Weeding out the facts on invasive species

Numerous species of invasive animals are making their home in the South Okanagan

Here in the South Okanagan we hear a great deal about invasive plants (weeds) and rightly so as the economic and environmental costs of these plants are significant. What we don’t hear about quite so often are invasive animals, even though North America in general and the South Okanagan in particular are now home to numerous alien invaders. Many, but not all, of these invaders have significant associated economic and environmental costs.

Some of the better known invasive species are European starlings, zebra mussels, bullfrogs and carp. Starlings arrived in North America (Central Park, New York City) in 1890 as part of an individual’s plan to introduce to the U.S. all of the birds mentioned in the works of Shakespeare. What an incredibly costly decision that was. Starlings compete with native birds such as bluebirds and flickers for nesting sites and cause significant economic damage to crops, including our own cherries and grapes. The annual economic cost in the U.S. is estimated to exceed $500 million in crop damage alone. In addition, they can cause significant structural damage with their corrosive droppings.

The common carp, native to Asia but introduced in the U.S. in the early 1800s, was first noted in the Okanagan in 1912. It is now found in many lakes and rivers in southern B.C. While it is a popular food fish in parts of Asia, it is highly detrimental to lakes in southern B.C., causing increased water turbidity and significant algal blooms. Its feeding habits are highly disruptive to many duck populations and it eats vast quantities of insects and fish eggs which would normally be food for native species.

Another very recently arrived alien in the South Okanagan is the Eurasian collared dove. This bird, about the size and weight of a city pigeon (itself an alien species in North America), has spread across North America faster than any other known bird species and has had a similar story in Europe. In the late 1890s this bird was found only in central, warm-temperate Asia. However, beginning in the 20th century it has made a remarkable advance across Europe. Climate seems to be no barrier as it is now found north of the Arctic Circle.

The Eurasian collared dove was introduced to the Bahamas in the 1970s (we just never learn!) and by 1982 had spread to Florida. As late as 2000 it was still mostly confined to the East and Gulf coasts of the U.S. with sporadic sightings elsewhere. However, since then there has been a veritable explosion in the population of this dove. In the early part of the 2000s it was consistently found in the Cawston area but in the last few years has rapidly expanded northward. This past summer breeding pairs were noted in Kaleden as well as elsewhere in southern B.C. So in less than 30 years this alien has effectively colonized all of North America.

Unlike most stories of alien species in North America, which generally range from bad news to really bad news, so far there appears to be few detrimental effects associated with the invasion of the Eurasian collared dove. These doves do best in altered habitats — rural to semi-urban areas with some farms and/or feed lots. The observational data indicates they do not seem to compete with the native mourning dove, which is the only widespread native dove in North America. Let us hope this continues to be the case.

The South Okanagan Naturalists’ Club meets monthly at the Penticton United Church on Main Street at 7:30 p.m. Our Nov. 24 speaker is Karilyn Long, fisheries biologist with the Okanagan Nation Alliance, who will talk about her work to protect and restore salmon resources and their habitat in the Okanagan Valley.



Robert Handfield is past-president of the South Okanagan

Naturalists’ Club.


Just Posted

(Pixabay photo)
Morning Start: Goosebumps helped scare off predators

Your morning start for Tuesday, June 15, 2021

Sue Birds captured this sunset photo that took place in between the rain and thunder Monday night, June 15, 2021. (Sue Birds)
Stormy sunsets over Okanagan Valley

Monday night had thunder, rain and stunning sunsets

Owner Daren McWhinney is really excited about the new location of Angry Vegan which just opened up at 536 Main Street. (Monique Tamminga Western News)
Penticton’s Main Street turns into foodie heaven

Angry Vegan, Wild Ginger, Twisted Chopsticks and Gratify recently opened

Penticton Overdose Prevention Society co-founders Desiree Franz, Shane Surowski and Stephanie Lines have created the city’s first unsanctioned public overdose prevention site using an old wine-tour bus. The site began operations in June 2021. (Desiree Franz/Facebook)
Volunteers launch Penticton’s first public supervised injection site

2021 is on pace to be the deadliest year for overdoses in Penticton on record

Four golfers from Fairview Mountain Golf Club in Oliver will golf from sunrise to sunset to raise funds for ALS on June 29. (Submitted)
Golfing from sunrise to sunset in Oliver for ALS

Four golfers from Fairview Mountain Golf Club have taken up the challenge June 29

People watch a car burn during a riot following game 7 of the NHL Stanley Cup final in downtown Vancouver, B.C., in this June 15, 2011 photo. THE CANADIAN PRESS/Geoff Howe
10 years ago: Where were you during the 2011 Vancouver Stanley Cup Riots?

Smashed-in storefronts, looting, garbage can fires and overturned cars some of the damage remembered today

Port Alberni court house (Alberni Valley News)
Coroners’ inquest into 2016 death of Port Alberni teen rescheduled for June 21

18-year-old Jocelyn George died of heart failure after spending time in jail cell

Children’s shoes and flowers are shown after being placed outside the Ontario legislature in Toronto on Monday, May 31, 2021. THE CANADIAN PRESS/Frank Gunn
Ontario commits $10 million to investigate burial sites at residential schools

Truth and Reconciliation Commission identified 12 locations of unmarked burial sites in Ontario

Two hundred and fifteen lights are placed on the lawn outside the Residential School in Kamloops, B.C., Saturday, June, 13, 2021. The remains of 215 children were discovered buried near the former Kamloops Indian Residential School earlier this month. THE CANADIAN PRESS/Jonathan Hayward
Days after Kamloops remains discovery, Tk’emlups families gather to unite, move ahead

‘We have to work together because this is going to be setting a precedent for the rest of the country’

In this Saturday, May 29, 2021, file photo, people crowd the Santa Monica Pier in Santa Monica, Calif. California, the first state in America to put in place a coronavirus lockdown, is now turning a page on the pandemic. Most of California’s coronavirus restrictions will disappear Tuesday, June 15, 2021. (AP Photo/Damian Dovarganes, File)
With COVID tamed, it’s a ‘grand reopening’ in California

No more state rules on social distancing, no more limits on capacity, no more mandatory masks

Montreal Canadiens goaltender Carey Price (31) is scored on by Vegas Golden Knights defenseman Alec Martinez, not pictured, during the second period in Game 1 of an NHL hockey Stanley Cup semifinal playoff series Monday, June 14, 2021, in Las Vegas. (AP Photo/John Locher)
Habs fall 4-1 to Vegas Golden Knights in Game 1 of NHL semifinal series

Match was Montreal’s first game outside of Canada in 2021

(Dave Ogilvie photo)
One injured after being pinned by fallen forklift near Peachland

West Kelowna emergency crews responded to reports of a person stuck under a forklift

Kelowna-Lake Country MLA Norm Letnick, assistant deputy speaker at the B.C. legislature, presides over committee discussions. The legislature is completing its delayed spring session this week, with most MLAs participating by video conference. (Hansard TV)
B.C.’s daily COVID-19 infections dip below 100 over weekend

Only 68 new cases recorded Monday, four additional deaths

B.C. ambulance station in Revelstoke is expected to get a new system called the Scheduled On-Call (SOC) this fall. (Liam Harrap - Revelstoke Review)
B.C. ambulance changes could put Revelstoke residents at risk, warn local paramedics

Paramedics said to expect a substantial increase in ambulance response time starting this fall

Most Read