Silver Bordered Fritillary – A NENHP Tier 1 species, photo by Colin Croft
While there are no butterflies in Nebraska that are on US Fish and Wildlife’s Endangered or Threatened Species list there are quite a number of species from the state whose future is of concern, either regionally or nationally. These species are tracked by a cooperative nationwide Natural Heritage Program. Dr. Rachel Simpson (Nebraska Program Data Manager/GIS Specialist) has consented to explain the Program to us. She writes:
“The Nebraska Natural Heritage Program (NENHP) was created in 1987 to gather information on rare plants and animals and native plant communities, such as prairies, woodlands and wetlands. The program is also involved in conservation planning, recovery of rare species, and native habitat management. Examples of current projects are Salt Creek Tiger Beetle recovery and the management of native prairies and oak woodlands.
The Nature Conservancy began establishing state heritage programs in the 1970s as a means to determine where to best conserve biodiversity. Prior to this there was no central storehouse for information on which species were rare, their abundance and where on the landscape they occurred. Heritage programs have now been established in all 50 states, 9 Canadian provinces and territories, and parts of Latin America. In the U.S. most programs are housed in state conservation agencies or universities. The Nebraska Natural Heritage Program is part of the Nebraska Game and Parks Commission.
In general NENHP and partners gather information about species that fall into one of two categories. ‘Tier 1 species’ are globally or nationally most at risk of extinction. ‘Tier 2 species’ are not at risk from a global or national perspective but are rare or at risk of disappearing from Nebraska.”
More information on the Nebraska Natural Heritage Program, including a link to a list of butterflies and other species tracked:
http://outdoornebraska.gov/naturalheritageprogram/
More information on the network of programs:
https://www.natureserve.org/
NENHP lists 14 butterfly species on their tier 1 list and another 84 as tier 2. Two of the Tier 1 species are the Ottoe and Arogos Skippers (Hesperia ottoe and Atrytone arogos). Both are prairie specialists and are two of what I like to call the “Golden Girls”. These two along with the Delaware Skipper (Anatrytone logan) can be nearly impossible to identify in the field. Here they are and how you might see them in the field. Get your field guide out and see how you do.
Golden Girls
OK, how did you do? Sometimes if you’re lucky and the skipper cooperates you’ll get a look at the upperside. Then things get a little easier. Ottoe Skippers can easily be separated. The Delaware and Arogos Skippers still are frighteningly similar. Delaware Skippers have black wing veins and a narrower, darker, more sharply defined wing margin while in Arogos Skippers the veins are not black and the wing margin marking is wider, a lighter brown with a more diffuse inner edge. All this and hoping you see a fresh skipper and not a worn one. So now try your luck.
Oh, did I forget to mention all three species are sexually dimorphic (the males and females are recognizably different). You should have been able to id the top row as Arogos Skippers (male and female), the middle row as Delaware Skippers (male and female) and the bottom row as Ottoe Skippers (male and female).
As I mentioned earlier both the Arogos and Ottoe Skippers are on the NENHP Tier 1 list meaning they are at an increased national risk of extinction. At the state level both are infrequently reported. Arogos skippers have been reported three times in the last 25 years (once in 2005 and twice in 2018). Ottoe skippers have been found twice in the last 15 years, in 2007 and 2010. Both are prairie specialists and suitable habitats are increasingly hard to find.
I hope you’ve enjoyed your foray into skipper identification. I call skippers the sparrows and shorebirds of the butterfly world – lots of them and hard to id.,