Nature Notes for June 27, 2014
If,
last Saturday, you encountered a group of people along a roadside staring at
something invisible to the onlooker and laden with a butterfly net, you
stumbled upon participants in the second official Rice Lake Plains Butterfly
Count. Butterfly Count. Regular readers
will know about bird counts, but butterflies? This is another way that
information about the natural world is collected.
Teams
are assigned to a particular geographic area and fan out to try to find as many
butterflies as they can. The ideal day is warm and sunny. Butterflies are not
very active below a temperature of 20ºC.
The
June 21 date was bit earlier than most butterfly counts in southern Ontario. The
date was chosen to coincide with the flight season of the Mottled Duskywing,
which has recently been listed as Endangered by the Committee on the Status of
Endangered Wildlife in Canada (COSEWIC).
Each
butterfly species has a particular flight season, some having more than one
flight during the warm months. Some, like the Mourning Cloak, have a very long
flight season. They overwinter as adults, emerge with the first warm weather,
and can still be found into September. Others, like the Mottled Duskywing have
a short flight season, about six weeks from mid-May through June.
The
Mottled Duskywing is not a particularly striking butterfly. It is small and
dark with various shades of brown splotching. It does, as do many butterfly
species, have very particular habitat requirements. The only food of the larva
(the caterpillar stage) is New Jersey Tea, a small flowering shrub of the dry
prairie/savannah habitat of the Rice Lake Plains.
Most
school children are familiar with the life cycle of the Monarch butterfly whose
larvae feed only on milkweed. Many other butterfly species are just as
particular. The Monarch mimic, the Viceroy larvae feed on willows and poplars.
Red Admiral and Milbert’s Tortoiseshell larvae feed on stinging nettle.
Baltimore Checkerspot feed on turtlehead (That is the name of a plant.) CommonBuckeye feeds on toadflax and snapdragon. Black Swallowtail feed on members of
the parsley family, including garden carrots. Quite a number of species feed on
a variety of grasses.
One of many Northern Crescents seen on the count
photo © Rod Lee
Locating
the larval food plants will indicate the likelihood of finding the butterfly at
the right flight season.
The
adult butterflies are often found nectaring on flowers. Last weekend was a bit
early for too many flowers to be in bloom, but roadside patches of vetch and
viper’s bugloss usually yielded a few butterflies. Often, butterflies are found
on patches of damp ground where they suck up dissolved minerals. Another place
to look for them is on animal scat. This doesn’t provide the most picturesque
background, but the butterflies also obtain nutrients for this source.
How
did we do on the count? The group’s tally was 39 species. Five Mottled
Duskywings were seen. The most abundant species was Common Ringlet, with 327
individuals seen.
Common Ringlet, the most abundant of the butterflies seen on this count.
photo © Rod Lee
Only two Monarchs were seen by the group. This species should have arrived back from Mexico by this date. Only time will tell whether this species’ eastern population will survive.
Perhaps some readers will study their butterflies
over the summer so that they might take part in the 2015 Rice Lake Plains
Butterfly Count, scheduled for June 2015. The count was sponsored by the Rice
Lake Plains Joint Initiative and organized by the Peterborough Office of the
Nature Conservancy of Canada.
