1. Trophic strategies of two sympatric endemic pigeons in insular ecosystems: a framework for understanding spatiotemporal frugivory interactions
- Author
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Manuel Nogales, Patricia Marrero, Organismo Autónomo Parques Nacionales (España), Ministerio de Medio Ambiente y Medio Rural y Marino (España), Consejo Superior de Investigaciones Científicas (España), and Cabildo de Tenerife
- Subjects
Columba bollii ,biology ,Ecological role ,Ecology ,food and beverages ,Canary Islands ,biology.organism_classification ,Diet ,Columba junoniae ,Frugivore ,Sympatric speciation ,Animal Science and Zoology ,Ecosystem ,Seed predation and dispersal ,Ecology, Evolution, Behavior and Systematics ,Trophic level - Abstract
Pigeons are considered to play key ecological roles in frugivory and seed dispersal. They have colonised numerous oceanic islands and diversified into several species in sympatry. How these species coexist in similar niches is poorly understood although dietary separation is among the mechanisms suggested to avoid trophic overlap. We investigated the trophic ecology of the two endemic Columba species co-occurring in the laurel forest and thermosclerophyllous relicts of two of the Canary Islands. This study includes diet description in spatiotemporal terms, its relationship with fruit availability and seed treatment in 10 study areas established on La Palma and La Gomera. We used non-invasive DNA analysis to identify the faeces of the two con-generic species and microhistological methods to examine their diets. The degree of trophic overlap was evaluated by niche similarity and breadth indices. Molecular faecal sampling determined the spatiotemporal distribution of both pigeons to identify their areas of coexistence. These frugivorous pigeons’ diets did not differ concerning the main plant species, but they diverged quantitatively in the proportions and parts of plants consumed. Lauraceae fruits were their staple foods although Rhamnaceae and some Fabaceae and Solanaceae were also important. Both pigeons showed selective preferences for some fruits. Significant spatiotemporal variations in their diets were observed along with a general tendency to increase fruit intake at its ripening times. Our results suggest that different trophic strategies facilitate the coexistence of these frugivorous columbids. These pigeons act as seed dispersers and/or predators depend ing on seed features (size and hardness), and this may have valuable implications for their conservation., This study was partially funded by the Organismo Autónomo de Parques Nacionales (80/2005), Ministerio de Medio Ambiente y Medio Rural y Marino of Spain. PM received grant support from Proyectos Intramurales Especiales (2004 3 0E 169) of the Spanish National Scientific Research Council. The manuscript was edited by Guido Jones, currently funded by the Cabildo de Tenerife, under the TFinnova programme supported by MEDI and FDCAN funds.
- Published
- 2021