Tomorrow i will be teaching six 20 minutes lessons at the school on the effects of DDT and the food web around the islands. The lesson will involve blowing out chicken eggs to represent California Brown Pelican eggs and bald eagle eggs that were affected by DDT. I will then put a decorated feather brick on top of the egg and hopefully the blown out egg will collapse. If time permits I will then talk about how the Island Fox were affected!
The DDT did not necessarily affect adult birds, but dramatically thinned the eggshells of nesting pairs so that when the adult birds went to incubate the eggs they would break and collapse. Needless to say nesting seasons were not successful. The pelican became endangered (recently unlisted) and the bald eagles left the islands to be replaced by the golden eagles who hung out for the easy food resources. The bald eagles were gone from the Channel Islands in the 1950's, so it is awesome they are back. DDT was banned in the US in the 1970's. It is still an important chemical for fighting malaria in other parts of the world, as i guess nothing better has been invented.
The bald eagles have been reintroduced (through monies from the Montrose Settlements Restoration Program) and have successfully without the help of mankind reproduced on Santa Cruz Island for the first time in over 50 years in 2006. The tags on these two are #10 (male) and #26 (female), they have a lovely nest on the top of a tree. The nest is pretty to watch even though the eagles are not there right now (the web cam has audio so it is fun just to listen to). The below link takes you to the web cam site where you can tune in. A lot of action starts at the end of February till banding (also viewed live) in late May. There are also other nests to view on Catalina Island (not part of the park, but part of the Channel Island chain).
http://www.iws.org/bald_eagles/nestcam.htm
I will try and get tommy to take a photo of one of the lessons to post tomorrow.
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