Changing Seasons in a Changing Climate Part One . A very personal concern . book research and years of observing nature have made me very aware of seasonal change and “what is normal”
book research and years of observing nature have made me very aware of seasonal change and “what is normal”
a growing awareness that the usual dates of events in nature are changing, as well as the numbers and kinds of many plant and animal species
a growing sense of loss
frustration that climate change story is not really being told and in the lack of any meaningful action
Algonquin Park 1963 with Doug Sadler and Haig Kelly
Bird in hand – Wallis Drive – 1963
Letter to the Editor The Globe and Mail, July 10, 2013
Climate change is being felt most acutely in late fall, winter & early spring
Average winter temperatures predicted to rise from 3 - 7 C this century, depending on how much is done to reduce greenhouse gas emissions Already 6 C warmer than average in winters of 2012 & 2013
Wood Frogs, Spring Peepers and Chorus Frogs overwinter in the leaf litter and essentially freeze solid. Increased freeze and thaw episodes disrupt hibernation and consume valuable energy.
Changes in bird populations in the Kawarthas Thanks to milder winters and bird feeders, “southern birds” have increased in number and have expanded their range northwards compared to 30 years ago.
Winter survival for deer will be easier as food will be more accessible and there will be less snow cover
Moose, however, may be forced further northward as deer populations increase (brainworm parasite)
Moose are declining drastically in many parts of their range, esp. southern regions
70% decrease in Minnesota since 2006, where all hunting is banned
Ronald Moen of University of Minnesota believes decline correlates with the warmer summers & winters (e.g., long, hot summers stressing the animals & compromising immune systems); milder winters making for more mortality from winter tick, etc.)
House Mosquito (Culex pipiens)
Late winter is mating time for many mammals * Generalists mammals like skunks and raccoons are also expected to prosper in a warmer climate.
Virginia Opossums, a southern species, are already extending their range into the Kawarthas as winters become warmer.
Earlier and warmer springs are being predicted
March 2012 saw:
Frogs calling four weeks early
Mourning Doves beginning to nest
Flower buds on apple trees opening a month early. Many flowers were killed by April frosts, resulting in an 80% loss in Ontario’s apple production.
Ice-out on March 20, a full month earlier than the long-term average
Great Blue Heron
* Early spring is mating season for mammals with a short gestation period
* With warmer winters, Southern Flying Squirrels are moving north and some are mating with Northern Flying Squirrels, a different species
* Akin to Polar Bears and Grizzly Bears mating
Hybrid squirrels are becoming increasingly common
Being explained as an effect of climate change
(Trent University/MNR study)
- earlier springs are resulting in an earlier start to the nesting season for resident birds & short-distance migrants
these species should be able to breed earlier and raise more young
One large-scale study showed that birds are laying eggs up at an average rate of 6.6 days earlier per decade
Salamanders are mating earlier, too.
Unprecedented numbers (300 million plus) of Red Admirals arrived in spring of 2012
was due to conditions in Texas where abundant rain followed a devastating drought (climate change?)
all predatory insects were killed off by the drought
with the rains, wildflowers were abundant and huge reproduction success
wave after wave came north out of Texas from April through May
arrived too early to reproduce here since nettles, their host plant, had not yet emerged
Monarchs arrived early, too, in some areas before milkweed were up. Poor reproductive success.
Red Admirals feeding on tree sap
Study by UBC, University of Sherbrooke & University of Ottawa in Global Change Biology (November 2013) has found that butterflies are highly sensitive to temperature
Emerge on average 2.4 days earlier per degree Celsius of temp. increase. Warmer temperatures will mean butterflies will emerge earlier
By merging too early, they could encounter frost and die. Or they might emerge before the food plants they rely on appear and starve
Even a slight decline in butterfly population will have consequences for other species going up the food chain.
- Black flies are now in peak numbers in late April through early May
in the 1960s, peak numbers were not until mid- to late May
traditionally, May 24th Weekend saw the worst black fly conditions
With climate change, tree pollen is emerging roughly two weeks earlier in the spring in much of North America.
Pollen counts are expected to more than double by 2040.
Many people are experiencing more serious allergy symptoms .
Jack in the
May: Long distance migrants arrive returning earlier as spring becomes earlier Their arrival may no longer coincide with peak insect numbers, leading to less reproductive success. Some species may extend their range northward and therefore no longer nest in the Kawarthas.