Background for Teachers
TPW Magazine, March 2009
Animals babies are adorable, aren't they? But they also offer a fun way to look at several concepts such as inherited traits, parenting, habitat needs and survival adaptations.
Some animals are born ready to roll (precocious) and others are quite helpless for a period of time (altricial). Why? Although there's no clear one answer, there are some hypotheses. Species that depend on much learned behavior tend to have young that are more helpless, thus affording time to their teach while they develop to independence. Compare insects, mice, birds, cats and people. Insects work on instinct, while people learn many behaviors for survival. Birds and cats come wired with some survival instincts, but learn others. Time being reared by their parents allows them time to learn those necessary behaviors. Fawns "know" how to hide quietly in brush; baby skunks can spray to defend themselves. Another thought Parenting in nature may be done by the mother, the father or both. Those with both parents active in rearing can afford the time and energy to rear young over time. Juvenile cardinals will beg Dad for food for some time, something that would have exhausted one parent.
Survival depends on several factors, including number of young and adaptations such as hiding, coloring and scent. Some young such as deer fawns have spots that help camouflage them in the dappled light of a forest edge, a favorite habitat for deer. Mice and rabbits have large litters to account for the many predators they have. We often comment about the pleasant smell of human babies, but rarely of the pleasant smell in adult locker rooms! Having a faint scent on young keeps them safe from "nosey" predators.
Another interesting point to ponder is the choice of where wildlife bears its young. Nests and dens are familiar to us, and with a little exploring, easily seen. But what about metamorphosis, where amphibians, butterflies, etc. have distinct changes as they develop into maturity? How might this be helpful to a species? It might be that species whose young live differently may have a non-competing effect. When food or shelter is at a premium, or if a species is especially vulnerable, metamorphosis may help the species survive.
Leaving wild babies alone is a lesson in self control. Often people think they are rescuing an abandoned or injured baby when in reality it's more like kidnapping. Typically a parent is nearby or has the ability to care for the young.
Some fun trivia:
- Opossums are the only marsupials in North America and related to kangaroos.
- Baby burrowing owls can mimic the sound of a prairie rattlesnake as defense!
- Skunks can spray even when very young. Skunks have nozzle-like ducts that can spray all different directions.