Tern nesting habitat restoration

Background

As nesting seabirds become more concentrated on a few managed colonies, nutrient inputs from their guano encourage the growth of vegetation in nesting areas. Common terns, which require a matrix of open ground and standing vegetation cover at nest sites, are rapidly losing habitat due to overgrowth of vegetation. Managers often address this problem on a case-by-case basis, with little or no formal research.

I compared the effectiveness of controlled burning and weed barriers for creating Common tern nesting habitat, assessing both vegetation characteristics and tern nesting success in treated areas, vegetated control plots, and unmodified nesting habitat.

Although burning created usable habitat at nest initiation, it quickly became unsuitable as annual plants invaded the open soil. By the time tern eggs hatched, the vegetation was too dense to allow adults to access their nests, leading to near-complete nest failure. However, weed barriers-- particularly second-hand artificial turf (AstroTurf) from miniature golf courses-- created nesting habitat with similar vegetation characteristics and tern productivity to existing habitat. Artificial turf represents an inexpensive, promising short-term solution to overgrowth and overcrowding in tern nesting areas.