A banded common tern (Sterna hirundo) returns to the nest for incubation. This image was remote-triggered on a hidden camera, toward which the terns are very tolerant!
Common tern activity levels on Ship have made an about-face, going from mostly quiet to positively booming! For the past 10 days or so, the birds have been active virtually all day long, courting their partners and tending their nests. At the time of writing, well over 150 nests have been established on the island. Of 100 nests being monitored for early-season predation, only 4 have been lost– and 3 of the 4 were taken out by the highest tide of the month. If you’re more of a visual learner, check out the figure below; a legend is available by rolling your mouse over the chart. If you want, you can even click to zoom in on any of the images.
Average clutch size from a subsample of 100 nests as it changes over time.
In simple terms: things are going well. Breeding savannah and song sparrows have begun to hatch, as have the common eiders, gulls, and double-crested cormorants on our neighboring islands. It should be a matter of days before our nesting spotted sandpiper fathers will escort their chicks to safe foraging, as well.
Between seal pups, tern eggs, and the numerous fuzzy chicks emerging all around us, we have plenty to observe at Ship. Later this week we hope to establish our productivity plots for the season and begin adult trapping efforts in order to band new birds recapture known individuals. Our projected first hatch date is June 19th, so knock on wood and stay posted for the big news in a couple of weeks!
A fuzzy creche of six common eider (Somateria molissima) chicks escorted by two hens! We hopefully theorize that the small number of adult birds escorting this creche is due to rampant nesting success of all the other eider hens out there on Trumpet and East Barge Islands.
As if all these babies weren’t enough, spring migration somehow persists on Ship. Our long-awaited Nelson’s sparrow (easily identified by its song, which sounds remarkably like a match being lit) has finally taken up residence on the island, along with an alder flycatcher that can be heard singing daily; the vocalization (a burry “fee-beeoh!”) of this bird is just about the only thing that sets it apart from its doppelganger, the willow flycatcher.
In birding parlance, focusing in on a single area to frequently document its species is known as “working a patch”, and that’s certainly what every Maine Coastal Islands seabird crew does. Because a daily birdwalk is part of our essential duties, we become very familiar with what species to expect on a daily basis and can quickly recognize oddities. In working our teensy patch called Ship Island, we have managed to document some 68 birds, including such bizarre wintertime lingerers as long-tailed duck, Bonaparte’s gull, and even a single black-legged kittiwake! And that isn’t even mentioning all of the freshly-molted warblers that continue to stream through in their alternate plumage.
Magnolia warbler (Setophaga magnolia)
American redstart (Setophaga ruticilla), a personal favorite.
Black-throated green warbler (Setophaga virens)
That’s the news from Ship Island this week. Hopefully our industrious tern colony will continue to grow despite gloomy weather! In the meantime, we’ll be counting birds and huddling in the warmth of our tiny cabin when it gets too miserable out.
Bonus bird fact: did you know that the scientific name of the common eider, Somateria molissima, literally translates to “very soft woolbody”? An apt name, considering how the seaducks are prized for their luscious down! And if you’ve ever had the pleasure of feeling an eider’s feathers, you’ll know this to be true.
Until next time!
Meredith Miles @ Ship Island
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