Tuesday 6 March 2018

Natural Areas of Chatham-Kent, Part 10 (Blenheim Sewage Lagoons)

Okay so the idea of a sewage lagoon maybe doesn't sound like much of a natural area. But wildlife have a different perspective, and therefore a complex of sewage lagoons is very much a magnet for wildlife.

If anyone has been out in the prairie pothole region of North America, you may realize that potholes filled with water are common place. Certain types of wildlife in particular are attracted to these potholes. So to wildlife passing through Chatham-Kent, and other areas where sewage lagoons are present, this concentration of 'potholes' filled with water are ideal places to visit, and in some cases nest at. As a result, some species historically found much farther west, have expanded their range to include sewage lagoons in southern Ontario.

These lagoons are easy to find for humans, as well. This particular set is located just west of Blenheim and north of Hwy 3/Talbot Trail on, appropriately named, Lagoon Road.

There is a condition for visiting, however, and that is an annual permit which is required to ensure not just anyone goes in and to protect the municipality from liability. The permit system has been in place for these lagoons since the mid 1980s, and is available from the municipal centre in Blenheim, located next to the post office.
To date there have been ~235 species of birds recorded here. What is so attractive to wildlife? I'm glad you asked.

Water birds, especially ducks, need places where they can rest safely from terrestrial predators.



Ducks, herons and shorebirds can feed on the abundant aquatic life, including invertebrates, fish, frogs, etc.
Shorebirds of various types are abundant especially during the spring and fall, including the Spotted Sandpiper shown above and Lesser Yellowlegs shown below.
Sometimes shorebirds can be extremely abundant.
Others are regular, but less common.
Short-billed Dowitcher
Long-billed Dowitcher
Wilson's Phalarope
 Wilson's Phalarope is really a species of the prairie pothole region, which has nested at these sewage lagoons on occasion. In the photo of them below, in their breeding plumage, it is the female that is the more brightly coloured, as it is the male that does most of the incubating.
Still other shorebird species are unusual, and if they occur immediately attract interest from other keen birders.
American Avocet
Buff-breasted Sandpiper
Marbled Godwit
Species of ducks that are more typical of the mid-western regions are more common place now, and include the following two species, both of which have attempted to breed here:
Northern Shoveler

Ruddy Duck

The next species, Greater White-fronted Goose, does not breed, but is sometimes seen on migration.
 It is sometimes called speckle-belly, due to the pattern of its belly shown here.
The waters of a sewage lagoon are nutrient rich, as one might expect, and this means aquatic insects are abundant. Land birds such as swallows benefit immensely from insect hatches. This is most evident during periods of cool weather when insects might not be available over the land, but with the warmer water retaining heat and with multitudes of insects hatching and becoming air borne, swallows can feed over these ponds to sustain themselves at a critical time. If one wants to see this, visit the lagoons during a cold spell. For example during a cold spell in mid-May of 2017 when the temperatures dropped close to freezing, there were thousands of swallows swooping over the water feeding, or resting on the berms separating the ponds.
 Tree Swallows were the most abundant, but Cliff Swallows and others were present in larger than usual numbers.
Cliff Swallow
Cliff Swallow
Tree Swallow
The shrubs surrounding the lagoon complex can be a great spot for land birds, especially on migration.
Rusty Blackbird

With such concentrations of birds, raptors that feed on birds such as Peregrine Falcon, are periodically attracted to the site.

Other species of wildlife are found, as well, with some being rare.....
Cattle Egret
 ...some uncommon....
Short-eared Owl
....and some not so rare.
Groundhog
The very openness of the lagoon complex and with it being so accessible to birders due to the berms surrounding the ponds, make it a great spot for birders. Having said that, since it is easy for humans to see wildlife, keep in mind that wildlife, which have great vision and survival instincts, can see humans even better and may be difficult to approach. Binoculars are a must, and a scope is highly recommended.
With all of the openness, there are lots of wildflowers present around the edges, making it a great spot for butterflies as well. It is a regular stopping point for us in our annual Butterfly Count in mid July, but it is sometimes better in the late summer when plants such as New England Aster, which is a favourite nectaring plant for butterflies, are abundant. The first three species are common here, as are others.
Clouded Sulphur
Common Ringlet
Orange Sulphur
 The next two species are rare and irregularly found here in spite of their names.
Common Buckeye
Common Checkered-skipper

All in all, sewage lagoons are a great place to find wildlife......you may be surprised!








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