title: Parallel adaptations to nectarivory in parrots, key innovations and the diversification of the Loriinae.
abstract: Specialization to nectarivory is associated with radiations within different bird groups, including parrots. One of them, the Australasian lories, were shown to be unexpectedly species rich. Their shift to nectarivory may have created an ecological opportunity promoting species proliferation. Several morphological specializations of the feeding tract to nectarivory have been described for parrots. However, they have never been assessed in a quantitative framework considering phylogenetic nonindependence. Using a phylogenetic comparative approach with broad taxon sampling and 15 continuous characters of the digestive tract, we demonstrate that nectarivorous parrots differ in several traits from the remaining parrots. These trait-changes indicate phenotype-environment correlations and parallel evolution, and may reflect adaptations to feed effectively on nectar. Moreover, the diet shift was associated with significant trait shifts at the base of the radiation of the lories, as shown by an alternative statistical approach. Their diet shift might be considered as an evolutionary key innovation which promoted significant non-adaptive lineage diversification through allopatric partitioning of the same new niche. The lack of increased rates of cladogenesis in other nectarivorous parrots indicates that evolutionary innovations need not be associated one-to-one with diversification events.
authors.affiliation: Naturhistorisches Museum der Burgergemeinde Bern Bernastrasse 15, CH 3005, Bern, Switzerland.
authors.forename: Manuel
authors.initials: M
authors.lastname: Schweizer
authors.affiliation: Naturhistorisches Museum der Burgergemeinde Bern Bernastrasse 15, CH 3005, Bern, Switzerland.
authors.forename: Marcel
authors.initials: M
authors.lastname: Güntert
authors.affiliation: Aquatic Ecology and Macroevolution, Institute of Ecology & Evolution, University of Bern Baltzerstrasse 6, CH 3012, Bern, Switzerland ; Fish Ecology and Evolution, EAWAG Seestrasse 79, CH 6047, Kastanienbaum, Switzerland.
authors.forename: Ole
authors.initials: O
authors.lastname: Seehausen
authors.affiliation: Department of Quantitative Economics, University of Fribourg Boulevard de Pérolles 90, CH 1700, Fribourg, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Leuenberger
authors.affiliation: Naturhistorisches Museum der Burgergemeinde Bern Bernastrasse 15, CH 3005, Bern, Switzerland.
authors.forename: Stefan T
authors.initials: ST
authors.lastname: Hertwig
keywords: Comparative methods; diet shift; digestive tract; evolutionary trait shifts; morphological adaptations