Date: Mon, 29 Sep 2003 20:59:42 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: "Peter A. Webb" Subject: Fwd: Mold & West Nile Virus kill feeder birds in Baltimore Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Fwd: Mold & West Nile Virus kill feeder birds in Baltimore - - - Sat, 27 Sep 2003 18:19 Carol Schreter cschreter@aol.com To: pwebb@bcpl.net (Pete Webb) Please post on MDOSPREY for me - - - Songbirds Die Of West Nile Virus at Baltimore Feeders (long) September 27, 2003 This message is from Carol Schreter of the Baltimore Bird Club. I live in Baltimore City, in Mt. Washington. I had six dead songbirds at my feeders between August 19 and August 30, 2003. Autopsy (necropsy) of one dead House Finch revealed a death caused by a combination of West Nile virus and a mild case of fungal pneumonia. I send this message to other Maryland birders to ask: 1) Are others seeing dead songbirds in numbers? 2) What can we as birders learn from this, or do about this? 3) Might anyone like to receive a copy of the necropsy report? What Birds Died: 1 Carolina Chickadee 5 House Finch Plus one adult male Goldfinch seen unable to fly off. (Neurological damage is a sign of West Nile virus.) Dr. Virginia Pierce of the Dept. of Agriculture's (DoA) Animal Health Lab in Frederick, Md. [(301) 663-9525] examined just one House Finch. She accepted this bird for examination because: 1) we know so little about the effect of West Nile virus (WNV) on songbirds (as opposed to crows); and 2) I offered to pay the $30 fee for West Nile virus testing, if appropriate. At the DoA lab in Frederick, Dr. Pierce determined that the carcass was a young House finch weakened with a touch of fungal pneumonia. This can travel in the air, by spores. The bird did not show full-blown evidence of West Nile virus ( i.e. enlarged brain or heart) visible by microscope alone. Primarily because this bird was one of six that died at my feeder, Dr. Pierce sent a tissue sample off for West Nile virus testing. The testing was done by the Texas Veterinary Medical Diagnostic Lab on September 10, 2003. Indeed, the bird tested positive for WNV, it just was not advanced enough a case to reveal itself by microscopic examination. Note that the Department of Agriculture has no budget for WNV testing anymore. They know that WNV is widespread. Don't think of taking birds for testing unless you are willing to pay the $30 fee yourself. Note that my feeders (1 filled with sunflower seed chips, 1 with thistle) are on a second story deck, with screen covering the deck surface. Anything that dies here is quite visible, unlike what may die in the wild amidst grasses and shrubs. What I have learned/decided so far. 1) In my small pond, starting in the spring, I will put a biological larvicide to kill mosquito larvae before they hatch. Put a powder form of Bacillus thuringiensis (Bt or Bti) into the water monthly. It is safe for birds. Available under various product names. Read the label to determine that the Bt product you buy is formulated for mosquitoes. It is available at Home Depot or Watson's Garden Shop in Towson. Or place mosquito-eating fish in the pond to control the growth of mosquito larvae. 2) When I find a dead song bird, I will place its carcass in the trash. West Nile can spread to hawks and other predators who eat smaller birds that have West Nile virus. 3) I'll stop feeding birds until after the first frost. Research shows that West Nile virus can travel from bird to bird in a laboratory setting. Thus, it can spread at feeders. Perhaps birds eating in the wild are less concentrated. 4) This unusually wet season may cause birdseed to grow moldy. Mold is poisonous to birds. So I'll be careful not to let wet seed pile up under a feeder, at any season. I'll dispose of old seed by putting it in the trash, not the woods. 5) Question: Might this usually wet season also increase the amount of airborne fungus (aspergilis) that causes fungal pneumonia -- which weakened and then killed the House Finch at my feeder, in combination with West Nile virus? I invite reactions from other birders. Feel free to write me via MDOSPREY or to phone me and talk further. Carol Schreter, Baltimore Bird Club Conservation Committee 1905 Dixon Rd., Baltimore, MD 21209 Phone: (410) 664-5151 Cschreter@aol.com post-word by Pete Webb: the Bti stands for Bacillus thuringiensis subspecies israelensis, rated at 7000 Aedes aegypti (AA) International Toxic Units (ITU) per milligram primary powder (dry weight). That is, it is so rated against Aedes aegypti, one of the more common mosquito species in our area known to transmit West Nile Virus from one bite victim to the next. The version I get from Home Depot comes in little donut shaped chunks; I put one in my back yard pond each month per directions, from May through October. Mosquito larvae continue to thrive in my back yard pond but fail to develop into adult mosquitos, being killed off by the bacteria at a certain stage molt before they can pupate into adults. Meanwhile, large numbers of Wood Frog tadpoles continue to develop to adulthood as frogs, unhindered by the introduced Bt bacteria. The toxicity of the bacteria is said to affect a number of aquatic insect species, not limited to mosquitos, but perhaps some other MDOsprey reader might better know what other insects are likely to be harmed. It doesn't seem to hurt the water striders in my pond. While Carol's goldfinch was still alive, I had one adult male fatality in my yard this spring, presumably victim of mold in the thistle seed. With the wet weather, I'll have to keep changing the seed in the feeder more often. I suspect that the mold is the greater threat this year with all the moisture about. Pete Webb Baltimore County, Maryland, USA pew ~at~ niroinc.com (work, M-F 830-5) pwebb ~at~ bcpl.net (home, after 6) Pete Webb pwebb@bcpl.net (home, after 6) pew@niroinc.com (work, 830-5 M-F) ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================