Southbound & Historic?

Painted ladies — one small sample — photo’d by Will Kerling at Cape May Point on 8-26-12.

August closed with a flurry of memorable sightings during the last week, including:

–> long-tailed skipper (the first one found by Chris Tonkinson on 8/29 and another found two days later by Chris Herz, Jean Gutsmuth, and Dave Amadio — our 92nd species for 2012);

–> giant swallowtail (found by Shawn Wainwright, on 8/30/12, our fourth report and third different county for the year — and the first ever for the species for our log for Ocean County);

–> Ocola skipper (our second report for the year, found by Chris Herz, Jean Gutsmuth, and Dave Amadio on 8/31);

Ocola skipper at the Triangle Garden in Cape May Point, photo’d by Dave Amadio, on 8-31-12.

–> and several other good finds you can see on our log (and to be noted in a future compilation).

In the meantime, the butterflies you can’t miss are painted ladies. Have we ever seen such an autumn flight? Even folks who do not normally pay attention to leps are talking about them, “What are they? They are all over my garden!”

Vanessa cardui, a.k.a. “the cosmopolitan lady,” is the world’s most widely-distributed butterfly, often flies in tremendous numbers, and has spread around the planet despite its inability to weather winter cold. Various sources suggest that North American painted ladies can over-winter only south of the US/Mexico border. (That seems hard to believe, but I cannot find any sources saying otherwise.)

The northbound flights in spring out of the wintering area in Mexico are often spectacular in the western U.S. where (several sources say) they sometimes stop traffic.

The fall migration is much more subtle, however, and something of a puzzle, even in western states.

And here in South Jersey, where V. cardui fluctuates year-to-year from moderately common to hard-to-find, detecting the southbound flight seems a real challenge.

Not this year!

We are having a fall flight that seems off the charts for any butterfly not named monarch or buckeye.

Will Kerling has been tracing the flight on NJ’s southern peninsula (and, as always, documenting finds on our log). He notes in an email today (9-2-12):

Cape May Point and West Cape May are the places to see a buildup of the painted ladies that have been filtering through Cape May County for weeks now. This past Wednesday and Thursday [Aug 29-30] were the best days, so far, to watch the movement for numbers and flight direction. Each day until around 10 am, the ladies were rapidly flying from N to S and then the flight direction shifted from E to W. Both days, the flights last ALL day! See our log for numbers and comments.

On Friday [Aug 31] Chris Herz, Dave Amadio and Jean Gutsmuth went to different places in Cape May Point and West Cape May and attempted to count them. Their count indicated over 800 painted ladies!!! Yesterday [Sept 1], I counted over 600 in Cape May Point and the Rea Farm of West Cape May. My count from the Avalon Golf Links to West Cape May was 109 individual painted ladies.

Chris and Cynthia have pointed out news on the Internet about massive numbers of painted ladies being observed in southern Canada.

Best,
Will

North of Cape May County the actual movement seems harder to detect than on the peninsula — although the numbers indicate a flight must be under way. The butterflies in our garden and at other gardens nearby (in Atlantic County) do not seem engaged in a directional flight — at least not one that is easy to trace. They circle around and nectar again and again on Sedum, Verbena, and a few other of their favorite plants. It’s hard to tell which have arrived most recently or where they go, or when they leave. Most look fresh and unmarked; a few show a mix of sharp colors and wing breakage or wing wear. Is it too much of a stretch to consider that combination a subtle sign of migration?

Painted lady in Port Republic on 8-31-12 showing mix of sharp colors and wing wear. Evidence perhaps that it has already flown a distance?

In his classic study, “The Migration of Painted Lady With Special Reference to North America” C.B. Williams describes numerous spring/northbound flights in detail and then asks in an intriguing passage:

If North America is repopulated each year from the south, do all the offspring of the earlier immigrants die out before the fall, or is there a partial or general return to south, to repopulate or replenish their winter headquarters? [There] is very little evidence …. that we have available at this point… only about a dozen observations of flights.

That was 1970. How many flights have been documented since? James Scott summarizes a few scattered reports in his 1986 The Butterflies of North America and writes, “The main puzzle regarding Vanessa cardui is the weak return flight in late summer and fall. The only return flights I have ever seen were to the southwest in late July and mid-August above timberline [in the western US].”

In a quick review of other sources I haven’t yet found details of well-documented southbound flights in more recent years. I’ll keep searching, and if anyone has info, please pass along. This flight seems the largest in recent memory, at least. Anyone with memories (or know of records) of similar or even larger ones?

Just counting the ladies in your garden each day as the numbers go up or down could give us numbers worth thinking about, wherever you live in South Jersey. And if you do see a flight with direction, please log that in as well.

Keep watching and reporting, everyone!

jc

Painted ladies on Sedum at Cape May Point, photo’d by Will Kerling on 9-1-12.

Updates/Comments to original posting:

Cynthia Allen:

Many of the Painted Ladies I am seeing in my yard in Cape May Court House are not fresh. Some are complete rags, although they run the gamut from rags to fresh.

Michael Gochfeld has also emailed in response to the original post. As he notes, we had those two large, northbound nymphalid flights through NJ (and elsewhere in mid-Atlantic states, New England, and Canada) in April/May. The species involved were red admirals, question marks, American ladies, but apparently only a few scattered painted ladies were mixed in.

Michael Gochfeld:

This is certainly the largest number of Painted Ladys I’ve seen since I began recording in 1987.

But, I have a question: In May the Red Admirals were streaming through central NJ. In August the Painted Ladys just seemed to appear—mostly fresh.

We did have some Painted Ladys in early summer. Based on what I’ve seen in my yard— a complete lack of “movement” — I think it possible that we are seeing local offspring of an earlier (and smaller wave).

I am up in the Albany [NY] today and there are definitely a few Painted Ladys around—maybe it’s even the commonest butterfly But there’s no evidence of movement here, either.

It will be interesting to see what the late-June/early July 4JC counts might tell us about Painted Ladys six weeks earlier.

Did you see migratory flights in South Jersey?

Conversely, what happened to the summer broods of Red Admirals we should have seen after the May flight? There were lots of caterpillars stripping the nettles locally. Did they eat themselves out of house and home?

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