After 13 years' residence in the Wet Mountains of Colorado, I have my own personal weather lore that says it usually snows only one more time after the first broadtailed hummingbird arrives.
The first male hummer arrived on Wednesday the 13th. Dare we hope? It has been a long, snowy winter.
Meanwhile, Roman rabbits
I usually think of "invasive species" as a New World problem, but here is archaeological evidence of the introduction of rabbits to Britain by the Romans, a significant change to that island's ecosystems>. (Via the archaeology blog Cronaca.