Warming up in the sun

  

I helped out with the Western Sonoma County Christmas Bird Count today (28 December 2025).  It was a very calm and warm day at the coast, with air temperatures reaching at least 56°F (13°C) and perhaps even higher.  (I think it's my first Christmas Bird Count wearing a t-shirt for part of the day!)  

Although it was a nice day for birding, I also saw quite a few insects — a half a dozen bumblebees, at least 4-5 butterflies, and possibly one dragonfly.  Some of the butterflies flew by too quickly for an i.d., but at least two of them were Red Admirals (Vanessa atalanta) basking in the sun. 

October sun

  

Air temperatures reached ~65°F (~18°C) in Bodega Bay this afternoon (17 October 2022).  With just a short time outside, I noticed six species of butterflies, including this beautiful Red Admiral (Vanessa atalanta).

Other species included Monarch (Danaus plexippus), Acmon Blue (Plebejus acmon), Cabbage White (Pieris rapae), Orange Sulphur (Colias eurytheme), and an unidentified lady (Vanessa sp.).

Looks like it's going to be even warmer during the next couple of days, so it won't be surprising to see more insect activity.

In the winter sun

It was sunny and the air temperature was ~60°F (~15.5°C) around midday in Cotati today (5 January 2020).  While eating lunch, a movement caught my eye, and I was a little surprised to see a Red Admiral (Vanessa atalanta) perched on the fence in our backyard.

 

I'm guessing this was an adult butterfly that had been overwintering nearby and felt warm enough to emerge to bask in the winter sun for a little while.

 

Warming up

Remarkably, air temperatures reached 70°F (21°C) in Bodega Bay this afternoon.  That's warm for February!  [Daily air temperature records were broken throughout the Bay area today.]

I decided to go for a short walk in the late afternoon to look for butterflies basking in the sun.

I wasn't surprised, but it was interesting to see five species of butterflies today.  I'll show all five below so you can compare them.  (Note: All five species can overwinter as adults in this area, hence their brief appearances on warm days.  In contrast, many other butterfly species overwinter as caterpillars or pupae.)

 

Monarch (Danaus plexippus) 

 

West Coast Lady (Vanessa annabella) 

Satyr Anglewing (Polygonia satyrus)

 

California Tortoiseshell (Nymphalis californica) 

 

Red Admiral (Vanessa atalanta)

 

Solar-powered

Air temperatures in Bodega Bay reached ~56°F (~13°C) this afternoon.  After a week of rain, it seemed like a lot of insects were taking advantage of the sun today:

 

Red Admiral (Vanessa atalanta)

 

Monarch Butterfly (Danaus plexippus)

 

Variegated Meadowhawk (Sympetrum corruptum)

 

Unidentified fly (Let me know if you recognize it!)

ADDENDUM (12 February 2017): One of the suggestions I received about the fly in this post was that it could be a hover fly.  I did a quick image search, and noticed a similar-looking hover fly here.  I don't think it's the same species (based on the abdominal patterning), but it's very close, and I think it's likely the fly in the picture above is in the same family (Syrphidae).

Then I skimmed some information about syrphid flies, and learned that sometimes they eat aphids.  In the field I had noticed that these flies were spending a lot of time around the tips of the Monterey Cypress.  I wondered about what they were doing there (i.e., what was attracting them to those sites).  Well, I went back and reviewed my photos and it looks like there might be tiny aphids on the cypress tips!  Check it out — and note the arrow pointing to one of the possible aphids:

 

Winter sun

Although air temperatures have been cool lately, it was surprisingly warm in the midday sun on 4 January 2013.  During a quick walk through a section of the Bodega Dunes Campground, I spotted a few insects basking in the winter sun:

 

Red Admiral butterfly (Vanessa atalanta) on eucalyptus bark.  To see what this species looks like with its wings open, review the post from 25 November 2012.  I only saw one admiral on 4 January 2013.

 

Monarch butterfly (Danaus plexippus) sipping from wet mud.  Note the long tapering proboscis arching down to the ground (just in front of the eye).  I saw at least 4-5 Monarchs on 4 January 2013.  For more about overwintering Monarchs, see the post from last February.

 

Variegated Meadowhawk (Sympetrum corruptum).  You can read a little more about Variegated Meadowhawks in the post from 16 August 2012.  They're not common in winter, but can be seen year-round in California.  I saw two individuals on 4 January 2013.