We conducted a biogeographic analysis based on a dense phylogenetic hypothesis for the early branches of corvids, to assess geographic origin of the New World jay (NWJ) clade. We produced a multilocus phylogeny from sequences of three nuclear introns and three mitochondrial genes and included at least one species from each NWJ genus and 29 species representing the rest of the five corvid subfamilies in the analysis. We used the S-DIVA, S-DEC, and BBM analyses implemented in RASP to create biogeographic reconstructions, and BEAST to estimate timing of NWJ diversification. Biogeographic reconstructions indicated that NWJs originated from an ancestor in the Eastern Palearctic or Eastern + Western Palearctic, diversified in Mesoamerica and spread subsequently to North and South America; the group has been diversifying in the New World since the late Miocene.Keywords: New World jays; Corvidae; biogeographic origin; divergence times
IntroductionThe New World jays (NWJs) are a monophyletic group of corvids [1,2], presently considered to comprise seven genera (Aphelocoma, Calocitta, Cyanocitta, Cyanocorax, Cyanolyca, Gymnorhinus and Psilorhinus); the~36 species [3,4] represent the product of a radiation across much of the Americas [1]. The group has long been a focus of research in behavioral ecology, in light of complex behavioral repertoires, particularly as regards social behavior [5][6][7].The origins of corvids can be traced to Australia, from where the ancestor of the family dispersed to Asia, followed by radiations in Asia, Europe and elsewhere [8]. Ericson and colleagues [9][10][11] provided evidence that the origin of the oscine passerines, to which the Corvidae belongs, dates to the split of the AustraloPapuan tectonic plate from Antarctica in the early Tertiary,~53M years ago. Thus, the replacement of the early Tertiary rainforests in Australia by drier vegetation may have placed presumably forest-adapted early corvids in more open habitats, resulting in a new radiation that led to the present global distribution of the family. However, a recent study [12] estimated the age of the family at~20M years. Colonization of the New World by corvids occurred more recently, apparently via a transBeringian route [8]. The ancestor of NWJs, thought to be jay-like lineages related to Cissa and Urocissa, reached North America 10−8M years ago, in the Miocene [13]. Once in the Americas, a rapid radiation in South America by the early Pliocene, was apparently followed by a secondary radiation in These previous studies, however, did not provide sufficient detail in terms of representation of taxa of NWJs and other corvids to permit thorough understanding the geographic origin of NWJs or to identify their closest corvid relatives. The key deficiency has been in terms of representation of taxa from the deepest branches of the corvid phylogeny; thus, we here derive a denser phylogenetic hypothesis by deriving DNA sequences for Neotropical Biodiversity, 2017 Vol. 3, No. 1, 80-92, https://doi.org/10.1080/23766808.2017 Published on...