Thursday 29 October 2020

An Insidious New Disease to contend with

 The natural world is having to deal with a relatively new and serious disease. It is known as Beech Leaf Disease (Litylenchus crenatae ssp. mccannii).

Beech Leaf Disease (BLD) was first noted in North America in 2012, in Lake County, Ohio, right across Lake Erie from Chatham-Kent. It has gradually spread through other jurisdictions, and as of late 2019, is now confirmed in New York, Pennsylvania and Connecticut on the US side of the lake. It was only a matter of time before it was also discovered in southwestern Ontario.

There are eight municipalities in Ontario, from Chatham-Kent in the west, to Niagara in the east and up to Toronto, where as of late 2019 BLD had been found. The key characteristics are dark, almost black areas in between the leaf veins.....

 

....in addition some of the leaves may appear partially shrivelled.

I first heard about BLD about a month ago, in late September, from a keen forest specialist: Gerry Waldron. Gerry wrote an invaluable book on Trees of the Carolinian Forest several years ago. To give Gerry his due, he is the only person who has discovered three new tree species for Canada in his career! Gerry wrote to me, advising me to be on the lookout for BLD. Shortly after checking out some of the characteristics to be looking for, I immediately thought the American Beech (AMBE) trees of Rondeau warranted a close look. For the last 3 years, I had noted Rondeau's beech trees exhibiting severe stress, even becoming partly or almost completely defoliated in mid summer. I thought that it was primarily due to the high water levels that Rondeau has been subject to. AMBE is largely an upland species, meaning they like to grow in a spot where there is good drainage. They don't like to have 'wet feet', at least not for long. They can do alright on the higher ridges of the Rondeau sandspit, and there are some decent sized ones there, indicating that they have been able to tolerate the changing water levels for many decades. However the consistent record high water levels of the last three years have caused major stress to many upland loving tree species at Rondeau.

I immediately started checking the AMBE along many of the trails at Rondeau, and over a period of several days, was quite concerned. I checked the north end of Rondeau Road and the south end of Rondeau Road (now the west side of South Point Trail). I checked the Tuliptree Trail, the Gardiner Deer Exclosure, the southeast corner of the east side of the South Point Trail, and the section of Harrison Trail between Gardiner Ave and Bennett Ave, including the Group Campground. I found evidence of BLD on virtually every AMBE tree I checked. In fact of the one hundred or more AMBE trees I was able to see clearly, there was at least some evidence of BLD on every one. There was a very small number of trees where I didn't see any evidence of BLD, but that was only because most of the leaves were either already off the tree, or they were too high up and obscured by the foliage of other nearby species.

It was easy to conclude that BLD is well established in Rondeau, and an unaffected tree would be a rarity. Here are some of the leaves I photographed at various parts of the park, which depict BLD.


South Point Trail (West)

Tuliptree Trail

Rondeau Road north

I contacted several people within the Ontario Ministry of Natural Resources & Forestry about BLD, and got some more detailed background information. A publication dated in the spring of 2020 indicated that there were only two confirmed locations for BLD in Chatham-Kent: Clear Creek Forest Provincial Park, and Sinclair's Bush, about half way between Rondeau and Blenheim. I sent several representative photos to them, and had BLD confirmed. So the abundance of BLD at Rondeau was new information. 

I checked a few other places that I had easy access to, and where AMBE were known, including:

-Clear Creek Forest Prov Park

-a woodland area along the road that crosses Morpeth Creek

-Sinclair's Bush

-McKerrall Woods, a few km northeast of Chatham

-Paxton's Bush, at the north side of Chatham, and

-a privately owned woodlot along the roadside between Ridgetown and Thamesville

I found evidence of BLD at Clear Creek and Sinclair's Bush, not surprisingly, as well as McKerrall Woods and some inconclusive evidence at the private woodlot between Ridgetown and Thamesville.

Clear Creek Forest Prov Park

McKerrall Woods

Sinclair's Bush
 There are lots of other woodlots harbouring AMBE, but it is getting almost too late in the season for satisfactory checking. A Forestry Health Specialist will be visiting some of these woodlots to collect samples of the leaves and twigs. While the symptoms are fairly apparent, forestry specialists want samples to check, to see if the nematodes that transmit the disease are present.

What does this mean for Rondeau and other woodlands where AMBE is an important component of the forest? It is hard to say for certain at this point. Some trees will likely succumb. However according to some of the persons who have been examining BLD and its affects, some trees show some resistance to the worst outcome.

At Rondeau, the American Beech-Sugar Maple forest type covers a major part of the park. There are other species in that forest type, including Basswood, Black Cherry, Tuliptree, Green Ash and various others. But for one of the main components to become potentially a very minor part, does not bode well. One particular concern is for an endangered bird species, the Acadian Flycatcher. It nests almost solely in the outer branches of AMBE.

Acadian Flycatcher nest in AMBE

For anyone familiar with Clear Creek Forest Provincial Park, you might remember that huge American Beech tree along the main trail. It was one of the largest, if not the largest, of its kind in Ontario. But it showed stress about 4 years ago and died and blew down about two years ago. Interestingly, a small AMBE right beside that massive tree was where I found evidence of BLD just a few weeks ago. It makes me wonder if BLD had some influence on the health, and subsequent death, of that huge tree.

This first image shows the huge AMBE tree in late 2011.

This is what the tree looked like in the spring of 2019, shortly after it blew down.

This next photo was taken just a couple of weeks ago, and the small AMBE in the lower left side of the photo is where I found some leaves showing BLD.

 Over the last several decades, trees like American Chestnut, American Elm and most ash species which at one time were dominant elements of southern Ontario forests, have been severely reduced. The American Chestnut is officially an endangered species. Let's hope that the American Beech does not follow that trend.

No doubt there are many more trees in various woodlots yet to be discovered, unfortunately. Please be aware of this unfortunate situation. I fully expect to be on the lookout for this next season!


Sunday 25 October 2020

Black-headed Gull, Autumn colours, and Seeds

The title may seem a bit eclectic, but there is so much to see in nature!

The great fluctuations in the weather at this time of year is perfect for putting birds on the move. And that means species not normally seen can show up, however briefly. Certainly in the last day or so, with the brisk north to north east winds, raptors continue to be on the move. Bald Eagles, shown first, continue to be frequently be passing through, while Red-tailed and Red-shouldered hawks are building in numbers. They are often too high for great photography, at least when I have seen them, so this image of a sub-adult Bald Eagle will have to suffice.

The bonus for watching for raptors along the north shoreline of Lake Erie is that waterbirds are seen as well. Common Loons, the occasional Red-throated Loon, grebes and scoters are seen but often well out from shore. On occasion some unusual gull may be found, such as the adult Black-headed Gull that showed up along the shoreline just north of Rondeau this past Friday. Steve C put the word out that both a Sabine's Gull and Black-headed Gull had been seen there within a 30 minute time frame. As I was already on my way out to the park, it was easy to stop by. The Sabine's Gull had gone from view awhile before (it was reported later in the day, but well away from this location), but the Black-headed was still in the vicinity, although it had moved down the shoreline a bit. Garry S and I struck out down the beach, noting two other birders intently looking through their scope. Kevin G joined us and by the time we got to where the birders were scoping some gulls, the Black-headed Gull flew into view and joined a small group of other gulls already resting at the shoreline. Although it was still a distance away, the light was good and the telephoto lens worked well. This first photo shows the Black-headed at the left, showing its characteristic red bill with a dark tip and red legs, and the black dot behind the eye. Several Ring-billed Gulls and a single Herring Gull in the group made for an easy comparison.
Although we wanted to get closer for better photos, we hesitated since there were other birders on their way to see this quite rare vagrant. But there were non-birders walking along the beach, some with dogs, and it was only a matter of time before the gulls flushed. We went a bit closer and then waited. But a dog was getting too close, and the gulls were getting restless. Then all of a sudden the Black-headed took to flight, and fortunately flew in our direction. With the nice light, it made for some good photo ops. This is only the third Black-headed Gull I have seen in the Rondeau vicinity in over 5 decades of birding!

I headed into the park, wanting to photograph some of the golden autumn colours before the forecast wind and rainstorm in a few hours, blew most of the remaining leaves off the trees. Bennett Avenue is one of my favourite places here. The colours aren't as vivid as sometimes, but were still nice to see,

Here are the trio of Tuliptrees along the Tuliptree Trail.

A slug of some sort was crossing the path. At first glance it looked like a species I photographed earlier in the year, which turned out to be an endangered species. I'm not sure about this one, though.

I also like to get to Clear Creek Forest Provincial Park for some autumn colour photography. Here is one of my preferred vantage points, a couple of weeks ago. It was still looking quite green, and the creek itself was totally dry.

  This is from the same vantage point, taken yesterday, two weeks later.
And just to provide a different perspective, this is a lower angle from the stream edge.
A few days ago I got a message from Fred, a retired OMNR colleague, about a white goose associating with the large flock of Canada Geese hanging out at Mud Creek, here in Chatham. Knowing that Snow Geese are arriving in the area these days, Marie and I decided to check it out.
 
This was one that we saw along the creek system.
But it wasn't the one that Fred was referring to. We also saw this one, which turns out to be a hybrid of a Greylag and domestic goose. Who knows where it came from, but hybrid geese involving the Greylag, native to Europe, are widespread.
This is also the time of year when the fruiting bodies of many plants are visible, although maybe not for long as some are highly sought after by wildlife. Big Bluestem is one of the most common grasses in a Tallgrass Prairie. The seeds will be a source of food for songbirds, especially sparrow types.
 
Seed of the Common Milkweed are quite photogenic, and they are often abundant, which bodes well for the species in the future, as well as for the endangered Monarch butterfly which relies heavily on the availability of this plant.


The seeds of the Swamp Milkweed, shown next, are very similar, not surprisingly, and the plant is just as important to the Monarch.
Although this next seed head is not that of a native plant species, it is photogenic just the same. It is that of Green Foxtail.
 The bright red berries of Winterberry will not last long. When they are found, they are consumed quickly by some of the thousands of migrating songbirds.
 
 This next photo shows the fruiting body of another member of the plant kingdom. The part of the fungus we see is just a small part of the extensive living fungus that is growing underground, inside the trunk of a tree, or wherever. I'm not sure what species this is, but thought it was photogenic.

 






Friday 16 October 2020

More migrants and late leps

 There's no question that the bird migration is slowing down, at least for songbirds and shorebirds. For waterfowl, that is another story as those numbers continue to build. And for the crows.....there is no question that they are just getting started, at least here in southwestern Ontario.

There are still a few of the songbirds around. In the warbler family, the main ones of recent days have been Blackpoll and Yellow-rumped, with a few other species mixed in just to keep things interesting.


An occasional vireo, such as this Red-eyed Vireo, lingers.

While the peak of raptors has passed, there are still lots to go through, although nothing like the tens of thousands of Broad-winged Hawks. Nonetheless, there still are a good number of hawks to be seen on a good migration day. The falcon group is always of interest. American Kestrels have been passing through in a steady stream....

...and there have been quite a few Peregrine Falcons, which is a real treat compared to not many years ago when it was highly unusual to see any of this Endangered species. We watched this particular individual, a first year bird below, harass a group of shorebirds from time to time at the Keith McLean Conservation Lands. It was not successful that we saw, so we weren't sure whether it was really trying to catch something or just practising its predatory behaviour.
At one point it even started chasing a Belted Kingfisher, again unsuccessfully, but it was interesting to see the chase, and hear the kingfishers alarm rattle calls. At one point the falcon flew right at us, low down, and we weren't able to get the cameras on it quickly enough before it darted away.

Shorebirds are dwindling at the shallow water mud flats of the KMCL. A small diversity continues, and it seems there is a different mix of shorebirds every few days as the birds arrive, feed and rest for a few days, and then depart for places farther south. This Semipalmated Sandpiper, shown next, has been around for a few days. Notice its leg, broken or at least twisted so that it is not functional. It just dangles behind, but the bird seems to be able to get around. It is not unusual at times, to see a shorebird missing a leg entirely, and just hopping around on one leg. It is hard to say what the future is for this individual.

Black-bellied Plover are hard to find these days, but one or two show up from time to time.
Long-billed Dowitcher, which always occurs in very small numbers, is more or less gone now, although there is an occasional report still coming in.
Least Sandpipers are almost gone, with an occasional one still around......
....and the same can be said for Stilt Sandpiper.
By far the most common shorebird around these days is Dunlin. There have been upwards of 40 individuals regularly occurring at the KMCL lately, and I expect a few to continue to be around for another few weeks, depending on the weather.

An Hudsonian Godwit was a very brief visitor a couple of days ago, but I didn't get to see it. It was only around for a 2-3 hours before something spooked it and it left. Perhaps a passing Peregrine?

Not a shorebird, but the always photogenic Great Egret can still be seen occasionally. There were three individuals around not so long ago, but that isn't to be expected for much longer.

There are still a few Monarchs passing through, but the numbers are rapidly dropping.

On sunny days like today, other butterflies may be out an about, such as this Red Admiral.....
.....or this Common Buckeye.
A few other members of the Lepidoptera group can be seen, but not in flight!  While looking for pollinators at a lingering patch of goldenrod, I came across this caterpillar. It is a Smeared Dagger Moth caterpillar, and will likely overwinter as a larva.
This Black Swallowtail caterpillar was on some dill in our garden a few days ago. By now I expect it has formed its overwintering pupa, and if it survives, will emerge on some sunny, warmer day next May.

While the flowering period for most plant species is long gone, there are still a few late bloomers, such as Fringed Gentian. On a cloudy day, they will be closed up like this....

....waiting for a sunny day to open up like this.
A late season goldenrod in woodlands is this Zig-zag Goldenrod, named for the zig-zag of it stem.
A sharp-eyed observer may see something like this although it is not quite fully out. It is the leaf of a somewhat rare orchid called Puttyroot. Its leaves are most obvious from about now until next spring, when they will then wither up as a flowering spike develops.
Berries are more noticeable, such as these Winterberries. But like so many berries, they won't be around long, as the remaining migrant songbirds will be quickly gobbling them up.