Darlene Bloomfield emailed me from her home in Parry Sound, Ontario, in Canada. She wanted my help in solving an avian “whodunnit” type of mystery.
“We had both a robin and a brown thrasher nesting in our cedar hedge,” Darlene wrote in her email.
“Both seemed to have babies,” she added. “The other morning we found a mound of robin feathers on the ground in front of the hedge along with many tiny feathers.”
She also noted that the robins are no longer around.
“Would a thrasher kill a robin?” Darlene asked. “We have seen them chasing each other.”
She also noted that they didn’t find the bodies of the dead robins.
So, in a case perhaps best filed under NCIS Ontario, I looked at the clues and responded.
Robins and thrashers are about the same size and will skirmish if they have to defend their territory, but sadly the evidence points to another culprit.
The little mound of feathers sounds like what a hawk (likely a sharp-shinned hawk or Cooper’s hawk) would leave behind after grabbing a meal in a yard or garden.
The absence of the bodies is also explained. The predatory hawk likely dined on robin and left only the plucked feathers as evidence.
I expressed sympathy that the incident happened. I’ve been somewhat light-hearted in my relation of the mystery in this column, but it’s important to note that hawks and other predatory creature are not evil. They are not villains. They are doing what they were designed to do.
The sharp-shinned hawk and its larger relative, the Cooper’s hawk, are classified as accipiter hawks. The sharp-shinned hawk and Cooper’s hawk are the two raptors most often encountered by people who feed birds. Part of the family of Accipiter hawks, these two species are widespread in woodlands.
The Cooper’s hawk is larger, often described as similar in size to an American crow. The Sharp-shinned, on the other hand, is usually described as the size of a dove. There’s some overlap in size, so it is not the only reliable means of identifying these hawks. For example, female Sharp-shinned hawks are roughly equivalent in size to a male Cooper’s hawk. As with many raptors, the female is larger than the male in both these species.
There are some other things to look for in telling these species apart. For instance, adult Sharp-shinned hawks often look like they have a dark cap or hood. The eyes on a sharp-shinned hawk also look like they are halfway between the front and back of the head. In addition, the head itself looks small in comparison to the overall size of this hawk’s body.
These two species feed heavily on songbirds, which causes some bird-lovers distress. I like to view predation incidents as good examples of how the the natural world is good at keeping things balanced.
The sharp-shinned is really beautiful, especially for a hawk. Preying on songbirds doesn’t make them “bad” birds. They’re extremely efficient predators, and if you’ve ever witnessed one of these raptors in action, you can’t help but be impressed by both the power and precision deployed by these raptors in capturing prey.
The Accipiter genus of hawks includes about 50 species. In Northeast Tennessee, as well as across much of North America, the two common species are sharp-shinned hawk and Cooper’s hawk. A third species, the Northern goshawk, is a rare visitor to the region.
The Northern goshawk is a large, powerful hawk, and it is also fiercely defensive of its nest. This hawk is known to attack other raptors, mammals and even humans that stray too close to its nesting site.
Goshawk is a term derived from “goose hawk,” referring to the ability of this bird when utilized in falconry to take down such large prey as geese.
Other Accipiter hawks around the world include spot-tailed sparrowhawk, rufous-chested sparrowhawk, grey-headed goshawk, chestnut-flanked sparrowhawk, semi-collared hawk, red-thighed sparrowhawk and tiny hawk, which is one of the world’s smallest raptors. This diminutive hawk is about the size of a European starling and lives in Central and South America.
The sharp-shinned hawk will feed on a variety of birds, ranging in size from sparrows, warblers and thrushes to birds as large as ruffed grouse and mourning dove. This hawk also feeds on small mammals, reptiles and insects.
To share a sighting, make a comment or ask a question, please email me at firstname.lastname@example.org.