Naturespeak A naturalist's view of the world

August 25, 2007

There’s Goatsuckers Up There!

Filed under: Uncategorized — wykes @ 4:25 pm

    Although country bird watching is usually more productive than city bird watching, I always keep my eyes peeled for feathered fauna when “in town” (the big town of Monroe, that is). When looking for something other than those of pigeon, starling or house sparrow persuasion, the trick is to keep looking up.  Look up into the morning sky and purple martins and ring-billed gulls will be there, look up in the mid afternoon airspace and you’ll be sure to spot chimney swifts twittering about. In fact, it’s not uncommon these days to see a bald eagle following the route of the River Raisin as it courses through our little ‘burg. The evening sky offers all of the above plus one more – the Common Nighthawk. 

  A pair of these graceful flyers greeted my skyward glance as I exited from choir practice at St. Joe’s church earlier in the week. It was about 8 pm and the evening sky was glowing a gentle blue against the dark silhouette of the bell tower. The pair was swooping down through a cloud of insects that had gathered over the air space above the still warm parking lot. This was their prime feeding time and the cityscape skyline their adopted turf.

  Despite their name, Nighthawks are crepuscular creatures who prefer the dim light of late evening and early morning as opposed to night. Their familiar forms are easy to identify as they loop and twirl through the air.  Dark and stub-headed, their long pointed wings (about 24 inches from tip to tip) are each marked with a clear white band.  A white chevron at the throat points the way to final identification.  Take a look at this fine web site to look at some great detail photos of this bird.  When at rest, they blend into their chosen background thanks to their mottled gray, brown and black feather wrap, so don’t bother seeking them out when the sun’s up.

  I usually end up gravitating to scientific names, and I think you’ll agree that this one has a nice one: Chordeiles minor. In rough translation this means “little stringed instrument of the evening.” How the Nighthawk Nome de plume got applied is questionable.  Indeed they tend to fly when things are getting night like, but have no resemblance to a hawk whatsoever. I suppose they are falcon-like with those swept back wings, but come on. The instrumental reference is apt because they frequently let out twangy “Peent” calls and execute impressive courtship dives that end in an harmonic “knee-ow” chord. Sounds emanated from the end of a dive are the product of wind rushing over the stiff wing primaries.  The resulting vibration is more comparable to the sound physics of a woodwind instrument as opposed to a string instrument, but let’s not get picky.  In some parts, the common name of Nightjar is applied to account for the jarring night sound, I guess.

  To put things into perspective, the hawk name thing is nothing compared to the ancient, though mistaken, belief that these birds were milk drinkers.  Nighthawks are members of a family called the Caprimulgidae, or Goat Suckers.  At some time in the misty past, farmers looking to blame someone for the poor milk production of their goats picked these birds as scapegoats.  The farmers were well aware of the fact that nighthawks and their kin have tiny beaks and cavernous mouths, but unaware that they use this mouth as a scoop for gathering in flying insects. Their un-natural conclusion was, therefore, that such a mouth was best suited for attaching to goat udders and sucking the poor things dry. The “capra” (goat) “mulago” (to milk) name still sticks today to all members of the Nighthawk clan, despite the silliness of its origin.

  The fact is that Nighthawks are superb insect catchers.  Why suck on a goat when you can feast on over 50 species of insects?  One Massachusetts bird was examined and found to have over 500 mosquitoes in its belly.  I don’t know who counted all those half digested little bloodsuckers, but my hat goes off to them for setting the record straight.  Goatsuckers are bug zappers extraordinaire.

  Fortunately for us, nighthawks find the flat-roofed urban landscape a perfect match for their nesting habits. They prefer open gravel roofs as nest sights.  As roof dwellers, nighthawks occasionally find themselves in a nesting situation that’s a little too hot for their taste.  To remedy this, the big mouth birds will scoop up eggs or young and fly them to a new location. I vividly recall being egged by one of these birds some 30 years ago as it dipped down close to my car windshield and dropped its cargo. It apparently was frightened by the close encounter. I only saw the egg carrier illuminated in my headlights for a brief moment, but was able to identify the egg shell after the fact.

    Your opportunities for observing Nighthawks is both waning and increasing. They begin to migrate south as early as late August and will disappear from our evening skies within the month. The fall migration, however, often provides a spectacle of hundreds of these birds passing overhead in huge flocks of up to a 1,000 individuals. 

  Ten years before the egging incident, I vividly recall seeing such a congregation coursing overhead on a late summer day.  The sky was full of nighthawks all heading to South America. In my youthful way I exclaimed “look at all those suckers!”  I guess I wasn’t too far off the semantic path, was I?

1 Comment »

  1. What a beautiful bird in flight. Thanks for the picture we could look at after reading your post.

    Comment by eriemermaid — August 27, 2007 @ 6:44 pm

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