8.28.2021

Scavengers!

“It’s a traveller, he says, it’s lost like us, a wanderer covering miles. A scavenger that lives amongst the rocks and steals to live. It’s beautiful.”

― J. A. DuMairier
South winds rendered some seriously steamy temperatures today, so I headed out early to look for tiger beetles along the Wisconsin River. At least here in the northern part of the country we don't have hurricanes to worry about. However, we have had a spate of small tornadoes the past month, mostly F0 and F1, causing only minimal damage to homes and trees. That's Hurricane Ida (below) taken this morning from GOES-East. I post-processed it a little in Adobe Photoshop ― the raw images don't quite have enough contrast to my liking. 
My morning mission was to find more Hairy-necked Tiger Beetles, but first I'd have to sort through dozens of Bronzed, which were extremely numerous on the shoreline. My vision isn't what it used to be and separating the two can be a little challenging. If I can get close enough to see the front maculation, a "C" indicates Bronzed and a "G" indicates Hairy-necked. Once photographs are taken, one can see other differences, especially the proportionally larger mandibles of Hairy-necked. 
After getting some quality portraits of Bronzed, I stumbled upon the coolest discovery ― a deceased beached carp with several tiger beetles scavenging it. I recall reading in Pearson et al that some tiger beetles will scavenge deceased animals, but what an amazing opportunity. I observed a couple of interesting things. Firstly, at any one time there were no more than 3 or 4 tiger beetles on the carp, but there were many more along the perimeter of the fish. Secondly, the beetles on the carp were either eating small insects that were feeding on the fish, and some beetles were actually feeding on the blood/fluids as seen in the last photograph of this series.
I wonder if at first the tiger beetles are merely attracted to the dead fish because of the presense of small insects flying around it, but then eventually discover that there's nutrition available in another form. Kind of gross, but utterly fascinating. I do so enjoy observing my favorite insect quarry in a totally different natural context. It was a little smelly, but it appeared to be a recent kill. I was the first to arrive at this location in the morning, so I'm not sure if a fisherman dumped it from a boat and it washed up on shore or what. Whatever the case may be, I really enjoyed documenting it ― death giving life.
And here we are! Hairy-necked Tiger Beetle Cicindela hirticollis ― nominate and zero Wisconsin subspecies. DNA doesn't lie! ;)
All images © 2021 Mike McDowell