Since the end of 2010, the following mass deaths of birds and fish have been recorded (some dates may be off by a day or so due to when they were reported):

12/30:  Paranagua, Parana, Brazil:  15 tons of sardines, croakers, and catfish

12/31:  Beebe, Arkansas:  More than 5000 blackbirds and approximately 100,000 drumfish

1/3:  Pointe Coupee Parish, Louisiana:  Approximately 500 red-winged blackbirds

1/4:  Coromandel beaches, New Zealand:  100’s of snappers

1/4:  Falkoping, Sweden:  Approximately 100 jackdaws.

1/5:  Faenza, Italy:  Possibly thousands of dead turtle doves, many with a blue stain on their beaks.

Tests are being made to determine the causes of these unfortunate deaths.  To date, it does not appear that they were due to illness.

Check out this Earthfiles.com link for more detailed information, speculation, and photographs:

http://www.earthfiles.com/news.php?ID=1803&category=Environment