Alvin! By now I am getting a little tired of singing chipmunks and I want to focus on the native chipmunks we have in Pennsylvania.

They might not sing like Alvin and his brothers, but chipmunks do vocalize. There are four distinct chipmunk calls: the chip (checking in with other chipmunks), the deeper chuck (warning others that this territory is “taken”), the startle call (impending danger) and a mating call where females use their high-pitched, birdlike vocalizations.

Research has shown chipmunks respond to the high-pitched alarm whistles of their relative the groundhog sometimes seeking cover after a warning call, but groundhogs don’t respond to the warning calls of the chipmunk. Obviously trouble for a chipmunk is not the same for a groundhog!

Eastern chipmunks (Tamias striatus) are basically squirrels that have adapted to burrowing. Other members of the squirrel family include groundhogs, prairie dogs, various ground squirrels and tree squirrels.

Excellent habitats for chipmunks would be a deciduous forest (trees that loose leaves and evergreens) woodland, logs, stumps, shrubs and rocks. I find it interesting that if there are no high spots with which to scope out an area, they will not be found in those areas. They’re also comfortable in areas that provide sufficient cover such as urban parks, fence lines, hedges and houses. Chipmunks can climb trees, shrubs and birdfeeders.

This past summer I had young birds at home that would self-feed and would fly up into nearby trees and then return to the food and shelter I provided them. The family of chipmunks that scamper along my rock walls would often be caught raiding the food at the feeders I had set up for the birds. They eat various types of seeds and berries, fungi, grain, fruit, nuts, insects, salamanders, worms, bird eggs and even nestling birds and baby mice.

Chipmunks are not true hibernators. Chipmunks go into a torpor or prolonged “sleep.” While in this torpor their heart rate declines from about 350 beats per minute to approximately four. Body temperature may drop from 94 degrees F to the temperature of the burrow — as cold as 40 degrees F. They retreat to their burrows but wake every few days, raise their body temperatures to normal, feed on stored food rather than using fat reserves, and urinate and defecate.

Chipmunks dig two types of burrows. One is rather shallow and is used as shelter as they scamper about and a deeper, more complex burrow where they nest, store food and spend most of the winter months. In case something should happen to the stored food chipmunks will begin caching stockpiles of food in various other locations close to the entrances of the burrow. Chipmunks rarely venture further than one-third mile from their burrows at any time.

So what is life like in those elaborate tunnels and chambers? Inside is a cozy nest of shredded wood and leaves created for sleeping and bearing young. Breeding occurs twice per year — once in the spring and once in the summer — when chipmunks give birth to four to five babies at a time. Deep in its tunnel (which can be up to 30 feet long, with many entrances and exits), chambers are stuffed with their harvest: all types of seeds, fungi, dead insects and hard nuts. These food stuffs are less likely to spoil over the many weeks of storage. Chipmunks have been discovered with up to 8 pounds of food cached away for the winter. There are a few interesting features about the burrows. They are often located on a slope that allows for water drainage. Also, because chipmunks are prey to a long list of predators, the chipmunks will seal the entrances and exits each night and right before they go into a state of torpor. That is essentially the same thing as checking that the front door is locked before we turn in for the night or we go on a mini-vacation.

While Alvin and his cohorts are about 59 years old, the life span of the average chipmunk is two to three years in the wild and five to eight years in captivity.

Jeannie Carl works at the Carbon County Environmental Education Center located at 151 W. White Bear Drive, Summit Hill. For information, please call 570-645-8597.