Humans have introduced so many exotic species, so long ago we now think of many as natural. Some become disruptive, but others find a place within their new ecosystem. What are some examples of beneficial invasive species? Why do we love some exotic species, when we fear others and call them pests?
Can Some “Invasive” Species Be Beneficial To Humans?
We use many words to categorize species into convenient boxes that we can classify and subjugate. There are many terms ecology professionals use to describe invasive species which have recently come into question. The term “pest” is one of the more controversial and politically motivated. We often use the words invasive and pest as close synonyms.
First, let’s make a habit of asking ourselves why we think an animal is a pest. Secondly let’s explore if it’s an adjustment in habitat or a new understanding that might change our perception. Part of pest control is rethinking and reimagining our relationship with certain species. For some of those species, one’s that don’t negatively interfere with humans or the environment, we call them naturalized.
When Were Honeybees Introduced?
In 1622 European colonists brought honeybees with them to Virginia. They wanted the capability of making honey in their new colony. Apparently from that introduction honeybees swarmed quickly across the Northeast in a few short decades. Colonists transported honey bees inland to the Midwest & around by sea to the West coast in the 1800’s. The spread of european honeybee colonies basically kept pace with the spread of european human colonies across the North American continent.
Importantly, the domestic honeybees purpose was always two-fold. To provide delicious sugary honey and to provide crop pollination services for farmers & horticulturists.
Before their arrival, bumblebees (bombus sp.) would have probably been the most social bee in the Portland area. Bumblebee colonies are in the dozens to hundreds in size depending on species, whereas honeybee colonies can contain around 25,000 individuals!
But besides bumblebees, many species of ground dwelling bees also live here. In Oregon we have Lasioglossum, halictus, seladonia, dialictus, agapostemon & andrena as some native ground-tunneling genuses of sweat bees. Similarly, mason bees, are in the genus osmia which represents approximately 70 different native species!
Attention bored parents. Check out this great OSU document on creating and responsibly maintaining mason bee habitat. The maintenance required to nurture a healthy mason bee habitat is a gold mine of great family time and hands-on ecology lessons.
You can also greatly encourage native pollinator habitat by leaving some bare ground in your yard. Indeed our ground-tunneling bees are great beneficial species to the soil and the plants. They will greatly appreciate un-mulched areas to lay their eggs in old worm holes and other necessary habitat.
Apparently North America did have a species of native honeybee around 14 million years ago. But it appeared to go extinct long before European colonists arrived.
Beneficial Invasive Species
European honeybees provide the absolutely essential service of pollinating our food crops. In particular, they physically fly from bean plant to bean plant or apple blossom to apple blossom. In doing so they exchange genetic material between plants is a highly specialized task they gladly do for free.
Humans domesticated honeybees for this purpose. Therefore their colonies are conveniently adapted to thriving in the colorful bee boxes seen in the back corners of farm fields and backyard pastures.
When honeybees make colonies outside of bee boxes in our environment, they’re sometimes referred to as feral honeybee colonies. These are common in Portland, I myself have observed one 15′ in a cedar tree in NE Portland. Another same height deep underneath ivy overgrowth on a old broken tree in St. John’s. They forge this habitat out of nothing. They build their colony from scratch. Honeybees are opportunistic, and adaptable.
What Are Beneficial Invasive Species?
Do feral honeybees harm or help the environment? I’d love to hear your evidence or opinion either way. My hope and belief is that they create additional biodiversity and aren’t bothering our native solitary bees that mostly live underground.
All Natural Pest Control
Virginia opossum is an introduced species in the Portland area and along the lowland West coast into the Columbia gorge. Although they sometimes eat native bird eggs, they also can eat mice, rats, and loads of ticks.
Ticks & Opossums
Mysteriously ticks aren’t as bad as they probably should be here around Portland. My confidence saying this comes from three years of full time work in tall grassy moist areas; ticks’ favorite habitat. In New England where I grew up it’s so bad, venturing a few feet into the tall grass could doom you to an evening of checking your body for ticks.
We do have lots of opossums. And they can eat 95% of the ticks they encounter. The ticks seek the warm blooded opossum like a magnet. The opossum then immediately eats the tick during it’s next grooming session. Do opossums control the ticks here to barely detectable levels?
Their introduced range does seem to overlap with Western black legged tick & Brown dog tick’s range.
Other Beneficial Invasive Species?
In this article the author nominates Chinese mystery snails as a potential beneficial invasive species. She noted native Pugest sound Signal crayfish loved to eat the mystery snails. Birds, fish and other aquatic animals benefit from this food source. Chinese mystery snails mostly eat decaying organic matter along the bottom. So they do not appear pose a significant hazard to the ecosystem.
Lastly, some exotic plants can be beneficial to humans. Humans use many exotic plant varieties as our favorite food crops. Weeds released long ago now provide key nutrition and medicine for foraging humans and animals.
Always consult an ecologist if you’re unsure. Many exotic species become naturalized and are generally innocuous. But some invasive species can cause real problems for the ecosystem. If you live in Portland and would like help distinguishing good species from bad ones, or would like help with removal, feel free to give us a call.