Along the south shore of the lake I heard both the calls of the Northern Flicker and Pileated Woodpecker. I didn’t see any migrant songbirds here, but views of the lake produced a good assortment of water birds including Great Egret, Great Blue Heron, Wood Ducks, Mallards, and a pair of Pied-billed Grebes. I also spotted a juvenile Green Heron fishing from a log about 30 feet from the shore.
These small herons are my favourite type of heron; I love their gorgeous green and chestnut colouring and the way they walk so stealthily on downed trees while hunting. They often will allow you to get quite close to them, if you can prove you can move just as silently and stealthily as they can.
I watched it for a while, and was dismayed when I saw it snatch a pair of meadowhawks in tandem and proceeded to gulp them both down!
I had no luck with any birds at the new footbridge or in the open area south of the lake. However, I did see a cicada perching in a shrub at eye level and watched a darner land in a shrub close by. A look at the thoracic stripes revealed it to be a Canada Darner, a species I’ve seen only a few times so far this year. As I was photographing it I noticed a bee kept buzzing around it as though trying to provoke it. Did the bee recognize the darner as a deadly predator? Or was there another reason why it kept circling the much larger dragonfly?
In the woods I heard and saw a few White-throated Sparrows moving around. I checked one of the swampy areas and was surprised to see another Green Heron, this one an adult as indicated by its mostly rufous neck. It, too, was hunting quietly from a fallen tree and took no notice of me.
From there I proceeded to the east side of the lake where I had seen the Fragile Forktails previously. So far I hadn’t seen very many odes; just a couple of Spotted Spreadwings and Eastern Forktails, the Canada Darner, and several Autumn and White-faced Meadowhawks. The Fragile Forktails and Slender Spreadwings from my previous visit were gone, but a young Rose-breasted Grosbeak and two Common Yellowthroats were in the exact same area where I’d seen them two weeks ago. This made me suspect that the yellowthroats were local breeders rather than migrants; however, it seemed unlikely that the grosbeak was the same individual I observed on my last visit.
I took the small side path to the east to check out the bay. Along the way I found my only robin of the day. A few Eastern Forktails were flying slowly in the vegetation along the beach, four American Black Ducks were swimming in the bay, and a Belted Kingfisher was perching on a rock close to the shore.
I made my way back to lawn south of the filtration plant, musing that I still hadn’t seen any Yellow-rumped Warblers, when movement in one of the trees caught my attention. I caught sight of a small warbler with streaks on the underside and thought I had finally found a Yellow-rump; however, when it moved into the open I saw the yellow undertail coverts and wagging tail of a Palm Warbler! I spent some time watching it, trying to get a photo, but it was too far above my head and moving too quickly among the sun-dappled leaves to get a good shot.
From there I headed to the small peninsula that follows the fence line and juts into the lake on the north shore; I could still see the Pied-billed Grebes in the middle of the pond, as well as a couple of Turkey Vultures soaring overhead and three American Wigeon several feet out! These ducks often spend a few weeks on Mud Lake in the fall, along with Hooded Mergansers and Ring-necked Ducks, and I wondered if they were the individuals that over-wintered here last year and had arrived early with the intentions of sticking around again this winter. There was no reason to think so; it was mostly just wishful thinking on my part as I enjoyed seeing them around throughout the fall and winter.
I crossed the lawn to check out the line of shrubs between the lawn and the river; this has been a great spot for migrants in the past, and today was not an exception. I finally added Yellow-rumped Warbler to the day’s list when I heard one calling “chup!” in the branches above me; however, the first bird I focused on turned out to be a Northern Parula! It was strange for a day in mid-September to come across 8 other warbler species before finally seeing a Yellow-rumped Warbler. What was even stranger was that I didn’t see a single vireo at all during my walk around the lake – although I heard the whiny call note of what was either a Warbling Vireo or a Red-eyed Vireo, I wasn’t able to set eyes on it and confirm the ID.
I started pishing to see what else was around, but the only birds I managed to see in that flock were Yellow-rumps. I proceeded from there to the area behind the ridge, encountering more Yellow-rumps, an Eastern Phoebe, a White-breasted Nuthatch, a probable Blackburnian Warbler, and a juvenile Yellow-bellied Sapsucker. These birds are easy to identify no matter what plumage they are in, as they are the only small woodpeckers in the northeast which have a vertical white stripe down the wing.
I was enchanted by the flock moving all around me, and when they disappeared I headed up onto the ridge to see if I could track the birds down. This little red squirrel gave me some attitude as I lingered too long in its territory, unable to spot the flock of migrants.
One other mammal on the ridge surprised me, a groundhog searching for food along the rocky slope. It was an odd place to see this large rodent, as I normally find them on the lawn closer to the filtration plant – though it’s been a while since I can recall seeing any there.
I finally caught up with a few birds at the western end of the ridge. A beautiful Black-throated Green Warbler popped into view, and to my delight it sat still on its perch for about three minutes. Warblers are hyperactive little birds that are constantly in motion, so it was a real treat to be able to watch this one take in its surroundings.
The Black-throated Green Warbler is named for the dense black throat of the breeding male as well as its olive-green crown and back. The face is yellow with a dark eye-stripe and olive auriculars; the belly and breast are white with black streaks along the flanks. These features help to identify the white-throated females and immature birds, such as this individual. Note that the green of its back isn’t the true green of a hummingbird or a Green Heron; you won’t see very many people on St. Patrick’s Day dressed in the hues of this “green” warbler.
This species is one of four species comprising the Setophaga virens “superspecies”; it is closely related to the other members which include the Golden-cheeked Warbler (Setophaga chrysoparia), Hermit Warbler (S. occidentalis), and Townsend’s Warbler (S. townsendi). It breeds in the coniferous Boreal forest across Canada and parts of the U.S.A., and has no range overlap with any other member except the Townsend’s Warbler, where the ranges meet in western Alberta. The Black-throated Green Warbler has been known to hybridize with the Townsend’s Warbler.
Here in Ottawa, I often hear them singing in Stony Swamp and Marlborough Forest into June. Last year I heard three singing on July 2nd at the South March Highlands Conservation Forest. All of these areas contain mixed coniferous-deciduous woods, their preferred habitat. Male Black-throated Green Warblers have two different songs: the quick “zee zee zee zoo zee” song is sung in the heart of his territory to attract females and is usually heard at the beginning of the breeding season. The slower “zee zee zoo-zoo zee” (sometimes rendered as “trees trees murmuring trees”) is usually sung around the edge of his territory to deter other males. This is something I will have to listen for next year!
While on the ridge I stopped to check out the gulls on the rapids. I could make out three adult Great Black-backed Gulls among the smaller Ring-billed Gulls, but without a scope I had to leave many juveniles unidentified. A pair of Double-crested Cormorants flew over while I was watching
From there I headed along the west side of Mud Lake toward the southwest entrance. I stopped to check out the ducks on the lake and found this male mallard molting back into breeding plumage. The bright green head feathers have started to come in, and the brown feathers of its back are slowly being replaced by the familiar gray ones.
Altogether I spent nearly 4.5 hours in the conservation area and found a total of 42 species. It was a wonderful day to be outside, and given that it was a weekday, there were few other people around. I enjoyed my Friday off, as Mud Lake is a dynamic place to enjoy watching the birds almost any time of year – and especially during migration.