Sunday 13 June 2021

Return to Rondeau

It had been way too long since my last visit to Rondeau, so that is where I decided to head yesterday.

Although birding was my main intention, I didn't really take any photos of birds, so you'll have to live with some plants and insects :)

First things first, I went to Keith McLean CA, along the Rondeau causeway. Always worth a stop I find. There had been a Yellow-headed Blackbird seen there the day prior, but no sign of it when I went. Plenty of Marsh Wrens however, as well as some more unusual birds for the time of year, like Blue-winged Teal, Ruddy Duck, and Semipalmated Sandpiper. In the group of gulls sitting in the field, I found a single adult Lesser Black-backed Gull. 

It was time to head into Rondeau. My first stop was the South Point Trail. Not too much bird song, other than the usual suspects, but a pair of Blue-grey Gnatcatchers and a Least Flycatcher (a species I often don't encounter in the summer, oddly enough) was nice. I went out to the beach at the light beacon, and found a new species of sedge for me, Sand Sedge or Mulhenberg's Sedge (Carex muehlenbergii). Much more robust and impressive than I imagined it being!


There were some loafing gulls further down the beach, so I decided to keep going. Nothing special among them however, only Bonaparte's, Ring-billed, and Herrings. I continued until I hit the washout, then headed back along the trail.

There were a few Painted Skimmers along the way.

I encountered this grass as well, which I have tentatively called Schribner's Grass (Dichanthelium oligosanthes var. scribnerianum).


I had originally keyed it out to Common's Grass (Dichanthelium commonsianum) using Michigan Flora, but have since revised my identification (this genus is hard!). While we're on the topic, the genus Dichanthelium is a real mess. It used to be the genus Panicum, however Panicum was then split into several more genera (while some species retained the genus name). Even within Dichanthelium, things are confusing. It seems every species name is a synonym for something else! Not to mention the numerous varieties. With some authorities, such as in the checklist of plants for Ontario's Carolinian zone, D. commonsianum is included under D. ovale ssp. pseudopubescens

Next, I decided to go to the Tulip Tree Trail. Largely had the place to myself, which was nice. Almost immediately, I heard an Acadian Flycatcher, soon followed by two more. This was my main target for the day, as it was a species I had never seen in Rondeau before. A couple other goodies rounded out the bird list here, including a Wood Thrush carrying food, a Prothonotary Warbler, and a singing Black-throated Green Warbler. Maybe it is just a very late migrant, but I guess it isn't out of reason for a Black-throated Green to attempt to breed here. 

Another Dichanthelium for you, this one a bit more straightforward: Broad-leaved Panic Grass (Dichanthelium latifolium).

I then intended to go to the Marsh Trail, but on the way passed Spicebush Trail. Last minute I decided to turn in and give it a go, because why not? Glad I did!

Nothing really of note bird wise, but as I was walking along I noticed this sedge (Carex).

I recognized it immediately as something in Section Griseae, and felt as though it was something I hadn't seen before. I had a sneaking suspicion it was Eastern Narrow-leaved Sedge (Carex amphibola), which is somewhat similar to the common Inflated Narrow-leaved Sedge (Carex grisea). I consulted a key, and found that my initial thought seemed to be correct, it appeared to in fact be Eastern Narrow-leaved Sedge, a rare species in Ontario, ranking S2 (between 5-20 known occurrences, I believe). Despite its rarity in Ontario, it is actually considered to be the most common species in its section further south of us. The perigynia of this species is triangular in cross section, and seems to be relatively a bit narrower and longer than in Inflated Narrow-leaved Sedge. 

Compare to Inflated Narrow-leaved Sedge. I took this photo back in late May in London. The perigynia aren't completely mature here, but they are mature enough to see the difference. 

I saw another member of the section Griseae along the same trail. Hitchcock's Sedge (Carex hitchcockiana) is a fairly distinct species, with hairy lower stems. 


My last stop in the park was the first little bit of the Marsh Trail. Not really much of note.

Flowering Rush (Butomus umbellatus)

Silverweed (Argentina anserina)

Swamp Rose Mallow (Hibiscus moscheutos)

Hairy Beardtongue (Penstemon hirsutus)

Greater Straw Sedge (Carex normalis)

My eBird checklist for the day: https://ebird.org/checklist/S90074662

I went to Shrewsbury after and drove around looking for the Eurasian Collared-Dove, but no luck. Only saw a few Mourning Doves!

I went to Stefina Line east of Blenheim, and saw the reported Dickcissels just before heading back home. Always a nice one to see!

I took some backroads home, but didn't see too much. I had debated about going to check a field that gets Dickcissels each year, but opted to just go home. One was found there this morning! Oh well. 

Gotta love this time of year!

1 comment:

  1. Looks like you had a decent day!
    We have had Black-throated Green Warblers in June at Rondeau. Not sure if they have nested, but certainly were at the probable stage in the previous atlases. I saw one in late June once!

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