The Rarest Heron

Black-and-white Warbler

On Sunday I had plans to meet up with Chris Lewis, Bev McBride, and two of their long-time birding friends Jean and Bev at Mud Lake for a morning of birding and scones. However, one of my best sightings of the day occurred before I even got there. I was driving on Old Richmond Road right where it passes through a marshy area of Stony Swamp when I noticed a mammal standing on the shoulder where the road. It was large, with a long, slender brown body. It stood there for a brief second, and when it turned and disappeared down the embankment into the cattails I realized it was a mustelid of some sort…and that it was far bigger than a mink. It appeared a uniform dark brown colour, and seemed heftier and darker than the Pine Marten I photographed in Algonquin last winter. My best guess is that it was a fisher, though I didn’t get a good enough or long enough look at it to note any pertinent field marks. I’ve never seen a fisher before, however, and thus have no experience with this species to call upon. Even so, seeing the mysterious mustelid was a fantastic way to start the day.

At Mud Lake, I was amused and touched to see the a small “tea party” Chris had set up for us. She had received a package from Bob Bracken’s sister in Hawaii that included lavender herb tea bags, jam, and ingredients to make scones, so before we started birding we gathered together to chat and eat. We didn’t have hot water for the tea, but we enjoyed the scones as other birding friends (Mike Tate, Paul Mirsky, and Bob Cermak) stopped by. A juvenile Ring-billed Gull and some ducks began edging closer to the food, and I was happy to see a male Wood Duck regaining his breeding colours.

Wood Duck

After we finished our morning snack we went up to the ridge to start birding. There was lots of activity, and plenty of warblers and songbirds to keep us entertained. A Warbling Vireo was still singing, and we saw several warblers including Black-and-white Warbler, Tennessee Warbler, Cape May Warbler, Northern Parula, Bay-breasted Warbler, and Yellow-rumped Warbler. The highlight of our stop there was a flock of Rusty Blackbirds that flew in and landed in a dead tree about halfway down the ridge, most showing the two-toned look of males in non-breeding plumage: rusty-brown on the head and upper body, black on the tail and lower body.

Chris called me over to take a look at a pair of bugs sitting in a Staghorn Sumac shrub. The shape is that of a Stink Bug, although they appear to be nymphs rather than full-grown adults. Like butterflies and most other insects, Stink Bugs spend a fair amount of time transforming from larvae into adults, going through different stages (called “instars”) as they feed, grow and molt. These two Stink Bugs were quite large and appear to be in the final stages of transformation.

Stink Bug Nymphs

We heard a Golden-crowned Kinglet’s three-part call note issuing from somewhere behind the ridge but couldn’t see the bird itself; this was my first of the fall. We also checked the rapids, and noticed a large number of Great Black-backed Gulls roosting in the middle of the river. There were at least 30 of them, compared to the seven I had first seen at the end of August.

After we finished birding the ridge, we headed to the sumac field west of the lake to look for a Grey-cheeked Thrush reported by Mark Gawn. I still needed this bird for my life list and, as I’ve seen and heard many thrushes in the tangled, overgrown thickets at the edge of the sumac field over the years, it seemed a good spot to check. We hadn’t proceeded very far when Chris, who was in the lead, called out that she had just seen a thrush dart into the vegetation. I was behind her, and saw something move quickly out of view. Although we peered into the dense thickets for several minutes, we never did catch a glimpse of the bird, and Chris wasn’t sure which species it was.

We stopped next to the temporary pond near Cassels Street where we heard the thrush call a few times; however, it refused to come out into the open. A little further along I saw a Chestnut-sided Warbler and heard a Gray Catbird calling. This pretty Eastern Tailed Blue posed nicely for some photos.

Eastern Tailed Blue

We circled the sumac field and headed back toward the pond to listen for the thrush again. We didn’t hear it, but we did see a large number of birds moving through the area, including a Blue-headed Vireo, a Red-eyed Vireo, a Rose-breasted Grosbeak, a Magnolia Warbler, a Black-and-white Warbler, a Blackpoll Warbler, and lots of Yellow-rumps. A couple of birds actually flew down to the puddle and started bathing as we watched.

Black-and-white Warbler

After that we headed over to Andrew Haydon Park to look for shorebirds. We found a Solitary Sandpiper and a Least Sandpiper on the mudflats west of the park, along with a Great Egret and two Great Blue Herons fishing in the water and a Green Heron strolling along the muddy spit. I saw my first American Pipit of the fall flying over, calling its name as it went. A few Blue-winged Teals were swimming close to the shore, but the overcast conditions made photography difficult. There were no males in breeding plumage.

Everyone started to leave after that, but I decided to walk around the park before going home. I heard a Brown Creeper and found another Great Blue Heron in a creek, and that was it; so when I saw a group of people photographing a small bird in the reeds at the edge of one of the ponds I decided to take look. Based on the size, I initially thought it was a Green Heron. However, as soon as I reached the edge of the pond I was struck by the warm brown colours of the bird and its extremely small size….much smaller than the Green Heron I had seen up close a few weeks ago. It was the rarest of the six herons found in the Ottawa area, a Least Bittern!

Least Bittern

I’ve only seen two Least Bitterns in the Ottawa area: one at Sarsaparilla Trail and one at Petrie Island, both seen flying out of the reeds before diving back in. I’ve never gotten a good look at one, nor have I ever seen one sitting among the reeds completely out in the open. This one is a young bird as evidenced by the downy white feathers sticking out of its head.

In Ontario, the Least Bittern is listed as threatened. While found in a variety of wetland habitats, it prefers cattail marshes with open pools and channels. Its diet consists mainly of frogs, small fish, and aquatic insects. Habitat destruction, including shoreline development, wetland loss and drainage, and the encroachment of invasive species, is the main threat to the Least Bittern. It does not generally tolerate human disturbance well and will leave a marsh if human activity (such as lighting from buildings, boat wakes, loud noise, etc.) or habitat alteration becomes too great.

Although small, the Least Bittern can feed in water that is too deep for other herons due to its habit of straddling reeds. I watched him do this while hunting for minnows.

Least Bittern

Opportunities to see and photograph Least Bitterns in the open are few and far between, and I felt incredibly lucky to have this one. I was a bit concerned with how exposed he was, with so little cover in such a popular park. Hopefully he will find safer, more secluded places to rest as he flies south to Central America for the winter!