The monarch butterfly is far from the only insect struggling to survive. Homeowners can take steps to aid insect populations, such letting grass grow longer and halting the use of insecticides. Russ Dillingham/Sun Journal
One topic I’ve written a lot about lately is the decline in insect populations. Whether we are talking about declines in fireflies and monarch butterflies, or the scarcity of insect-eating birds like swallows and flycatchers, the “insect apocalypse” is a frequent topic for me. So when Maggie Dumais wrote in recently asking specifically what homeowners can do to help insects, it seemed like we should devote a column to answering just that.
I hope many of these answers are familiar to long-time readers, but let’s start with the basics. First, insects need a place to live. When you look in your yard, how much grass is there? For most insects, mowed grass is the equivalent of pavement. There might as well not be anything there, since there is nothing to benefit the insect.
Insects also need food, which is where native plants come in. Insects have been in an evolutionary arms race with the plants around them. To oversimplify, insects want to eat plants, but the plants want to be pollinated, just not eaten. This has led to much specialization and often very specific diets of our insects. The relationship between monarchs and milkweed is well known, milkweeds being the only plant that the monarch’s larval stage can feed on; this is similar for most insects and the foods they eat. Without native plants, we won’t have insects, which are some of the lowest tiers on our food chain and will have rippling repercussions. Fall can be a great time to plant natives, and a great website to help pick plants for your yard is mainenativeplants.org.
The next big thing we need to change is our use of insecticides. I worry that too many people think narrowly of insecticides as just something sprayed on crops, but we are talking about all the chemical and “organic” options for controlling insects. While we’ve made huge steps in banning insecticides like DDT, we’ve got a long way to go with newer threats from neonicotinoids. I encourage everyone to read Herb Wilson’s Aug. 14 birding column on this subject.
Before we make those big changes, which will require local, state or federal bans, we can take a closer look at the insecticides we are using at home. Balancing health concerns is always challenging, especially with browntail moths and ticks increasing in Maine, but the widespread use of tree and lawn treatments to kill these is having a greater effect than on just those target pests. Most applications will affect any insect that ingests or contacts it (depending on the substance), so while it might help with your “problem” insect, it is nondiscriminate in what else it is killing. Even cutting back on the use of bug spray can be a simple step. Way too many people are conditioned to lather on a thick layer of bug spray as soon as they step out of their cars. I see it all the time on bird walks I lead when there are hardly even any biting insects around.
Other things you personally can do: reduce soap run-off activities like washing cars; switch to using a biodegradable soap; and think carefully before you use plant-killing salts that are often spread on driveways and walking areas in the winter. Perhaps most importantly, if you are not an insect lover, try to change your perception of insects. I’ve always like the “5 Ps” that Dr. Akito Kawahara, an entomologist at the Florida Museum of Natural History, encourages us to remember: Insects are 1) pollinators, 2) prey, 3) physical decomposers, 4) they help progress in science and technology, and they 5) provide pleasure.
DON’T PLAY WITH YOUR FOOD
An easier question to answer came in recently from Tom Leonhardt of Sentry Hill in York, who observed a great blue heron “playing” with a dead frog. As described by Tom, the heron would “toss it up, let it fall into the water, pick it up and toss again. This went on for quite a while.”
Birds (or other wildlife) rarely have time to “play” so there is likely some more purposeful behavior going on here. In this case, the dead frog is a food item, and since the heron kept tossing it in the water, it was likely to make it easier to eat!
It is well documented that herons will do things to prepare their meals to be easier to consume. Small (furry) mammals are often dipped in water and wetted before being consumed, much like how competitive eater Joey Chestnut gets hot dogs down in record time. Herons will also do things like remove the spines off fish before consuming them, so I think it is safe to assume this heron was just trying to make that frog a little easier to consume before gobbling it down.
Remember that in the fall, herons are wandering around as they get ready to migrate, and they’ll often show up in atypical locations. In past years we have answered questions about herons foraging in yards and meadows, and even one stalking chipmunks under someone’s bird feeders!
Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 7 to 9 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.
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