Wildlife photos: Visit to a Great Blue Heron Rookery

June 14, 2021 • 8:00 am

Today’s readers’ wildlife feature will be presented by our own Greg Mayer, who visited a heron rookery.  All the following text is Greg’s.

by Greg Mayer

Last weekend, my friend Andy Buchanan had reported to me seeing large birds in trees at the Mt. Pleasant, Racine County, WI, village compost site. He thought they resembled the storks he knew from Florida, but which don’t occur in Wisconsin, so we went this past week to take a look and see what they were. We found an active Great Blue Heron (Ardea herodias) rookery in big, dead trees, in a flooded wetland (about 6 acres of open water in a Google Earth image from this past April) to the NE of the compost site.

Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021. Note the nests, and also the bird standing on the horizontal branch. Seven of the active nests are in the center and right side of this photo.

Careful, repeated, counts gave 10 active nests; each nest was a set of sticks a few feet wide and deep. There were 2-3 inactive nests/piles of sticks, the latter smaller; adults would alight on these unused piles, so it was necessary to see young in the nest to be sure a nest was active.

A ground-level view of the wetland in which the rookery is located.

The nests were high in the dead trees, and could be fairly close to one another in the same tree. Adults are about 4 feet tall, to give you some idea of the spacing. There are 3 active nests in this photo (plus the inactive smaller pile of sticks to the left). How many herons can you find? How many are adult/how many young?

Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021.

Nests held up to 3 young, which were fairly large and well-feathered, but unable to fly. The total number of herons was probably 20 adults and 20-30 young. The adult in this nest, with nape and chest plumes, is flanked by one standing young– notice how big it is– and two sitting behind.

Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021.

Nests might have 0-2 adults in attendance at any instant. Here, both adults attend to their three young. In addition to having nape and chest plumes, adults can also be distinguished by their white crowns; in the young, the entire top of the head is dark.

Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021.

When an adult arrived at a nest, the young ones would make a persistent duck-like clucking, evidently begging for food. In the following picture, the adult has just landed, and is being eagerly greeted by 3 young.

Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021. An adult greeted by 3 young.

Adults were flying in and out, and might land on a nest, a pile of sticks, or a branch or stump of a tree; and, they might move within the stand (i.e. not just into the stand or out of the stand). In flying they of course flap up . . .

Flying into the Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021.

. . . and then flap down (these two images were taken .2 seconds apart):

Flying into the Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021.

One felled and another nearly-felled tree trunk (part of the same tree, it appeared) showed that Beavers (Castor canadensis) had created the wetland that drowned these trees. I was surprised to see in a Google Earth image that the trees were a flourishing green in July 2011, and at least mostly green in June 2015, so that the flooding and tree deaths must have occurred in the 2010’s, after 2011 or even 2015; there must be, or have been until quite recently, beavers present.

Beaver (Castor canadensis) chewed tree trunks at the Great Blue Heron (Ardea herodias) rookery, village compost site, Mt. Pleasant, WI, 9 June 2021.

There was a Great Egret (Ardea alba) in the wetland, walking about in the water; look carefully and you’ll see it.

Great Egret (Ardea alba), village compost site, Mt. Pleasant, WI, 9 June 2021.

There were also three Sandhill Cranes (Grus canadensis) at the edge of the farm field next to the wetland; they moved back and forth between the open field and the brush at its N edge (which separated it from the wetland). All were warm-reddish-brownish, and one was very rusty– they’re usually grayer. They were probably parents and a young one, but we could not be sure which was which, since all had red foreheads (which they lack when first hatched).

Sandhill Cranes (Grus canadensis) in a farm field adjacent to the village compost site, Mt. Pleasant, WI, 9 June 2021.

Andy used a pair of German officer’s binoculars from WW II. They had belonged to his father, who served in the Royal Navy during the war, and probably got them as a souvenir. The binoculars were very well made, with leather cladding on the barrels, and still tight with good optics. (The outer surface of the lenses can always be cleaned; it’s when moisture or dirt gets inside that binoculars go bad.)

Andy Buchanan observing the Great Blue Heron (Ardea herodias) rookery at the village compost site, Mt. Pleasant, WI, on 9 June 2021.

(All the pictures can be clicked on to enlarge.)

Christmas ducks

December 31, 2020 • 2:00 pm

by Greg Mayer

On Christmas Day, I went down to the harbor in Racine, Wisconsin, and saw a male and female pair of mallards (Anas platyrhynchos) amidst a group of Canada geese (Branta canadensis).

Canada geese and mallards, Racine harbor, Wisconsin, December 25, 2020.

Canada geese were migratory in this part of Wisconsin when I first moved here (1992), disappearing for a month or two at the height of winter. In even earlier times, they were not even breeding here, just passing through on the way to and from their more northern breeding grounds. Now they are year-round residents, with pairs setting up breeding territories starting in February-March. (On the campus of the  University of Wisconsin-Parkside, the nesting sites are atop buildings, a shift from the ground nesting habits they had in the 1990s.) They join up in flocks after the breeding season, frequenting open water (as at Lake Michigan, shown here) and farm fields, which have unharvested corn and other food supplies. I’m not sure what has caused them to stay year round, but the local increase of development– leading to higher temperatures (heat islands), more open water, year-round lawn grass growth in some areas, and more handouts from people– along with global warming– leading to higher temperatures in general– may be contributing.

As I approached to get a picture, I realized there were many more mallards than a pair– 17, in fact, among the 23 geese. Also, the mallards were much more apprehensive about the approach of a person on shore. As you can see, they are all streaming away, while the geese remain serenely contemplative.

Canada geese and mallards, Racine harbor, Wisconsin, December 25, 2020.

Root River turtles

July 1, 2018 • 3:00 pm

by Greg Mayer

A couple of Sundays ago, June 17, 2018, my wife and I took a paddle along the Root River, in Racine, WI. Starting out at the Root River Environmental Center (REC), we went upstream, around the island in Island Park, and back down to the REC. Along the way we saw quite a few turtles– 15-20, although at least a few were the same turtles seen going both up and back.

Here, a shelled reptile and a glorified reptile share a tree trunk in mid stream.

Female mallard and map turtle in Root River, Racine, WI, 17 June 2018.

On the next picture, it’s a bit of “spot the turtle”– the smaller one is inconspicuous. Both these two and the one in the previous picture appear to be map turtles (Graptemys). These turtles are typically more riverine than lacustrine, and thus might be expected in the river, except that the Root River is outside the range of map turtles, which occur in Illinois to the south and along the larger rivers of western Wisconsin. The map turtles of southeast Wisconsin are almost certainly introduced. What species they are is not clear to me. The species-level taxonomy of map turtles is not completely worked out, especially down South, where each river that drains into the Gulf of Mexico seems to have a more or less distinctive population of map turtles.

Two map turtles in Root River, Racine, WI, 17 June 2018.

Although it might be natural to think that one of the midwestern species was introduced into southeast Wisconsin, southern turtles can be found in the pet trade, and there may be more than one species present in the Root River. (In Kenosha, just south of Racine, I’ve seen at least two map turtle species.) It’s not known if they are breeding, and if so, whether different forms are crossing. I did find a hatchling in Kenosha, but I can’t rule out– in fact I lean toward– the possibility that it was released, rather than bred, there.

This next turtle is definitely a map turtle. Note the hint of serration or knobs on the shell along the midline, and the white neck markings.

Map turtle in Root River, Racine, WI, 17 June 2018.

The next turtle is a snapping turtle (Chelydra serpentina), hauled out on the island in Island Park. It’s not a very good picture– that’s its tail you’re looking at– as the turtle slipped into the water as we maneuvered for a better shot, but snapping turtles so rarely bask on land that I though it worth showing. (They often float right at the surface, which is their usual way of ‘basking’.)

Snapping turtle on island in Island Park, Root River, Racine, WI, 17 June 2018.

The species we saw the most of were midland painted turtles (Chrysemys picta marginata), which, like snapping turtles, are more of a pond than river species. The Root River is shallow and slow-moving, though, so the conditions are fairly pond-like. You can tell it’s the midland subspecies because the seams between the costal (‘rib’) scutes don’t line up with the seams between the vertebral scutes

Painted turtle in Root River, Racine, WI, 17 June 2018.

We saw a bunch, but the gal above let us get the closest, so she gets a closeup. (You can tell it’s a she by the large size and the short ‘fingernails’– males are smaller, and have longer front claws.)

Painted turtle in Root River, Racine, WI, 17 June 2018.

We did see two or three of southeast Wisconsin’s classic native river turtle, the smooth softshell (Apalone mutica). They are baskers, but very skittish, and thus hard to approach. I was using a 55-200 zoom lens on this trip, and got a decent picture of one. Notice that the ‘log’ it is on is actually an old piling or dock piece– note the bolt, nut, and metal plate.

Smooth softshell turtle in Root River, Racine, WI, 17 June 2018.

Finally, towards the end of our two-hour paddle, we encountered what I believe to be the same two map turtles we saw at the start of the trip, who are in the first picture above– it is the same log. Sexual size dimorphism is stronger in map turtles than painted turtles, so this could be a female and a male.

Two map turtles on the Root River, Racine, WI, 17 June 2018.

The possible male dove first, but we got close enough to see the neck markings and hint of dorsal serration in the probable female. Of the two native map turtles in western Wisconsin, the plain old map turtle, Graptemys geographica, is less serrated than the false map turtle, Graptemys pseudogeographica, so this would be a geographica, except that the two Wisconsin species aren’t the only possibilities. (One of the two map turtle species I’ve seen in Kenosha is definitely a ‘white-eyed’ southern form.)

A probable plain old map turtle on the Root River, Racine, WI, 17 June 2018.

Given that it’s a small river hemmed in by human development on all sides, with a past history of industrial usage, four species of turtle, all reasonably abundant– all with multiple sightings during the trip, except for the snapper, which, as a non-basker, is often not seen– is actually a decent amount of biodiversity.