Butterflies buffeted by climate change

Spectacular garden in King, attracted few butterflies on bright July afternoon suggesting problems with our fragile friends. Donald McClure photo

Spunky little Red Admiral has been a constant visitor to Bloomfield garden since early May. Donald McClure photo

Walked through an incredible garden in the heart of King Township north of Toronto last weekend — with fantastic floral displays.  It was a warm sun-filled afternoon, a day after a good rain had freshened everything into a summer lushness that would lift the spirits of any gardener.  Only thing missing: the butterflies.

In all of this large, meandering butterfly-perfect environment we only spotted one Monarch, one Eastern Tiger Swallowtail and

Easy care, low growing Bonica rose makes a charming display all season long in County gardens.

another specimen that I couldn’t readily identify. A few years ago this site might have been vibrating with a host of fluttering wings.

Noting what is happening on our own Bloomfield garden this summer, we wonder what on earth is happening to this most elegant, welcome and fragile garden visitor?

Wellington artist Margaret McFetridge supplied a possible answer when she brought to my attention an article recently published in the Globe an Mail written by London-based Matthew Hart. His conclusion:  while climate change is expanding the range for some species of butterflies (like the Giant Swallowtail seen fairly often in the County) others beset by the results of ongoing environmental exploitation are gradually fading from the scene.

Peter Hall, a research associate at the Canadian National Collection of Insects and one of the authors of my favourite authority, Butterflies of Canada,  knows of no butterfly species that has disappeared from Canada, but latest surveys reveal that there are 17 listed for protection under Canada’s Species at Risk Act.

Most of the negative pressure on butterfly populations, says Mr. Hall, appears to come from human development and consequent loss of butterfly habitat. In fact, a recent report from the Commission for Environmental Cooperation in Montreal warned that migrating monarchs are increasingly threatened by pesticides and urban sprawl.

In a report on Canada’s butterfly populations, Mr. Hall has identified the same trend in Ontario. In the past 15 years, the Pearl crescent (now commonly found in Sandbanks Park and the Eastern tailed blue (in our back field) have joined the Delaware skipper “in a range shift to the north. In addition, the Tawny-edged skipper, which used to cycle through two generations in a single summer in Southwestern Ontario, but only a single generation at the more northerly latitude of Ottawa, now goes through two generations in both locations.” Yet while some butterflies find climate opportunities, others vanish altogether.

The Globe report points out that the apparent bonus we get from climate warming on some specific butterfly species may be offset by negative factors such as habitat loss in which some species thrive and others lose.

Although there seems to be no concrete evidence that there is  downward trend in most United Kingdom butterfly species, Jeremy Thomas an ecology professor at Oxford notes that “there is growing evidence, of declines occurring in other monitored insects, such as moths and bumblebees. It used to be thought that butterflies were not the same as other insects, but we have found that, in fact, they are pretty representative. What’s happening to them is happening to other insects too, and insects are half of all known species of animal in the world.”

One of the most  dazzling displays of garden-ready roses I have seen for some time were radiating summer splendour this week when I dropped by Rambling Rose Nursery on Wesley Acres Road near Bloomfield.  I was looking for a low growing Bonica rose that would provide plenty of bloom and not require a lot of maintenance and be disease resistant.  The Bonica voted the World’s favourite in 1997, will act like a showy specimen rose in our garden although it is equally at home as a hedge rose because of its  ground hugging characteristics.  Proprietor Tim Bucknell selected a beauty for us in excellent condition despite the stupefying heat we have all been subjected to recently

Tim is now working full time at his farm he tells me, and bringing to bear his extensive rose-growing experience to the nursery.  At one time he was in charge of the huge rose growing facility of the late lamented White Rose Nurseries in Unionville, Ontario growing hundreds of thousands of roses annually.  Today he is putting all of his knowledge and skills into his own operation.

A word on  hose equipment.   Many of the hose nozzles being sold today, leak from the get-go and break if you drop them on the ground too hard.  Many of them will not give you a full season without some malfunction.   Look for ones with sold brass (rather than plastic) working parts like the series produced by Lee Valley Tools.  They are are drip free in my experience and precision parts allow easy control and powerful applications of water where you want it.