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Thursday, September 03, 2009

Peeps & Skippers

In the avian world the term "fall migration" is a bit of a misnomer. A more accurate (but less elegant) label might be "post-breeding migration", because some North American species actually begin their southward migration as early as July. Several species of arctic nesting shorebirds wrap up their breeding cycle during the "Dog Days" of summer, stopping off at New York City's Jamaica Bay Wildlife Refuge. At the refuge they fatten up and rest before continuing their long journeys to Central and South America, where they will spend the winter. I both love and dread this period of birdwatching.

Being witness to the spectacle of tens of thousands of shorebirds in one location is intoxicating, exhilarating and, often, frustrating. The frustration comes into play when trying to identify some of these long distance travelers, in particular, the calidris sandpipers or "peeps". This small shorebirds represent one of the greatest identification challenges for birdwatchers. They are the Least Sandpiper, Semipalmated Sandpiper, Western Sandpiper, White-rumped Sandpiper and Baird's Sandpiper. All are, generally, about the same size and shape with varying amounts and patterns of white, gray and brown. The plumages also vary between adults and juveniles of the same species. Also, unlike songbirds, which can be observed in habitats with differing amounts of shade, studying peeps usually requires standing for hours in stifling summer heat at the edges of smelly, insect infested (usually biting insects) ponds, marshes or other wetlands. In August's heat, I'll generally spend a few days at Jamaica Bay attempting to gain some nugget of insight into shorebird identification before packing it in until next year. I've come to accept that if I learn just one new thing with each day of shorebirding, I'll probably be ahead of the game come next migration.

This summer, for some unknown reason, between looking at sandpipers, plovers, dowitchers, yellowlegs and the like, I began examining the local butterflies. I started off by searching Prospect Park for the wildflowers that attracted large numbers of butterflies. When the park's limited plantings of coneflowers, bergamot and buddleia began to fade, I headed over to the Brooklyn Botanic Garden. Eventually, I hit the jackpot when my friend Heydi and I went exploring Green-Wood Cemetery. The cemetery's abundant and varied plantings attracted a treasure trove of butterflies, moths and other insects. At the soldier's monument on Battle Hill we discovered swarms of skippers on plantings of sedum, verbena and mixed mint species.

As we were running from butterfly to butterfly, snapping pictures and trying to identify these tiny, winged creatures I had an epiphany of sorts. I had foregone the frustration of peep identification for something just as difficult - skippers. The primary differences are that sandpipers don't usually fly away when you are looking at them and that they are always much larger than one's thumb nail! All the skippers that we were seeing were patterned in various shades of brown and orange, ranging in size from extremely small to very small. One of the difficulties with skipper ID is that you frequently need to see the upper and lower surfaces of both the forewing and the hindwing. On the days that I was looking, it seemed like they rarely cooperated or I needed to study my photos on the computer to have a reasonable chance at identification. Fortunately, there were other butterflies and moths that were easier to identify, plus a few migrant songbirds already passing through the area. Some of those birds were most certainly feeding on the abundance of butterflies.

Near the main entrance to the Green-Wood Cemetery I noticed a large patch of, what appeared to be, fennel. I crushed some of the feathery leaves and they had the unmistakable fragrant of licorice. The only insects that I observed feeding on the nectar of the yellow flowers was a species of small, black and yellow wasp. It occurred to me that the insects could actually absorb the aromatic licorice scent and flavor so, when a bird gobbles one up, I wonder, do they smack their bills and say, "Mmmm, refreshing"?

For more on shorebird identification, click here. For a list of migratory insects, click here.

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