המועדפים של richard_bulva

Dia 82, un individuo.

Day 82, one individual.

Relacionado con // Related to:
https://www.inaturalist.org/observations/2667158
https://www.inaturalist.org/observations/2667199
https://www.inaturalist.org/observations/2667420

Lindneromyia flavicornis male. Rock Creek Park, Washington, DC, USA.

Keys to Platypeza flavicornis in Johnson 1923. The current valid name for this species is Lindneromyia flavicornis according to diptera.org.

I returned from the Texas this week straight into my annual commitment to survey the Western Migration/Overwintering Sites of the Monarch ( Danaus plexxipus ) in San Francisco County.
With Mr. Adolph Sutro's "gift " of Blue Gum Eucalyptus to our city more than 100 years ago, this is a great deal more difficult than it sounds - complete "needle in haystack " work for three weeks and, to be honest, not really...fun. I've done this now for 8 years and we have so few Monarchs that a real Natural Bridges-them-flying-everywhere-in-the-canopy is something I never see. Dr. John Hafernik reported 700 in Golden Gate Park in 1997. I've never seen anything coming close to that at any historic site I visit...
Until today...
Reports had come in from the staff at the Presidio Trust of "dozens and dozens" in certain areas. Took two buses and climbed up the known north-facing wall of Rob Hill, a historic roost that had been radically altered due to restoration for the endangered San Francisco Lessinga ( Lessingia germanium ). The Presidio Trust has been working with Dr. Stuart Weiss to protect the known habitat for the Monarchs while drastically thinning the north-facing wall of Eucs. I walked to the far eastern portion of the Hill and...there they were. Numbers I've never seen it San Francisco. Most of them sunning themselves. Nothing much to nectar on but...clearly a healthy roost.
Counted approximately 225 - the most I've ever seen in our county in one day.
Not really interested in the never-ending politics of this creature - what are we doing right/what are we doing wrong - just...reveled in it's...phenomenon today.

Male Pachydiplax longipennis being eaten by Opheodrys aestivus

Like a lot of these predation shots I heard the irregular beat of frantic, chafing wings before locating the scene.

I was taken aback when I first realized what was happening. That quickly wore off though and I was on the ground trying to get as close as possible without disrupting or having any meaningful influence on the situation.

Two great predators. In the end the dasher broke free and clumsily flew off (though he was lucky there were birds looking for an easy catch). I can't say for sure whether or not I played any part in the snake not succeeding in this struggle. If it were venomous I think (though I don't know if venomous snakes spend their venom on dragonflies or if they specialize in more protein-rich options) the dasher would've been done for.

But, the snake maneuvering his jaws to clamp down on the dragonfly gave some room for escape--especially since his jaws were over the thorax and wings, which were already beating trying to escape.