Dan and I set out to solve two mysteries this morning. The first goal was to finally make a concerted effort to identify the Florida Lake Mystery Sparrow (see yesterday’s blog). We walked the dike, and as expected, the sparrow flushed into the woods about 50 yards ahead. But, since there was two of us, we were able to divide and conquer. Dan headed into the trees, and I sat down on the dike.

It was working, Dan was pushing the sparrow towards the edge. Then, there it was! WAS is the key word. I got my binoculars to my eyes in time to see it fly deeper into the woods – back towards Dan. What I did see however, was that this bird clearly had dark brown streaking below – it was not a Swamp Sparrow as I hypothesized. Plus, those streaks looked thick and very dark – unlike the fine streaking of a Lincoln’s Sparrow. Was this a Song Sparrow afterall? I was still convinced that we were dealing with a Melospiza however.

Then, I heard a fine, high-pitched “seep” call coming from behind us. It did not fly deeper into the woods, it had doubled back, right between the two of us! (This bird was really playing hard to get!). The call note sounded good for Song Sparrow, but it did not eliminate Lincoln’s, as I didn’t hear it well enough (I also have difficulty distinguishing very minor differences between high-pitched calls).

We slowly worked our way back towards the call note. We did not see it. I picked up the call of a Pine Grosbeak overhead, and so we diverted our attention from the forest edge to the sky in hopes of spying the Grosbeak. We did not. But, as I turned around to take one last glance at the edge of the trees, there it was! On the ground, in perfect light, only 25 feet or so away. . . My binoculars seemed to take eons to reach my eyes . . . .Please don’t fly . . . my eyes slowly focused . . . it’s still there. . . it’s a . . .it’s a . . . Song Sparrow. Close observation revealed that the tail feathers were in fact worn, giving the bird the shorter - and less rounded - appearance that I and others, including Dan today, had noted. Well, at least I was right about the genus!

So, with that mystery solved, we set out on our quest to find gulls. Moderately-large numbers of gulls are regularly seen traveling between Casco Bay and the Lewiston-Auburn area. Dan and I both seen them traveling north-northwest over our houses in Freeport and Pownal, respectively, in the morning, and back south-southeast towards the ocean in the evening. They are clearly commuting somewhere inland to feed. But where? Mystery #2.

Our first stop was the Lewiston Landfill. Gulls sure like dumps. But, no gulls were in the air nearby. We had a pleasant conversation with a landfill employee who informed us that gulls no longer frequent the dump as municipal waste is no longer dumped there. Instead, it is burned, and then the ash is landfilled. Not even gulls eat ash, so this was not the answer.

We traveled up the river, looking at ducks here and there (we saw handfuls of Common Goldeneyes and Mallards, and a few Common Mergansers, but with so little ice on the river, the diving ducks were not concentrated. No gulls at the Lewiston sewage treatment plant either, so that’s not the food source. A Peregrine Falcon kept a close watch on the city from atop the church steeple on Cedar Street, looking completely satisfied as it dozed off with it’s bulging crop (a little squab for breakfast perhaps?). Crossing back over to Auburn, and turning south, we checked the river just below the main bridge via the new riverside walkway. There’s always a concentration of ducks (about 60 Mallards today) here, and usually a few dozen gulls loafing (but not feeding) on the ice or shoreline. Today, 100 gulls were present, mostly Herring, a handful of Ring-billed, but also a single first-cycle Iceland Gull and an adult Iceland Gull.

But, wait, the wingtips of that adult Iceland Gull look black – real black! Could it be a Thayer’s Gull (a real “mega” here in Maine)? We watched it for a while. It really didn’t have the “fierce” look of a typical Thayer’s, and the legs were very pale pink. We needed to see the wingtips, especially the underside. Dan jogged down the road to find a convenience store for some chum (popcorn). By the time he returned, I was fairly convinced this was “just” an Iceland Gull – it stretched it’s underwing and I saw that it was completely white – no dark trailing edge on the outermost primaries. Also, the iris looked pale (should be darker in Thayer’s). But, we chummed a bit anyway.

Many of the gulls came in, but not the Iceland. It just watched the feeding frenzy from the other side of the river. It did stretch a couple more times though, which allowed me to confirm that the underwings were indeed completely white, and the pattern of black verses white on the tips on the uppersides of the outer primaries also did not fit Thayer’s either (gull identification, by the way, is not birding’s easiest pursuit!). Satisfied that it was just an extremely dark-winged Iceland, we continued on south along the river.

Our next stop was a leading candidate for the gulls’ destination. The John Deere shop at the edge of a farm always has lots of bird activity nearby. Hundreds of gulls can often be seen circling overhead (as they were today), and there’s always lots of crows and starlings – other scavengers. Was this the gulls’ destination? I have always felt that this was just a periphery site – maybe a roosting spot, or smaller feeding area? What could be behind that small hill that would feed so many birds? To be honest, we were less concerned about what they were eating rather than if they were eating. If these birds were foraging there, there had to be a regular, plentiful food source. If they were just roosting there, there need be nothing more than a small farm pond.

I have scanned this area, and the river across the street, from the roadside, but gulls are usually only visible if they take flight. Furthermore, many times, such as today, when they do take flight, they head east-north-east from here, towards the Lewiston Landfill. That gives more credence towards this being a peripheral feeding area, not the main destination of these commuting gulls. So, we went inside the office there as asked permission to look behind the buildings. We were told we couldn’t due to “liability,” specifically the chances that the bulls could charge us and run through the fence. Well, I’m not going to argue with someone – it’s private property, and if he didn’t want us there, we weren’t going to be there. But, it does leave the question unanswered as to whether or not they are feeding nearby – and on what.

We checked the nearby composting facility - as recommended by the helpful landfill attendant, but no gulls were to be seen there. We also checked Bell Farms, where gulls often roost – and may feed a little on waste grain – but today it was gull-less, and the maximum number that I have seen there does not come close to the numbers that pass over my head in the Pownal/Freeport area. We know the gulls are not traveling just to sit in a dirt field or loaf on some ice in the river. They are traveling up here for some reason. But what?

Any ideas? Anyone have any suggestions as to where to look? Any farming operations with lots of waste grain, or perhaps a nearby slaughterhouse? Gulls are not known for their gourmet tastes, so I am sure there is someplace rather unpleasant that they are heading. Any suggestions are more than welcome!