Hen Harrier is Actually Two Different Species

New research confirms that the (), a medium-sized bird of prey found in parts of North America and Eurasia, is two different species of bird that are only distantly related.

The study, led by Dr. Graham Etherington of the University of California’s Museum of Vertebrate Zoology and the Earlham Institute, explores the phylogenetic relationship between two currently recognized forms, the Palearctic form C. c. cyaneus (hen harrier), and the Nearctic form C. c. hudsonius (), to distinguish their ancestry and evolution.

“Molecular phylogenetics was applied to the hen harriers and the northern harriers to see if genetics could shed some light on whether the accepted morphological nuances between the species indeed represent a genuine distinction,” Dr. Etherington said.

Already accepted as different species by the British Ornithologists’ Union, the American Ornithologists’ Union and other avian taxonomic committees are yet to classify the bird of prey as separate species.

“From a conservation point, our work shows the Palearctic form is not the same as the Nearctic form and should receive appropriate recognition and protection,” Dr. Etherington said.

Hen Harrier (Circus cyaneus) – Photo by Graham Catley

“Before the advent of sequencing technology, species were categorized by shared and divergent morphological features,” he noted.

“However, new technology allows us to quantify the amount of genetic change between populations and identify divergent lineages.”

In the research, Dr. Etherington and his colleague, Dr. Jason Mobley from the Museum of Vertebrate Zoology at the University of California, Berkeley, collected tissue samples from museums around the world.

Using both DNA sequencing and morphology, along with differences in plumage, breeding biology, vocalization, habitat, distribution, dispersal and migration, it was possible to show the differences between the two forms.

“These genetic indicators distinguish the hen harrier and its close relative, the northern harrier, genetically as well as morphologically, suggesting geographical isolation is enough to form two distinct lineages,” Dr. Etherington said.

This research is published in the journal Avian Research.


Graham J. Etherington & Jason A. Mobley. 2016. Molecular phylogeny, morphology and life-history comparisons within Circus cyaneus reveal the presence of two distinct evolutionary lineages. Avian Research 7 (17); doi: 10.1186/s40657-016-0052-3

This article was first published by Sci-News.com on 24 Nov 2016.

The article was then republished by Focusing on Wildlife 6 December 2016

1 comment to Hen Harrier is Actually Two Different Species

  • so does that now mean all the northern harriers that have difted across the pond over a lot of years will now breed with paleartic harriers causing a new dna strain. any thougts please, I for one being an independent Raptor Researcher have found a lot of records of northern harriers in Europe and have in the past photographed very strange red belled paleartic harriers.which now makes me think they probably do cross-breed.i would love to know more….