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Friday, November 6, 2015

LONG- & SHORT-BILLED DOWITCHERS, TIGERTAIL BEACH, MARCO ISLAND, FL

   At Tigertail Beach yesterday morning we sighted and were able to photograph numerous shorebirds.  Among these shorebirds were many Dowitchers.  Short-billed and Long-billed Dowitchers often mix with each other and forage together.  The two species of Dowitchers are very difficult to differentiate from each other, but as luck would have it, I was able to photograph the two species side-by-side, both in nonbreeding plumage.
   We have identified the Dowitcher on the left as a Short-billed Dowitcher and the one in the middle as a Long-billed Dowitcher.  We were able to differentiate the two species as follows:
  • You can see in the photo that the Dowitcher on the left has a bill considerably shorter than the other one.  The bill sizes of the two species do overlap, particularly since the female generally has a longer bill than the male of the same species.   However at the extremes there is definitely a difference: the bird on the left is probably a male Short-billed Dowitcher and the one in the middle, a female Long-billed Dowitcher.
  • The bill of the Short-billed Dowitcher has a a slight downward curve, while the bill of the Long-billed Dowitcher is straight.  You can see this in the photo.
  • The Short-billed Dowitcher's eyes are at a higher angle above the bill (loral angle) than the Long-billed Dowitcher's eyes.  This is obvious in the photo.
   The Long-billed Dowitcher is already on our Life List, but the Short-billed Dowitcher is a new species to the list, which now stands at 239.





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