The method described in this booklet was devised to enable a person with relatively little experience to assess the changes in abundance of butterflies in their locality. This booklet follows closely the one distributed to independent recorders by the British butterfly monitoring scheme (Hall, 1981).
The method was originally developed at Monks Wood Experimental Station in Great Britain, and the details have been published (Pollard,1991; Pollard and Yates, 1993). Routine periodic transect counts are used in the monitoring scheme which is a national scheme organized by the Institute of Terrestrial Ecology (ITE) at Monks Wood Experimental Station, and supported jointly by the ITE and the Nature Conservancy Council.
Approximately ten years ago, a group of naturalists started a monitoring program in the vicinity of Chicago, Illinois, U.S.A.
A similar butterfly monitoring scheme was developed by Sonja Teraguchi and Mark Rzeszotarski at the Cleveland Museum of Natural History. An initial transect was established in 1995 at Koelliker Fen, a Museum preserve in northeastern Ohio. Data from the first year were analyzed, and the methods for conducting a survey using parameters suitable for Ohio was defined. The first instruction handbook for recorders was written in early 1996. The program was expanded in 1996 to include transects from the Cleveland Museum of Natural History, Lake County, Lorain County and Cleveland Metroparks, the Ohio Division of Wildlife, and the Cuyahoga Valley National Recreation Area. In 1997, twelve sites were included in the survey.
A workshop on Long Term Butterfly Monitoring was held in April of 1998. The Ohio Division of Wildlife, The Ohio Lepidopterists, The Cleveland Museum of Natural History and the Ohio Biological Survey jointly sponsored the workshop, which was held at Killdeer Plains Wildlife Area near Marion, Ohio. There were approximately one hundred participants. At the present time, only Ohio has a state sponsored Long Term Butterfly Monitoring Program in the United States.
This booklet explains simply how a count is made and how to use and interpret the results. It is important to follow the instructions exactly to ensure a standard method of recording which is, as far as possible, independent of observers. In order to obtain useful information from a transect, several years' data covering complete seasons are needed to provide the comparisons between the numbers of butterflies from year to year.
A site information form is included in the booklet and is to be filled out by each site that conducts a survey. The form and the required attachments should be mailed to the contact person listed under records at the end of this booklet when the site is first established. This provides a mechanism for keeping in touch with all sites. It should be reviewed annually to insure that the information on file is correct.