Last January I came upon this immature Northern Harrier expelling a pellet sitting on a fence at one our favorite locations on a cold, blustery winter day. At first the harrier was rather still but then I noticed that it appeared the harrier was about to expel a pellet by it’s behavior. The black blob in the harrier’s bill is the un-expelled pellet.
Observing birds behavior, watching their movements and actions can often lead to photos with loads of action. These photos aren’t my best, the light was not striking the bird at a very good angle and these are large crops.
Owls, hawks, eagles, kites, falcons and harriers expel pellets of undigested bone and fur of the prey they eat usually at a rate of one pellet per meal. With harriers I’ve noticed a bulging of the throat area before a pellet is expelled and then the birds will open their bill to try to hack it up.
This Northern Harrier took about a minute to expel the pellet and I filled my buffer several times trying to catch all the action. The harrier appeared to be concentrating so hard on regurgitating the pellet that it nearly fell off of the fence.
The immature harrier was able to right itself without falling off of the fence but I was ready in case it did fall. As you can see the fence was not snow or frost covered so the bird didn’t slip because of that, I tend to believe that the slip was caused by the bird concentrating on expelling the pellet. It fluttered its wings to regain its position on the perch.
In the image above at the lower right side of the frame you can see the expelled pellet as it falls to the ground. Not long after the pellet was expelled the harrier took off, perhaps on a hunt for its next meal.