![]() ![]() We found support for the effects of habitat type on breeding densities of prairie warbler (Dendroica discolor) and yellow breasted chat (Icteria virens) the effects of habitat type and year on densities of blue-winged warbler (Vermivora pinus), eastern towhee (Pipilo erythrophthalmus), and field sparrow (Spizella pusilla) the effect of year on densities of indigo bunting (Passerina cyanea) and northern cardinal (Cardinalis cardinalis) and no effects on densities of white-eyed vireo (Vireo griseus). In evaluating breeding densities in these habitat types, we compared support for a global model with year, habitat type, and a habitat type x year interaction to several reduced models and a null model with only an intercept, and we used model-averaged coefficients to evaluate effect size. We monitored 8 bird species using spot mapping and total mapping techniques, searched for and monitored nests, and measured vegetation structure within nested circular plots. We studied shrubland bird communities in 3- to 5-year-old regenerating forest (n=3), glade (n=3), and forest-pasture edge (n=3) habitat types in the predominantly forested Missouri Ozarks in 1997-1999. We used an information-theoretic approach to evaluate hypotheses concerning factors affecting breeding bird densities in different early-successional habitat types. I personally removed my feeders and water sources in December as a proactive move to prevent an outbreak in my neighborhood, but we have received reports of up to 30 or more birds perishing in a single yard over a 24-hour period in the Fisherman Flat area (Monterey) before the feeders were removed.Population numbers of many bird species associated with early-successional or disturbance-dependent habitat types are declining. “It was not long after their arrival that we began to receive inquiries from people who were discovering lethargic or puffed-up birds around their feeding station. “In Monterey County, we noted a large influx of Pine Siskins early in the fall with flocks exceeding 250 birds,” said Paul Fenwick, vice president of the Monterey Audubon Society. But they are most easily identified by the pronounced streaking, usually more visible than the streaking of other types of finches. Siskins are small and heavily streaked on their breasts and have yellow-accents that typically appear on the ends of their wings and also on their tail feathers. While salmonellosis is particularly lethal for siskins, it can also infect other species of songbirds that hang out at feeders, such as lesser goldfinches. Pine Siskins can be messy eaters, spraying seed on the ground where it becomes mixed with feces and becomes an additional source of infection. In this way, the feeder becomes a vector for the disease, spreading it to other birds. Infected birds shed the bacteria in their feces, and if they are frequenting a bird feeder, the surface of the feeder or the food itself is likely to become contaminated with their feces. Once a bird is infected it stands little chance of survival. It comes down to the birds congregating near each other, which is the catalyst for the spread of the bacteria. ![]() Īs much as backyard birders love the feeders, Brookhouser and other experts say the only way to curb the die-off is to temporarily remove the feeders. Some infected birds may show no outward signs, but are carriers of the disease and can spread the infection to other birds.Ī video produced by My Backyard Birding shows how the illness affects siskins. They are often lethargic and easy to approach, which is not normal. Sick birds may appear thin, fluffed up, and depressed and may have swollen eyelids. It is a common cause of mortality in feeder birds, but the symptoms are not always obvious. MONTEREY - Birders across the Central Coast and all the way up into Oregon and Washington are lamenting the loss of thousands of Pine Siskins, a small songbird belonging to the finch family that are dying in large numbers in the Monterey Bay Area from a bacteria that is spread through bird feeders.Īnd the backyard birders are not going to like the cure: They are being advised to pull down their feeders and stow them away until the end of this month and likely until the end of April until the siskins disperse.īeth Brookhouser, the vice president of marketing and communications for the SPCA Monterey County, said the birds are dying from salmonellosis, an infection caused by the bacteria belonging to the genus Salmonella.
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