The population genetics of non-migratory Allen's Hummingbird (Selasphorus sasin sedentarius) following a recent mainland colonization

Brian Myers, Kevin Burns, Christopher Clark & Alan Brelsford
Allen's Hummingbird comprises two subspecies, one migratory (Selasphorus sasin sasin) and one non-migratory (S. s. sedentarius). The non-migratory subspecies, previously endemic to the California Channel Islands, apparently colonized the California mainland on the Palos Verdes Peninsula some time before 1970, and now breeds throughout coastal southern California. We sequenced and compared populations of mainland non-migratory Allen's Hummingbird to Channel Island populations from Santa Catalina, San Clemente, and Santa Cruz Island. We found no evidence of...
17 views reported since publication in 2020.

These counts follow the COUNTER Code of Practice, meaning that Internet robots and repeats within a certain time frame are excluded.
What does this mean?