RELICT HUMID TROPICAL FOREST IN MEXICO PROMOTES DIFFERENTIATION IN BARRED WOODCREEPERS Dendrocolaptes (AVES: FURNARIIDAE)

Abstract

Humid tropical forests in Mesoamerica are distributed along the Atlantic slope and, in scattered locations, along the Mexican Pacific slope. These poorly explored Mexican forests include microendemic bird species. Two species in the genus Dendrocolaptes occur in lowland and foothill humid tropical forests of Mesoamerica. One of these, D. sanctithomae, is comprised of four subspecies, of which the two that occur in Mexico, D. s. sanctithomae and D. s. sheffleri, are distinctly different morphologically, and the latter is a poorly known microendemic taxon of the Mexican Pacific humid tropical forest in the Sierra Madre del Sur. We used both nuclear (nDNA) and mitochondrial DNA (mtDNA) to evaluate the genetic variation of D. sanctithomae in Mexico, and complemented this with a quantitative analysis of phenotypic traits. We also conducted analyses of environmental niche models to test the hypothesis of niche differentiation of D. s. sheffleri from other taxa of D. sanctithomae. Our phylogenetic reconstructions of mtDNA consistently recovered D. s. sheffleri and D. s. sanctithomae as reciprocally monophyletic, while they shared alleles of nDNA. These mtDNA differences are comparable with differences reported between other Dendrocolaptes sister-taxa pairs. Our analysis of phenotypic traits also indicated that the taxa differ in measurements of hallux and feather barring. In contrast, niche differentiation tests suggest that the niches of both taxa are more similar than expected by chance. Our evidence leads us to propose species status for D. sheffleri. This is an additional example of recent speciation in Mexico that indicates active and peripatric evolutionary differentiation in the northern Neotropics.

An elevational shift facilitated the Mesoamerican diversification of Azure‐hooded Jays (Cyanolyca cucullata) during the Great American Biotic Interchange

“…Some arid, open‐habitat bird species, like the Inca Dove ( Columbina inca ) managed to spread all the way into the United States after the GABI (Sweet & Johnson, 2015 ). But other lowland forest specialists—such as the Great Curassow ( Crax rubra ; Hosner et al, 2016 ), the Northern Barred Woodcreeper ( Dendrocolaptes sheffleri ; Navarro‐Sigüenza et al, 2020 ), and the Gray‐chested Dove ( Leptotila cassinii ; Johnson & Weckstein, 2011 )—only reached the southern coastal lowlands of Mexico. Similarly, several humid forest tanager species moved north after the GABI, but many did not make it past Nicaragua, with only a few reaching as far north as southern Mexico (Burns & Racicot, 2009 ; Sedano & Burns, 2010 ).…”

“…Individual case studies are still adding to our knowledge of when and how the GABI took place (Barker, 2007;Cortés-Ortiz et al, 2003;Navarro-Sigüenza et al, 2020;Núñez-Zapata et al, 2016;Rull, 2011;Sedano & Burns, 2010).…”

“…Much work has focused on the time period between 3 and 4 million years ago (Mya; Coates et al, 1992 ; O'Dea et al, 2016 ), but other studies suggest prior connections throughout the last 20 My (Bacon et al, 2015 ; Montes et al, 2015 ; Weir et al, 2009 ). Individual case studies are still adding to our knowledge of when and how the GABI took place (Barker, 2007 ; Cortés‐Ortiz et al, 2003 ; Navarro‐Sigüenza et al, 2020 ; Núñez‐Zapata et al, 2016 ; Rull, 2011 ; Sedano & Burns, 2010 ).…”

Diversidad alfa y beta de la avifauna en bosques tropicales húmedos y semihúmedos de la sierra de Atoyac, una región prioritaria para la conservación del sur de México

“…22201/ib.20078706e.2020.91.3344 familias Trochilidae, Trogonidae y Thraupidae están presentes en su gran mayoría en ambos tipos de vegetación. De particular interés son las especies endémicas como Lophornis brachylophus cuya distribución abarca ambos bosques (Sierra-Morales et al, 2016), así como linajes bien diferenciados que constituirían nuevas especies, e.g., Dendrocolaptes sheffleri (Navarro-Sigüenza et al, 2020).…”

“…Por otra parte, en esta región existen gradientes climáticos que promueven la formación de microambientes, además de que la SMS presenta la precipitación anual más alta del país (Hernández-Cerda et al, 2016). Así, tanto los bosques mesófilos como los tropicales subcaducifolios que se distribuyen en las montañas de la SMS han originado que varias especies de aves de origen neotropical como algunos trepatroncos (Dendrocolaptes sheffleri; Navarro-Sigüenza et al, 2020), colibríes (Phaethornis mexicanus, Lampornis margaritae, Lamprolaima occidentalis; Arbeláez-Cortés y Navarro-Sigüenza, 2013; Cortés- Rodríguez et al, 2008; Zamudio-Beltrán y Hernández-Baños, 2018), tucanes (Aulacorhynchus wagleri; Puebla-Olivares et al, 2008) y rascadores (Arremon kuhenerii; Navarro-Sigüenza et al, 2013) desarrollen un alto grado de especialización a estos bosques tropicales y a las condiciones de humedad que allí prevalecen. Aunado a ello, la poca conectividad que muestran varias poblaciones de aves en estos bosques dentro de la SMS, ha promovido la evolución de numerosos taxones endémicos (e.g., Chlorospingus albifrons, Cyanocorax speciosa, Cyrtonyx sallei; Navarro-Sigüenza y Peterson, 2004;Ornelas et al, 2013;Peterson y Navarro-Sigüenza, 2000), que a su vez incrementan la biodiversidad en la región.…”