Today marks the 100 year anniversary of the death of the last Passenger Pigeon, and thus the extinction of the species. Once the most numerous bird in America, Passenger Pigeons traveled in flocks that numbered in the millions, often darkening the sky as they blotted out the sun. Humans are 100% responsible for their demise. Hunting and habitat loss decimated their numbers from 3.7 billion birds to 0 in only 40 years. In 1914 the last Passenger Pigeon, a specimen named Martha, died in captivity (having never lived in the wild). Today is a good day, then, to reflect on how powerfully we impact the environment, and how important it is to protect and maintain all living things.