The Sunflower Hill Chronicles, Part 6: Observations and Factoids
May 14, 2022
By Birgitta Jansen
When I go out for a walk and my husband Neal asks me where I am going, the now-usual reply is, “Sunflower Hill.” I walk “The Hill” about two or three times a week to see what there is to see. In these days of spring, it is remarkable how fast everything changes. We had a few days of overcast and gentle rain on May 5, 6 and 7. That reminded me of how the Navajo, Native American people who live in the desert, describe rain. The gentle winter and spring rains are the female rains because they nurture the landscape. The male rains, those heavy downpours that are part of Navajo life in the summer, are the sculptors of landscape. Our gentle rain brought water to thirsty ground. Plants were ready and responded eagerly. Suddenly, fresh-looking, bright green was everywhere.
There are two reasons for the vibrant light-green spring colours. The chloroplasts, the organelles within the plants’ cells that contain the green pigment chlorophyll, are still developing. It is the chloroplasts that are responsible for photosynthesis. When that process goes full blast, we’ll see the deeper summer-green. In the early stages, the leaves are also thinner and do not yet have the waxy or tough layers that darken leaves in summertime.
The Oregon grapes, however, seem to be one of a few exceptions. The leaves of many of the plants are a burnished dark red. Dark red?
Plants that show red leaves in the early days of spring, such as the Oregon grape (Mahonia aquifolium), convert sugar into a red pigment called Anthocyanin that colors the leaves red. As my California friend and botanist Jane Cipra explains, “Anthocyanins basically work like a sunscreen to protect plant tissues and chloroplasts from too much sun. In the case of the Oregon grape, it could well be that the Anthocyanin protects the leaves until they are more developed.” As a final conclusion, Jane wrote, “It is likely more complicated than that. It is possible that Anthocyanins protect the plant from disease or even from being eaten, but scientists are still in the process of figuring that out.”
Even though we may not have a definitive answer as to why exactly the young leaves are red, the Oregon grape is nevertheless a remarkable plant. It is strong; it tolerates poor soils, blooms early, and is fairly resistant to summer drought. This western native species is as happy as part of a forest’s understory as it is in a brushy landscape, from southeast Alaska to northern California. But even though this plant is described as “drought resistant,” I am noticing that already many plants show leaves that are turning a lighter red, yellow, and brown, and drying up. Food for thought…
One more thing: this plant is actually not a grape. After its lovely clusters of yellow flowers have bloomed, the dusky blue berries form and are beloved by many birds. These berries are reminiscent of grapes, so I think we can safely assume their appearance contributed to the plant’s name.
Now, to a different observation that raised a question for me. On the trail that runs along the ridge of Sunflower Hill, and in the wooded area, there are two aspen that have some mysterious scrapes on them. I wondered who could have done this and asked around. Elk? Deer? A bear? Quite a few of us were thinking “bear,” but the question lingered until retired ecologist Gary Tipper came to the rescue.
Here is his reply: “The height of the marks is what points to elk, plus the size of the marks. Additionally, elk are known to forage in this manner. Cervids (members of the deer family) only have incisors on the bottom jaw, so an upward motion of the head is used to remove the bark. In these scrapes the individual tooth marks are visible.”
Gary continued: “Eating bark is likely low on the choices for foraging opposed to eating shrubby vegetation that is available above the snow line or herbaceous vegetation that is available by cratering. A lack of alternative forage, which can be caused by deep and/or crusted snow, would lead to this behavior. This is called ‘barking.’ Moose do this as well, but not often.” But “barking” aspen is not the only barking that elk do. One of their vocalizations is also referred to as barking.
My next observation was about the butterflies I started seeing in the beginning of May. The butterflies surprised me because I associate them with summertime. But when I saw them, it was still quite cool. So I wondered, what’s up with these butterflies?
The first one I saw was the Mourning Cloak (Nymphalis antiopa). The wings’ upper surface of the Mourning cloak is a fairly dark reddish-brown with a thick yellow border along the outer edge of fore and hind wings. On the inside edge of this border are bright blue elongated spots. What I thought most remarkable is that these butterflies are one of the few species whose range extends into Europe and Asia.
Here in Canada, the Mourning Cloak is found from coast to coast, and as far north as the tundra. This butterfly is quite adaptive as to what habitat it lives in; could be shorelines, woodlands, forests, or fields. Their preferred food is sap from (mostly) deciduous trees but they do appreciate the nectar from flowers as well. But in the Sunflower Hill area, I saw them around damp sand and mud puddles to obtain minerals.
But how did these butterflies manage to be happily fluttering about so early in the spring?
As it turned out, the Mourning Cloak is one of the few butterflies that overwinter as adults by snuggling into well-protected places. They emerge in early spring, even when there is still snow on the ground. Since they are cold-blooded and need to warm up before they can fly, they vibrate their wing muscles to generate heat. Once they’ve warmed up, they can leave their winter spot, find food, and mate. I must admit I’m amazed. Butterflies that can vibrate their wings to warm up. I have never witnessed this, but if I’m ever lucky enough, I’ll know that the butterfly is waking up from winter sleep and getting ready to fly!
The next butterfly I saw was the diminutive Boreal Spring Azure (Celastrina lucia); such a pretty butterfly. The ones I saw were a lovely pale blue with tiny dark markings along the outer edge of its wings. As it turns out, this butterfly also overwinters but not as an adult. It builds its chrysalis and emerges in the spring. The ones I saw were, like the Mourning Cloaks, also congregating around damp sand.
The third kind I saw in various places on the hill was the Satyr Comma, which belongs to the Anglewing family. These butterflies have only one brood per year. The adults that emerge in the summer feed in the fall and then go into hibernation as adults. After they mate the following spring and lay their eggs, they reach the end of their life cycle. But then, as the Earth turns, the pattern repeats when the next generation emerges.