I have seen the pretty violet and yellow flowers in the Whitemud Ravine all summer long, but have somehow not stopped to try to identify them yet. Since they are likely to going to be astound for much longer + because most other flowers are gone by now I figured I better do something about this omission before it is too late. Identifying these flowers was not hard. They are Smooth Blue Asters (Symphyotrichum laeve) and is found throughout North America in fields, open woods and along roadsides. They have composite flower heads where each flower actually is made up of smaller flowers consisting of ray flowers (petals) surrounding disk flowers (the yellow centre). The asters are often one of the latest plants flowering after all other species are past their flowering stage.
Summer is not even over yet but the fall colours are impatient and the Prickly Wild Roses are already turning red. The process of leaves changing color in the fall is surprisingly complex. Perhaps the most common explanation for color change in leaves is the withdrawal of chlorophyll. This appears, however, to only be true for leaves that turn yellow. The yellow seen in some autumn leaves result from the loss of chlorophyl unmasking the yellow carotenoids that were there all along. Red leaves, on the other hand, come from stopping the production of chlorophyll and starting the production of anthocyanin, which also gives raspberries their red colour. The Prickly Wild Roses along the trails have rapidly turned red over the last week while most other plants still are green.
The Blue Spruce (Picea pungens) can be found natively through the Rocky Mountains with Alberta being its northern limit. These evergreen shrub with their blue-green needles and perfect conical shape have a regal looking about them. In traditional First Nations medicine the needles are used for an infusion to treat colds and an upset stomach. These are slow growing trees that with as lifespan of hundreds of years. The squirrels in the river valley have a particular fondness for the cones of the Blue Spruce. It’s not uncommon to see squirrels with in full speed with carrying spruce cones to their middens where they store them for the winter.
The seeds of the Creeping Thistle are about to get airborne. All it will take now is the slightest of wind puffs and they are on their way. This inflorescence almost looks like it has a bad hair day. But it will not last. Soon the seeds will be gone with the wind. Each Creeping Thistle plant can produce thousands of seeds at the end of the summer. In addition to reproducing using wind-dispersed seeds, the Creeping Thistle also reproduced vegetatively by creeping roots (rhizomes). These two reproductive methods result in the plant being a formidable weed that, once established, is virtually impossible to eliminate. It often invades crop fields and grasslands where it lowers crop yields and forage productivity.
It was a late sunny afternoon down at the Whitemud park and I noticed that a lot of crows were flying around, all seemingly heading in the same direction.It turns out that these were crows on a mission. The were all heading to a grove of dead trees for their night roost. A crow night roost is basically a corvid slumber party. The crows were pretty mellow with only the occasional squawk and scuffle disturbing the peace. I can see that there could be numerous benefits to such a corvid sleeping party. Perhaps one of the more obvious benefit is safety in numbers. There are more eyeballs to keep watch for predators at night of the crows roos together. It would be interesting the come back to this location to see if they use the same roost location every day (I suspect that might) or come back in early in the morning to see if they are still there.
Looks like the warm and sunny weather that did not arrive this summer has arrived in the eleventh hour of the summer. The beautiful weather was simply impossible to resist and we decide to go for a family walk in Whitemud park tonight. It was a sunny afternoon, the hot air balloons were out and the fitness buffs were out burning far too many calories far to fast. We did not see much in terms of birds other than around 50 crows gathering for the night. We came across a gentleman with a large bucket harvesting Chokeberries along the trail. The rainy summer has resulted in a bumper crop of all manners of berries, including the Chokeberries. The Chokeberry bushes were heavy of large, plump and ripe fruit. This is my first encounter with a plant that is native to North America but has been introduced in Europe. Usually the situation seems to be the other way around. Chokeberries can be processed into jam, syrup, tea and wine, but can also be eaten raw off the bush. We tried some fresh berries. The flavour was quite tart and made the mouth feel dry. Apparently the technical term for this sensation is astringency. It also turns out the fleshy part of the berry is pretty much the only part of the plant that is non-toxic. The rest of the plant, including the leaves, twigs, bark and the pit in the fruit are toxic and can cause cyanide poisoning in humans and livestock. As I was sampling the berry I recall being surprised at the size of the pit and I am happy that I decided to spit it our rather than consume it.
It started raining as soon as I arrived at Hawrelak park. I sat in the car for a few minutes debating if I should call off my nature walk or if I should brave the rain and proceed with my planed walk. In end end I decided to go for the walk. Is was not raining too hard and I had brought my camera’s rain gear so I should be good. Perhaps not surprising most birds had taken refuge from the rain and were nowhere to be seen, but – perhaps unsurprising – the waterfowl were out. An assortment of waterfowl were hanging out on the pond, seemingly oblivious to the rain. There were quite a few what looked like immature Common Goldeneye hanging chugging around, diving and popping up all over the place. I am not 100% sure about the identification as these fellas were all brown with black bills and eyes. Common Goldneyes seem to be the best match.
It’s not often you see a coot on dry land and this fella appears oddly disproportionate as it is standing at the waters edge at the Hawrelak park pond. Coots look quite craceful when chugging through the water this one is more plump-looking, chicken-like with a too small head, or too chunky body. It was a balmy end-of-the-summer day and the coot and its nearby chicks looked quite comfortable just hanging out on the well-manicured lawn. Coots do migrate a south in the winter, but tend not to go far south. It seems that they are just flying far enough to avoid the coldest of the deep freeze. The coot may be an accomplished swimmer and diver, but it is an awkward and clumsy flier often requiring long running takeoffs across the waster surface. It sort of makes sense that it would keep its winter migration short.
On the banks of the North Saskatchewan River there are a large number of outfalls. An outfall is a drainage facility that conveys stormwater into a natural receiving water body (ex. creek, river, etc…). There city has a map online of all the outfall locations and, well, there are quite a few of them. The other day, as I was walking along the southern shore of the North Saskatchewan River I spotted Outfall 23 across the river. I noticed that the water coming out of the culvert was foaming and getting stuck along the shore as it drifted down stream. Foamy water in itself does not necessarily mean that the water is contaminated (see my previous post number 131 on foam lines). This time, however, it was clear that the foam originated from the outfall culvert. Outfalls convey stormwater that has been collect from runoff from impervious surfaces (e.g., roofs and roads) typically from entire neighbourhoods. This means that pollutants from roadways, lawns and roofs are essentially concentrated and discharged at a single point making the outfall a point source for pollution. The water quality in the North Saskatchewan River changes throughout the seasons with high runoff seasons such as spring resulting in more silty and polluted water. A 1994 study found that discharge of stormwater during summer rain storms does affect water quality in the North Saskatchewan River, including increasing levels of heavy metals and fecal coliform bacteria. The same study also found that the composition of invertebrate animals are dramatically affected downstream from Edmonton due to the change in water chemistry as it flows through the city. One of the effects is an increase in the nutrient levels in the river (think lawn fertilizers) which on one hand can augment the food base for the invertebrates but it can also wreck havoc with the levels of disolved oxygen, similarly to lake suffering from eutrophication (nutrient enrichment).
The Creeping Thistle inflorescences, which are everywhere along forest edges and open fields, are slowly undergoing a metamorphosis from pretty fuzzy purple flowers to mangy-looking fuzzy grey bunches of seed. The seeds have a feathery appendage, aka as a pappus, that enable the seed to be carried by the wind. Wind dispersed seeds is, however, only one trick the Creeping Thistle has up its sleeve when it comes to reproducing. It is also able to make new copies of itself by reproducing vegetatively by developing an extensive lateral root system.