In late February 2020, Bryce, Luke, and Mark teamed up in eastern Kansas to trap two dark morph, non-harlani Red-tailed Hawks. The objective was to deploy GSM transmitters to better understand where this phenotype breeds, and along with blood and feather samples thus discover their proper subspecies designation. In the past, this type was considered to belong to calurus, but given the status of light calurus in the eastern plains and the current understanding of winter distributions of abieticola, Jerry Liguori and Brain Sullivan suggested that these dark birds may represent the previously undescribed dark morph abieticola. Because of some evidence of where this phenotype ends up during migration and the breeding season, this idea held some favor. So, we decided to organize and attempt to discover the proper subspecies designation for this subtly unique type.
On 1 March, after ten days of trapping we successfully outfitted two dark non-harlani birds with GSM units. Below are photos of each bird, as well as a summary of their movements up to 20 April 2020.
Kansas 01, Transmitter 67
Kansas 02, Transmitter 97
These birds are still moving, and we are yet to receive indication on where they will settle to breed. As expected, each is headed into the northern boreal forests. The GSM transmitters depend on the cellular network to transmit data, so we may not hear from either bird until they come back into cell reception next fall.
In the future, we will be adding more birds to this dark morph abieticola effort, as well as birds of other migratory subspecies. You can find a full list and photos of our current birds on the Movement Ecology page.
A special thanks to John Bolin and Dave Rintoul for their help in Kansas!