Nature Center Notes: Spring Fever for the bees, the birds and the bears
Humans aren’t the only ones who have been patiently awaiting the arrival of spring. With the landscape transforming after bitter winter, many of our animal neighbors are ready to answer to a driving force of their own.
As leaves unfold and flowers begin to bloom, many food sources that were unavailable over the last four months are now growing in abundance. This spark of renewal brings birds, insects, reptiles and mammals out in droves. While the sun thaws the ground, our local amphibians and other cold-blooded creatures will begin to rise from their brumation, an adapted form of reptile hibernation, to reawaken their metabolism and prepare to search for food sources. Birds will be flying through the area as they migrate from their “overwinter” sites to their mating grounds, while our native species may already be building nests for their next clutch of eggs.
If you follow the WNC Nature Center’s Facebook page, you may have noticed that we’ve celebrated a slew of birthdays recently. The majority of the animal ambassadors at the Nature Center were born around this time of year. The long days and warm weather ignite the reproductive drive of many native mammals. Some larger mammals, such as black bears, are finally able to see through the pregnancies they have been carrying since autumn. These larger mammals, including deer, otters and red foxes, mate in the fall to better ensure the arrival of their young at a time when resources are plentiful. These animals had prepared for their long, overwintered pregnancy by stocking their fat reserves to maintain both mother and young throughout an unpredictable winter. Deer will see a metabolic drop of about 50 percent to maintain themselves and their young through periods of harsh weather. Bears will enter a half-sleep state known as torpor for nearly the full winter. Due to their larger size and months-long gestational period, most of these animals rarely have more than three young.
On the other hand, rodents are capable of birthing more than 10 babies per litter, at a rate of about one litter per month beginning when resources become most abundant. Since these small mammals (such as mice, chipmunks and rabbits) are lower on the food chain, rapid population replacement is necessary to maintain stability.
Birds, however, will mate only once or twice a year. Many migratory birds will begin building their nesting sites as soon as they are in their preferred breeding grounds, then will find a mate to share the responsibility of raising young. They may have one to four eggs per breeding season with the responsibility of sitting the nest generally going to the female, who is fed by the male. After about a month, eggs begin to hatch, and the offspring relies on their parents until they are strong enough to leave the nest.
Reptiles have quite a few adaptations involving their reproductive process that vary from species to species. Timber rattlesnakes give birth to up to 20 young, while garter snakes can birth up to 80 snakes. Nothing surpasses the amount of young eggs laid by amphibians, which can number in the thousands within each individual clutch. Because of the multi-stage life cycle of these creatures, they are much more likely to become prey before they can carry on the next generation. Keep an eye out for the squishy, jelly-like eggs of amphibians in pools of shallow water such as puddles around your home to make sure they don’t dry out.
Jordan Shepard is social media manager for Friends of the WNC Nature Center. The center is temporarily closed. For updates, visit https://wildwnc.org.