CHECKLIST AND POLLARD WALK BUTTERFLY SURVEY METHODS ON PUBLIC LANDS

Checklist and ''Pollard Walk'' butterfly survey methods were contempor aneously applied to seven public sites in North Dakota during the summ er of 1995. Results were compared for effect of method and site on tot al number of butterflies and total number of species detected per hour . Checklist searching produced significantly more butterfly detections per hour than Pollard Walks at all sites. Number of species detected per hour did not differ significantly either among sites or between me thods. Many species were detected by only one method, and at most site s generalist and invader species were more likely to be observed durin g checklist searches than during Pollard Walks. Results indicate that checklist surveys are a more efficient means for initial determination of a species list for a site, whereas for long-term monitoring the Po llard Walk is more practical and statistically manageable. Pollard Wal k transects are thus recommended once a prairie butterfly fauna has be en defined for a site by checklist surveys.