Habitat modification as a means of restoring crested auklet colonies

Published source details Major H.L., Buxton R.T., Schacter C.R., Conners M.G. & Jones I.L. (2017) Habitat modification as a means of restoring crested auklet colonies. Journal of Wildlife Management, 81, 112-121.
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Summary

Remove vegetation to create nesting areas

A replicated, paired, controlled, before-and-after study in 2009–2013 in the Aelutian Islands, Alaska, USA (Major et al. 2017) found that clearing vegetation and peat from rocky habitat did not significantly affect the abundance of crested auklets Aethia cristatella and reduced the proportion of crested auklet nests. Clearance had no significant effect on the abundance of crested auklets: any changes over four years were statistically similar in both cleared and uncleared plots (reported as statistical model results). This was true for both abundance of all crested auklets and for breeders only. Between years, individual birds were 1.7 times more likely to switch from preferring uncleared plots to preferring cleared plots, than to switch in the other direction. However, clearance reduced crested auklet nest density (as a percentage of total auklet nest density): it declined in cleared plots (before: 72–77%; after: 51–71%) but increased in uncleared plots (before: 68–79%; after: 58–81%). Thirty-four pairs of 100-m² plots were established within an auklet colony on Gareloi Island. Vegetation and peat were completely removed from one plot/pair in August 2009 or 2010 – always after auklets had departed the colony for the year. Plots were surveyed in 2009–2013, before and after intervention. Surveys recorded (a) crested auklets visible on the surface during daylight (coloured bands allowed individual identification) and (b) active nests (containing an incubating adult or egg) of both crested and least auklets (Aethia pusilla).