A late summer visit to Marlborough Forest

Philadelphia Vireo

Marlborough Forest has become one of my favourite spots to visit because of its bounty of butterflies, breeding birds, and dragonflies. The best month for visiting is June, when birds are are still singing and insect diversity is at its peak. The first few weeks of July are also a fine time to visit, as different butterflies are present than were initially flying in early June. By mid-August, however, it is harder to detect birds as most have stopped singing, and insect diversity is on the wane. Still, I thought I would visit the E4 trail on the third Saturday of August, a place I hadn’t been to since Canada Day. I was curious to see what birds might still be present, and whether it might be a good spot to see different darners and meadowhawks.

I arrived a little later than I usually do at the height of nesting season – 9:00 am instead of 7:00 am – to give it time to warm up. The biting bugs were not as bad as they are in the middle of summer, but I was annoyed to still find myself slapping mosquitoes away. The woods were very quiet compared to June; the Red-eyed Vireos and one Eastern Wood-pewee were still singing (both sing late into the season, sometimes into September), but the Ovenbirds, Scarlet Tanagers, Veeries, Nashville Warblers, Black-throated Green Warblers, White-throated Sparrows, and Swamp Sparrows were silent.

I stopped to check the small pool of water where I’d had the Twin-spotted Spiketail in June and the Ocellated Emerald a year ago (also in June). The Ebony Jewelwings and Aurora Damsels were long gone, and I didn’t see any other odes flying over the water or perching on the branches above. Still, it turned out to be the birdiest spot of the trail as I found a flock of songbirds foraging together in the trees overhead. This included a couple of Red-eyed Vireos, an American Redstart, a Bay-breasted Warbler, and two Red-breasted Nuthatches. I was also happy to see a bright yellow Philadelphia Vireo among the flock, suggesting these were migrants rather than local birds. It flew into the shrubs close to where I was standing, and when I started pishing it popped out into the open. Unlike the similar-looking Warbling Vireo, the Philadelphia Vireo has dark lores extending to the bill and is often completely yellow underneath from throat to undertail…some birds may have paler bellies, but the yellow is always the brightest on the throat. On the Warbling Vireo, the yellow is brightest on the flanks.

Philadelphia Vireo

Philadelphia Vireos aren’t rare, but they are not very common either. They usually join flocks of mixed migrants, and I don’t think I’ve ever seen more than two in the same flock or area before.

A Great-crested Flycatcher made itself heard in a distant tree on the other side of the road, and a Brown Creeper scuttling up a tree trunk was great to see. I wasn’t sure how great Marlborough Forest would be for finding migrants, as the best places usually occur at migrant traps or edge habitats where water meets shrubs and trees; finding groups of migrants in the middle of the woods is much more difficult – the needle in the proverbial haystack – so I was thrilled to meet this particular group.

I didn’t find any other flocks of songbirds, though I did find birds scattered throughout my walk to the marsh. I found a Common Yellowthroat and a single Common Grackle at the marsh, but no Red-winged Blackbirds or kestrels. Only one Song Sparrow was singing, a Least Flycatcher was still calling, a Gray Catbird was skulking in the shrubs, and a single Turkey Vulture flew over.

The dragonflies and butterflies became more active as it warmed up, and in the large open field where the dirt bikes have scarred the dirt I found two meadowhawk species: the first, the Autumn Meadowhawk, was no surprise as I’d had this species here last year.

Autumn Meadowhawk

The second was a Band-winged Meadowhawk. This was the first time I’d seen them on the north side of Rogers Stevens; I’d had them before at the Cedar Grove Nature Trail (E3) near Rogers Pond in July 2019. This one allowed me to get close enough to get a full shot of the extended wings, showing off the large bands of the hindwings.

Band-winged Meadowhawk

I was also surprised to see a Common Whitetail still flying. They have a late flight season, but even so there were so few dragonflies present that I expected all of them to be meadowhawks. I didn’t even see any darners zipping up and down the trail!

Common Whitetail

There weren’t many butterflies on the wing either; I photographed a Northern Spring Azure resting in the vegetation and a White Admiral on the trail. I missed the early days of summer when the skippers and fritillaries and brown butterflies (Satyrinae) and commas were so abundant that I saw constantly saw the movement of their fluttering wings out of the corner of my eye.

White Admiral

I decided not to continue past the marsh, but turned around and headed back without checking the large open water at the end of the trail. The trail runs past an area of dead trees before re-entering the woods, and as I was walking I caught sight of a medium-sized bird at the top of one of the trees. I thought it was just a Northern Flicker at first, two of which I had already seen, but when I got my binoculars up I was surprised instead to find an Olive-sided Flycatcher! This dark flycatcher is immediately identifiable with its white belly, dark vest and peaked head.

Olive-sided Flycatcher

This species is more difficult to find than the Philadelphia Vireo, so I was particularly thrilled to see it out in the open and relatively close! It darted out after a couple of flying insects from time to time, landing on different perches. I spent a few minutes watching it before being distracted by a pair of finches that flew in and landed in the tree next to me. They were both Purple Finches, but one was a young male transitioning to adult plumage. I thought the plumage was neat:

Purple Finch

Although insect diversity was just as low as I had expected, I had two interesting encounters before I left. The first was what looked like a butterfly with deep pinkish-orange wings flutter across the wooded path and land on the trunk of the tree. The shade was not right for Compton Tortoiseshell or one of the commas, and when I walked up to it I found this plain moth instead:

Pink Underwing (Catocala concumbens)

If I hadn’t seen the flash of colour while it was flying I might have dismissed this as a large but uninteresting moth, but the colours meant it was an underwing of some sort. I had found a dead Ilia Underwing in my garage once and thought it gorgeous with the bands of colours hidden on the hindwings – it was intact, so I placed it on a leaf in my garden to photograph it. When I uploaded this one to iNaturalist it was identified for me as a Pink Underwing, which has similar bands underneath that are more pink than the orange of the Ilia Underwing. This turned out to be the most interesting species of the day.

The last species of interest I saw was a small yellow beetle on a dandelion at the edge of the parking lot. I recognized it as a Spotted Cucumber Beetle, a species I had seen in Marlborough Forest before – though five years ago.

Spotted Cucumber Beetle

These beetles are considered pests as the adults eats the leaves of crops such as squash, cucumbers, soybeans, cotton, beans, and corn; even the larvae eat the roots of emerging plants in late spring. Still, I thought it was pretty, even though the picture didn’t turn out to be the best.

It was a shorter outing than usual, mostly due to the low numbers of insects and singing birds, but also in part due to the rising temperature; it later reached 32°C. Still, I had a good time and was thrilled to find both Philadelphia Vireo and Olive-sided Flycatcher, as they were both year birds for me. Although I didn’t find any surprising odonates (where WERE those darners?), the Band-winged Meadowhawk was great to see, and resulted in one of my photos of this species to date. June is still my preferred month to visit, but I’m glad I made this late summer visit and hope there will be more opportunities to uncover its secrets.