A new experience for me, screening Beauty on the Wing for schools in Ontario, Canada. I am not foreseeing any, but with so many kids involved, just praying there are no technical issues.
Monarch Distribution in Canada
The southern regions of Ontario are a beautiful province in which to see Monarchs, especially during the the late summer migration. The Great Lakes act as a barrier on the Monarch’s southward journey. The butterflies gather at the southern most points of Canada to cross the lakes, including Point Pelee in Lake Erie, and Monarch Point Conservation Reserve in Lake Ontario, both on the Ontario side. Just as the Monarchs form overnight roosts at Eastern Point in Gloucester while waiting for the right conditions to cross Massachusetts Bay, they do the same at Point Pelee and Monarch Point in Ontario.
The presence of the Eastern Monarch population in Mexico’s transvolcanic mountain forests was 22 percent less this winter compared to last winter, according to the World Wildlife Fund (WWF) annual count.
Rather than counting individual butterflies, the Monarchs are counted by the number of hectares they occupy. This past winter, the Monarchs occupied 2.21 hectares, down from 2.84 hectares in 2021-2022. A hectare is approximately 2.47 acres. A threshold of at least 6 hectares is recommended to sustain the eastern population.
For more precise information on how the Monarchs are counted read more from Monarch Joint Venture –
Estimating the Number of Overwintering Monarchs in Mexico
Contributors: Gail Morris, Karen Oberhauser, Lincoln Brower
Every year we anxiously await news of the monarch overwintering population count from Mexico. When are they done and how are the monarchs counted?
Monarchs go through four phases while overwintering in Mexico: their arrival, the establishment of an overwintering colony, colony movement and finally the spring dispersal.
The first fall migrating monarchs usually arrive at the overwintering sites in late October through mid-November. In this early phase, the monarchs are largely scattered and diffuse in their flight, moving frequently through an area and eventually creating small clusters at night, while still continuing to move through the forest. During the day, their movement is common and widespread, as they search for the perfect sheltered location to spend the winter.
As temperatures dip colder, monarchs begin to form larger and denser clusters, settling into smaller and protected areas at elevations of 2900-3300 meters (9,500 to 10,800 feet.) This usually occurs from mid-December through early February and the monarchs principally roost in oyamel trees although they use pines and other trees as well. This is the coldest time of the year where monarchs are most compact and stationary in their clusters, a time of winter survival with little movement.
By mid-February, temperatures are gradually climbing and the monarchs begin expanding their clusters. They slowly begin to move down the mountain on warm, sunny days searching for water to drink in nearby creeks. They return to the safety of the nearby forest as temperatures drop. The final phase is the monarch dispersal as the population gradually begins its movement north.
The traditional time of the annual overwintering count in Mexico is in late December when the clusters are most compact and movement is minimal. So how are the estimates done? How do you estimate how many monarchs there are in an area?
The World Wildlife Fund and the MBBR have measured the monarch population each year since the winter of 2004-2005. The occupied trees are mapped in each colony. Beginning with the highest tree in the periphery, the counters use a measuring tape or distance meter and compass to measure the perimeter using a series of lines connecting trees along the boundary. The enclosed area is then calculated in hectares.
Researchers have estimated that there are approximately 21.1 million butterflies per hectare, although this number most certainly varies with the time of the winter as the colonies contract, expand, and move. It also varies with the density and size of the trees in the colony. Based on this estimate the largest population of monarchs occurred in 1996-1997 when the colonies covered over 18 hectares and contained an estimated 380 million butterflies. To date the lowest population recorded was in 2013-2014 with 0.67 hectares and approximately 14 million monarchs.
While population estimates are recorded back to the winter of 1976-1977, long term counts of monarchs previously occupying the overwintering sites for comparison are limited due to a lack of complete data.
Keep in mind that the monarch overwintering estimates in Mexico are done when the monarchs are most compact in the trees. While counts continue biweekly during the time the monarchs are in the area, the end of December counts are used for comparison from year to year.
A very brief Monarch population status update – For the second year in a row, the Western Monarch population is seeing an uptick in numbers. The population is at roughly at 335,000, up from the historic low of only 2,000 counted in 2020. Two years of relatively good numbers gives us all hope the Western population can be saved.
It appears as though the Eastern Monarch population is not doing quite as well as last year. The final count for the winter of 2022- 2023 is not yet in. We’ll check back in on that count as soon as the graph becomes available.
Sunday afternoon, I’ll be screening Beauty on the Wing at the New Providence Memorial Library in New Jersey. New Providence is only about 20 minutes from my Mom and Aunt’s childhood home and it was at my Grandmother’s gardens where I first fell in love with the natural world.
I am also super excited to share that we will be screening Beauty on the Wing for school children (and grownups) across Prince Edward County on June 23rd. Prince Edward County in on Lake Ontario and is a late summer gathering point for Monarchs before crossing the Lake into the US. The entire long point peninsula on the South Shore of Prince Edward County is a designated International Monarch Butterfly Reserve (established in1995).
“The land area of the IBA (editor’s note- Canadian acronym for Important Bird Areas) is comprised of shallow soil over limestone bedrock with areas of alvar habitat. Much of the habitat consists of old field (savannah) and shrub thickets, with small deciduous and coniferous forests being present. In addition to several natural wetlands, the IBA contains two large wetland areas created after berm construction by Ducks Unlimited. The IBA is important for concentrations of migrating birds, bats and butterflies and also supports several rare vascular plants including Four-leaved Milkweed, Butternut, Bicknell’s Sedge, Short-stalked Chickweed, Brainerd’s Hawthorn, Limestone Hedge-hyssop, Green Arrow-arum, White-tinged Sedge, Eastern Few-fruited Sedge, Ram’s-head Lady’s-slipper, and Carolina Whitlow-grass. Largely undisturbed sites are important to ensure survival of these plants.”
The PEC south shore is also home to the Prince Edward Point Bird Observatory, where a diverse and extraordinary number of birds concentrate during migration.
Monarch and Whorled Milkweed (Asclepias verticillata)
The zinnia and milkweed patch has been attracting a magical assemblage of butterflies, hummingbirds, bees, hover flies, and other insects throughout the summer. Stay tuned for part two coming soon – Monarchs and Friends in Marsh and Meadow!
Plant and they will come!
Monarchs and friends in the mid-summer garden. A host of pollinators finds sustenance in our zinnia and milkweed patch.
Cast
Monarch
Tiger Swallowtail
American Lady
Black Swallowtail
Ruby-throated Hummingbird
Clouded Sulphur
Cabbage White
Various bees and skippers
