On Saturday, December 6, Washtenaw Audubon escorted more than 20 enthusiastic birders to the largest landfill facility in the county, and one of the largest in southeast Michigan. Now owned by Advanced Disposal and occupying most of a square mile tucked into the extreme northeast corner of the county, this landfill is a magnet for gulls patrolling the region for some calories.
This popular trip, limited to Washtenaw Audubon members, has had varying success over the years, but usually something out of the ordinary can be found, and this year was no exception. New this year was permission to bring in two 12-passenger vans, thus expanding the availability of this trip and allowing us to meet the demand of the "regulars" as well as many who had never been before. However, renting two large vans runs into the hundreds of dollars, and to be able to continue to offer this trip in the future, Washtenaw Audubon will be suggesting a donation by participants to cover the van and fuel costs.
As the group arrived at the landfill and was led to our viewing position by the staff, it was clear that there was an abundance of gulls. However, we only had a brief period of decent viewing early, but then the local red-tailed hawks awoke and began cruising the skies around the landfill. The raptors made the gulls skittish and kept them high in the air for most of the morning. Although this made gull-watching very difficult, a bonus was that one of the 8-10 raptors was a dark morph red-tailed hawk. An adult lesser black-backed gull was found during this time, but not much else that could be confidently identified.
Finally in the last 30-40 minutes of our available time (the landfill closes at noon, and if we miss the departure time we risk spending the night inside the fence) the gulls came down low and started feeding. As they were sifting through the trash, we were sifting through them. We eventually found a fairly cooperative first-winter Thayer's gull that allowed multiple people in the party to get photographs. The identification was debated later in the day, but photographs that clearly showed dark tertials ultimately ruled out Iceland gull and clinched the field i.d. With minutes remaining in our time there, another pale gull caught our attention and was also photographed. The identity of this gull (which we knew to be a second-winter plumage) was debated in the field and when we all got home. But further photographic study and consultation with others led to its i.d. also as a Thayer's gull, with reviewers noting that the tail and wingtips were too dark for an Iceland gull.
Thanks to Ben Lucking, Don Chalfant, and Bob Bochenek for providing photographs that helped with the identification, and to those who offered post-trip identification comments. Thanks also to the management at Advanced Disposal for continuing to be very accomodating to our group of gull-watchers.