Heatwave, Milkweeds, and Fireflies (video)

5 July

Let’s start with a hot bird on a hot day - an American Goldfinch on Joe Pye Weed, wondering when the flowers will open properly and start making seeds to eat. Also the first Rudbeckia hirta of the season, there will be many more to come.

This week, Quebec caught up to Europe in terms of abnormal heat and humidity - several days in the low 30C range but with Humidex temperatures up to 44C or more. Consequently, not a whole lot of walking and exploring has been enjoyed. Brief excursions to water tomatoes and check for the first arrival of the hated Japanese Beetles being as much as we could bear. Recent days have been something like this young lady, in fact …

Nevertheless, the garden, having plants that evolved to cope with hot summer days, seems to be bearing up well and the trees and bushes are alive with newly fledged birds testing their wings accompanied by nervous parents. The bees, of course, have been very busy, gradually transferring their attention from the roses to the just opening Milkweed flowers … sadly I can’t find a photo of a Monarch on Milkweed, but as we all like Monarchs regardless, here is one to enjoy anyway - this time on what looks like Wild Parsnip:

And, having found myself thinking about Milkweeds, let’s consider them a bit more closely. Milkweeds are all in the genus Asclepias. There are some 200 or thereabouts different species, of which perhaps 70 are native to North America and many fewer in your top right corner. So not “just” Milkweed as most people think of it, but lots of different species - the thing to know is which are adapted to your locality. In our garden, in our area there are three principle species. We enjoy Common Milkweed (Asclepias syriaca), Swamp Milkweed (Asclepias incarnata) and Butterflyweed (Asclepias tuberosa). The first two of those are in flower right now and A.tuberosa can’t be far behind.

Asclepia incarnata (Swamp Milkweed) and Asclepia syriaca (Common Milkweed)

One thing to be careful of is that Milkweeds contains toxic cardiac glycosides, which can lead to serious health issues if ingested by humans, or livestock. Not all species seem to be so affected though - just a few days ago, a Ground Hog was testing some of our plants with his teeth. Then there are the Monarch Butterflies which are quite unaffected by the plants and their sap - in fact they are the only plants on which the Monarchs can lay their eggs and on which their larvae can feed and grow although the adults will take nectar from a wide range of other flowers. Hence, why one of the reasons that there is so much work being done to persuade gardeners and communities to grow Milkweeds, because if the plants become scarce - as they have - then we risk losing the butterflies too.

The Milkweed “flower” is complex and composed of many small flowers, each of them remarkably complex - this diagram shows the basic structure of a single milkweed flower with its distinctive gynostegium column formed by the fusion of stamens (male reproductive parts) and styles (part of the female reproductive system). This fused structure aids in attracting pollinators and facilitates the transfer of pollen, enhancing the chances of successful fertilization.

Although the flowers of all species of Milkweed have five petals, five sepals and a corona that contains the gynostegium column, they vary widely in color, shape, size and structure. Many species have showy globe-like umbels with numerous flowers, like antelope-horns milkweed, while others are less dense and less organized and droop, such as Carolina milkweed. They have the same reproductive structures that function in the same way, but they all look different.

The seeds develop in a capsule ready for release when they float through the air supported by long “silk” to land where they may and take their chances on germination and growth. A bit of naturalist aided, guerrilla seed distribution in choice habitat can help the species survive.

By chance, I was dripping sweat near the end of the garden pond when I became aware of more than a dozen really smart Yellow-legged Mud Dauber Wasps (Sceliphron caementarium) whizzing around at quite a speed. Over an inch long and hard to get a sharp photo of as I only had a manual focus macro lens on the camera that was in my hand.

These are solitary parasitoid wasps that make mud nests. After building a cell in the nest, the female wasp captures one or more spiders, paralyses it with a sting and places it in the nest. A single egg is deposited on the prey within each cell to feed the larva when it hatches, and then the wasp seals the cell with a mud plug and departs. They are not aggressive and you would have to try hard be stung by one. Those yellow bands on the legs are very striking.

Also seen was a Florentine Wool Carder Bee (Anthidium florentium). They get their name from the action of females collecting hairs from leaves of plants such as Lambs Ear and using these hairs to line their nests. They are generalists and will take pollen from flowers of various families, preferring blue flowers with long throats and Old World origins. This is a male as shown by the grey hairs on either side of the thorax (who knew - you can learn many useful things like that by trying to ID creatures).

Unlike the majority of solitary bees, a study found that there are more females than males, males are bigger than the females, and the sexes fly at the same times of year. P. Wirtz and colleagues suggest that this pattern is explained by the prolonged sexual receptivity of the females, along with the males' use of readily defended resources in their territories.

Value in Urban Nature

Consider an urban park: When designed with biodiversity and climate resilience in mind, the park’s green spaces slow and absorb storm water, provide habitat for pollinating insects and birds, and mitigate urban heat. As storms become more severe, the park supplements the performance of grey infrastructure without the need for additional investment. As well, over time, the park creates a “nature premium,” adding value to every adjacent home and commercial property.

The upfront capital investment is marginal, but the value added is significant. In urban areas, private assets such as real estate benefit from nature’s premium, which also reduces the risk of their becoming stranded due to climate change and environmental degradation. Properties become more attractive to tenants as adjacent natural parks mature and flourish. Nature- based infrastructure reduces liabilities, including insurance premiums and clean- up costs.

(Quoted from the Globe & Mail)

World’s loneliest tree

I came across an encouraging bit of conservation news and would like to share it.

The Juan Fernández Islands lie about 700km off the coast of Chile. One of them being the island on which Alexander Selkirk (the original Robinson Crusoe, no less) survived alone for four years. It’s also where, clinging to a steep cliff to which it has been roped, grows the last known wild individual of Dendroseris neriifolia, a rare tree daisy found only on this island group. In 1980, only eight wild trees remained. Today, there is just the one, hanging on, literally, after decades of habitat loss, forest clearance, and intensive grazing by introduced mammals. Repeated fires have not helped at all.

This year, 400 seeds were collected from that single tree and 29 were sent to Kew’s Millennium Seed Bank in Sussex. X-ray analysis showed 25 were potentially viable. Eight were selected for germination trials. All eight sprouted. Three of those seedlings are expected to transfer to Logan Botanic Garden in Scotland.

The challenge is significant. Because all seeds come from a single parent, the species faces serious genetic limitations. Around 90% of wild seeds are non-viable due to the tree’s isolation. Garden specimens cannot be used because many have hybridized. The Juan Fernández Islands are home to many species found nowhere else on Earth, including the critically endangered Juan Fernández firecrown hummingbird, which depends on Dendroseris flowers. Eight seedlings from the loneliest tree on the loneliest island. That counts as good news.

Dendroseris neriifolia, is a species of flowering plant in the family Asteraceae. This link takes you to an article from Kew that explains more about the process they are working with to ensure the species does not go extinct.

https://www.kew.org/about-us/press-media/critically-endangered-tree-on-cliffside-finds-hope-at-kew-and-logan-botanic-garden

Baby birds need bugs

Birds have evolved so that the hatching of their eggs synchronizes with the peak availability of insects to feed the young - but the rapid changes of climate mean that in many places the insect numbers are at their highest some two weeks ahead of egg hatching these days. A change that has happened very rapidly - the shift is estimated to be around three days per decade on average and which leads to underfed young and young not reaching maturity.

https://www.cbc.ca/news/science/climate-change-swallows-insects-ontario-9.7254512

This is yet another factor that gardening for wildlife can help. Quote:

… insect declines are something that can be addressed at a local level … planting native wildflowers and reducing pesticide and herbicide use so that vegetation can grow and harmful chemicals don’t leach into the environment. Not removing wood and leaves can also help create habitat for insects, which in turn helps the birds. “Everything is connected,” Elsayed said. “One change in a specific group really does impact the rest of the food chain.”

The anxiety of the perfect loaf: the illusion of culinary precision

This week, I did not find a book, per se, on the top shelf, but was pleased to read this article about the biology of baking and the importance of intuition and understanding, compared to absolute numerical precision when there are so many variables that we cannot control in a domestic environment. This is a good read, especially if you bake bread. I, for one, long ago learned that bread recipes are just a starting point; to get good results you must trust to experience, instinct and the “feel” of your dough. It’s right when it feels right.

https://iza.ac/posts/2026/06/intuitive-cooking/

“There is a generation of cooks paralyzed by precision. I find it funny whenever I painstakingly measure water out to exactly 426g just because a recipe told me to, my anxiety spiking if the digital scale accidentally flickers to 427g. We have become terrified to deviate from the written instructions, fearing that a single gram will ruin the bake … But we forget that our kitchen is a living, breathing environment, not a laboratory clean room. That flour is an agricultural product, not a synthetic chemical. Its moisture content, protein level, and enzymatic activity change from country to country, and even from season to season. Blindly executing a command to add exactly 426g of water on a humid summer day with the wrong type of flour might leave you with a puddle.”

Fireflies