Spotted hastata. Ibis 2005. is monotypic. Bull. BOC. 2007. Taxonomic status of the Forest Buzzard. Ostrich. 2007. Taxonomic status of the Mangrove Black-hawk. Bull. BOC. 2011. Gray Hawk ( nitidus) is two species. Condor. 2011. White-collared Kite (Leptodon forbesi Swann 1922) is a valid species: Wilson J. of Ornith. 2012. The eagle Hieraaetus is distinct from Aquila, Bull BOC. PDFs available at: http://www.globalraptors.org/grin/ResearcherResults.asp?lresI D=155 Carole Griffiths and I sent the AOU Checklist committee a memo

We pointed out that the citations justifying lumping New World vultures with storks are incorrect. And cited new papers too.

Turkey Vultures are still raptors! HARLAN’S HAWK: described as Buteo harlani by Audubon (1830), based on his Louisiana adult specimen. Ornithological Biography i:442-443. Type specimen is in the British Museum. The tail is gray.

British Natural History Museum Harlan’s Hawk Range They breed in Alaska, Yukon, & ne British Columbia & winter over much of North America. It occurs in two color morphs, dark and light. The AOS considers Harlan’s Hawk a subspecies of Red- tailed Hawk, Buteo jamaicensis harlani, but my paper in Zootaxa advocates it as a species. Clark (2018) Taxonomic status of Harlan’s Hawk Buteo jamaicensis harlani (Aves: ) Zootaxa concludes: “It [Harlan’s Hawk] should be considered a full species based on lack of justification for considering it a subspecies, and the many differences between it and B. jamaicensis, which are greater than differences between any two subspecies of diurnal raptor.”

To get a pdf of Clark (2018), Go to: http://www.globalraptors.org/grin/ResearcherResult s.asp?lresID=155 Scroll down to Papers and click on “pdf” after Clark (2018) Harlan’s Hawk is a species:

1. Lack of taxonomic justification for inclusion with Buteo jamaicensis. 2. Differs from Buteo jamaicensis by:

* Frequency of color morphs; * Adult plumages by color morph, especially in tail pattern and color;

* Neotony: Harlan’s adult & juvenile body plumages are almost alike; whereas those of Red-tails differ.

* Extent of bare area on the tarsus. * Some behaviors. Taxonomic history Harlan’s Hawk: Buteo harlani 1830’s to 1891 1944* to 1973 * with taxonomic justification.

Subspecies of Red-tailed Hawk: B. jamaicensis harlani

1891* to 1944 1973* to present * without taxonomic justification. 1891: AOU check-list committee: harlani was a subspecies of Red-tailed Hawk. Apparently based solely on Ridgway (1890). He claimed a hybrid specimen. But we know now that many hybrids exist between good species.

Light-morph adult Harlan’s Hawk - Canadian Museum of Nature Specimen: late September in Iowa. I was unable to locate it. Ridgway’s description fits many adult light Harlan’s. 1944: AOU reinstated B. harlani , citing Peters 1931 & Taverner 1936.

Peters (1931) treated B. harlani as a species, perhaps based on the work of Kirk-Swann.

Taverner (1936) changed his mind (from Taverner 1927) & considered harlani a species based on plumage differences.

Wood (1932) (not cited) described plumage differences between 137 harlani specimens & > 200 of B. jamaicensis and considered Harlan’s a species. AOU check-list committee cited three publications to justify its 1973 decision:

1. Brown & Amadon. 1968. Eagles, Hawks, and Falcons of the World. 2. Godfrey 1966. of Canada. 3. Van Tyne and Sutton. 1937. Fuertes RT NONE offered taxonomic justifications for lumping NO rebuttals of arguments given by Taverner, Peters, and Wood. Questioning of this decision Dr. Richard Banks, then chairman of the AOU Check-list committee, gave me copies of four letters regarding this taxonomic decision. Dr. Laurence Jerome wrote to the then AOU check-list Chairman (1974). He pointed out the lack of justification. He noted the lack of reference to Wood (1932). He suggested the committee review its decision. He urged studies to better understand the taxonomy. Questioning of this decision The Chairman, Eugene Eisenmann, wrote a long response to Jerome, but he: Gave no taxonomic justifications for lumping. Cited accepted ‘taxonomic opinion.’ Referred to alleged interbreedings between the taxa as a justification, but now not in itself a factor in taxonomy. Did not refute the differences mentioned by Wood (1932) or Taverner (1937) nor address the request for further studies. Two other committee members, Dr. Amadon & Dr. Storer, also wrote letters to Jerome but offered no taxonomic justifications. Harlan’s Hawks consistently differ from Red-tailed Hawks harlani calurus

British Columbia British Columbia

My presentation on the differences is on The Peregrine-Fund’s GRIN web site: http://www.globalraptors.org/grin/researchers/uploads /155/harlansplumagesdifferrev2-14_(1).pdf Liguori & Sullivan (2010) show and discuss many of these differences

Jerry Liguori Fig. 4b. Adam Hutchins

They show a new field mark for some Harlan’s adults, the white tufts at the base of the wings. My presentation: EXTREME VARIATION IN ADULT HARLAN’S HAWKS’ TAILS CMN CMN KU

Available on The Peregrine Fund web site GRIN. Go to: http://www.globalraptors.org/grin/researchers/ uploads/155/harlanstails11-15.pdf RED-TAILED HAWKS Tails of adult Red-tails vary little; >99% are like one of the six below Texas Texas RoyalBC

British Columbia Texas British Columbia My presentation: HARLAN’S HAWKS BREEDING IN WESTERN CANADA

Alberta BC

Available on The Peregrine Fund web site GRIN. Go to: http://www.globalraptors.org/grin/researchers/uploads /155/breedinginwesterncanadarev1-14.pdf The many records of Harlan’s Hawk in summer in western Canada are summarized on this map. But this is just a small fraction of the breeding Red- tailed Hawks in this large area ’HARLAN’S IS A VALID SUBSPECIES OF RED- TAILED HAWK’ Mindell (Auk 1983): Mindell, when a grad student, surveyed for raptors along rivers in west central Alaska for three summers. During the 3rd summer, he noted the tail color of adult Harlan’s seen (Dark and light circles). He did not report any other traits.

>10% All Mindell (1983) He saw 82 adults. Nine had some rufous in their tails and were judged intergrades, but adult harlani can have some rufous in tails. He offered no good taxonomic reasons to support his assertion that this is a valid subspecies. He could also have used his results to justify considering Harlan’s as a species. Important result: ONLY harlani OCCURS IN THAT AREA OF ALASKA!

Mindell has since published monumental papers on raptor phylogeny using DNA. Hull et al (2010) BMC Evolutionary Biology Presented results from sampling DNA (non- coding areas) of Harlan’s (AK) & Red-tailed Hawks (CA, UT, & WI). Found gene flow between these taxa. Found that harlani is closer to borealis than to calurus. They concluded: ‘…our findings are inconsistent with the historical description of harlani as a separate species.’

Hull, J. M., Mindell, D. P., Talbot, S. L., Kay, E. H., Hoekstra, H. E. & Ernest, H. B. (2010) Population structure and plumage polymorphism: The intraspecific evolutionary relationships of a polymorphic raptor, Buteo jamaicensis harlani. BMC Evolutionary Biology, 2010, 1–12. Hull et al do not reject the hypotheses that harlani is a separate species, they just found no support for such in the DNA they sampled, likely due to interbreeding. Winker (2009): Urged using both phenotype (results of natural selection) & genotype (results of time and random mutations) to evaluate speciation.

Hull et al (2009) used only genotype and concluded by recommending further studies. Finally, Hull et al. ended by recommending many further investigations: 1. Determine the mechanisms influencing plumage patterns in B. J. harlani, and 2. Identify the gene(s) responsible for variation in the plumages of these taxa, and 3. Determine factors responsible for the dark plumages, and 4. Perform a controlled study on environmental influences on the plumage characters of harlani.

As in lots of papers, there seem to be more questions than answers. HARLAN’S HAWK SPECIES STATUS

Harlan’s Hawk is more different from the various subspecies of Red-tailed Hawk than they are from each other.

Harlan’s Hawk differs from Red-tailed Hawk more than any two subspecies of any other raptor species. HARLAN’S HAWK SPECIES STATUS The adherents of the Phylogenetic Species Concept would have no problem assigning species rank to Harlan’s Hawk.

Harlan’s Hawk should be restored to species status by the AOS Check-List Committee. LITERATURE CITED:

AOU. 1891. Third supplement to the American Ornithologists' Union Check-list of North American Birds. Auk, 8, 83–90. AOU. 1944. Nineteenth supplement to the American Ornithologists’ Union check-list of North American birds. Auk 61:441-445. AOU. 1973. Thirty-second supplement to the Check-list. Auk 90:414. Audubon, J. J. 1830. Ornithological Biography i:442-443. Brown & Amadon 1968. Hawks, Eagles, & Falcons of the World. McGraw Hill, New York. Godfrey, W. E. 1966. The Birds of Canada. Rev. ed. Natl. Mus. Nat. Sci., Ottawa, ON. http://www.globalraptors.org/grin/researchers/uploads/155/harlanstails 11-15.pdf http://www.globalraptors.org/grin/researchers/uploads/155/harlansplum agesdifferrev2-14_(1).pdf http://www.globalraptors.org/grin/researchers/uploads/155/breedinginw esterncanadarev1-14.pdf Hull, J. et al. 2010. Population structure and plumage polymorphism: The intraspecific evolutionary relationships of a polymorphic raptor, Buteo jamaicensis harlani. BMC Evolutionary Biology 10:224. Liguori, J., and B. L. Sullivan. 2010. Comparison of Harlan’s Hawks with western and eastern Red-tailed Hawks. Birding 42:30-37. LITERATURE CITED (continued):

Mindell, D. P. 1983. Harlan’s Hawk is a valid subspecies of Red-tailed Hawk. Auk 100:161-167. Peters, J. L. (1931) Check-list of Birds of the World, vol. 1. Harvard University Press, Cambridge, Massachusetts, 345 pp. Taverner, P. A. 1927. A study of Buteo borealis, the Red-tailed Hawk, and its varieties in Canada. Victoria Mem. Mus. Bull. No. 48 Biol. Series 13:1-25. Taverner, P. A. (1936) Taxonomic comments on Red-tailed Hawks. Condor, 38, 66–71. Van Tyne, J., and G. M. Sutton. 1937. The birds of Brewster County, Texas. Misc. Publ. Mus. Zool. Univ. Mich. No. 37:20 Wood, N. A. 1932. Harlan’s Hawk. Wilson Bull.44:78-87. Thanks Grants to support field work:

Sea and Sage Audubon and the Wilson Society for Ornithology (Hall-Mayfield Grant).

Thanks also to The Peregrine Fund for my web page of their Global Raptor Information Network (GRIN) web site. Thanks The following people made helpful comments on earlier drafts of this presentation: Richard Banks, Donna Dittman, Darren Irwin, Jim Lish, Brian Millsap, Van Remsen, Ildiko Szabo, Kevin Winker, & Chris Witt. David Mindell kindly shared his photos and information. Bob Dittrick, Chuck Susie, and many others freely shared their photos of these taxa with me. Thanks I thank with great enthusiasm the curators and collection managers for permission to look at and study their specimens and for their freely given help, especially Mark Robbins (KU), David Willard (Field), Tamaki Yuri (OU) Jean Woods (Del MNH), and Carla Cicero (MVZ). Theirs is a most valuable and important resource for bird study! THANKS FOR YOUR ATTENTION

Thanks also to The Peregrine Fund (especially Lloyd Kiff, Chris McClure, & Travis Rosenberry) for making this presentation available on their Global Raptor Information Network (GRIN) web site.