Protecting and enhancing the natural values of Salt Spring Island and its surrounding waters

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Butterflies

Copy by James Miskelly

Butterflies of Salt Spring Island

In the early 1900’s, several prominent butterfly researchers documented the butterflies of the Victoria area and Cowichan Valley, but historic information on the butterflies of Salt Spring Island is almost non-existent. To date, thirty species have been recorded from Salt Spring Island, including a few that haven’t been seen in decades.  There are up to twenty additional species that, based on their known ranges and habitats, seem like they should occur on Salt Spring Island.  Many areas of the island have not been completely surveyed.  Visiting an area at different times of year and over a multi-year period is the best way to see all the butterflies that may occur there.  There are likely still some interesting species left to find on Salt Spring Island.

Photo by James Miskelly

General Information

All butterflies have a four-part life cycle, which includes egg, larva (or caterpillar), pupa (or chrysalis) and adult.  The egg stage is usually short-lived.  In most local species the egg hatches one to two weeks after being laid.  Only a few local species overwinter in the egg stage.  The larvae are feeding machines.  All local butterfly larvae feed on plant parts, which may include leaves, flowers, or fruits.  Most species are quite host specific, and will feed only on a small selection of related plants, sometimes just a single species.  Larvae often have elaborate means of protecting themselves, including camouflage, defensive chemicals, or construction of shelters using silk and leaves.  When a larva has completed its task of feeding and growing, it often wanders a short distance and finds a hiding place before becoming a pupa.  Pupae can wiggle, but are unable to move around and are usually attached to a substrate.  The adult butterflies emerge from the pupae and must stretch and dry their wings before they can fly.  Males usually emerge first, and spend their time searching for females.  Some species hold territories and defend them from other males.  Females are less active than males and spend their time looking for suitable egg-laying sites. Most butterfly species feed on nectar from flowers.  Some species may prefer other sources of nutrients and energy, including tree sap, rotten fruit, animal droppings, or carrion.  Depending on the species, the lifespan of the adult butterflies may range from only a week to several months.  A few local species even pass the winter hibernating as adults.

Common Woodnymph

Cercyonis pegala incana [Red Listed] - Photo by James Miskelly Range: The Common Woodnymph ranges across southern Canada from Pacific to Atlantic, south to the southern United States.  The local subspecies (subspecies incana) is restricted

Dun Skipper

Euphyes vestris [Red Listed, Threatened]  Range: There are two separate populations.  One is found from east of the Rocky Mountains to the Atlantic coast.  The local population is much rarer and occurs from southwestern

Moss’s Elfin

Callophrys mossii mossii  [BlueListed] - Photo by James Miskelly Range: Moss’ Elfin ranges from southern BC to southern California, east to the Rocky Mountains.  The local subspecies (subspecies mossii) is found only in the region

Propertius Duskywing

Erynnis propertius [Red Listed] Photo by Laura Matthias Range: The Propertius Duskywing is found from south-western BC to Baja California.  There are no recognized subspecies. Wingspan: 3.5 – 4 cm Habitat: open areas with oak

Zerene Fritillary

Speyeria zerene bremneri Photo by Laura Matthias Range: The Zerene Fritillary is highly variable species with many varieties.  The species as a whole is found from southern BC and Alberta south to California and New

Status and Threats

South-eastern Vancouver Island and the Gulf Islands have by far the highest butterfly diversity in coastal BC.  Many species and varieties found in this area occur nowhere else in Canada, and several are endangered throughout their ranges.  Unfortunately, local butterflies have declined greatly.  The Victoria area has lost roughly twenty species, about half of its original number, since record keeping began in the late 1800’s.  Most of this loss is due to historic conversion of native meadows and woodlands, first to farmland and then to residential and commercial uses.  More subtle threats come from habitat change.  Many butterfly populations have disappeared even from parks and protected areas.  There are several reasons for this.  Many local meadows and woodlands were historically maintained by fire.  In the absence of fire, these open ecosystems become closed forests and shrub thickets.  Almost all of the butterflies that have disappeared from the region have herbaceous host plants, while most species whose larvae feed on shrubs and trees have persisted.  Other threats include invasive plants like Scotch Broom, which transform meadows into shrublands; trampling, which can harm larvae or reduce host plant populations; and overabundant deer, which can reduce host plant populations or ingest the larvae incidentally while eating leaves.

 

What can you do?

  • learn about your local species and their habitat needs
  • support habitat protection and management for rare butterfly species
  • include native plants, especially host plants, around your home
  • leave some dead plant material around your yard or garden
  • leave an area of your yard wild and messy
  • participate in a Broom Bash or other invasive species control program and work to eliminate invasive species from your property.

 

What is SSIC doing?

Protect habitat – acquire conservation covenants and land acquisitions to protect ecologically significant habitat in perpetuity.

Enhance habitat – restore habitat by planting native plants required by rare butterfly species, implement wetland construction to increase habitat for rare butterflies, maintain key habitat features in our nature reserves for butterflies.

Survey –work with experts to increase our understanding of the status and distribution of butterflies on Salt Spring Island

Outreach – work to build knowledge of Salt Spring Island butterflies and their habitat needs in the local community to encourage other landowners to enhance habitat on their own properties.

Mitigate Threats – work with partners and user groups to restrict habitat destruction and damage in sensitive areas.

Photo by James Miskelly
Photo by James Miskelly