Aug. 21, 2011 - Birds of Hawaii-Part 1
Read MoreOn our way back from New Zealand, Diana and I stopped for a few days on the Big Island of Hawaii. I took a birding tour with a company called Hawaii Forest and Trail ( http://www.hawaii-forest.com/) and one of the birds we saw was this critically endangered species, the Palila. These birds live only on the Big Island of Hawaii, on the slopes of Mauna Kea volcano from 6000 to 9000 feet elevation. At 6 – 6½ inches, it is the largest living member of the Hawaiian Honeycreepers. The Audubon website ( http://www.audubon2.org/watchlist/viewSpecies.jsp?id=157 ) says that Palila population estimates have been conducted annually from 1980 to 1996. They range from a low of 1584 to 5683 birds. It seems to fluctuate depending on the seed production of the Mamane tree (see next photo) but no clear trends have been noted. A fact sheet from Birdlife.org ( http://www.birdlife.org/datazone/speciesfactsheet.php?id=8901 ) suggests that the 2010 population was only about 1200 birds. That’s a very low population so I felt privileged to see this species.
This is a seed pod from the Mamane (or Himalayan Knotweed) tree. It is toxic to most birds and other animals, but the seeds are the main food for the Palila which is somehow able to avoid being harmed by the poison. Feral goats and sheep are apparently able to deal with the toxicity as well, because their feeding on the seed pods has negatively impacted the population of Mamane trees and therefore the Palila. Efforts are now underway to create areas free of sheep and goats so the Palilas have a place in which to survive.
This Pacific Golden Plover in breeding plumage was foraging on a large lawn. I am on a list to receive regular e-mails from a birder and photographer named Jim Stevenson. He has explained why species (like this one) which nest in the Arctic, often have black bellies for their breeding plumage. In the areas where they nest, the sun shines 24 hours a day but is low in the sky. By aligning themselves with the rays from the sun, these birds are able to use their black plumage to gather more heat from the sun to help incubate their eggs. That’s a pretty ingenious adaptation.
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