Bay Area Birds: Decline of pollinators is alarming
By Charlie Frisk
On July 2, the federally endangered rusty patched bumblebee (Bombus affinis) was found at a home in Appleton and documented by Lawrence University Biology Professor Israel Del Toro.
Del Toro isn’t alone.
In the summers of 2019 and 2020, Wisconsin Department of Natural Resources Biologist Jay Watson also found rusty patched bumble bees during pollinator surveys at Woodland Dunes Nature Preserve in Two Rivers.
The bees were found on a 100-acre restored prairie plot adjacent to the forest.
“We have the perfect situation on this property for the rusty patched to thrive,” Jen Klein at Woodland Dunes, said. “They need that combination of wildflowers and forest edge to complete their life cycle.”
The major threat to the rusty patched bumblebees at Woodland Dunes is the encroachment of non-native Eurasian honeysuckle.
Woodland Dunes received a grant to hire two summer interns to remove the honeysuckle.
“If we make a conscious effort to keep invasive shrubs from encroaching, the bees will do well here,” Klein said.
To most people, a bumblebee is a bumblebee, but it never occurs to them there are approximately 255 species worldwide, 46 species in North America, and historically 20 species in Wisconsin, with only 15 remaining today.
You may ask, as long as we have bumblebees left, what difference does it make if we lose a few species?
Every bumblebee species occupies a slightly different niche or the role of a species in the biological community.
They live in different habitats and pollinate different species of plants.
Loss of species is to ecosystem function like a carpenter losing most of his tools and then trying to build a house.
In 2017, the U.S. Fish and Wildlife Service (FWS) listed the rusty patched as federally endangered.
According to the FWS, the rusty patched bumblebees have declined by 87% in the last 20 years and are likely to be present in only .1% of their historical range.
This decline is one example of the overall decline of pollinators around the world.
More than 100,000 species including bees, butterflies, moths, flies, beetles, wasps, birds such as hummingbirds, mammals such as bats and even lizards such as geckos perform the important job of pollinating plants, and most of them are experiencing a decline.
The decline of pollinators has occurred because of habitat loss, the conversion of smaller, more diverse family farms to single crop industrial farms, pesticide use, disease and climate change.
In recent years, we’ve heard a lot about the decline of honey bees.
Honey bees are an introduced species from Eurasia which pollinate approximately $10 billion worth of crops in the U.S. each year.
However, of the 100 or so crops which make up most of the world’s food supply, only 15% are pollinated by domestic bees, while at least 80% are pollinated by native wild bees and other wildlife.
Bees in general are in peril.
According to the Center for Biological Diversity, more than half of North America’s 4,000 native bee species are in decline, with 25% at risk of extinction.
However, the rusty patched bumble bee is a classic example of how human actions can help species recover.
Del Toro said conservation efforts in the Appleton area such as NoMowMay and native plant gardening make a difference.
“Some of the most important things that you as a citizen can do to help our rusty patched bumble bee population is reducing your pesticide use, reducing the number of times you mow your lawn and planting native wildflowers and grasses in your yards,” he said.
The importance of planting native species cannot be overstated.
According to ecologist and author Doug Tallamy, oak trees support more than 500 species of insects, particularly many types of caterpillars; while non-native trees, such as the ginkgo from China, typically support none.
Baby chickadees will consume between 6,000 and 9,000 caterpillars in the 16 days between hatching and leaving the nest, so native trees such as oaks are essential for survival.
All wildlife, as well as human life, depends on insects.
Insects are the second step in the food chain and most animals either eat insects or eat other animals that eat insects.
The most important thing people can do to encourage the survival of insect species is replace the non-native plants on their property with natives.
Editor’s note: To read another Bay Area Birds article by Charlie Frisk, CLICK HERE.