|A Red Admiral (Vanessa atalanta) butterfly shares a sap flow on our ash tree with an ant.|
Just like Monarch butterflies, who are visitors to our area and undergo seasonal migration, so too do Red Admirals. We normally get to see Red Admirals on the wing from late April through early October. This year, though, they arrived a little earlier. I saw a few in late March, and I've seen much higher numbers of them all season. It's been a stellar year for the Red Admirals! I didn't know much about Red Admiral migration, so I checked my books but didn't find much. After a quick internet search, I found admirals do not overwinter here because they cannot survive cold winters. Some individuals from the fall generation migrate south to winter in the Carolinas, Georgia, Florida, and other southern states, but not all, and research is still needed on why some stay. Mostly North America is recolonized each spring by butterflies coming up from the south (click here and here). It always amazes me that creatures seemingly so fragile can undertake these massive migrations and survive.
|The profile of a Red Admiral butterfly with an extended proboscis.|
|...peace and quiet again. When the wasp would give up and fly away, the butterfly would go back to feeding on the tree sap.|
|...eventually the Admiral had enough and flew off to another branch to find an unoccupied sap flow. The dorsal view of this butterfly is gorgeous. Bright orange-red stripes and white bars stand out easily against the dark brown-black background.|
No wonder I saw so many Red Admirals this season. It was an irruption year. The butterflies did very well overwintering in the south, and the extra mild spring helped usher them in during their northward migration. For more accounts, click here for a post titled, "Red Admiral Invasion," by Jim McCormac from Ohio Birds and Biodiversity, and here for an article titled, "Naboko's Favorite Butterfly Invades NYC (and Other Places)," from the Gothamist.