Differences and Similarities…

I’ve still got some pictures left over from the weekend, if you can believe it, so here they are.

This first one features a pair of mute swan cygnets, and I took it on Sunday after I was inspired to look up just how big they are by the spectacular Saturday fly-over. I read that gray turns out to be the “natural” cygnet color, and ones with the white color morph are known as “Polish swans”, they are “found only in populations with a history of domestication,” and “Polish swans “carry a copy of a gene responsible for leucism.”

They all turn white when they grow up, so I guess it’s a moot point anyway.

Mute swan (Cygnus olor) cygnets. "The cygnet on the right is of the "Polish swan" colour morph, and carries a gene responsible for leucism."

Here’s a handsome common wood pigeon (Columba palumbus), which I first showed you back in May. It is close cousins with the smaller rock pigeons that nest under the bridges over the Milwaukee River at either end of Estabrook Park. I see them here often enough and usually leave them alone, but this one just seemed to be begging for a photograph.

Common wood pigeon (Columba palumbus)

Here’s another ruddy darter dragonfly, which are pretty common lately, but this one perched on such a nice bright red stem that I thought it was worth another shot.

Ruddy darter (Sympetrum sanguineum)

On Sunday, the thistles I was wading through to photograph butterflies were also full of bees, as you can probably imagine, and I am happy to report that we all left each other alone. Once in a while, however, the expected buzzing would sound disturbingly near and incessant, and upon closer inspection, I witnessed this fascinating behavior, where one “bee” would hover over another.

Hoverflies hovering over each other

It turns out that these little pollinators are not even bees at all, but hover flies instead, evolved to mimic bees for the protection from predators such appearance affords. There are “about 6,000 species” of hover flies, and I’ve seen several in Estabrook, but it might take me awhile to pin down exactly which ones these are.

Hoverflies hovering over each other

Some mate in flight, and perhaps that’s what these mid-air traffic jams are all about.

Hoverflies hovering over each other

The hover fly below, however, stood out for a different reason. It was absolutely huge, and that helped me look it up pretty quickly. It’s a hornet mimic hoverfly (Volucella zonaria), and “can reach a length of 25 mm (0.98 inches)!” Further, they mimic “the European hornet (Vespa crabro), by its size, by its appearance and [by] its buzzing flight,” and thank goodness I haven’t yet met any of the real thing yet!

Hornet mimic hoverfly (Volucella zonaria)

Finally, there were also several bumblebees hard at work, and here’s one on a different variety of thistle.

Bumblebee on thistle

Published by Andrew Dressel

Theoretical and Applied Bicycle Mechanic, and now, apparently, Amateur Naturalist. In any case, my day job is teaching mechanics at UWM.

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