Print PageCitizen science efforts have been applauded for increasing ecological literacy, promoting stewardship, and contributing to ecological understanding. Yet it is unclear how effective different citizen monitoring efforts are in providing information about species of conservation concern. Such evaluations are especially limited for densely-populated urban landscapes where citizen science might be most effective. To assess the ability of citizen monitoring to contribute to urban-based conservation, we compared butterfly data collected by citizen scientists in the metropolitan areas of Chicago, IL and New York City, NY. For each city, we compiled all butterfly observations reported by citizen scientists within a 56 km radius of the urban center of each city for a ten year period (2001 to 2010). Monitoring in Chicago followed a standardized protocol (“Pollard transects” conducted in 58 specific locations) while data in NYC had no set protocol, instead including sightings from any location of interest. Our goal was to identify strengths and biases of the citizen-collected data from each city, and to determine how the data might be used to inform urban conservation.
Results/Conclusions
From 2001 to 2010, 73 primary observers in Chicago identified 89 butterfly species (101,525 individuals) while 94 primary observers in NYC identified 108 butterfly species (148,721 individuals). In NYC but not in Chicago, the number of species observed per year increased with the number of observers, likely because the Chicago efforts maintained the minimum number of volunteers needed to monitor sites. In both cities, there were several “very important observers” (VIO’s) who accounted for the majority of the observations over the ten year period (e.g., the ten most active observers were responsible for 58% and 90% of the individual butterflies reported for Chicago and NYC). Simulated removal of these VIO’s altered species accumulation curves and impaired our ability to generalize across locations, indicating the importance of these highly active volunteers. In NYC, a greater number of localities sampled (>350) and lack of standardized monitoring biased the data towards rare species. However, in some cases, this provided useful information such as cross-validation of rare species by different observers and increased locality data for distribution maps. For both cities, citizens identified a total of over 100 rare species (those contributing less than 1% of the individuals in either city, including five endangered species), providing important information on the distribution of species of conservation concern inhabiting densely populated and heavily developed urban landscapes.
