Molecular and iridescent feather reflectance data reveal recent genetic diversification and phenotypic differentiation in a cloud forest hummingbird

Abstract

The present day distribution and spatial genetic diversity of Mesoamerican biota reflects a long history of responses to habitat change. The hummingbird Lampornis amethystinus is distributed in northern Mesoamerica, with geographically disjunct populations. Based on sampling across the species range using mitochondrial DNA (mtDNA) sequences and nuclear microsatellites jointly analysed with phenotypic and climatic data, we (1) test whether the fragmented distribution is correlated with main evolutionary lineages, (2) assess body size and plumage color differentiation of populations in geographic isolation, and (3) evaluate a set of divergence scenarios and demographic patterns of the hummingbird populations. Analysis of genetic variation revealed four main groups: blue‐throated populations (Sierra Madre del Sur); two groups of amethyst‐throated populations (Trans‐Mexican Volcanic Belt and Sierra Madre Oriental); and populations east of the Isthmus of Tehuantepec (IT) with males showing an amethyst throat. The most basal split is estimated to have originated in the Pleistocene, 2.39–0.57 million years ago (MYA), and corresponded to groups of populations separated by the IT. However, the estimated recent divergence time between blue‐ and amethyst‐throated populations does not correspond to the 2‐MY needed to be in isolation for substantial plumage divergence, likely because structurally iridescent colors are more malleable than others. Results of species distribution modeling and Approximate Bayesian Computation analysis fit a model of lineage divergence west of the Isthmus after the Last Glacial Maximum (LGM), and that the species’ suitable habitat was disjunct during past and current conditions. These results challenge the generality of the contraction/expansion glacial model to cloud forest‐interior species and urges management of cloud forest, a highly vulnerable ecosystem to climate change and currently facing destruction, to prevent further loss of genetic diversity or extinction.

Genetic and morphometric divergence in the Garnet-Throated HummingbirdLamprolaima rhami(Aves: Trochilidae)

“…This pattern of high genetic differentiation is congruent with other studies of Mesoamerican vertebrate species ( Barber, 1999 ; Zarza, Reynoso & Emerson, 2008 ; Bonaccorso, 2009 ; Bryson et al, 2011 ; Smith et al, 2011 ; Arbeláez-Cortés, Roldán-Piña & Navarro-Sigüenza, 2014 ; Castañeda Rico et al, 2014 ). In Trochilidae, high levels of geographic structure have been previously reported, related to differences in current or historical ecological conditions ( Adelomyia melanogenys : Chaves et al, 2007 ; Lampornis amethystinus : Cortés-Rodríguez et al, 2008 ; Ornelas et al, 2016 ). Also, moderate levels of differentiation have been found in hummingbird species co-distributed in Mesoamerican cloud forests ( Campylopterus curvipennis : González, Ornelas & Gutiérrez-Rodríguez, 2011 ; Amazilia cyanocephala : Rodríguez-Gómez, Gutiérrez-Rodríguez & Ornelas, 2013 ).…”

“…Despite the well-known movement abilities of Trochilidae species, some studies have found that geographical barriers are crucial in promoting high levels of differentiation and the diversification of independent evolutionary lineages in various regions, such as the Andes region (e.g., Adelomyia melanogenys , Chaves & Smith, 2011 ), Mesoamerica ( Ornelas et al, 2016 ), the Motagua fault region ( Rodríguez-Gómez & Ornelas, 2014 ), and the Isthmus of Tehuantepec ( Cortés-Rodríguez et al, 2008 ; González, Ornelas & Gutiérrez-Rodríguez, 2011 ). In contrast, in lowland Neotropical birds, high levels of intraspecific diversification are better explained by the hypothesis of limited dispersal ability ( Burney & Brumfield, 2009 ).…”

Phylogeography indicates incomplete genetic divergence among phenotypically differentiated montane forest populations of Atlapetes albinucha (Aves, Passerellidae)

“…This population decrease, followed by rapid population growth and range expansion is coincident with the Last Glacial Maximum during the Late Pleistocene (~21,000 ya), when colder conditions may have allowed the formation of corridors between previously isolated humid montane forest patches (Figure 4a), likely enhanced by the downward altitudinal range changes of the forest belt (Hooghiemstra et al 2006, Gutiérrez-Rodríguez et al 2011, Rojas-Soto et al 2012, Ornelas et al 2010, 2013, Ramírez-Barahona and Eguiarte 2013). Such a scenario, probably promoted gene flow between previously isolated populations (e. g., Hewitt 2000, Zink and Blackwell-Rago 2000, Weir 2006, Hooghiemstra et al 2006, Barber and Klicka 2010, Pérez-Emán et al 2010, Wachowiak et al 2013, Bagley and Johnson 2014, Ornelas et al 2016). In addition, an interesting result emerging from our ENM is that regions inhabited by yellow-plumaged and grey-plumaged populations in Chiapas-Guatemala have apparently never been isolated, which seems to support conclusions by Paynter (1972, 1978) regarding the weakness of a low river valley as an effective barrier in separating these populations.…”

Genetic and Ecological Divergence of Cinnamon Hummingbird Amazilia rutila (Aves: Trochilidae) Continental Populations Separated by Geographical and Environmental Barriers

“…The first pattern has been found in hummingbirds (Trochilidae), with strong geographic structuring ( i ) in species with populations separated by biogeographic barriers such as the Isthmus of Tehuantepec, the Trans-Mexican Volcanic Belt, and/or the Motagua-Polochic-Jocotán fault system (Hernández-Soto et al, 2018; Jiménez & Ornelas, 2016; Malpica & Ornelas, 2014; Rodríguez-Gómez et al, 2013, 2021, Zamudio-Beltrán et al, 2020, 2020b); ( ii ) species with disjunct distribution of populations (Arbeláez-Cortés & Navarro-Sigüenza, 2013; González et al, 2011; Licona-Vera & Ornelas, 2014); ( iii ) or in species inhabiting naturally fragmented habitats such as cloud forests (Cortés-Rodríguez et al, 2008a; Ornelas et al, 2016; Zamudio-Beltrán & Hernández-Baños, 2018). In contrast, the second pattern of weak geographic structuring and high levels of gene flow has been found in hummingbird species inhabiting lowland humid forest edges and coastal habitats, oases in tropical deciduous forests and arid montane scrub (González-Rubio et al, 2016; Licona-Vera et al, 2018a; Miller et al, 2011; Rodríguez-Gómez & Ornelas, 2015, 2018).…”