
The crocuses in my yard began popping up at the end of February. By early March, they were blooming, over a month earlier than usual. I worried that a snowfall would harm them but the lone snowstorm we had at the end of February quickly melted. Now some of my other spring bulbs are popping up. They do not typically appear until April.
How do a mild winter and early spring affect animals and plants? Most people I know are enjoying and taking advantage of temperatures between 50-70ºF. It's usually about 20-40ºF colder at this time. While humans may love a break from the harsh winters of the northeastern U.S., the warmth may not be a good thing for some species.
Insects
Some insects benefit from a mild winter while others suffer. The Asian ladybug is beneficial to gardeners because it feeds on aphids. They emerge from hibernation early when the weather is warm and if there are no aphids to feed on, they starve.
A species of butterfly called Mormon fritillary are suffering from a lack of food. Early snow melts in the Colorado Rocky Mountains are killing wildflowers. The flowers bud early in warmer temperatures and then are killed by snow melt or fall. The butterflies are left without a food source when the nectar is gone. This in turn causes the butterflies to lay fewer eggs. If the cycle repeats every year, species decline.
Animals
Some animals will emerge from hibernation with higher-than-usual fat stores. This can lead to increased reproduction and a larger population. In cases of so-called nuisance animals, like raccoons and groundhogs, this is not necessarily a good thing.
Bird migration can happen earlier with an early spring. This can hurt birds over the long term. If birds arrive at breeding grounds too early, they risk trying to survive in winter conditions. Death and decreased egg production are two potential consequences. They can also struggle to find food sources as they move up to coast, for example.
Plants
- Maple trees that bloom early produce less sap. This leads to less and lower quality maple syrup.
- Apple trees have a shorter growing season and produce a smaller harvest when winters are mild. Buds can be damaged if there is a cold snap in the midst of an early spring.
- Plants may bloom and fade before insects are ready to pollinate them.
- Trees that bud early will have a longer pollen season. (Those who suffer from allergies to trees and weeds will in turn experience a longer sneezing season.)
- Growing zones are changing across the country. These affect when plants should be started outdoors and which plants can be planted.
This blog entry lists only a few of the species affected by an early spring. If spring has already sprung where you live, please share some of the unusual things you've noticed this year.
Resources
Ellwood City Ledger - Warm weather brings out better moods, but more bugs
Live Science: Spring Shows Earlier and Earlier for Many Plants, Animals
NPR: Can an early spring confuse nature's clock?
Our Amazing Planet: Early Spring is Bad News for Butterflies
The Province: Video: How early spring affects allergies
ScienceDaily: Climate Change, Increasing Temperatures Alter Bird Migration Patterns
Yahoo! Voices: Mild Winter and Early Spring May Have Consequences
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