We are fast approaching the end of spring migration. It always feels like the season moves much too quickly. There’s so much natural excitement crammed into a short time frame that it can be difficult to absorb it all. By this point in the year, many species have already passed through and others are pairing off and raising young. I’ve come across a fair few nests in the past month, some full of hungry chicks being doted on by their parents. On Thursday, I found a trio of hungry baby cardinals, and Saturday featured a pair of Yellow Warblers bouncing around together and Baltimore Orioles building a nest. There are still plenty of Neotropical migrants to be found, including local breeders, lingering individuals from early waves, and larger numbers of late-season movers.
When I arrived at Hempstead Lake on Saturday morning, I discovered that the annual Boy Scouts of America Camporee was taking place this weekend. I have many fond memories of the activities and adventures from this weekend overnight trip, but the various troops end up filling a parking lot and the entirety of the picnic area with their gear. As a result, I had to park at the second space and stroll down a little further to reach my usual route. I was unable to access some of the areas I usually check on my route, but I got to scope a few underchecked spots on my way between lots. The diversity and numbers were somewhat reduced from peak migration in recent weeks, there were still plenty of interesting birds in the area. Yellow-billed Cuckoo, Wood Duck, Yellow-crowned Night-Heron, Swainson’s Thrush, and Spotted Sandpiper were among the 50+ species I tallied over the course of the morning.
I was planning to do a brief check of the wooded waterway at the far edge of the picnic area as a final stop and then take my fortunes elsewhere. I worked the edge of the tangled vegetation bordering the lawn as I approached Lot 3, and I was stunned when a loud song with a series of “churree” phrases erupted from the leaves within spitting distance of where I stood. The singer cut its performance short when it became aware of my proximity, and I was set on high alert. I knew I’d found myself an interesting bird because the song pattern is only used by a few species that are quite uncommon on Long Island. I momentarily wondered if I’d located a Kentucky Warbler of my own. When the bird sang again, I realized that the fourth and fifth parts dropped lower than the uniform first three. Oh. Mourning Warbler!
The Mourning Warbler, named for the somber black patch on the male’s breast, is one of the least common and most elusive of New York’s “expected” migrant warblers. The species is seen in the City only a handful of times each year, and it is even more irregular on Long Island. I’ve actually seen one in my home county one other time, when a first-year individual landed in my yard’s birch tree for a few moments in September 2009. These birds, like many of their closest relatives, typically keep to dense cover and often pass through areas undetected when traveling. I immediately got in touch with Brendan, knowing he’d want this rare county bird on his bid for a high year total. I put word out on the listserv as we searched and strained for a glimpse or whisper of the Mourner, but for several minutes we could find no trace of it. We finally relocated our target when we realized it had crossed the road to the lakeshore bridle path. Here, we were able to observe and enjoy the warbler as it increased its activity level and began singing at regular intervals. We got some great, close views of this characteristically secretive species, and once again Brendan managed to obtain superior photographs. All in all, this bird was a mighty fine find for the final stages of spring migration.
Shortly after posting about my sighting, I received an email from Dr. Jay Pitocchelli, a professor who researches Mourning Warbler populations. He informed me that different sections of the bird’s range have unique song patterns called regiolects, and he asked if it was possible to collect a recording of my find’s voice. I’m always happy to contribute to science! Brendan and I circled back to our most accommodating friend, and I managed to tape a few seconds of the song cycle. This file was forwarded to Dr. Pitocchelli, and I spent some time perusing his informational website. It appears, based on sonograms of song types, that my bird was a member of the Eastern population. The project maps where regiolects are recorded in an effort to sketch out migration routes for the distinct populations. The surprising opportunity to improve our understanding of this sneaky species made my unexpected discovery all the more exciting and meaningful. If you have the time to search, I wish you luck in refinding the warbler in the thick undergrowth along the shores of Hempstead Lake. If you are fortunate enough encounter a Mourner of your own, I highly recommend trying to record it for Dr. Pitocchelli’s project. Who knows what you’ll learn in the process!
Year List Update, May 21 – 316 Species (+ Mourning Warbler)