Emergence of Spring Butterflies and Mustard Whites

Eastern Pine Elfin

So far it’s been a strange spring. It took a long time to warm up to 0°C and then a while longer to warm up to double digits. Early April was cold and very windy; it didn’t get consistently above 10°C until April 21, but even then it was too gusty in the afternoons to go looking for butterflies. My first butterfly of the year was a Mourning Cloak seen on April 5th at the Rideau Trail on Old Richmond Road. It was a beautiful day of 13°C, and I figured I had a good chance of seeing my first butterflies of the year there….though it was a toss-up as to whether it would be a Mourning Cloak or an Eastern Comma, both of which hibernate as adults in woodlots. While I saw a few more Mourning Cloak in mid-April, butterfly season didn’t really start until the second last day of the month.

Mid-May Butterflies

Dreamy Duskywing

The first butterflies that emerge in the spring – usually in late March or April – are the ones that hibernated as adults in deciduous woodlots: Mourning Cloaks, Eastern Commas and Compton Tortoiseshells are the first ones I see every year on those warm, sunny days when the temperature starts reaching 13°C. The next wave emerges when it warms up long enough for those that hibernated in the chrysalis stage to emerge as adults: the elfins and azures and whites and swallowtails are included in this group, although I usually see the first Northern Spring Azures and Henry’s Elfins first, in late April and early May, with the Canadian Tiger Swallowtail and Black Swallowtail following in mid-May. Next come the species that overwintered as mature caterpillars, such as the duskywings – the first skippers to appear each year – and the crescents. All of these are typically seen in May in our region, while butterflies that overwinter as younger caterpillars (the browns and fritillaries) and eggs (coppers and hairstreaks) don’t emerge until June and July. This means that while you will never see all of Ottawa’s butterflies on the wing at the same time, the diversity is ever-changing up until the end of July. Even after that the appearance of regular but unpredictable influxes of migrants keeps things exciting throughout August and September: large population booms of Red Admirals, Painted Ladies, American Ladies and Monarchs might mean a wildly successful breeding season here in Ottawa, while smaller numbers of Orange Sulphurs, Common Buckeyes and American Snouts often find their way here from their breeding range further south.

Henry’s Elfins

Henry’s Elfin

After the early start to spring, migration stalled with the arrival of a long-lasting weather system that funneled the dreaded north winds back down into the Ottawa Valley again. The past week has been filled with gray, overcast days, a bit of rain, a bit of snow, and several days of gusty winds. I’ve added a few new birds to my year list, but they are mostly species that have been present for a while now that I never got around to seeing earlier: Gadwall, Barn Swallow, and Yellow-rumped Warbler at the Richmond Sewage Lagoons, Red-necked Grebe at Shirley’s Bay, American Bittern and White-crowned Sparrow in Stony Swamp, Eastern Meadowlark and Osprey on Rifle Road, and the return of the neighbourhood Chipping Sparrows back on April 15th. The birds that returned early this spring and tripped the eBird filters a few weeks ago are all birds that overwinter close by in the southern US; while they took advantage of the warm southern winds to return to their breeding grounds early, birds that winter in Central and South America are still thousands of kilometers away and will return on their normal schedule.

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.

The South March Highlands

Yellow Trout Lily

One of my favourite places to go birding in late May and early June is the South March Highlands in Kanata North. It is said that this forest has the highest ecological value and biodiversity of any area within the City of Ottawa, with more than 654 species found within its borders – some of which are considered to be species at risk, such as the Blanding’s Turtle, Least Bittern, and Butternut Tree. These Canadian Shield uplands are rich in wetlands and mature forest, with marshes, ponds, deciduous forest and coniferous forest all accessible via a network of trails. Despite its ecological significance, the City of Ottawa has allowed parts of the forest to be sold to developers and clear-cut for new homes and the infamous Terry Fox Drive extension. Still, the forest that remains is a beautiful spot for birding, though it is extremely popular with mountain bikers and caution should be taken not to block the trails while scanning the tree tops for warblers!

Elfins and Emeralds

Eastern Pine Elfin

The Stony Swamp trail I spend the least time at, other than Lime Kiln, is Trailhead P11 on West Hunt Club. It’s a lovely trail, but it doesn’t have any marshes with boardwalks; the spring flooding requires knee-high rubber boots; and turning left back onto West Hunt Club into the Saturday mid-day traffic can be a nightmare. Still, it’s a great trail system through some prime mixed deciduous and coniferous forest, and I’ve been trying to visit more often to see what kinds of species make their homes here. It’s better for breeding Wood Thrushes than the other Stony Swamp trails, possibly because the forest is denser with fewer open areas, and I’ve had more Broad-winged Hawks here in the summer than anywhere else. I visited one morning in May while on vacation, hoping to find some new species to add to the hotspot list and perhaps to see some butterflies now that the weather has gotten warmer.

Dragonflies and an Elfin at the Bill Mason Center

Eastern Pine Elfin

When I got back from Costa Rica I didn’t much feel like doing any birding back here in Ottawa. I’d been spoiled by all the colourful, tropical birds and exotic species that I’d seen – Costa Rica was a dream come true for me, and it was hard to return to reality. As soon as I got back I started thinking about a return trip there, wanting to spend more time in the rainforest so I could see birds such as Cotingas, Jacamars and Bellbirds. And oh, the hummingbirds and tanagers there!

It was difficult to get excited about birding in Ottawa, and the weather didn’t help. It was cold and rainy when we left and still cold (only 16°C) when I returned. The thought of going dragon-hunting stirred my interest somewhat, and when the weather warmed up the weekend after we got back, I decided it was time to take my net out of hibernation.

Dragonfly Season Begins!

Northern Spring Azure

By the third week of May the weather finally warmed up enough to do some dragon-hunting, so on May 21st I made plans with Chris L. and Jakob M. to go to Roger’s Pond in Marlborough Forest to look for birds, bugs and herps. We had great luck with all three, though mammals were sadly lacking. I’m not sure why I don’t see many mammals at this trail; the only one I can remember seeing with any certainty was a Snowshoe Hare right on the gravel trail as it ran by me.

Spring Beauties: Butterflies, a Porcupine and Spring Ephemerals

Spring Beauty

The Beaver Trail is one of my favourite trails to visit in mid-spring: spring ephemerals such as violets, Trilliums and Hepatica are in bloom, a good variety of butterflies – including various anglewings, Mustard Whites, elfins and azures – are on the wing, and both breeding birds and migrants alike can be found along the edge habitat surrounding the ponds. Although one of the shorter trails in Stony Swamp, the variety of wildlife that can be found here makes it worth visiting in any season. Spring, however, is my favourite season for visiting. On May 7th I arrived at the parking lot just before 8:00 am, and found only a few chickadees and Song Sparrows. It wasn’t until I reached the first marsh that I heard my first good bird of the day – an American Bittern. This was a year bird for me, and not a bird I hear very often in Stony Swamp, making it a great find.

Waiting for Migration to Resume

Raccoon

The long-awaited south winds arrived on Saturday, and I was eager to get out the door early and see if any new birds had blown in with the gorgeous weather. I started off the day at Jack Pine Trail where I hoped to find the Black-backed Woodpeckers again. Though I didn’t see the woodpeckers or any new birds (where are the Winter Wrens? The Field Sparrows?), I did come up with 25 species, including two Tree Swallows flying over the marsh at the back, three different Brown Creepers singing, two Ruby-crowned Kinglets, a flock of 10 Cedar Waxwings flying over, half a dozen White-throated Sparrows singing, and a single Purple Finch.