While the rest of us are barely surviving the heat, humidity, and drought, a couple of southern waterbird species had a banner year on the Cape and islands, where their populations seem to be on the rise.
If you pay attention to the birds in your backyard, it’s no secret that southern birds have been moving northwards over the last century as our winters have gotten milder on average. The Red-bellied Woodpeckers that you undoubtedly have breeding in your suburban neighborhood didn’t occur in Massachusetts until the late 1970s, and on the northern half of the Outer Cape until just 10 years ago. Carolina Wrens had not colonized the entire state until the last 20 years. Looking further back, the cardinals and titmice we take for granted at our bird feeders were rare vagrants from the southern states within the lifetimes of many Cape Codders. So it should come as no surprise that a couple of waterbirds with decidedly southern affinities are getting increasingly cozy in Massachusetts.
One of those is a flying oddity you may have encountered on the beaches of Florida, the Black Skimmer. Recently, Susan Whiting and Robert Culbert on the Vineyard counted over 30 skimmers, including 13 fledged chicks, on the flats near Katama. This represents an all-time high count for this species in the state, at least when it comes to breeding birds. There are historical counts of many hundreds of skimmers brought here by hurricanes from dusty decades past, but those counts were anomalous and temporary. The few dozen currently holding court on the Vineyard represent a genuine increase in the state’s breeding population. Skimmers used to nest at Monomoy in Chatham and Plymouth Beach, as well as in the now defunct New Island tern colony in Nauset Marsh in Orleans. But this year they literally put all their eggs in one basket, and by all appearances it worked out pretty well for them. So much for that old chestnut.
Skimmers - big, strikingly black and white relatives of gulls and terns - are like no other birds in the world; they are the only species to have an underbite. Their lower mandible is considerably longer than the upper, and with good reason, since they forage by flying along and dragging that weird lower bill in the water. When they feel a fish, the bill snaps shut like a mousetrap. Because they find their food using touch, they can forage in lower light than their competitors the terns and gulls. The eerie sight of a Black Skimmer knifing that bill along the surface of some placid bay in the failing light of dusk is one of my favorite birding experiences.
I’ll talk about the other southern waterbird on the rise next week. In the meantime, let’s all remember the life lesson the Black Skimmers of Martha’s Vineyard have taught us – maybe it’s ok to put all your eggs in one basket. Which reminds me – I have an excellent investment opportunity I’d would love to discuss with you…
