Hi everyone. I'm really sad about the 6th egg breaking here, too.
For those interested, I'm re-posting two posts from this thread on Feb. 4th of this year - one from Emyrauld, with some history and notes, and one from me in reply to that.
My post includes a link to an article that may be of interest to those who have questions about what may possibly be an environmental factor here related to possible cause of egg-breaking issues. It's a long article, and it requires continuing to scroll past the irritating embedded ads in it, but the reader will be rewarded with
good info all the way to the end of the article, which is related not just to California Condors, but also to other raptors, such as Eagles, who may feed on the animals in this part of the country who have been shown by research to still have DDT in their systems - leftover in the marine environment from long ago, and passed up the food chain - as explained in the article link in my quoted post below. I think this is one possible explanation for why these eagles sometimes are able to hatch eggs, and why sometimes the eggshells are so thin that they break easily... I think it depends on their diet and what toxins are in what they are eating. Just my thoughts, obviously. I will be looking forward to hearing if Dr. Sharpe is able to do any follow-up research and testing specific to these eagles at this location to determine the cause of the eggs breaking.
Here are the two posts I am referencing - remember, they are from Feb 4th, 2017, from this thread...
Posted 2/3/17 on the IWS Facebook page:
"The Sauces birds laid and lost another egg today. Looking at the history of the nest, it has failed in 5 of the 9 previous nesting attempts, with 2 different males and 3 different females. Male A-28 was present 2008-2011, and the male A-40 from 2012 to present. Female A-02 was present in 2008-2009 and failed both years. Female A-27 was present from 2010 until she was displaced by A-48 in 2013. A-27 was successful every year except 2013, when ravens took the eggs. Female A-48 was unsuccessful in 2014 and 2015, and had two chicks last year. Why the eggs are breaking so quickly with the current pair is hard to say. Unfortunately, we can't get information on potential contaminates from eggshells; only from egg contents."
Oh, such sad news. Emyraud, thank you for posting the pics and info, though I wish it were more upbeat. I feel like there must definitely be some environmental/contamination issue for such easy egg-breakage, and so often, even though different eagles nested here.
There are many articles on the topic, but this one from about 3 years ago talks about the study of California Condor eggs that were tested and measured and showed at least half still were affected by DDT. This is an excellent article that talks about how and why DDT is still affecting the birds and marine life on the Pacific U.S. coast... If you are patient enough to read the whole article, which is not long, and is easy to follow, there is reference near the end of it about a planned study, at that time, for the effect on other raptors in that area, such as eagles - not just the condors:
http://www.oregonlive.com/environment/index.ssf/2013/09/california_condor_study_finds.html
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Topic: Sauces Bald Eagle Cam, California (Read 279355 times)