López-Segoviano Gabriel, Nuñez-Rosas Laura E, Arenas-Navarro Maribel, Huerta-Ramos Guillermo, Arizmendi María Del Coro
Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado México, México.
Escuela Nacional de Estudios Superiores (ENES) Unidad Morelia, Universidad Nacional Autónoma de México, Morelia, Michoacán, México.
PLoS One. 2025 Jun 11;20(6):e0324881. doi: 10.1371/journal.pone.0324881. eCollection 2025.
Floral resources in the mountains of northwestern Mexico are strongly seasonal. This influences latitudinal, local, and altitudinal migration patterns in hummingbird species, resulting in temporal changes in hummingbird community structure over the flowering period. In this study, we evaluated how the seasonality of floral resources and latitudinal migration of hummingbirds influenced taxonomic, phylogenetic, and functional diversity along an altitudinal gradient. We examined the functional and morphological space occupied by resident and migrant hummingbird species, as well as the species' functional niches and the phylogenetic structure of species assemblages in three sites of northwestern Mexico. We recorded hummingbird and flower abundance using two transects with 15 point counts on each altitudinal gradient in the Sierra Madre Occidental. The transects spanned from tropical deciduous forest to pine-oak forest and the ecotone between them. We recorded 20 hummingbird species and 70 flowering plant species belonging to 30 families. We found that taxonomic, phylogenetic, and functional diversity were linked to the flower abundance. Seasonal latitudinal hummingbird migration was less important for functional diversity (since migratory species performed redundant functional roles) than taxonomic and phylogenetic diversity. Seasonal flowering along the altitudinal gradient drives various types of hummingbird movements (local, altitudinal, and latitudinal), which increases the number of hummingbird species fulfilling each functional role. Apparent phylogenetic clustering in the ecotone may be due to a convergence between temperate and tropical forest flora and the midpoint of hummingbirds' altitudinal migrations. Our study highlights the temporal dynamism and strong influence of floral seasonality on the structure of hummingbird communities in the mountains of northwestern Mexico.
墨西哥西北部山区的花卉资源具有强烈的季节性。这影响了蜂鸟物种的纬度、局部和海拔迁徙模式，导致花期内蜂鸟群落结构随时间发生变化。在本研究中，我们评估了花卉资源的季节性和蜂鸟的纬度迁徙如何沿海拔梯度影响分类、系统发育和功能多样性。我们研究了墨西哥西北部三个地点的留鸟和候鸟蜂鸟物种所占据的功能和形态空间，以及物种的功能生态位和物种组合的系统发育结构。我们在西马德雷山脉的每个海拔梯度上使用两条样带，每条样带进行15个点计数，记录了蜂鸟和花朵的数量。样带从热带落叶林延伸至松栎林以及它们之间的交错带。我们记录了20种蜂鸟和70种开花植物，这些植物隶属于30个科。我们发现分类、系统发育和功能多样性与花朵数量相关。季节性的蜂鸟纬度迁徙对功能多样性（因为迁徙物种发挥着冗余的功能作用）的重要性低于分类和系统发育多样性。沿海拔梯度的季节性开花驱动了各种类型的蜂鸟移动（局部、海拔和纬度），这增加了履行每种功能角色的蜂鸟物种数量。交错带中明显的系统发育聚类可能是由于温带和热带森林植物群之间的趋同以及蜂鸟海拔迁徙的中点所致。我们的研究突出了时间动态性以及花卉季节性对墨西哥西北部山区蜂鸟群落结构的强烈影响。
