Diet of the endemic Madeira Laurel Pigeon Columba trocaz in agricultural and forest areas: implications for conservation

Abstract

The diet of the endemic Madeira Laurel Pigeon Columba trocaz in agricultural and forest areas of Madeira Island was studied in 1997 by means of microhistological analysis of 157 faecal samples, 94 from two of the main agricultural zones and 63 from a laurel forest. Cabbage was the most important component of the diet in agricultural areas, representing more than 54% of the optical fields analysed. Samples collected further from the forest contained a higher proportion of cabbage. Native fruits did not figure highly in the samples collected from agricultural areas and crop plants did not appear in the forest samples, suggesting a degree of dietary separation and that some individuals may concentrate on crops. Madeira Laurel Pigeon is normally a highly frugivorous species and fruit availability is relatively high in winter when the birds go to agricultural areas to feed. This suggests that it is not a shortage of natural foods that causes them to leave the forest. The unpopularity of the pigeon as a result of its pest status is the main threat to its existence. More information on the seasonal physiological requirements of Madeira Laurel Pigeon and the pattern of individual use of crops is needed to ensure the future conservation of this species.