Vegetation sampling
In 2002, we measured vegetation height for all plants encountered every 0.5m along 5-m
transects extending from the front of both active nesting cavities and cavities used in
previous years. In one comparison, active (n510) and old (n513) cavities were located in
different sections of the same colony (X). In another comparison, active cavities (n53)
were located in a newly established colony (L) while old cavities (n513) were located in a
nearby colony (M) abandoned after the 2001 breeding season. We used Mann–Whitney U
tests to investigate vegetation differences in front of abandoned and active nest cavities in
these two comparisons.
In another analysis, we used a photograph of one colony (Y) and selected 20 random
nesting cavities and 20 random points. We then measured the distance from each cavity or