Invasive plants reduce number of bird songs
Invasive plants could make forests a bit more dull. According to a study in Ecology, birds that live in areas infested with weeds sing a smaller repertoire of songs.
The authors studied six sites in Lolo National Forest, Montana. Three were overrun by invasive spotted knapweed, and three were relatively unaffected by the infestation. In 2005 and 2006, the team surveyed chipping sparrows at each site and recorded their songs.
The infested sites had fewer native forbs and grasses and a lower proportion of older birds, the researchers report. Young birds typically mimicked their elders’ songs. The team detected an average of 9.2 songs per year at the sites with native plants, but only 7.6 songs at the invaded sites.
The results suggest that plant invasions “may erode song diversity,” the authors write. The yearlings have fewer old birds to learn from in these habitats, “resulting in increased similarity among songs and fewer song types overall.” — Roberta Kwok | 30 August 2013
Source: Ortega, Y.K., A. Benson, and E. Greene. 2013. Invasive plant erodes local song diversity in a migratory passerine. Ecology doi: 10.1890/12-1733.1.
Image © rck_953 | Shutterstock
Mountain lions survive near cities, but at what cost?January 30th, 2015
What affects the fate of wind farms?January 29th, 2015
Shifting California forests reveal complex effects of droughtJanuary 28th, 2015
Citizen scientists find good news for Puget Sound seabirdsJanuary 23rd, 2015
Did the Soviet Union collapse harm wildlife?January 22nd, 2015