Another great season for butterflies in north country
BY John weber
In July, wife Marlene and I completed our 21st season of “4th of July” counts in north central Minnesota.
Aided by a small, but dedicated band of fellow counters, we have now attained our 119th count since 1993. Altogether we have tallied a 21-year total of 137,694 living butterflies.
As I noted in last year’s count article, I “expected” a very good count season in 2012 given the early warm spring filled with many butterflies on the wing.
On the other hand, the cool, damp, late-arriving spring we had this year had me puzzled. Would we see any butterflies at all?
At times, both before and even during some of our six counts, we did see only a few butterflies.
Where does 2013 stand?
For a number of years, I considered the 15,577 butterflies tallied on the counts in 2001 produced a “gold standard” year. Last year’s 10,630 butterflies produced a second-place or “silver” finish behind 2001.
So it was totally unexpected that this year-2013-produced a new silver-place finisher. Yes, that’s right, somehow almost 12,000 (11,977 to be exact) showed up on our six counts this summer! That is an increase of 12.7 percent over last summer’s10,630.
Our 119th count was at the Bemidji area. The 5,170 butterflies observed there that day now rank as our “best” count in terms of individual butterflies spotted. That late-season surge pushed 2013 into second place.
The count season began in the Nevis area with 25 species and 1,708 individuals. Then we moved to the Bluestem Prairie area in Clay County with 24 species and only 303 individuals (our 10th poorest count).
At Deep Portage area we found 32 species and 2,656 individuals. The Fertile area in Polk County produced 32 species and 778 individuals. Before being totally rained out, 32 species and 1,362 individuals were found on the Itasca State Park count. Then came the Bemidji area count with 46 species and a whopping 5,170 individuals.
Purpose of counts
As I let the impact of the 2013 season sink in, I’ll say that our six “4th of July” butterfly counts are part of a much larger effort that spans the North American continent.
The North American Butterfly Association (NABA) compiles data each year collected from over 400 counts held in the U.S., Canada and Mexico.
A 15-mile diameter count circle is established. All living butterflies found in that circle on a single day are reported to NABA. 2013 marks the 39th year that these counts have been held. They are providing valuable citizen-gathered data on butterfly population trends.
Northern Crescent update
Northern Crescents are the small orange and black butterflies that a number of people recently have remarked having seen quite a few. They are the only butterfly species appearing on all 119 counts.
Last year the consecutive-appearance string barely continued: only 32 were spotted on the Bemidji area count. However,on this year’s Bemidji area count, they roared back big-time with 2,481 present and accounted.
Overall, the 6,652 Northern Crescents tallied this year represented 55.5 percent of all butterflies seen. Cumulatively, over these 21 years of counts, Northern Crescents represent almost one of every four butterflies we’ve tallied.
Northern Crescent caterpillars thrive on wild asters in unmowed, unsprayed areas.
Other 2013 tidbits
Needless to say, Northern Crescents were the most common butterfly species this season. However, a new number two has just emerged: European Skippers. We tallied 733 this season. A few years ago, there were few, if any, Europeans on a count.
Gold standard year 2001 was helped immensely by members of the whites, sulphurs and Vanessa/ ladies butterfly families. In fact, they accounted for 50.5 percent of the 15,577 butterflies we tallied in 2001.
In sharp contrast, only 157 or a mere 1.3 percent of this year’s butterflies, were found in those butterfly families. However, Northern Crescents ably filled the void left by the general absence of whites, sulphurs and Vanessas this year.
Only six species were found on all six counts this summer: Eastern Tailed-Blue, Silver-bordered Fritillary, Silvery Checkerspot, Northern Crescent, White Admiral and Monarch. All but Northern Crescents had close calls at being a “no show” on a count.
(Last year, 12 species were present on all six counts.)
Ten species present in 2012 were “no shows” this summer. On the other hand, 15 species not present last year did show up this year. However, they did show up in very small numbers (i.e. a total of 77 individuals for those 15 species.
We did record our 99th different species in 2013: a lone Brown Elfin.
Monarchs and more
In 2012, Monarchs which sizzled in the spring around here, fizzled when it came time for a migratory generation that should have been heading to Mexico.
A census of over-wintering Monarchs last winter bears this out. They occupied only 2.95 acres – the lowest in 20 years.
On last year’s counts we recorded 889 adult Monarchs. This year only 58 adults showed up. We had more Mourning Cloaks at 60!
Monarchs have even been scarce on non-count days this summer. Over the seven weeks from June 18 through July 28, I examined 2,152 Common Milkweed plants on my weekly Monarch monitoring visits. I found only 20 eggs and five first instars. Monarch caterpillars need to go through five stages or instars before turning into adults.
Will there be a migratory Monarch generation around here this year? That’s a very good question. Given how late it took for the butterfly season, in general, to develop ... there still may be time.
Some whites and sulphurs, largely absent from the count season, are beginning to take wing. Also a few of the anglewings and tortoiseshells that can overwinter are starting to emerge.
But it will probably take weeks to determine when the final chapters of the 2013 season can be written. In the meantime, enjoy every butterfly you come across. They are truly winged wonders!