Swengel & Swengel Surveys

Independent scientists Scott & Ann Swengel began surveying butterflies in 1986 in Wisconsin. They quickly expanded their incredibly productive survey program to include Minnesota, North Dakota, Iowa, Illinois, and Missouri. Most of their surveys in states other than Wisconsin were conducted in the 1980s and 1990s over multiple consecutive years. Some of their past and present surveys target sensitive species like Regal Fritillary and Frosted Elfin, and/or sensitive habitats like muskegs and native prairies. One goal of their work is to seek out new locations and previously unknown populations. In Wisconsin alone, for example, they have surveyed over 250 sites, and many sites continue to receive at least annual surveys.

Monitoring Activity Tracker


Coordinator: Swengel, Ann & Scott
Program Started: 1986
Species Focus: All butterfly species
Contact: Ann & Scott Swengel (aswengel@jvlnet.com)


Protocol Type: Open search, Count, Opportunistic, Restricted search, Pollard, Plot, Transect
Data Type(s): Abundance
Survey Focus: Adults
Incidental Data Collected: Weather, Habitat notes
Protocol Notes: Protocols vary by site and project purpose. Modified Pollards are used as one of several survey methods.

Program Results


Swengel A, and SR Swengel. 2018. Patterns of Long-Term Population Trends of Three Lupine-Feeding Butterflies in Wisconsin. Diversity 10(2):31  DOI:10.3390/d10020031

Swengel A, and SR Swengel. 2017. Complex Messages in Long-Term Monitoring of Regal Fritillary (Speyeria idalia) (Lepidoptera: Nymphalidae) in the State of Wisconsin, USA, 1988–2015. Insects 8(1):6; DOI:10.3390/insects8010006

Swengel SR, and A Swengel. 2016. Status and Trend of Regal Fritillary (Speyeria idalia) (Lepidoptera: Nymphalidae) in the 4th of July Butterfly Count Program in 1977–2014. Hindawi Publishing Corporation Scientifica Volume 2016, Article ID 2572056

Swengel A, and SR Swengel. 2015. Grass-skipper (Hesperiinae) trends in Midwestern USA grasslands during 1988-2013. Journal of Insect Conservation 19:279-292

Swengel SR, and A Swengel. 2014. Assessing abundance patterns of specialized bog butterflies over 12 years in northern Wisconsin USA. Journal of Insect Conservation 19(1):293-304

Swengel A, and SR Swengel. 2014. Twenty Years of Elfin Enumeration: Abundance Patterns of Five Species of Callophrys (Lycaenidae) in Central Wisconsin, USA. Insects 5:332-350

Swengel AB, and SR Swengel. 2014. Paradoxes of Poweshiek Skipperling (Oarisma poweshiek) (Lepidoptera: Hesperiidae): Abundance Patterns and Management of a Highly Imperiled Prairie Species. ISRN Entomology, Hindawi Publishing Corp 2014:Article ID 216427

Swengel A, and SR Swengel. 2013. Decline of Hesperia ottoe (Lepidoptera: Hesperiidae) in Northern Tallgrass Prairie Preserves. Insects 4(4):663-682

Swengel SR, and A Swengel. 2013. Jutta Arctic (Oeneis jutta) (Lepidoptera: Nymphalidae) Populations in Central and Northern Wisconsin: Localized Butterfly Populations in a Naturally Fragmented Landscape. Great Lakes Entomologist 46(3-4):174-192

Swengel A, and SR Swengel. 2011. High and dry or sunk and dunked: Lessons for tallgrass prairies from quaking bogs. Journal of Insect Conservation 15(1):165-178

Swengel SR, Schlicht D, Olsen F, and A Swengel. 2011. Declines of prairie butterflies in the midwestern USA. Journal of Insect Conservation 15:327-339