Abstract/Summary

Several species around the world are expanding their distribution principally by anthropogenic disturbance. In Ecuador, the Shining Cowbird Molothrus bonariensis has been recorded more frequently outside its known range; therefore, we analyzed its chronological records, finding evidence of an altitude expansion of 580 m in the last 44 years. Additionally, we performed maximum entropy models that showed that areas of habitat suitability for M. bonariensis would increase under conditions of climate change. Finally, as M. bonariensis is an obligate and generalist parasite of nests; we present unpublished information, which together with published data, constitute a total of 21 parasitized species in Ecuador. Due to the implications for the conservation of vulnerable species, it is important to continue documenting the extension of the range of M. bonariensis and its parasitized species.