[Pollinator] Butterflies are early warning system for climate change

[Scott Black]

Butterflies are early warning system for climate change


By Hanneke Brooymans, Edmonton Journal June 30, 2010


A butterfly at the Devonian Gardens near Edmonton, Alberta, o

A butterfly at the Devonian Gardens near 
Edmonton, Alberta, on Tuesday, June 29, 2010. 
Photograph by: John Lucas, edmontonjournal.com


EDMONTON - They may look like lightweights, but 
in a biological sense butterflies are heavy 
hitters when it comes to protecting species threatened by climate change.

As the world warmed, a butterfly called Edith's 
checkerspot was the first organism to show a 
documented range shift, said Camille Parmesan, an 
associate professor of biology at the University 
of Texas at Austin, who is in Edmonton for the 
sixth International Conference on the Biology of Butterflies.

Edith's checkerspot has been dying out in 
northern Mexico and doing well in Canada, 
Parmesan said Tuesday during a break in the 
conference. It's also dying out at lower 
elevations and flourishing in the Sierra Nevada's highest elevations.

Parmesan and some colleagues also did a study of 
57 European species that showed two-thirds were 
moving northward. Research shows many species 
move northward because of changes in the growth 
pattern of plants the butterfly relies on for food.

"People think of changes in timing as not 
important, at least a lot of the general public 
do -- who cares if a plant is flowering two weeks 
earlier?" Parmesan asked. But work on the Edith's 
checkerspot showed its host plant was drying up 
too quickly, making it inedible to the larvae and causing local extinctions.

As long as the host plant grows further north, 
where it's still cooler, and the butterfly can 
make its way to those spots through connected 
habitat patches, the butterfly could shift northward.

Butterflies that already live at high altitudes 
or in northerly sites are the most likely to be 
in serious trouble, Parmesan said.

"What we're seeing at the highest elevations is 
the species with nowhere to go are essentially 
evaporating off the tops of those mountains and 
we're losing those species," said Jeremy Kerr, 
associate professor of biology at the University 
of Ottawa, who has also studied the insects.

"Butterflies are this kind of canary in the coal 
mine that may be useful guides for what other 
species will eventually do and the pressures that 
other species, or species groups, may face," Kerr said.

"Whether those species respond the same way or 
not, the pressures that those species are confronted with may be comparable."

Humans have been paying close attention to 
butterflies for centuries. Data sets on 
butterflies go back to 1760 in the United 
Kingdom, Sweden and Finland, Parmesan said.

In Canada, they go back to the 1860s, said Kerr.

Kerr has used this data and models to show that 
butterflies have responded as expected to the 
changing climate and landscape. Generalist 
species, such as the common roadside butterflies 
that everybody sees, are expanding their ranges 
and becoming more common, he said.

"And they are doing so essentially at the expense 
of the specialist species, the things that really 
distinguish the regions of Canada from one 
another biologically, the species that are 
relatively uncommon and specialize on narrower 
sets of floral hosts. These species are slowly fading away from our landscapes.

"If you look at the list of observations of 
endangered butterflies, every single observation 
of an endangered butterfly species in this 
country -- every single one, 100 per cent of them 
-- are in exactly the areas of southern Canada 
that these models predict they should be found 
within, where human activities have their deepest footprints."

What this means is that we can't rely on 
protected parks alone to conserve biological 
diversity, Kerr said. "They are not like zoos. 
You can't just keep species intact in those 
places. The terrestrial area of this country is 
about 10 million square kilometres. Something 
less than 10 per cent of that land mass is in a 
park. Almost all of those parks are in places 
where almost no species exist. So we protect ice 
and snow remarkably well. And we protect the 
places where biological diversity is concentrated remarkably poorly."

Kerr said parks actually protect species worse 
than randomly selected areas in some places. "So 
parks are not the answer. What we need to do is 
change the way we use landscapes."

Simply leaving unused margins or fields in 
agricultural areas unmowed would go a long way to 
protecting biodiversity, he said. "You don't have 
to do a lot of restoration. You don't have to do 
a lot of conservation to maintain vital habitat in these landscapes."

Granted, he is not saying these spots would 
conserve grizzly bears. But allowing native 
prairies to take root in the margins would be 
good for lots of birds, all kinds of insects, 
including pollinators, and wildflowers.

"These are the species that are in many instances 
the keys to conserving ecosystem function."

We also need to anticipate the changes climate change will bring, he said.

"The trick here in terms of climate change is not 
to think about where we are today but to think 
about where the puck is going. And the puck is 
going to be moving in roughly a northern 
direction here. We need to be thinking about 
conserving areas that are the kind of frontiers for the near future."

Parmesan agreed. "Canada will become increasingly 
important for preserving North American 
biodiversity because a lot of the U.S. species 
that are even common species, as they're moving 
up into Canada, they're dying out in the U.S.A.," she said.

"And so we need to be thinking more 
continental-scale in terms of conservation, not 
just country-scale. In other words, the U.S. 
should be partnering with Canada to try to 
preserve species that are moving into Canada."

<mailto:>hbrooymans at thejournal.canwest.com

HOW TO HELP

- -Butterfly enthusiasts can add their sightings 
from throughout the country to the website of the 
Canadian butterfly monitoring project. The main 
goal of the project is to figure out if species 
are shifting their home ranges because of 
land-use changes and climate change. The second 
goal is to predict future impacts of these changes on Canadian butterflies.

- -To visit the site or contribute your 
observations go to 
<http://www.macroecology.ca/butterflies/>www.macroecology.ca/butterflies/
© Copyright (c) The Edmonton Journal




*************************
Scott Hoffman Black
Ecologist/Entomologist
Executive Director
The Xerces Society for Invertebrate Conservation
4828 SE Hawthorne
Portland, OR 97215
Direct line (503) 449-3792
sblack at xerces.org

The Xerces Society is an international, nonprofit 
organization that protects wildlife through the 
conservation of invertebrates and their habitat.

To join the Society, make a contribution, or read about our work,
please visit <http://www.xerces.org/>www.xerces.org.


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