Last week, the Fellows and I helped with an annual butterfly count at the Niobrara Valley Preserve. Since 1985, Neil Dankert has been coming up to the Preserve around July 4 each year to conduct a butterfly survey. As a result, we have a great species list for the site, but also some indications of which species are more or less abundant/present nowadays than in the past.
In addition to these once a year counts, Neil and former University of Nebraska-Kearney professor, Hal Nagel, conducted an intensive two year survey (including multiple visits per year) in the mid 1980’s. The pandemic interrupted an effort to repeat that two year survey effort and learn more about potential changes in the butterfly populations, but we hope to restart that effort. During Neil’s once-a-year counts, some species haven’t been found for quite a few years, but it’s possible they’ve just adjusted their schedule to come out earlier or later than his annual visits. Looking across the entire season and multiple years will help us better understand what’s actually changed.
In the meantime, Neil’s annual counts continue to give us valuable data. Maybe just as importantly, they are also a chance for him to pass on his incredible knowledge to others. This year, those others included our Hubbard Fellows, Kate and Sarah, as well as a few other volunteers. We visited the spots Neil goes to each year and counted everything we found – catching anything we couldn’t identify with certainty. We’d transfer the unknown butterflies from net to ziplock bag and then hand them to Neil for identification before releasing them again.
Hanging around with an absolute expert in their field is always fascinating and inspiring. I’m an ecologist with a lot of years of experience, but my knowledge is pretty shallow in many areas. I can identify most of the common butterflies, for example, but when it comes to skippers (the shorebirds of butterflies) or other tricky groups, I need Neil to point out why the pattern of spots on one fuzzy brown butterfly is different from the pattern on another one. We found 11 different skipper species and many of them looked awfully similar to each other.
Even more impressive is listening to Neil describe what species are going to be at each of the sites we visit and where we’ll find them. Our group was split into smaller pieces and I got to walk with Neil and his wife Jennifer at our first stop. We hiked the public trail and Neil pointed to a grove of oak trees surrounded by some smooth sumac in bloom. “We’ll find banded hairstreaks in those oaks”, he said. Sure enough, on both the oaks and surrounding sumac plants, we found several of the intricately-patterned little critters. The same thing happened later with other species in other habitats, including Acadian hairstreaks, two-spotted skippers, dun skippers, and others. We didn’t find any ottoe skippers or silver-bordered fritillaries in their respective spots this year, but that might have been timing or just bad luck – he’s found them in recent years.
By the end of the day, we’d found at least 37 different butterfly species. Great spangled fritillaries were the most abundant of the day, followed by little wood satyrs. Also common, but less showy than the great spangled fritillary, was the long dash skipper – a species I would not have identified without Neil’s help. Other species that were new to me, or just highlights because of their usual scarcity, were the Delaware skipper, two-spotted skipper, northern broken-dash, little glassywing, and coral hairstreak.
This kind of annual survey is a really important way to track what’s happening with a group of organisms. Combining these annual counts (to get a broad pattern) with some more intensive season-long surveys should help us better understand how populations might be responding to landscape changes, climate change, and other factors. A place like the Niobrara Valley Preserve is in a landscape that has seen changes, but less dramatically so than many others. If we pick up big shifts in butterfly populations there, it could have particularly important implications. Stay tuned – I’ll let you know what we learn.