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The Monarch's Migration Marathon

Early June 2023

Featured Species: Magnificent Migrant Monarchs & Butterfly Wildscaping

The migration of the magnificent Monarchs is slowly making its way across the US / Canada border and will likely peak in early early to mid-June.  However, Monarchs aren’t too adventurous this year.  As of late May, the first Canadian sightings have been limited mostly to areas of southern Ontario, with only the two outliers on the Bay of Fundy.

Most of these arrivals are the offspring of the Monarchs that originally began the migration in México (well, actually by migrating to Mexico last fall) - an incredible trip for an insect weighing less than a gram. We can welcome the Monarchs by providing a hearty native plant nectar meal and a cozy milkweed habitat. 

In Canada, their natural habitat includes southern Alberta, Saskatchewan, Manitoba, Ontario, Quebec and the Maritimes. The monarch has also been found in other areas of the country, including locations as far north as James Bay.

Monarchs feed on the nectar of many plants, but only breed where milkweed occur. Females identify milkweed by smell-testing the plant juices with their antennae. Fertilized eggs are laid singly, mostly on the underside of milkweed leaves, and a single female may lay as many as 400 eggs. Within 4-5 days the eggs hatch, and tiny caterpillars (the larvae) emerge. The caterpillars become brightly-coloured with yellow, black, and white bands and chow down exclusively on milkweed. They grow 2700x their original size over the course of two weeks! Growing that fast requires them to grow new skin (molt) five times. Milkweeds, named after their milky sap, are poisonous to many vertebrates, and by eating it the caterpillars also become poisonous, which persists in the adult stage. At about three weeks old, caterpillars enter the inactive pupal stage, and change into jade green chrysalises with golden dots. Inside the chrysalis, the caterpillar undergoes metamorphosis and emerges after about two weeks as a colourful, winged adult!

Dedicating part of your yard to milkweed species such as Common MilkweedSwamp Milkweed, and Butterfly Milkweed can attract Monarchs . There are a lot of other beautiful butterflies that can be attracted too. Adult butterflies visit a variety of flowers for nectar such as Wild Bergamot, New Jersey Tea, Joe Pye WeedCommon Boneset, Black-eyed Susan, and goldenrods.  Host plants are plants that eggs are laid on, and are a food source for the caterpillars. Here are just a few examples (note: these plants are not a complete list of host plants, and are not native to all parts of Canada split names show both adult and larvae): 

Planting species native to your area is ideal. More butterfly gardening tips can be found here.

Other happenings:

  • As May was the month of migration, June is the month of mating and nesting.
  • Some of the long-distance migrants, such as the graceful Whimbrels that were seen in the Great Lakes area in late May are just arriving to their sub-Arctic and Arctic breeding habitats. Postel is a Whimbrel that gained a satellite transmitter while feeding in Virginia in 2012, and was still transmitting three years later (over 1300 days).  Hope, tagged in 2009, transmitted for almost 1300 days, and six other birds transmitted through Spring of 2017 or beyond, one into 2020.  We can see their journeys north here.
  • Male songbirds are singing it up to establish and maintain a territory, and attract a mate. Bird song is at is best at the break of dawn, hence the term ‘dawn chorus’. Just before sunrise different species pipe up at different times, and from a previously quiet forest emerges a flurry of noise. Taking in a dawn chorus is a good spring ritual. To catch it in style, wake up early (~4:30am), and head outside with a head lamp, lawn chair, and thermos to enjoy the gradual crescendo and climax, which usually occurs 30 minutes before sunrise. 
  • Wildscaping efforts can benefit Ruby-throated Hummingbirds. Their tiny hearts beat more than 600 times a minute. At the normal metabolic rate they could starve within a few hours without food. Luckily, they can enter a state of torpor to conserve energy. Ruby-throated Hummingbirds  prefer red and orange tubular flowers for nectar such as Jewelweed and Bee-balm (note: Bee-balm is native to parts of Ontario, Quebec and the Maritimes). Their heart rate is even higher during their startling courtship. The male displays (starts at 1:30) by diving in a U-shape pattern from as high as 12-15m above the female, and doing side-to-side arcs and dips in front of a perched female.
  • Chimney Swifts, often described as “cigars with wings”, can also be seen performing courtship displays. ‘V-ing’, most pronounced after pair formation, involves two swifts flying together. The rear bird snaps its wings upwards to form a ‘V’, the leader joins, and the pair gracefully glides downward. As their name implies, Chimney Swifts nest in chimneys or the walls of abandoned buildings. Historically and currently where suitable habitat still exists, they nest(ed) in large hollow trees. Logging removed most natural sites, and Chimney Swifts adapted to ‘human’ chimneys. Contrary to common belief, Chimney Swifts do not nest in colonies. Unmated birds, however, commonly roost together in large flocks, and sometimes in a chimney with a single nested pair. Like many other aerial insectivores in North America, Chimney Swifts are experiencing strong population declines, and are listed by COSEWIC as threatened in Canada, Ontario (scroll down), Manitoba, New Brunswick, and Nova Scotia, and protected in Quebec.
  • Midland Painted Turtles and a bit later in the month Snapping Turtles, searching for nest sites, become a familiar sight along roads and train tracks. Well-drained, loose, sandy soil or fine gravel is preferred. The females use their hind legs to create a depression to lay eggs in. Painted Turtles lay 5-10 white eggs, and Snapping Turtles lay 15-30 eggs. She then covers them up. The eventual sex of the baby turtles is determined by the incubating temperature.  Cooler temperatures (22-26ºC) produce males, while warmer temperatures (≥30ºC) usually result in females. Hatch success is low, and many nests are dug up by raccoons, skunks, and foxes.  Road mortality also causes significant loss of adult and hatchling turtles.
  • Adult mayflies, also known as fishflies, emerge from lakes and rivers forming mating swarms. Mayflies belong to the Order Ephemeroptera. In Greek ephemeros means ‘short lived’ and pteron means ‘wing’. Depending on the species, adults only live for 30 minutes to a day, just enough time to mate and lay eggs. There are hundreds of known species of mayflies, all which have slender bodies and two or three long terminal filaments.
  • Clear, cool, moonless June nights provide the perfect opportunities to observe the Milky Way, and to contemplate that not only are you looking at it, but you are in it.  Our solar system is located on one of the spiral arms of the Milky Way galaxy, about two-thirds, or 25 000 light years, out from the galaxy’s centre. Binoculars will reveal the tiny stars in the “river of milk”. 
  • Venus reaches its greatest distance from the sun on June 4th (scroll down), while Mercury reaches its highest altitude in the morning sky on the 7th. The moon approaches Saturn on the 9th.