River Springs 9.9.2018

Stopped at River Springs in the afternoon to bird and look for tiger beetles. Spent 1-2 hours walking the alkali grass stubble hoping to find Cicindela parowana. I didn't find any of those, but encountered good numbers of C. tanquebarica and one C. oregona in the dry grassy, alkaline uplands.
The wetland I stopped at for the next couple hours was incredible for tiger beetles. Literally standing in place I observed 6 species! The ones listed here plus C. oregona. Good numbers of individuals as well. Patches of the mud were covered with tiger beetle activity! I estimated 8-10 Susan's Tiger beetle. At least 2 pairs were in mate guard position (only species I saw doing that), plus several singles.
Williston's TB - estimated 10 or so individuals. All of them had a green sheen, and I strongly suspect these are psueudosenilis, or perhaps that mixed with echo. I've been doing a project on Williston's TB's this summer with a small grant, and have observed and collected them at Owen's Lake, Mono Lake, Alkali dry lake in Mineral Co NV, and middle alkali lake in Modoc. These River Springs ones looked alot like the Owen's ones.
Oblique-lined tiger-beetle - very common. Didn't estimate a number, but present in dry grassland and mudflats. As in observation listed below, several individuals appeared exceptionally hairy - more so than I'm used to for this species.
Short-legged: only 3-4 observed. However, in the field they are easily over-looked among the C. tranquebarica. They look slightly greener and have a thinner front maculation. Seen pulling small inverts from the mud & eating them (Williston's did this also).
oregona - fairly common on shoreline
wetsalts Tiger Beetle: also common in the mudflats. Ranged from jet black with bold crisp yellow maculation to ebony black

Birds here were very slow given the time of year. One Least Sandpiper, a handful of Red-necked Phalarope, a dozen or less WF Ibis, and a few waterfowl and PB Grebe with a juvenile.
About 90 feral horses out in the meadow to the east of this location, and horse damage around this spring was bad. I took some documentary photos. Though the Tiger beetle spot was so muddy & soft, the horses seemed to avoid it.
Also in the meadow to the east were about 25 pronghorn. The Pronghorn are relatively new arrivals here as far as I know (I've occasionally birded here for 15+ years). I saw 26 pronghorn last time I was here in late summer, and pronghorn appear to be increasing in western Mono Co. this year. Reports have come from Black Point (first pronghorn there since the 80's - since the late 90's for the Mono Basin) and out Hwy 167
Also encountered a swarm of what I suspect are broad-striped lady beetles in the alkali grassland. I have also seen these in Long Valley while looking for tiger beetles in alkaline grassland habitat. Crossidius coralensis (spelling?) still active, one individual on rabbitbrush

Posted on 10 de setembro de 2018, 10:23 PM by storm_petrel