Can birding really harm birds?

There is not a lot research on the impacts of birding on birds; and what there is tends to be done at very important areas. There are also studies that show negative impacts of "visitors" (including general wildlife watchers as well as birders) such as noted in the following abstracts:

• "Humans visiting natural areas often disturb wildlife, possibly displacing animals from desirable habitat. To hold ecotourism at acceptable levels refuge managers need to know which species are likely to be affected and which response occurs at different levels of disturbance. Displacement of waterbirds at J. N. "Ding" Darling National Wildlife Refuge, Florida (U.S.A.), by specific human activities was demonstrated experimentally by Klein in 1993. We assessed the extent of this effect of ecotourism on the distribution of 38 species of waterbirds by surveying birds in plots of known distance from a dike along which wildlife tours occurred. Most resident species were less sensitive to disturbance than were migrants. Migrant ducks were most sensitive when they first arrived, mid-October to mid-December, usually remaining more than 80 m from the drive, even at low levels of human visitation. Herons, egrets. Brown Pelicans (Pelecanus occidentalis), and Anhingas (Anhinga anhinga) were most likely to remain close to areas of high human activity. Shorebirds were displaced at intermediate distance and visitation levels. Mottled Ducks (Anas fulvigula) and several of the ardeids seemed to include two groups differing in behavior, one habituated to humans and one sensitive to disturbance. Public education and changes in management practices are needed to reduce disturbance. Guided tours and low-disturbance zones where people stay in their cars could reduce the negative effects of tourists, especially in the fall when migrants arrive. The number of human visitors may have to be reduced or the wildlife drive closed on certain days during the tourist season." Conservation Biology Volume 9 Issue 6 Page 1454 - December 1995 doi:10.1046/j.1523-1739.1995.09061454.x Effects of Ecotourism on Distribution of Waterbirds in a Wildlife RefugeMary L. Klein, Stephen R. Humphrey, and H. Franklin Percival

• "Traditionally, observing, feeding, and photographing wildlife were considered to be 'nonconsumptive' activities because removal of animals from their natural habitats did not occur.... nonconsumptive wildlife recreation was considered relatively benign in terms of its effects on wildlife; today, however, there is a growing recognition that wildlife-viewing recreation can have serious negative impacts on wildlife" (p257) Knight, Richard L. and Kevin J. Gutzwiller, eds. Wildlife and Recreationists. Covelo, California: Island Press, c.1995.

• "Abstract. This study investigated the influence of recreational trails on breeding bird communities in forest and mixed-grass prairie ecosystems in Boulder County, Colorado during 1994 and 1995. . .Results indicated that composition and abundance of birds were altered adjacent to trails in both grasslands and forest ecosystems. In particular, some species like interior forest species did not occur, or occurred in lower densities, near trails than they occurred at a greater distance from trials; whereas some species, mainly generalists like edge species, were more abundant near trails." INFLUENCE OF RECREATIONAL TRAILS ON BREEDING BIRD COMMUNITIES By Scott G. Miller, Richard L. Knight, and Clinton K. Miller,

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