Friday 25 August 2017

Transformation of a monarch

It is always fascinating to see the transformation of invertebrate life. In my opinion, there is no more interesting example than to follow the development of a butterfly, and in this case, the Monarch butterfly.

The following images weren't all taken in the last few days, but many of them were. This first one shows an adult female with the tip of her abdomen turned up to the underside of a milkweed leaf as she lays an egg.

 The egg is very small, as to be expected. It is only a couple of millimetres in diameter.
 After a few days, it hatches (hopefully!). Ants are known to find and consume the developing larva, so not all eggs will hatch. Upon hatching, the larva consumes the remains of the egg and will chew a small hole through the leaf.
 This next one shows a larva that is probably 2-3 days old. It hatched out on a small milkweed plant that I was growing from seed in some plug trays.
 Over the course of several days it feeds ravenously.

 After several periods of growth, it gets to the point where it seeks out a place to change to its pupa stage. This usually is in a more obscure location, and often happens well away from the milkweed plant. The caterpillar hangs upside down with its hind end producing a sticky mass of threadlike substance which will provide an anchor, holding it in place while it develops into the adult. While hanging upside down, the caterpillar splits its skin and wriggles out of it, revealing this beautiful chrysalis of the pupal stage. It is decorated with black and gold spots.
When the above photo was taken, it shows a slight darkening of the chrysalis at the bottom. Just before the adult emerges, the outer part of the chrysalis turns clearer and somewhat brown. A close look will show some of the detail and colour of the newly formed adult inside. I wasn't expecting it to happen quite so quickly, and so I missed that part! This next photo was taken less than 24 hours after the one above. The new adult emerges and climbs a bit to a surface where it can hang for several hours while its body fluids are pumped into the venation network making the wings rigid.

 Usually within 4 or 5 hours of emerging, the butterfly is able to take flight and will hopefully survive to continue the propagation process.
It truly is an amazing transformation!

Now that the end of August is close at hand, over the next few weeks, Monarch butterflies will be heading south and west by the hundreds of thousands, on their long journey to the wintering ground in some Mexican mountains. In southwestern Ontario, the peak of their migration seems to occur from about the middle of September to the end of the month, although some individuals can be seen up to the end of October or even after. It all depends on when the latest generation emerges as an adult, which is somewhat weather related. Corridors of natural vegetation and lots of milkweeds are critical for the butterflies to make it to Mexico as well as for future generations to return.

Friday 18 August 2017

Phalaropes and Orchids

I realize that Phalaropes and Orchids may seem like an odd combination, but sometimes the events just go that way.

Some readers may recall an earlier blog post, describing an unsuccessful attempt in predicting the appearance of one of Canada's rarest orchids, Nodding Pogonia, to be in flower at Rondeau Provincial Park. I was determined to see this species in flower, and on August 13, the overnight temperature dipped lower than it had been for several days, down to about 11C. With that bit of information in mind, I figured that August 15 might be the day to see these amazing little flowers fully open.

It so happened that at about the same time, there was an appearance of up to 8 Wilson's Phalaropes at the Blenheim Sewage Lagoons. This species has nested at the lagoons on very rare occasion, but in recent years even seeing them on migration has been a challenge. So on my way to Rondeau to check out the orchids, I made a stop at the sewage lagoons.

There was, as expected, a lot of shorebirds scattered along the gradually expanding muddy edges of the ponds. And there in one corner, were three of the aforementioned phalaropes, spinning around as phalaropes do.


 On occasion, one or two would come up to the very muddy edge and preen.

After viewing these phalaropes, I continued to Rondeau. Putting on my boots and gathering my equipment, I struck off, hoping that this would be the day. Some years I don't ever see them in flower. The mosquitoes were present but tolerable. Sometimes they are a formidable presence, making this foray very uncomfortable. On this occasion, putting up with the mosquitoes was worth the effort, as I came across a few orchids in flower!




 At best, these little plants are small, typically no more than 12-15 cm in height. However some are extremely diminutive, as the one in this last image was no more than about 5 cm!
Since I might not have a chance to see them in flower again this year, and who knows what the next year or so might result in, I took lots of photos. This declining orchid, in Canada, grows only at a remote place or two at Rondeau, and some years not a single plant will flower.





Monday 14 August 2017

Field Botanists visit Bickford Oak Woods

Last Saturday I had the privilege of meeting a group of about 20 enthusiastic members of the Field Botanists of Ontario at the Bickford Oak Woods Conservation Reserve in west central Lambton County. The outing was planned several months in advance, and the main target species from a botanical standpoint was to see the one and only place in Canada where Swamp Cottonwood (Populus heterophylla) occurs. It was first discovered by the trio of Gerry Waldron, John Ambrose and Lindsay Rodger back in 2002 while they were doing a vegetative inventory in the early stages of this site becoming a Conservation Reserve. It isn't an easy species to find, even when you know where it occurs at this site. One has to access the spot through a planted prairie, then along the woods for several hundred metres, and eventually following an overgrown logging trail for several hundred more metres. It is then necessary to strike off through the woods, cross a muddy creek and then venture another couple of hundred metres to find the buttonbush swamp which has a number of stems of this rare tree. The FBO members were eager, so off we went.

On the way to the spot where the cottonwood grows, we came across a number of interesting species. This first one, Whorled Milkweed (Asclepias verticillata) was a new one for some of the members.
 The wet spots along the trail, of which there were many, had a few stems of this Square-stemmed Monkey Flower (Mimulus ringens).
We came across a Giant Swallowtail butterfly. In this area, one of the main plants that the larvae of the Giant Swallowtail survives on is Prickly Ash (Xanthoxylum americanum). As one might guess by its name, it is a thorny species, and not one that is fun to hike through. Seeing this beautiful large butterfly was a bit of compensation for the time spent shortly after trying to get through the Prickly Ash thickets without getting too scratched up.
 At one point along the creek and floodplain area there were some of these Cardinal Flower (Lobelia cardinalis) in fine shape. It isn't a rare species by any means, and in fact is quite widespread across southern Ontario and beyond, but the brilliant scarlet colour of the flowers is always a treat to come upon.

 Most oaks at this conservation reserve have been logged at one time or another. There are very few large examples remaining. However this White Oak (Quercus alba) is relatively large. Probably because it is growing right along the edge, and has lots of large lower branches, it was less valuable from a timber standpoint at the time the site was logged half a century or more ago.
As mentioned, the intended target species for this hike was the Swamp Cottonwood. This next image shows what the site looks like in the spring, with lots of variable sized trunks of this rare species growing in standing water.
 And this is the characteristic leaf: it is large for a cottonwood, has a heart-shaped base, and the leaf stem is round, not flattened as most Populus species are.

This is the happy group of FBO members, in front of a cluster of Swamp Cottonwood tree trunks.

After achieving our target of seeing the Swamp Cottonwood, we returned to the parking lot and had some refreshments. With about 4 hectares of planted prairie adjacent to the parking lot, we took a bit of time to explore the species present. Big Bluestem, a.k.a. Turkeyfoot (Andropogon gerardii) is the most common grass in most tallgrass prairies.

Gray-headed Coneflower (Ratibida pinnata) is often quite abundant.
 False Sunflower(Heliopsis helianthoides) is one of the many sunflower types found in a prairie.
 Dense, or Spiked, Blazing-star (Liatris spicata) is probably one of the best known, iconic prairie wildflowers. It is a Threatened species in Ontario.
 Compass Plant (Silphium laciniatum) is not common at all, but really stands out on a prairie.

 Another Silphium species is Cup-plant (Silphium perfoliatum). The close-up of the paired leaves show the cup-like aspect which gives it its name.

 Prairie Dock (Silphium terebinthinaceum) is another iconic tallgrass prairie species. The shovel-shaped leaves are clustered at the bottom of a tall, quite rigid stem that sometimes grows more than 3 metres high.
 Tall Coreopsis (Coreopsis tripteris) is another rare prairie plant restricted to the tallgrass prairies of extreme southwestern Ontario.
 Yet another member of the sunflower family that is common on the prairie is Tall Sunflower (Helianthus giganteus). It too often grows 3-4 metres high or even higher.
It was an excellent day, and with great weather right up until the end of the outing. Just as the last of us were packing up the vehicles, it started to sprinkle and there was the occasional rumble of thunder in the background. Before we got too far down the road, the rain came down in torrents.

Friday 11 August 2017

An unpredictable orchid, and other Rondeau stuff

August is the time when one of the rarest orchids in Canada is to be looked for. As it turns out, the only known location for it in the entire country is Rondeau. There are some historic records for it in the southern Essex County area, where it was first discovered in Canada back in about 1950. However that woodlot is small, heavily grazed, and the orchid has not been seen there in over 25 years.

The orchid I refer to is Nodding Pogonia (Triphora trianthophora), and it is a provincially and federally endangered species. While numbers of this orchid have, on occasion, been more than 1000 plants, in recent years the numbers are considerably lower. Unfortunately there has been more than one year recently where flowering was minimal and there was no successful seed production at all.

The other day, I ventured to Rondeau in the morning to check on the orchid. I have been monitoring it via some study plots for over 30 years, and for more than a decade before that, I searched for it regularly with varying degrees of success. One of its peculiarities is that the flower buds of the entire population develop to a certain stage, then on the second morning following a significant night-time drop in temperature, all of the blooms will open up....but just for the one day. It may be several days, or more than a week before the process repeats itself. Timing is everything, and one of the things we don't know is just how much of a temperature drop is required to trigger the buds to open up.

When I arrived at the spot where there were a few plants, I saw this:
The buds were developing nicely but seemed like they had a way to go before being ready to open. So I waited for a couple of days, and this is what I found upon my return:
They had opened the morning before, and were now closing up!

This is what I was hoping to find (photos from previous, more successful times):


But it wasn't to be on this day. Perhaps later in August.........

To get a fuller appreciation of the unusual nature and complexity of this endangered orchid, check out my earlier blog post here.

Even though I was not successful on this trip to capture the Nodding Pogonia in good flower, I did manage to see a few other things. On the walk to the orchid site, I noted these seed pods developing. This is an uncommon woodland milkweed, known as Poke Milkweed (Asclepias exaltata). The seed pods are smoother and considerably slimmer than the more abundant and widespread Common Milkweed (Asclepias syriaca).


There were some flowering grasses along the way. Grasses do have flowers, and they are wind-pollinated. These are the flowers of Big Bluestem (Andropogon gerardii), a typical prairie and savanna species. This photo shows the male parts--the anthers--dangling down, as well as the smaller purplish female flowers sitting tightly to the stem.
 Sometimes the flowers are distinctly yellowish rather than purplish.

On a part of the walk along the Tuliptree Trail, I came across this little critter.
 It is the nymphal stage of a Leaf-footed Bug. It is less than 10 mm in total length, and being an active little critter, was difficult to get in focus all the time.


A much larger invertebrate critter was this meadowhawk, probably a Ruby Meadowhawk, but sometimes the several meadowhawk species found in the area are difficult to tell unless you examine genitalia.
Along the beach dunes, there is a profusion of Cylindrical Blazing-star (Liatris cylindracea) coming nicely into flower. It is not a common species, but restricted to sand prairies and the sandy beach dunes of Rondeau's east beach area are perfect for it.





Maybe on my next trip to Rondeau, I will have had some success in photographing Nodding Pogonia, but if not, there is always lots of other things to focus on!