Establishing Forster’s Tern Nesting Colonies
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Establishing Forster’s Tern Nesting Colonies


[C. Alex Hartman]: Hello and welcome to the
Don Edwards San Francisco Bay National Wildlife Refuge. My name is Alex Hartman and I am a biologist
with the U.S. Geological Survey. Just behind me is the managed Pond A16 in
the Alviso complex of the refuge and the site of our Forster’s Terns social attraction
effort. Islands within managed ponds like A16 have
historically supported large numbers of breeding terns. In 2012 the South Bay Salt Pond Restoration
Project constructed 16 additional nesting islands within pond A16 in an effort to maintain
waterbird breeding populations in South San Francisco Bay even as other managed ponds
are restored to tidal marsh. Yet today, Forster’s terns have not returned
to this historic nesting area where in some years over 300 hundred terns and avocets nested. Through a generous grant from the Santa Clara
water district, USGS will be using social attraction to attempt to re-establish breeding
colonies of Forster’s terns to pond A16. Here is one of our Forster’s tern decoys. They are carved out of wood and painted to
resemble real Forster’s terns as they would look sitting on their nests. On each of six islands, we are putting out
50 of these tern decoys, and anchoring them in place with rebar stakes. On each of six islands with tern decoys, we
will also deploy an electronic call system. These systems include a portable MP3 player
with amplifier that is powered by two six-volt batteries and recharged using this solar panel
array. Pre-recorded Forster’s tern colony calls
are broadcast through two omnidirectional speakers that we place among the decoys. This system allows us to broadcast Forster’s
tern colony calls continuously over the entire breeding system. [Forster’s tern colony calls] [C. Alex Hartman]: With the decoys and electronic
call systems, these islands will look and sound like real Forster’s tern nesting colonies. With luck, Forster’s terns will find these
colonies and nest here. USGS will monitor nesting activity on these
and other islands within Pond A16 as well as other locations in South San Francisco
Bay throughout the breeding season. Thank you for watching. [Forster’s tern colony calls] Credits: Many thanks to the Santa Clara Valley
Water District, for providing funding for this project. And to our partners:
U.S. Fish and Wildlife Service Don Edwards San Francisco Bay National Wildlife
Refuge South Bay Salt Pond Restoration Project
San Francisco Bay Bird Observatory

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