DIET OF THE ENDEMIC MADEIRA LAUREL PIGEON AND FRUIT RESOURCE AVAILABILITY: A STUDY USING MICROHISTOLOGICAL ANALYSES

Abstract

Abstract We studied the temporal diet variation of the endemic Madeira Laurel Pigeon (Columba trocaz) and fruit resource availability in the laurel forests of northwestern Madeira Island, during 1996 and 1997. We studied a total of 224 fecal samples using microhistological methods and conducted surveys of fruiting phenology throughout a year. Fruits (pulp and seeds) represented 57% of the optical fields analyzed. Leaves and flowers constituted 38% and <1% respectively. Over 33 plant species were identified in the fecal samples. Fruits of Ocotea foetens, Laurus azorica, Persea indica, and Ilex canariensis (fruits and leaves) were the most frequently detected food items. Most seeds were defecated intact (Ilex canariensis, Myrica faya, Visnea mocanera, Ocotea foetens, and Apollonias barbujana), except in the case of Laurus azorica where most were damaged. The diet showed a marked seasonal variation. Fruits constituted the major component of the diet in winter and autumn, whereas leaves were frequent in sprin...