MCR Monthly Newsletter

May 2026

Of Mice and Voles

Mice and voles…. For several years I’ve been talking about the remarkable abilities of foxes and owls to detect the heartbeat of a mouse under 2 feet of snow (WOW! This has always amazed me!) Fortunately, there is an over-abundance of these little rodents to supply the demands of predators. Mice and voles are fodder for a vast assortment of predatory animals including snakes, shrews, weasels, racoons, skunks, bobcats, foxes, coyotes, domestic dogs and cats, hawks and owls and even black bears!

There are 3 different species of mice and 2 species of voles in New Jersey. Accurately differentiating between the various genus and species of mice and voles can be quite involved and beyond the scope of this newsletter. So here is a simplified generalization.

Deer mouse (6-81/2 inches long including the tail, brownish-gray with pure-white undersurfaces, large eyes)

House mouse (small 2 2.5-3.75 inches long brown sometimes dark gray with creamy color belly)

White-footed mouse (reddish-brown, with white belly and feet, 2.5-3.5 inches with shorter tail than deer mouse)

All mice are very prolific! The gestation period for most mice and voles is around 21 days.  About 8 young are born without fur (like pink jellybeans) called “pinkys” with their eyes closed, the mother nurses them. They grow rapidly growing fur in a week, now called “fuzzys”. Litters are weaned and on their own within a month and the mother, who has already ovulated and bred again, gives birth again within another few weeks. FUN FACT:  In one of the most prolific species of meadow vole, a female can potentially give birth to 9 litters with a total of 72 offspring per year! And those offspring themselves are also breeding within the first year!

It is not hard to see how quickly a population might explode were it not for constant attrition from predators, parasites, disease, and accidents such as fires and flooding. Mice have a very high metabolism, living short fast lives and seldom live beyond 18 months!

 There are 2 types of voles in New Jersey: the meadow vole and the pine vole.

In New Jersey, the primary difference is that meadow voles are larger (4.5–7 inches) and live above ground in surface runways, while pine voles are smaller (up to 5 inches) and live in underground tunnels. Meadow voles have larger ears and eyes with dark brown/gray fur, whereas pine voles have small eyes, tiny ears, and reddish-brown fur. Both are stocky “mouse-like’ with a blunt head and have a scantily furred tail.  The meadow vole generally inhabiting fields, marshes, and grassy areas whereas the pine vole prefers hardwood forests and pine forests.

There are hundreds (perhaps thousands) of meadow voles in the field below the MCR Visitors Center and they can often be viewed eating seeds from the wildlife/bird viewing windows at the Visitors Center. They are not rats; they are meadow voles! Children are always excited to watch them and the chipmunks!

Come visit and you may see some!

Enjoy Nature!

Ranger Rich

P.S. Hummingbirds are back at the viewing window! (always a treat!)