Integrative assessment of intraspecific diversification in Loggerhead Shrike (Lanius ludovicianus) provides insight on the geographic pattern of phenotypic divergence and process of speciation

Integrated studies of the geographical, ecological, and historical factors that shape intraspecific phenotypic and genetic variation can help us to decipher the processes leading to geographic patterns of population divergence and speciation. We quantify and compare morphological and genetic variation in the Loggerhead Shrike (Lanius ludovicianus Linnaeus, 1766), a broadly distributed passerine in North America with both migratory and non-migratory populations that occupy a diversity of habitats and topographies. The geographic distributions and patterns of differentiation among subspecies suggest that migration has strongly impacted population divergence, including the habit of migrating itself, but also dispersal. Patterns of mitochondrial and nuclear genetic differentiation can be attributed to female-biased dispersal and to increased dispersal rates and distances in migratory populations. Weak phenotypic differentiation among migratory versus migratory and non-migratory populations suggest that migration may more strongly affect morphology than adaptation to local habitats. Our results generally support previous subspecific designations with two notable exceptions. We found little genetic differentiation between two subspecies (Lanius ludovicianus gambeli Ridgway, 1887 and Lanius ludovicianus mexicanus C.L. Brehm, 1854), but identify a new, distinct subspecies, which we refer to as Lanius ludovicianus centralis ssp. nov.

Depredación de lagartijas por Lanius ludovicianus (alcaudón verdugo) en el Parque Nacional La Malinche

En esta nota documentamos eventos de depredación del alcaudón verdugo (Lanius ludovicianus) sobre dos especies de lagartijas en el Parque Nacional La Malinche.

DEPREDACIÓN DEL “CAMALEÓN” DE COLA PLANA (Phrynosoma mcallii) POR EL VERDUGO AMERICANO (Lanius ludovicianus)

En esta nota describimos el caso de un sitio ocupado como almacén de alimento, donde el verdugo americano (Lanius ludovicianus) empala o acuña a su presa el “camaleón” de cola plana (Phrynosoma mcallii) en la región del Alto Golfo de California, San Luis Río Colorado, Sonora, México.