Fall has arrived and warblers are heading south. I have spent quite a few hours trooping through various woods trying to first spot and then identify tiny birds who are equally intent on nabbing an insect.
Finding that insect has become more difficult in recent decades, though that may seem hard to believe as you flee your back yard pursued by a hoard of mosquitos. Studies from around the globe have found an alarming decline in insect biomass. This is not a good thing.
A seminal study in German nature preserves from 1989 to 2014 found a decrease in insect biomass from an average sample of 52 ounces to 10. That’s an 80 percent drop in just 25 years. Bear in mind this is not urban or suburban areas but nature preserves, areas dedicated to maintaining all wildlife.
Studies from Stanford University and the Zoological Society of London have also identified an alarming decrease, particularly in flying insects. The reasons for this are multiple; use of pesticides, monoculture crops such as corn and soybeans, urbanization, and habitat destruction – many of the same reasons that over a third of North America’s bird species are in decline.
In addition to birds, fish and small mammals who are insectivores – dependent on insects as food – three-quarters of all flowering plants need insects for pollination. That includes about a third of our food crops worldwide, and almost all fruits and vegetables.
The first real public awareness of this trend was the collapse of honeybee colonies. Pesticides are linked to Colony Collapse Disorder, in particular Neonicotinoids pesticides which has caused them to be banned in Europe.
Commercial honeybee colonies that are transported on an agricultural circuit, from California almond trees, on to Florida to pollinate citrus, through the Southeast to the Northeast for the production of apples, blueberries, cherries and other fruits and vegetables, declined 40 percent over a one year period from spring 2018 to 2019. This is an unsustainable loss for both the beekeepers and the bees. Without the pollinators, crop productivity plummets.
The Latin suffix cide means “killer”; pesticide, herbicide, homicide, suicide. The problem is that most pesticides are indiscriminate. They kill the target insect and a host of others, including many beneficial native pollinators. Habitat destruction makes us think of swaths of forest being cleared for pesticide sprayed crops or a shopping mall, but a yard of turf grass, paving, and a privet hedge is equally sterile in terms of ecological function. Invasive and non-native plants don’t offer the food resources that insects evolved to utilize.
A recent webinar by Douglas Tallamy for Florida Audubon (available on Youtube, https://www.youtube.com/watch?v=xAbO1a67_mM ) focused on the interdependence between insects, native plants, birds and wildlife. Doug Tallamy is a professor of entomology, wildlife ecology and biology at the University of Delaware and author of “Bringing Nature Home.” On his website, he boils this problem down to a short manifesto.
We have destroyed natural habitat in so many places that local extinction is rampant and global extinction accelerating. This is a growing problem for humanity because the plants and animals around us produce the life support we all depend on. Every time a species is lost, that ecosystem is less able to support us.
Humans and nature must live together. Though vital, nature preserves are not large enough to be meet our ecological needs so we must restore the world where we live, work, and play. Nearly 85% of the U.S. is privately owned, so our private properties are an opportunity for conservation if we design them properly.
New Conservation Goals
To succeed we need to redesign residential landscapes to
1. Support diverse pollinator populations and complex food webs,
2. Store carbon, and
3. Manage our watersheds.
How can we do this?
Plants accomplish all of these goals so we must replace half of the area dedicated to lawn with diverse plantings of woody and herbaceous species. But plants differ widely in how well they support wildlife. Native plants support pollinators and food webs far better than introduced ornamentals, and some native plants support much more life than others. Choosing the best plants for your area is the key to success.
Starting the revolution at home can be as simple as adding pollinator friendly native plants like asters or goldenrod (which doesn’t create hay fever) or long term, like planting a native oak.
Here’s an easy way to select native plants appropriate to our region, www.nwf.org/NativePlantFinder/ The North Shore Audubon Chapter ( www.northshoreaudubon.org ) has many resources under Bird-Friendly Habitat.
How to make fall more bird and insect friendly? Put away the spray, Renee. Leave the un-shredded leaves in flower beds and under shrubs and trees, Steve. Don’t cut down grass or flower seed heads until spring, Ming. Plant a native tree, Bree, fall is the best time to get them established. Plan to plant perennials next spring. Weird but true- replace outdoor lights with yellow LED bulbs. Learn a new mantra- insects aren’t creepy, they are essential to life on earth.