Wednesday, August 4, 2010

A Cowbird, Starling, Goose, and Mallard walk into a rave…

and promptly left because the lasers were annoying. Well, not really according to a 2002 article. Bird damages to aircraft have left to abundant studies to determine effective means for deterring birds from airstrips and heavily utilized flyzones. Various methods have been attempted (auditory, visual, chemical, etc.), but a study actually looked to determined the effectiveness of lasers as a bird deterrent.

Using a 10-mW, continuous-wave, 633-nm laser, Blackwell et. al (2002) tested aversion of commonly plane-crashing birds to perches where the lasers were pointed or targeted at the birds directly. Neither European Starlings nor Brown-headed Cowbirds were deterred by laser treatment. Rock Pigeons (some of the least intelligent of all birds) only avoided laser targeting for the first five minutes of an 8-minute trial before the finally wised up. As for the waterfowl, Canada Geese were effectively dispersed from patches treated by the lasers during the 20-minute period, unlike the brave and magnificent Mallard who grew accustomed to the lasers after 20 minutes.

The obvious conclusion from this article is that birds are more amazing than lasers, and we should be prepared to become much more inventive when trying to fly our laughable steel imitations in their space. This article reminded me of one of my favorite XKCD comics.

Mercury & Migration

This is an old post that I could get to work because my blogger account was acting funny.

I just started working in the lab at William & Mary last Friday, and I've been trying to read lots of papers to come up with research ideas. I just read a great literature review that's still in-press and it's given me a few interesting ideas. Mercury is a toxin which readily influences bird physiology causing neurological and reproductive impairment in addition to many other detrimental effects. I'm interested in how mercury affects birds at the population level. For migratory passerines, migration can be a great source of mortality, and Saracco and Desante (2008) named 1st year survival to be the major contributing factor for maintaining bird population levels. Undoubtedly, this is most readily influenced by habitat destruction and fragmentation, but ecotoxins could have an effect.

Mercury's physiological effects could impair the ability to successfully migrate. Mercury reduces haem production, an essential cofactor for the production of hemoglobin. Mercury also increases asymmetry, which may impair flight


Saracco, J. F., and D. F. DeSante. 2008. Identifying proximate causes of population trends in migratory birds: An analysis of special variation at the scale of Bird Conservation Regions in vital rates and population trends from the Monitoring Avian Productivity and Survivorship (MAPS) program. A report by the Institute for Bird Populations funded under NFWF Project No. 2005-0260-000.