Question: A friend recently asked if we have heard of reports of dead birds on Seabrook Island Beaches. They have heard reports of at least 9 dead birds on Kiawah recently. Do you know what could be causing this? – Anonymous
Answer: Seabrook Island Birders has not heard of any increase in dead birds on Seabrook Island. I did notice several reports on my daily “Rare Bird Report” I receive from eBirds of rare birds in Charleston County. One recent report had Kiawah Island Biologist (and eBird reviewer) Aaron Given reporting Great Shearwaters on Kiawah. His siting on eBird stated: “Three alive and alert Great Shearwaters found while driving the beach. Picked them up and transported them to the far eastern end of the island. Also picked up 3 dead Great Shearwaters.”
I reached out to Aaron and asked if he had any insight into what was going on. His response: This is a cyclical thing that happens with Great Shearwaters. There was another mortality event since my time here but I can’t remember the exact year – at least 10 years ago. Most of the birds found dead are emaciated. I don’t think we really know the cause of it but it probably has something to do with a historically predictable food source not being available and causing the birds to starve.
Here’s a link to a paper published in 2013 about it: https://seanetters.files.wordpress.com/2015/07/grsh_mortality.pdf. In summary, my interpretation is that the causes of this apparent increase in strandings are unknown but may be due to an increase in reporting effort over the past two decades combined with changing oceanographic conditions in the South Atlantic Ocean, leading to large-scale mortality of emaciated Great Shearwaters along the east coast of the United States.
A later eBird siting by another observer stated: 1 deceased on beach near ocean course; appeared to have been washed up with the tide. 3 others resting on beach at far end, pointed out to us by DNR. One of the three seemed to be doing slightly better than the others but all were alive. My take away from this is that not only is Aaron aware but so is DNR.
Honestly, before seeing these reports, I had never heard of a Great Shearwater. Audubon’s Guide to North American Birds states Great Shearwater is: A common seabird off our Atlantic Coast, seldom coming close to shore except during storms. Since I haven’t been off shore and luckily I haven’t seen the stranding birds, I shouldn’t be surprised they weren’t on my life list of birds seen.
After I wrote this blog, someone forwarded Judy Drew Fairchild’s blog on Great Shearwaters are Unusual Guests on our Beaches. It has more good information.
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Submitted by: Judy Morr