Earlier this week, I noticed this young Great Black-backed repeatedly scratching its face. Face scratching has become a good reason for me to further inspect the head and face of a gull:
|Juvenile Great Black-backed Gull. Cape May, NJ; 06 August 2012. Photo by Amar Ayyash|
|Note the dark spots on the lower cheek. This region is impossible to preen, hence the need for scratching.|
The Black-legged Kittiwake pictured below spent several weeks at Montrose Harbor in Chicago early last year. It shows louse spots that were overlooked when I photographed it. Indeed, this bird was in trouble at the time (click here for that story) and it ended up dying shortly after being picked up on 31 March 2011.
|Juvenile Black-legged Kittiwake. Chicago, IL; 31 March 2011. Photo by Amar Ayyash.|
Note the dark gray spots above the back of the eye.
An example of an adult with lice spots is Minnesota's first recorded Slaty-backed Gull:
|Adult Slaty-backed Gull. Grand Marais, MN; 22 July 2006. Photo courtesy of Laura Erickson.|
I recently inquired about this bird after finding its photos online and was not at all surprised to learn that it was found dead on 14 August 2006. It lingered for over 3 weeks and was unusually tame (very similar to the Black-legged Kittiwake's story). Again, these spots could have served as an obvious red flag regarding its condition. It's this message that I hope my readers take from this post.
|Juvenile Ross's Gull. Björnhuvudet, Öckerö; 25 December 2011.|
Photo by Martin Alexandersson.
|Juvenile Iceland Gull. Osøyro, Norway; 01 January 2012.|
Photo by Urban Ringing.
A special thanks to Jason Weckstein, an ornithologist at Chicago's Field Museum, who provided me with engaging information on this subject. Weckstein was able to confirm for me that the spots on the GBBG and BLKI are indeed louse spots, and are very likely of the genus Saemundssonia (living specifically on the head and neck of birds).