Blogger’s Note: You can also hear me read this as a commentary on Vermont Public Radio.

Pay no attention to Phil and the pranksters in Punxsutawney, Pennsylvania, today. Instead, listen for bird song. Black-capped Chickadees offer their wistful fee-bee serenade. Northern Cardinals launch into a series of rich, repeated whistled notes. And Carolina Wrens begin an energetic tea-kettle, tea-kettle, tea-kettle!

It can sound like springtime in February, regardless of whether or not the groundhog sees his shadow. That’s because the real significance of Groundhog Day isn’t about sunshine. It’s about day length. Around February 2 we start getting more than 10 hours of daylight. And that matters to wildlife.

It doesn’t mean that spring is around the corner. Far from it. Songbirds schedule breeding to coincide with an abundance of food for their offspring, mostly insects, which comes around May and June. But now, as the days grow longer, birds do start thinking about … well, um, you know, making more birds. It’s why they sing.

It’s not entirely clear how birds measure day length, but we do know that photo-receptors in bird brains sense increasing light. It triggers the production of hormones that act like birdie Viagra. So when the food is there in May, songbirds will be ready … you know, physically.

Why February 2? Well, it falls about halfway between the Winter Solstice and the Spring Equinox, a period reflected in human traditions from Paganism to Christianity. But why the groundhog? Couldn’t we have picked a loftier critter to represent the coming of the light?  I’ve got nothing against woodchucks, by any other name. But, as it turns out, this rodent is indeed a worthy harbinger of spring.

In the light of February, woodchucks emerge from hibernation hot to trot. They need to breed now so that females produce litters during greater food abundance in April and May.

The same goes for other rodents, particularly squirrels, which have an unusual mating ritual. Female squirrels are in estrus, receptive to males for breeding, for about eight hours on only a single day during this season. And males outnumber females in the wild by as much as five to one. Among males competition for a female is fierce. So the boys spend a lot of time following a given female in the days leading up to their one big day.

Any male who’s too forthcoming, too anxious before she’s ready, will get from the female a swat to his face or a painful bite. But when those precious eight hours finally do arrive, on their day in the sun, males compete and fight for a copulation that might last only about 20 seconds.

So let’s recognize the real significance of Groundhog Day. In the growing light of February, this isn’t a holiday about six more weeks of winter. It’s a celebration of romance, even if it turns out to be a tribute to rodent romance.