B.C. has long been a magnet for two-legged North Americans with a taste for mild weather. Now, thanks to an ever warmer climate, the province has hung out an irresistible welcome sign for creatures with four legs, six legs and, for ocean dwellers, no legs.
B.C. is becoming a destination for crawling, flying and swimming immigrants as part of a global trend in which fish, bird, bug and land animals’ ranges are expanding northward, researchers say.
“Some organisms may not have reached B.C. but will make their way here,” says University of B.C. Okanagan biology professor Karen Hodges. “Would we get jaguars? That’s unlikely over the coming decades. We’re really looking at things in the 200- to 300-mile range.”
Wild animals that had rarely, if ever, been glimpsed in B.C. decades ago are already taking up yearlong residency.
Take Anna’s hummingbird, one of the wildlife success stories of B.C.’s warming climate.
Vancouver adores the bird that has been called a flying jewel for its emerald colour. City residents almost voted it Vancouver’s official bird in a recent contest.
But Anna’s hummingbird is a foreign conqueror, an iridescent Genghis Khan that built an empire on the back of the Pacific Northwest’s warmer weather. Bird books used to insist its range was limited to south of San Francisco. Five decades ago, even the sharpest-eyed birdwatchers would have been lucky to spot it in the Lower Mainland.
Peter Arcese, a conservation biology professor at the University of B.C., says a warming climate has helped the hummingbird conquer the Pacific Northwest.
“These birds are very dependent on temperature,” Arcese says. “In the late 1970s, when I was teaching at the University of Washington, I had to go halfway down Oregon to find one.”
B.C.’s biodiversity is poised to get a boost as new wildlife species currently holding U.S. citizenship join Anna’s hummingbird in colonizing a warmer B.C., scientists say.
Scientists say sharks and giant squid may find more northerly living space as rising temperatures extend their habitat into B.C. waters.
“One of the things most folk do not know is that in terms of biodiversity British Columbia is the richest north temperate jurisdiction on the planet,” says Fred Bunnell, a retired UBC forest sciences professor. “Nepal might edge us out if it had a coastline. It doesn’t.”
THERE WILL BE LOSERS
But the list of wildlife losers in a changing B.C. climate is longer than the list of winners.
“We will see species disappearing,” says Jens Wieting, forest and climate campaigner with Sierra Club B.C. “We will also see new species. But I believe that, overall, we will lose way more species over the coming decades than we will get new ones.”
Globally, land is warming three times faster than are oceans, UBC zoology professor Mary O’Connor says.
In B.C., wildlife in the eastern part of the province will be forced to adjust to sharper temperature changes, O’Connor says.
Waterfowl love smaller, shallower wetlands. Water birds and other creatures living there are vulnerable as wetlands less than two hectares in size dry 16 per cent faster than larger ones, Bunnell says.
As a wetland dweller, the tiger salamander, already an endangered species in B.C., faces a challenging future, Bunnell says.
“Many bird and fish species that depend on today’s river and wetland ecosystems will disappear,” Wieting says.
Some new arrivals will out-compete native species, experts say.
New pathogens and diseases will come along for the ride as host species cross the border, Hodges says.
“We’re not used to thinking of sub-tropical diseases affecting us but it could become a reality,” she says.
MORE SQUID, SHARKS AND SHEEP
Creatures able to adapt to increasingly hot, dry climates in the Southern Interior could be among the winners as B.C.’s climate changes.
The Great Basin gopher snake, B.C.’s largest snake at up to 2.4 metres, might become more common if sage-steppe and grassland habitats expand in a drier, warmer Okanagan, says Hodges.
A climate-induced shrinkage in the Okanagan’s low-elevation forests could also open up country for bird species such as the sage thrasher, as well as bighorn sheep, she says.
“They (bighorns) like rocky open country, and as forests recede upwards it’s possible we might get more of them.”
Arcese says fox sparrows did not live on Mandarte Island off Sidney before the mid-1970s. The birds were deterred by too many winter nights where temperatures dipped below freezing, cutting them off from ground food.
Today, the fox sparrow is thriving on the island, Arcese says.
“The fox sparrow has built its numbers and is starting to exclude the song sparrow from habitat they co-occupy,” Arcese says.
Off B.C.’s coastal waters, warmer temperatures are already causing big changes.
A study last year co-authored by UBC fisheries professor William Cheung said expected climate changes will push West Coast marine species northward an average of about 30 kilometres per decade.
O’Connor says cod landings grew between 1970 and 2005, even as landings of pink shrimp, one of the cod’s prey, declined.
“Temperature was found to be the main driver of this trend,” she says.
The giant Humboldt squid, once rare in B.C. waters, has been reported in growing numbers off the province’s coast.
Called “diablos rojos” (red devils) in Mexico, the voracious squids are armed with more than 1,000 suction cups and lethally sharp beaks. The Humboldt, which grows up to more than two metres long and 100 pounds in weight, has been known to attack scuba divers.
They hunt in schools of up to 1,200 and eat most things they can get their suckers on, including salmon, shrimp, mollusks and, when they’re hurt or trapped in nets, other Humboldt squid.
Researchers in California say the Humboldt could be a role model for other species aspiring to be ruthless invaders in a time of climbing temperatures. “Squid power is the up-and-coming thing,” Stanford University biologist William Gilly says in Bay Nature magazine. “They’re extremely adaptable and they’re probably going to be teaching us lessons on how to adapt to climate change and ocean change.”
Warmer temperatures may result in more sightings of great white, thresher and seven-gill sharks in B.C. waters, says Christopher Lowe, a marine biologist and director of the shark lab at California State University Long Beach.
Great whites and threshers can handle northern waters because they can keep their bodies warmer than the water, Lowe says. But he doesn’t expect them to take up residence off B.C.
“I suspect they’re just unusual migrants,” he says. “Orcas may be a deterrent because they are one of the only marine animals I know capable of killing an adult white shark.”
Sandy McFarlane, a retired marine biologist with Fisheries and Oceans Canada, says that great whites, which prefer temperate waters, could visit B.C.’s coast more frequently if the coast of California gets too warm for them.
“They would perhaps come closer to shore and move further north as waters warmed,” McFarlane says.
SALMON COLLAPSE COULD BE CATASTROPHIC
Scientists worry more about the impact of climate change on the future population of salmon than they do about its effect on any other single species.
Salmon are a keystone species. The foundation of coastal B.C. eco-systems, salmon are relied on by other living things for food and nutrients, experts say.
Things are not looking good for salmon as oceans and spawning rivers warm. A study published last year in the journal Nature Climate Change said there is a five per cent chance of a catastrophic loss of chinook salmon by 2075.
Upwards of 98 per cent of chinook will be gone by 2100 if climate change continues unchecked, the study concluded.
Juvenile salmon suffer from serious heart troubles when water temperatures rise above 24.5 C, say researchers.
Peter Ross, who heads the Vancouver Aquarium’s ocean policy research program, says salmon are also being harmed as melting glaciers release toxins stored from rain and snow.
“Spawning waters for several species of salmon, pretty much throughout the province, are likely to become more contaminated as a result of climate change,” Ross says.
“Salmon embryos, emergent fry and juveniles can be affected by exposure to toxicity through embryo death, malformations in emergent fry and increased susceptibility to disease.”
The threats facing salmon are bad news for B.C.’s endangered southern resident killer whales. These whales are chinook addicts, Ross says. Chinook account for 90 per cent of the 100 to 150 kg of fish they eat each day.
In poor salmon years, the mortality rate for killer whales goes up by at least 25 times for all age groups — but not necessarily just from starvation.
Ross speculates that whales suffering from poor nutrition are forced to use the blubber layer where toxins have lodged.
Those toxins may be released into the whale’s bloodstream, affecting its immune system.
“This is an example of how climate and contaminants may conspire to weaken killer whales in the future,” he says.
Southern resident killer whales currently number 77, down from 99 in 1999.
On land, scientists and environmentalists point to several species of mammals at higher risk from a warming climate.
“Among mammals in the Pacific Northwest, marmots may be in the greatest trouble,” says retired University of B.C. forestry professor Fred Bunnell. “Their sedentary nature makes them ill-prepared to seek higher or more northerly mountains.”
A shrinking range will make remaining marmots less resilient when their population is struck by random events such as fire, he says.
The pika, a tiny member of the rabbit family that likes alpine habitat, is also expected to struggle as B.C.’s climate warms.
UBC zoology professor Mary O’Connor says research done by one of her students shows that for every degree of increase in temperature during an August or September afternoon, pikas lose three per cent of their foraging time as they stay in the shade to keep cool.
“A loss of foraging time is expected to have negative effects on their population sizes,” O’Connor says.
Jens Wieting of Sierra Club B.C. says the province’s caribou will also suffer from the warming climate as a thinning snowpack affects their food sources. The B.C. government says there are about 16,500 caribou in the province, down from 30,000 to 40,000 at the time of European settlement in the 1820s-1850s.
FORESTS AT RISK FROM VORACIOUS BUGS
Tree-trashing bugs just can’t wait for B.C.’s climate to warm.
Retired University of B.C. professor Fred Bunnell says insects are already reaping the benefits of milder temperatures — and this spells a troubling future for B.C.’s forests.
The mountain pine beetle, which has thrived in the province’s milder winters, destroyed millions of hectares of lodgepole pine in B.C.’s Interior. And the mountain pine beetle is not finished yet.
“Throughout the province there are … extensive tracts of young lodgepole pine that were not large enough to attract the beetle during its initial attack,” Bunnell says in a study he co-authored in 2012. “The beetles will remain, ready to attack once trees grow large enough.”
The mountain pine beetle is just one of many insects that are gaining destructive vigour as temperatures climb.
Among its destructive colleagues are the terminal weevil, pine engraver beetle, western balsam bark beetle, spruce bark beetle, western spruce budworm, Douglas-fir bark beetle, aspen leaf miner, pissodes weevil and tent caterpillar.