Connect with us
[bsa_pro_ad_space id=12]

Environment

Urban avian rivalry: Birds fight it out for food and shelter in big cities

Published

on

If you like this, share it!




  • Competition’s tough in the big, bad city. Just ask a chickadee.

    Research has found that urban birds aren’t shy about throwing their weight around against weaker rivals — and the richer the city, the tougher the underdog’s daily struggle for food and shelter.

    “As we see economic development, we see this intensifying of competitive interactions,” said Queen’s University biologist Paul Martin, whose paper was published Monday in the Proceedings of the National Academy of Sciences.

    Martin and his colleagues were curious about how competition between closely related species differs in the natural and urban worlds.     

    “We know these kinds of interactions are really important in nature and they determine which species has the best access to resources,” he said. “But we have no idea how these things relate to urban environments.”

    Researchers looked at almost 300 bird species in 250 cities from Bangalore to Budapest to Bogota. The species were grouped into 142 closely related pairs such as the mountain chickadee and the black-capped chickadee, the house finch and the purple finch, the song sparrow and the swamp sparrow. 

    Biologists then looked at the behaviour of each species in the pair wherever their urban territories overlapped. Even when both species were well-adapted to city life, researchers found that the stronger species of the pair tended to let the weaker know that the town wasn’t big enough for the two of them.

    “The larger size can often predict who’s going to win,” Martin said. “More muscle mass, larger weapons like bills or talons — all those things provide a benefit to larger species in a fight.”

    The real surprise came when researchers realized that the law of the streets may not apply everywhere.

    Dominant species seem to run off the subordinate pair mostly in economically developed cities. For the rich, dominants ruled. 

    Not so in developing cities.

    “In those countries, we find species living alongside the dominant species in cities,” said Martin. “The competitive effects that we found for developed countries are completely missing.”

    Why is that? Martin doesn’t know.

    Perhaps it has something to do with how resources such as food are distributed in developed cities. Large, centralized food resources for birds — for example, managed waste disposal sites — may be easier for a flock of bigger birds to defend against a smaller rival.

    That’s for future study. For now, Martin’s content with the new insight into how wildlife behaviour varies as it comes into human communities — research he calls vital as humanity becomes more and more urbanized.

    “There’s been a lot of interest in our impacts on wildlife,” Martin said. “We’re seeing more and more evidence of actual evolution in organisms in response to urban environments.

    “The public is interested as well. Those are the organisms they see everyday.”

    — Follow @row1960 on Twitter

    Bob Weber, The Canadian Press



    If you like this, share it!

    Environment

    Real-life tsunami threat in Port Alberni, B.C., prompts evacuation updates

    Published

    on

    If you like this, share it!




  • VICTORIA — When tsunami-alert sirens rang out in the dead of night in Port Alberni 14 months ago, most people fled for higher ground but some didn’t recognize the emergency signal, says a new study.

    A magnitude 7.9 earthquake off the coast of Alaska Jan. 23, 2018, at 1:31 a.m. prompted a tsunami alert along much of Canada’s West Coast, including Port Alberni on Vancouver Island. Port Alberni, population of about 17,500, was hit by Canada’s largest tsunami in March 1964 after a 9.2 earthquake off the Alaska coast.

    The January 2018 tsunami alert was lifted at 4:30 a.m. but not before thousands of people left their homes in various states of  fear and confusion, say researchers from the University of British Columbia’s school of community and regional planning in a report released Thursday.

    Ryan Reynolds, one of the report’s authors and a risk modelling expert, said the report serves as a preparation blueprint for coastal communities that face the ever-present threat of tidal waves.

    “This was really an opportunity for us to re-evaluate our own preparedness in terms of coastal hazards,” he said in an interview. “This is really the only test we’ve had recently of a tsunami evacuation to see what impact that has on a community.”

    Port Alberni saw more than 90 per cent of households in warning zones evacuate to the safety of higher ground, but there were glitches before the alert was lifted at 4:30 a.m., said Reynolds

    Some people didn’t understand why community sirens were blaring and others were looking for confirmation of the alert on social media, but the community’s emergency response system did not immediately inform residents of the potential danger, he said.

    “The first thing people do is they try to verify the information,” Reynolds said. “They’re not sure if the siren is a warning or if perhaps the siren’s broke and it’s just going off.”

    Elderly people try to verify the alert on television or radio while younger people look to social media, he said. Confusion arose in Port Alberni because as emergency response teams were being activated, the city’s social media sites stayed blank for much of the alert period, said Reynolds.

    The research involved interviews with about 450 local residents and numerous city officials, he said.

    Reynolds recalled meeting a family that had moved to the community three days before the alert and were roused by neighbours who urged them to flee.

    “They didn’t know what the siren meant and they had young kids,” he said. “Suddenly, they’re faced with a sound they don’t know. They look out their door and all they see is neighbours getting in their vehicles. For them this was kind of like the Apocalypse.”

    But Reynolds said the research found more than 60 per cent of residents have updated their tsunami evacuation plans since the alert, and community and regional officials have better co-ordinated social media services and response tactics.

    “Our community is very tsunami aware,” said Port Alberni Mayor Sharie Minions. “The tsunami definitely caught people’s attention to make sure they definitely have a plan.”

    She said the threat of a tsunami in Port Alberni is something that’s never far from the minds of those in the community.

    Reynolds said Port Alberni is better prepared today for a tsunami than it was last year.

    “If this were to happen tonight at 2 a.m. the events would be much smoother, much quicker and we would have much better communication with people,” he said. “They’re kind of battle-tested.”

    Dirk Meissner, The Canadian Press


    If you like this, share it!
    Continue Reading

    Environment

    The hard life of a wild Sable Island horse:’Eking out a living on this sandbar’

    Published

    on

    If you like this, share it!




  • HALIFAX — Researchers studying the carcasses of Sable Island’s fabled wild horses have discovered many had unusual levels of parasites and sand, suggesting they are tougher than most horses, even as many died of starvation.

    A team from the University of Saskatchewan and Parks Canada performed necropsies on more than 30 dead animals during trips to the isolated sandbar about 160 kilometres off Nova Scotia in 2017 and 2018.

    “We showed up in 2017 not knowing whether there would be any dead horses to find,” said researcher Emily Jenkins.

    “Scientifically we really didn’t know anything about the causes of mortality in this population because the last work that was done was in the 1970s.”

    The horses have roamed there since the 18th century and become synonymous with the island’s romantic and untamed image.

    Jenkins said conditions on the wind-swept, 42-kilometre long island were particularly harsh in the early spring of 2017, and that had an effect on the horse population.

    “It was very hard on the horses,” she said. “When we got there they were taking shelter behind anything they could find.”

    With the help of Parks Canada, Jenkins said she and other University of Saskatchewan researchers were able to find 30 carcasses that were suitable for examination during their initial foray to the island.

    Jenkins said they estimated there were another 20 carcasses that were either unsuitable for examination or that were just too inaccessible to get to.

    She said the overall findings were “very similar” to a previous study carried out by graduate student Daniel Welsh in 1972.

    “The main finding was emaciation or starvation and hypothermia, especially for the young horses,” said Jenkins, who noted vegetation is sparse on Sable during that time of the year.

    The researchers found the yearlings in particular, had little or no reserves of body fat to rely on.

    “All of the young horses we looked at were just basically out of reserves,” Jenkins said. “They had nothing left, they were emaciated.”

    However, the adult animals, who would have higher social status and better access to the best grazing, were generally in better body condition and died of a combination of other causes.

    Jenkins said Sable Island’s omnipresent sand tends to grind down teeth, affecting nutrient intake, and also ends up in the horses’ system, blocking their gastrointestinal tract.

    “In several horses that we looked at there was quite a lot of sand. We were picking up the intestines and the stomach and saying ‘these weigh a tonne,’ because there was in many cases more sand than plant content.”

    Jenkins also noted that some pregnant mares had died while giving birth.

    The 2018 trip, meanwhile, focused more on looking for pathogens and diseases, and that’s where Jenkins said the researchers were able to find things such as respiratory and reproductive diseases including a parasite lungworm.

    She said, in fact, research over the last 10 years has turned up astounding levels of parasitic worms in these small horses, many of whom are no bigger than 14 hands long.  The average fecal egg count from the live horse study was 1,500 per gram.

    “I just about fell over because we call a high fecal egg count in a domestic horse 500 eggs per gram,” said Jenkins. “So the average Sable horse is walking around shedding three times more parasites than our domestic horses.”

    Jenkins said the horses’ genetic resistance to the parasites could render clues for horses in the domestic world, where veterinarians are “fighting a losing battle” to worms with a growing resistance to various treatments.

    The scientist said she believes domestic horses are dewormed too much to begin with, and the Sable research could help bear that out.

    “Look at what those guys are surviving with — massive levels of parasitism and no treatment. So we are probably overdoing it for most horses that are just companion animals.”

    Jenkins said the overall mortality rate in 2017 was about 10 per cent of the population, while the 2018 figure represented about one per cent, which is more the norm.

    She said the current population sits at around 500 horses, up from the 300 or so recorded in the 1970s.

    From a scientific perspective, Jenkins said it’s fascinating to see a system of untreated and unmanaged horses living in what amounts to their ancestral conditions.

    “But there’s the little girl in me who has always loved horses who can’t believe these horses are eking out a living on this little sandbar,” she said.

    Keith Doucette, The Canadian Press



    If you like this, share it!
    Continue Reading

    march, 2019

    fri8mar - 30aprmar 85:30 pmapr 30Real Estate Dinner Theatre5:30 pm - (april 30) 10:00 pm

    sat30mar - 31mar 3010:00 ammar 319th Annual Central Alberta Family Expo10:00 am - 5:00 pm (31)

    sat30mar1:00 pm- 4:00 pmMAGSaturday @ the MuseumMAGnificent Saturdays welcomes all ages and abilities to participate in a fun art project every week! 1:00 pm - 4:00 pm

    Trending

    X