A big plump robin was eating dry, withered crab-apples in my driveway last week, a great sign of spring!

Male robins migrate before the female. The earliest migrants may get the best territory with lots of food and nesting areas. If a big April snowstorm hits, food may be hard to find. But robins are hardy and can subsist on frozen fruit that has lasted all winter.

Even if a late snowstorm covers the ground, it doesn’t last long on south-facing slopes. Despite the cold air, the sun is strong. It warms the bark of trees, which radiate heat. An empty “bowl” forms around the tree trunk as the snow melts around it. Soon, robins will find worms once more.

It’s mating time for the gray squirrel. Male squirrels chase the females, and try to chase other male squirrels away from females. There is much activity, tail snapping and foot-stomping.

At this time of year, squirrels bite off maple twigs and lap up the sap that comes out. Sometimes when the squirrel finishes eating and leaves, a sweet icicle hangs down from the branch. That’s a sign of spring.

If the squirrel’s twig falls on the snow, the sun warms the twig. Soon the twig melts its way down into the snow. That’s a sign of spring.

A killdeer, always an early spring migrant, just arrived on a nearby school’s expansive athletic fields. It kept running in little bursts of speed across the ball field, looking for insects or worms. Killdeer get their odd name from their call.

They are well known for their “broken wing trick” in which they drag one wing, flash their bright orange rump and call loudly “Killdeer, Killdeer” to lure a predator away from the nest. Actually, all birds that nest on the ground do that to some extent, but the killdeer has developed it to a high level.

It’s too early and too wet for the killdeer to nest on that cold, wet athletic field, but its arrival is another wonderful sign of spring.

There are so many signs of spring, despite the cold air. I never have understood why people sometimes say, “We don’t have spring in Maine.”

For information on Fields Pond Audubon Center, call 989-2591.