I'll be the first to admit that some of my favorite shorebird sightings involve red birds. Maybe it is because most shorebirding I do here in Colorado involves dull fall birds and often the most red I get to see is the little racing stripe in the scapulars of Western Sandpipers or some vestigial red in Red-necked Phalaropes that come through. The first Red Knots and Curlew Sandpipers I saw were fall birds, pretty gray although still very exciting. Then I went to Cape May in the spring and saw nice red versions of both- danged cool, especially a deep red Curlew Sandpiper along with a more pinkish companion! Well, on Sunday I upgraded my previous Red Phalarope sightings (all of which involved gray fall birds) by picking up a drop-dead gorgeous breeding-plumage female. A friend and fellow Boulder-area birder, Bill Kaempfer, was leading a trip to the Pawnee National Grassland and danged if they didn't find the bird on a little muddy ephemeral pond near the Wyoming Border, probably no bigger than an acre and a few inches deep. I couldn't make the hour's run on the Saturday when they found it, but I headed up on Sunday morning. Initially scanning the playa with my bins as I pulled up, it appeared to be birdless- Noooooo! But the pond sits back a way from the road, and when I combed it more carefully with my scope I found the red beauty against the far side, sleeping in emergent vegetation. WOW!
The bird seemed pretty healthy and content, considering it was thousands of kilometers away from either the pelagic or arctic tundra environs where I would expect it. It was successfully feeding on invertebrates, some quite large. I wasn't sure what could be in an ephemeral pond out on the shortgrass prairie like that, but a couple of knowledgeable correspondents (Henry Armknecht and Steve Larson) suggested that they were probably Fairy Shrimp &/or Tadpole Shrimp. I did some brief online research and both seemed plausible and indeed likely. While I didn't go into much depth in my studies, I found that both reside in ephemeral ponds, the eggs and/or embryos of both can survive complete desiccation for long periods of time- years if necessary (in fact they many species' eggs require drying before they will hatch when the water returns.) They can also survive extremes of temperatures while dried out. Some species of both groups can grow to decent size in short periods of time, with some reaching several centimeters long in just a few weeks. There are many species in these two invertebrate groups (both are crustaceans in the class Branchiopoda, Tadpole Shrimp in the order Notostraca and Fairy Shrimp in the order Anostraca), some with very narrow ranges and even endangered status and some quite common. It seems that in many settings Tadpole Shrimp will eat Fairy Shrimp, along with about everything else animal or vegetable they can find in their ponds, including each other! I did notice that some of the prey items the Red Phalarope captured were eaten quickly and pretty easily, while others required a lot of effort (dashing, lashing, thrashing, bashing, crashing, smashing and occasionally just giving up and trashing.) Perhaps the Fairy shrimp were the easier prey and the Tadpole Shrimp the troublesome items?? I did get one blurry series of the bird with a critter in its bill. I wasn't sure what I was looking at until I compared it to Tadpole Shrimp pictures, when I realized that their horseshoe crab-shaped carapace was almost certainly what I was seeing. Another acquaintance with lots of ecological experience and knowledge of invertebrate biology, David Leatherman, confirmed that the victim in this picture is indeed a Tadpole Shrimp (click on the pic to enlarge.)
While there, I also enjoyed the vigorous singing, skylarking, and chasing behaviors of many shortgrass prairie birds. Horned Larks ruled by numbers, but Lark Buntings seemed to be everywhere, too, seconded by McCown's Longspurs. But one song amongst the cacophony tweaked my radar and I turned my attention north of the pond to find a Mountain Plover skylarking, giving its display song as it glided above the horizon. A bit later, three Mountain Plovers blew by me in a heated chase, giving their little wherrt calls as they went, which took them all around the perimeter of the pond and then out of sight beyond the road to the NE. I wonder if males of the species chase females- it appeared that one bird was being pursued by two followers. After that, one of them, or another Mountain Plover, snuck in from my right to the pond's edge and walked around to where the Red Phalarope was hanging out again near the west shore in emergent vegetation. Maybe I was imagining things, but it seemed like the Mountain Plover walked down to take a look at the weird red thing that was in its pond... Sorry that this pic isn't real sharp but there was a lot of bad air to shoot though across the whole lake. I had to try, though- after all, when was the last time you saw a picture of a breeding Red Phalarope and Mountain Plover in the same frame?I digiscoped these pics through my Leica APO-Televid 77 using a 32X WW eyepiece and Digital Adapter 2 with a new camera I got last week- a Leica C-Lux 2. I had been using the C-Lux 1, which I loved, but the great folks at Leica upgraded me to the current model. It sports a little better resolution (7 MP) but perhaps more importantly, the new sensor has a bit less noise at high ISOs. Other than re-positioning my shutter release bracket a bit, I can still use my same digiscoping rig with this camera. It shoots pretty cool video, too- I'll leave you with a little compilation of some scenes that I shot of the bird in action. The preening clip almost seems speeded up but that is just the frenetic phalarope's pace, I guess. Enjoy- Bill
Spring Migration 2017, Part 2
2 weeks ago