A Discussion of Theories Relating to Population Dynamics of Passenger Pigeon Populations: Abundance and Extinction

Samantha Cassista


The passenger pigeon was an extremely abundant species in the 16th-19th century that suffered a rapid extinction by the turn of the 20th century. Historical accounts place the population of the species at 3 to 5 billion by the 18th century, and extinct by the early 20th century. The accepted reasons for this extinction include a drastic increase in the logging of deciduous forests, an improvements in firearms, and an increase in professional hunters aided by the mobility afforded them with the introduction of the railroad. This paper addresses the debate within the academic community as to whether the passenger pigeon is an example of an outbreak species or if it was consistently abundant for at least the last thousand years. An outbreak species can be defined as a species that became abundant over a brief period of time. These species are characterized by wildly erratic population sizes before and after the “outbreak” accompanied by massive disturbance of surrounding ecosystems. I used archaeological, ethnographic, and ecological evidence to debate both arguments. The results were not conclusive, but point towards passenger pigeons as an outbreak species that arose with the expansion of deciduous forests and the reduction of predators and competitors for food.  

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