Spring at the Richmond Lagoons

Sora

The Richmond Sewage Lagoons (formally known as the Richmond Conservation Area) is one of the few places in Ottawa that did not close its parking lots during the COVID-19 pandemic, and as such, it is one of the few birding spots I visited regularly during the months of April and May. The habitat is unique: there are three cells left from the former sewage lagoons, each containing its own mini-ecosystem. The first cell as one approaches from the parking lot on Eagleson (the southernmost cell), has deep water and extensive cattails, making it great for Pied-billed Grebes, rails, bitterns, Swamp Sparrows and waterfowl, mainly geese and dabbling ducks. The middle cell has deeper water and very little cattails, making it a better spot to see diving ducks. The third cell used to be almost entirely choked with cattails interspersed with small patches of open water, making it the best spot to watch and listen for rails. This spring when I arrived on my first visit I was dismayed to see that not only had the cattails been chopped down, but so had some of the tall trees bordering the cell. The cell looked like a soup of water and what was left of the churned up marsh bottom and vegetation, although a deep puddle ringed with a few cattails remained.

Snippets from Migration

Common Yellowthroat

Migration has been strange this year. Because of the lengthy cold spell at the beginning of May it seemed as if migration had stalled; for so long I felt as though I were waiting for it to begin, then things happened so quickly that now I wonder whether it has passed me by. The White-crowned Sparrows that usually show up in my backyard every year between May 3rd and 5th didn’t arrive until the 14th; the Common Terns that arrive at the Eagleson Ponds between May 10th and May 14th didn’t arrive until May 19th. Neither species stayed long, either. The terns were only there for one day before moving on, instead of spending two or three days. It is harder to know if the White-crowned Sparrow I saw over the course of a few days was the same one or a different one, as many have been singing in our area in the middle of the month.

The warblers came, and the warblers went. I’ve had several Black-throated Blue Warblers this year, and many repeat sightings of local breeding species – but of the ones that only pass through, I’ve sometimes only been lucky to get one: one Cape May Warbler, one Blackburnian Warbler, one Tennessee Warbler, one Bay-breasted Warbler. Again, is this a reflection of my spending time mainly in Kanata south, rather than heading for the migrant traps along the river? There have been excellent reports from the usual spots (Mud Lake, Andrew Haydon Park), but even as the city parks reopened on May 6th and the NCC parking lots reopened on May 22nd as a result of declining Covid-19 cases in the city, I’ve been reluctant to go to the normal spring hotspots to avoid the crowds that tend to gather there, both birding and non-birding alike. This has less to do with any fear of the coronavirus than my preference for quiet birding experiences, away from the loud chatter and narrow, crowded trails that both increase exponentially as the spring wears on and weather warms up.

Early Spring Wildflowers

Canada Violet

Spring not brings the birds and butterflies back to the Great White North, it also brings wildflowers, the earliest of which are known as spring ephemerals. These perennial woodland wildflowers grow early each spring, quickly blooming and producing seed before the deciduous trees leaf out and prevent the sunlight from reaching the forest floor. Once these wildlflowers have gone to seed, the leaves and stems above ground often wither and die off, leaving only the underground structures (including the roots, rhizomes, and bulbs) alive during the remainder of the year. This strategy allows many different plants to thrive in deciduous forests by taking advantage of the early spring sunlight prior to the development of the tree canopy.

Butterflies of Early Spring

Spring Azures

Butterflies emerge in late winter or early spring as soon as the first warm, sunny days arrive and the temperatures reach about 13-15°C. This could happen as early as mid-March here in Ottawa, although the butterflies usually don’t stay out for very long – the nights are still cold in late March and early April, and they may not become fully active until the weather warms up to a consistent 15°C in late April. The first butterflies that emerge are those that spent the winter in their adult form, hibernating in mixed or deciduous woodlands beneath the bark of trees, in brush piles, or in other nooks and crannies where they are protected from the wind and biting cold Arctic air. Only a few species hibernate as adults; others overwinter as caterpillars, eggs, or pupae contained within their protective chrysalises. Still others are unable to tolerate Canadian winters in any form, and migrate south to warmer regions – the Monarch is the most familiar of these.

Spring Arrives in midst of the Pandemic

Mourning Cloak

It’s been another slow spring; although the snow was quick to melt this year without any flooding, it took until the last week of April before temperatures reached a daily high of more than 10°C, and not once did Ottawa reach 20°C – in fact our highest temperature last month was 16.8°C (normally the highest temperature falls in between 20.7°C and 28.5°C). This is only the eighth time since records began in 1870 that April temperatures stayed below 17°C. Migrants have been slow to trickle in, however, this may be a reflection of the greatly reduced number of trails and habitats I visit rather than the actual number of birds passing through, as eBird sightings have been steady despite the cooler temperatures and persistent north winds. Despite the weather and the smaller area in which I’ve been birding, I’ve had some good mammal sightings in the past few weeks, and have seen my first butterflies of the season.

Early Morning Fogbow

A fogbow is something I’ve heard of, but have never seen before – until now. This morning I went for an early morning walk at the Eagleson Ponds, and was dismayed at first to see how foggy it was. It was only a couple of degrees above zero, with a low fog and an otherwise bright blue sky. I started walking south along the shoreline, and when I looked across the water, I saw it – a bright white patch resting on the water with a thin, pale arc reaching toward the sky like half of a rainbow. There was no colour within the arc – it appeared the same ghostly white colour as the mist.

I followed the direction of the arc with my eyes, and found another bright white patch of fog shining just at the water’s surface of the central pond, with a second arc curving toward the first. It was not a complete “bow”, but I knew what it must be – a fogbow.

Fogbows are created much in the same way as rainbows, with sunlight shining through the fog droplets and causing the light to refract at predictable angles. Fogbows can be found anywhere provided the conditions are right: thin fog and fairly bright sunshine. In addition, the the sun must be fairly low in the sky – less than 30-40° above the horizon unless you are on a hill or a ship where the mist and fogbow can be viewed from above. This is why they are most commonly seen from hills, mountains and on ships sailing through the sea mist. In fact, sea or river fog is an excellent source of fogbows. This fog forms quite frequently when warm air comes in contact with the cooler water and is chilled.

The smaller water droplets within the fog diffract light much more extensively than the rain droplets that create rainbows. Because of this, fogbows are usually white with faint reds on the outside and blues inside. They may also contain a glory at their center – a small, bright patch of colour containing the colours of the rainbow. Glories form directly opposite the sun whenever the mist or fog is below the observer, and are often photographed by mountain climbers.

I did not see a glory, and the fogbow itself was very faint. Some fogbows have very low contrast, so they are best found by looking for small bright patches in the misty background – this type of bow is brightest at the two points where it appears to meet the sea or ground. This is exactly how I managed to find it.

It didn’t last long, and disappeared as the sun climbed higher and the mist faded. I was happy to see it and add a new type of atmospheric phenomenon to my list.