But climate change might affect this outcome for chipmunks. Historically, after the chipmunk and squirrel populations crash because of a mast year, these populations rebuild slowly over several years to the carrying capacity of the land. This year, I can sometimes walk the entire park without seeing even one. Most falls, I see an enormous number of frenzied squirrels burying acorns among the autumn leaves. Fewer acorns meant that many of these chipmunks and squirrels did not survive the winter. Unfortunately for these critters, however, during the autumn after a mast year oak trees produce fewer acorns than normal. I remember neighbors saying they saw chipmunks in parts of Somerville where they had never seen chipmunks before. These critters found abundant food and raised large families. Plenteous numbers of acorns was good news for the chipmunks and squirrels during the winter and spring of 2019-2020. It is not known when or why this occurs, but somehow every two to five years all the oak trees in the region act in unison to produce a prodigious number of acorns.
Do you remember the acorn explosion back in the fall of 2019 – when acorns were bouncing around everywhere, when they covered the sidewalks and plinked off cars, when you skidded down hills on top of acorn marbles? That was a mast year for acorns, which means oak trees produced an unusually high number. If you have noticed that there seem to be far fewer of their furry faces than normal this year, you would be right. Gotta love their cute, furry faces stuffed with seeds. An eastern chipmunk collects nuts on Nov.