Genetic Differentiation, Niche Divergence, and the Origin and Maintenance of the Disjunct Distribution in the Blossomcrown Anthocephala floriceps (Trochilidae)

Abstract

Studies of the origin and maintenance of disjunct distributions are of special interest in biogeography. Disjunct distributions can arise following extinction of intermediate populations of a formerly continuous range and later maintained by climatic specialization. We tested hypotheses about how the currently disjunct distribution of the Blossomcrown (Anthocephala floriceps), a hummingbird species endemic to Colombia, arose and how is it maintained. By combining molecular data and models of potential historical distributions we evaluated: (1) the timing of separation between the two populations of the species, (2) whether the disjunct distribution could have arisen as a result of fragmentation of a formerly widespread range due to climatic changes, and (3) if the disjunct distribution might be currently maintained by specialization of each population to different climatic conditions. We found that the two populations are reciprocally monophyletic for mitochondrial and nuclear loci, and that their divergence occurred ca. 1.4 million years before present (95% credibility interval 0.7–2.1 mybp). Distribution models based on environmental data show that climate has likely not been suitable for a fully continuous range over the past 130,000 years, but the potential distribution 6,000 ybp was considerably larger than at present. Tests of climatic divergence suggest that significant niche divergence between populations is a likely explanation for the maintenance of their disjunct ranges. However, based on climate the current range of A. floriceps could potentially be much larger than it currently is, suggesting other ecological or historical factors have influenced it. Our results showing that the distribution of A. floriceps has been discontinous for a long period of time and that populations exhibit different climatic niches have taxonomic and conservation implications.

Realized niche and microhabitat selection of the eastern green lizard (Lacerta viridis) at the core and periphery of its distribution range

“…Additional to differences in niche breadth, niche differentiation can also be found when comparing core and peripheral populations. Studies investigating niche differentiation in animal species are focused on evolutionary niche divergence among populations across the species' distribution range (Ahmadzadeh et al, 2013;Cadena & Loiselle, 2007), with the niche of relict populations being usually found to be differentiated from that of more central populations (Lozano-Jaramillo, Rico-Guevara, & Cadena, 2014). Many approaches exist for such studies, such as occupancy models with climatic, land cover, or other environmental variables as covariates (Araújo & Peterson, 2012;Chefaoui, Hortal, & Lobo, 2005;Hirzel & Le Lay, 2008), and models that use presence/pseudoabsence data (Morales, Fernández, Carrasco, & Orchard, 2015).…”

Niches and radiations: a case study on the Andean sapphire‐vented puffleg Eriocnemis luciani and coppery‐naped puffleg E. sapphiropygia (Aves, Trochilidae)

“…Third, field recordings in the bioacoustic database xeno-canto (<www.xeno-canto.org>) were assessed. The continuous bioclimatic and elevational variables have been widely used in ENMs for birds, particularly hummingbirds (Lozano-Jaramillo et al 2014, Sonne et al 2016, Ramoni-Perazzi et al 2017, Sornoza-Molina et al 2018, and likely reflect the meaningful environmental conditions to which they are exposed and by which their physiology is constrained. We assessed specific ornithological gazetteers (Stephens and Traylor 1983, Paynter 1993 and the above cited publications to Table 1.…”

“…We ran the ENMs using the set of six environmental variables (the first four components from the principal component analysis of the continuous variables in addition to soil type and geology). The continuous bioclimatic and elevational variables have been widely used in ENMs for birds, particularly hummingbirds (Lozano-Jaramillo et al 2014, Sonne et al 2016, Ramoni-Perazzi et al 2017, Sornoza-Molina et al 2018, and likely reflect the meaningful environmental conditions to which they are exposed and by which their physiology is constrained. Soil type and geology have been successfully used in ENMs for Andean flying vertebrates (Ramoni-Perazzi et al 2012, 2017, and possibly reflect deep ecological and historical constraints.…”

Modeling Avian Distributions and Niches: Insights into Invasions and Speciation in Birds

“…One avian case study analyzed a disjunct population of a hummingbird, the Blossomcrown Anthocephala floriceps in Colombia, where the population from the Sierra de Santa Marta is disjunct from the Andean population. Both live under different climatic conditions as cross-projections of population-specific SDMs show (Lozana-Jaramillo et al 2014). In addition, SDMs were applied for recently described taxa; a prominent example is different members of the Neotropical tapaculos (Rhinocryptidae) (Avendaño and Donagan 2015;Nemésio et al 2013).…”