Conservation of Butterflies in Southern Ontario

efforts for these butterflies must take that into Conservation of Butterflies account. Re-discovered butterflies One of the great thrills for butterfly enthusiasts in Southern Ontario in North America is to re-discover colonies of by Peter W. Hall a butterfly species in a region where it had not been, or rarely, seen for many years. This has happened with two species in the province. In June, 1891, four Gorgone Checkerspots were found at Scarborough just west of Introduction dramatically, a number of formerly restricted Toronto. A few other historical records from Butterflies at the edge of their range often range species in southwestern Ontario have the late 19th century exist from London and expand or contract their distribution and been breeding farther north and east in from the Humber Valley west of Toronto. numbers based on factors such as annual large numbers. Finally, for some butterflies, As well, there were a few specimens taken migration, climate shifts and habitat loss. In particularly those annual migrants with in 1907 at White Rock, Algoma District southern Ontario, many butterfly species are fluctuating breeding numbers or special case in Northern Ontario. Then there was no at the northern, or in some cases southern, species, the jury is still out on possible range indication that the butterfly existed in the edge of their range and in recent times have expansions or shrinkages over time. province for almost a hundred years. exhibited shifting ranges and numbers that However, in 1996 a small colony was raise conservation challenges. Sometimes Extirpated butterflies encountered near Kemptville in eastern these shifts are very noticeable such as the Although no butterfly species that were Rick Cavasin Ontario and subsequently about a dozen final disappearance of ‘Karner’ Melissa Blues found in Ontario have gone extinct, three Gorgone Checkerspots rolled in and then more colonies were found in the same in the 1980s or the appearance of the Giant eastern North American butterflies have been rolled out, apparently in concert with vicinity. These colonies were all in dry, sandy abandoned farm fields, roadsides and along Swallowtails in large breeding numbers in extirpated in the province towards the end of Blackeyed Susans. July 9, 2010. Oxford Mills, eastern Ontario in the 2010s. the 20th century. All three were previously Ontario. hydro lines. These were areas characterized Much is known about the distributions and found in the Carolinian region of the by many Blackeyed Susans which turned numbers of butterfly species in the province province’s south-west, and the caterpillars of lupines. The last eastern Persius Duskywing in out to be a newly discovered foodplant for thanks to more than a century of often intense all three feed on lupines. Ontario was seen at its single colony in the St. the species. In subsequent years, many of monitoring and research. Ontario has used ‘Karner’ Melissa Blues were resident in a Williams Forest in 1987, while the last record these colonies have disappeared coinciding this knowledge, combined with information number of colonies in sandy, oak savannahs for the Frosted Elfin at its only colony at the with a decline of Blackeyed Susans in the on other organisms, to produce a wide range along the north shore of Lake Erie east to same location was in the following year. habitat. Despite many observers looking for of monitoring tools, legislation and protected Toronto on Lake Ontario. The oak savannahs Since the 1980s, much consideration has the butterfly, it appeared in only one farmer’s areas to try to preserve species at risk, supported large stands of Sundial Lupine. been given to whether any or all of these three clover field with abundant Blackeyed Susans. including butterflies. However, when a species During the 20th century, most of these oak species, particularly the Karner Blue, could In 2013 that field was planted to corn. of concern disappears, or is found to be more savannah habitats were largely destroyed be re-introduced into the province with proper For an ephemeral, population-shifting widely distributed than at first thought, how by urban development, agricultural clearing restoration of the habitat with the lupine species like the Gorgone Checkerspot what can this be taken into account in a timely or the establishment of pine plantations. foodplants. These had pretty well disappeared would be the best conservation strategy? fashion in terms of protection? In recent years, As the habitat and the caterpillar foodplant in the province. Some appropriate habitat Creating a protected area for it would this question has come to the forefront as disappeared, so did the butterfly until the last restoration has taken place, especially at a probably not work. Legislation would also more and more species appear to be impacted ones were recorded in 1988 at St. Williams new Karner Blue Sanctuary on the south not necessarily protect such a species. It negatively or positively by habitat disruption Forest, Norfolk County, and near Port Franks shore of Lake Huron and in High Park in is anticipated that there are probably low and changes to the planet’s climate. in Lambton County, as a result of an extended Toronto. However, all the necessary conditions numbers of the butterfly in a few scattered and Some butterfly species in southern Ontario drought that year. for re-introduction, including permission ever-shifting populations that may re-populate have become extirpated in recent times while As went Karner Blues, so too did to move individuals from their limited U.S. new colonies in the region when conditions still others have shrinking ranges. A few which Frosted Elfins and the eastern race of Persius populations, have not yet been met. Such became right for the caterpillar foodplant. had historical records have been re-discovered Duskywings in the province. They too were re-introductions take considerable effort Perhaps extensive Blackeyed Susan plantings in seeming viable populations while, most dependent on the presence of large stands of and resources and any future conservation should be undertaken in the region to attract 26 American Butterflies,Fall/Winter 2013 27 disappeared from its northeastern United States breeding sites, but still exists in substantial numbers in eastern Ontario. A Peter W. Hall W. Peter butterfly of dry alvar and rocky habitats, it has strongholds in areas such as the Marlborough forest south of Ottawa and the Carden Alvar north-east of Peterborough. Why it has disappeared in the northeastern United States is still a mystery, so populations in Ontario should be carefully monitored. Expanding range butterflies In the past two decades a large number of Rick Cavasin butterflies found in Ontario at the northern edge of their range appear to be expanding their range north and east in the province. Just Diminishing-range butterflies among the skippers, these include Delaware A number of butterflies in eastern North Skipper, Little Glassywing and Wild Indigo America, including Ontario, have exhibited Duskywing. declining ranges and numbers in the last few Wild Indigo Duskywing had been a decades. These are of special conservation species restricted to the most southwestern concern as they are exhibiting all the signs of part of the province feeding on Horseflyweed species at risk. (wild indigo) as a caterpillar. In the last Rick Cavasin Mottled Duskywing is a species of the 30 years, it has adopted Crownvetch as an Mottled Duskywings are diminishing throughout eastern United States north into southern alternate hostplant. As Crownvetch became eastern North America, including Ontario while Ontario, Quebec and southeastern Manitoba. commonly used in the province to prevent Tawny Crescents, in similar habitats, are still doing well in Ontario. In Ontario it has been a rare and very local erosion along newly constructed transportation resident found in widely scattered populations corridors, the butterfly has followed the Above: A burnt lands alvar on which Mottled Duskywings were previously found. Aug. 17, in drylands, such as alvars, as far north as plantings into more northern and eastern parts 2008. Almonte, ONT. Manitoulin Island and the Ottawa area. This of southern Ontario. The butterfly has moved species has been declining throughout its from being local in a highly restricted range Inset: Mottled Duskywing. June 3, 2012. Marmora, ONT. North American range, including Ontario, as to being widespread across the southern and its localized distribution and low dispersal eastern parts of the province. Clearly it is not Opposite page: Tawny Crescent. May 31, 2012. Ottawa, ONT. capability make it subject to local extirpation. now in need of any conservation measures. Pesticide drift and deer browsing may also be Even more dramatically, Giant adversely affecting the New Jersey Tea and Swallowtails, which had been restricted to Jersey Tea stands where the caterpillars feed. Carolinian parts of southwestern Ontario, and maintain the butterfly. One option may be a few assumed strays showed up in the late It has disappeared from many of its known have in the last ten years spread their breeding to plant Blackeyed Susans in medians or along 20th century. However, in 2008 a small colony sites in southern Ontario. Experts have listed range north and east as far as Ottawa. The the verges of local highways and adjust or was found south of Sarnia in Lambton County it as an endangered species and the Canadian caterpillar foodplant used in this move is cease grass-cutting

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