Last week I spent a lovely Sunday morning hiking up Blue Hill Mountain in Blue Hill with members of the Maine Outdoor Adventure Club. It was a treat to revisit the place I had first lived upon moving to Maine. A few bird sightings were an added bonus to the beautiful day and the good company.

On our way up, I spotted the silhouette of a robin-sized bird at the tip of a tree across the slope. Although it was too far away for a positive identification, I guessed it was a northern shrike. These birds frequently hunt for small mammals or other birds by perching at the very tip of a tree like this.

A number of shrikes have been seen in the state this season. They are winter visitors only, as they breed in the taiga and tundra-taiga zones of Canada and the United States. In some years we may not see many here at all. The birds will not migrate as far from their breeding range if prey is abundant and the weather is not too severe.

Shrikes are very intriguing birds. They are called songbirds, yet they hunt other birds and small mammals much like a true raptor does. They have a small hooked beak, similar to a hawk or falcon, but do not have talons as do the larger birds of prey. They have the ordinary and comparably puny feet and claws of a songbird. In addition, they look very similar to a northern mockingbird. This presents an innocuous profile to their fellow unsuspecting songbirds.

I mentioned above that shrikes lack the stronger feet and talons of a true raptor. Such attributes are needed in order to stabilize their food while they consume it. Because of this, shrikes have developed a macabre habit: they impale their prey items on sharp twigs, thorns, or barbed wire, earning them the nickname of “butcher bird.” Sometimes the shrike will kill more than what it eats in one sitting, maintaining a larder of food items all similarly placed.

Shrikes may lack the specialized feet and talons of a raptor, yet they do have a powerful grip of their own. They are known to strike birds in flight with either their bills or their feet and are overall very strong for their size, able to carry prey larger than themselves. Researchers have observed them carrying birds as large as stilt sandpipers and rock doves to their nests or eating perches.

I thought about all this as I watched the shrike survey the landscape from its lofty perch. Soon, it took off down slope as we continued our way upslope.

Several times on our way up, I thought I heard call notes from a small group of birds, but I was never able to pinpoint the sounds. As we neared the top of the small mountain, we passed through a spruce-pine forest. A friend whom I had invited along, Mary Knowlton, remarked on the cone bracts that lay scattered around beneath the trees. She thought a red squirrel had left them after a meal of conifer seeds, which they love. However, squirrels will often take a cone to a little perch, such as a rock or tree stump, to eat, leaving tidy little piles of bracts behind.

This, I thought, was the work of crossbills. These sparrow-sized songbirds breed and winter throughout northern North America, including Maine and Canada. There are two types: red crossbills and white-winged crossbills. Their name refers to a peculiar adaptation: their bills are indeed crossed at the tip. This has enabled them to efficiently extract conifer seeds from their cones, making them specialists in this food source.

The birds don’t remove the cones from the trees, but instead often hang upside down on a branch as they remove the seeds from the cones. Hence, the widely scattered bracts beneath the trees.

Judging from the evidence above, and the fact that crossbills travel in flocks, I guessed it was the call notes of either white-winged or red crossbills I had heard every so often, but I was never able to confirm this. Still, it was fun to put this neat puzzle together while enjoying a late winter hike on my favorite little mountain.

BDN bird columnist Chris Corio can be reached at bdnsports@bangordailynews.net