An assessment of the use of volunteers for terrestrial invertebrate biodiversity surveys

Abstract

Species' distributions, assemblage patterns and the processes influencing these are poorly understood, and urgently require study. Use of volunteers to collect data is becoming increasingly common in biodiversity research. We assess the effectiveness of volunteers sampling terrestrial savanna invertebrates in comparison to experienced researchers, and examine the potential contribution of volunteers to terrestrial invertebrate surveys. There were relatively few differences in the diversity sampled by 54 Earthwatch Institute volunteers when compared to expert researchers. The major difference was in the results from the less spatially constrained method, where experience (microhabitat selection) most affected results, and experienced researchers performed better both quantitatively (more species sampled) and qualitatively (more unique and rare species). For the more constrained and less subjective methods, our training enabled the volunteers to quickly equal the experienced experts. Volunteers' experience in invertebrate research influenced both the researchers' perceptions of volunteers' capacity and the actual performance of the volunteers. This suggests that appropriate training for the methods used can help to improve volunteers' success with the sampling. We demonstrated that volunteers collect valid data; for the most part they sample invertebrates as effectively as a trained researcher, and that using volunteers has enormous direct benefits in terms of volume of work accomplished. For invertebrate studies using volunteers, we recommend that the subjectivity of the method be minimised, that experience is compensated for by increasing volunteer effort (two volunteers = one researcher), and that there is close management of volunteers in the field to ensure ongoing data quality. Volunteers provide a valuable resource to researchers carrying out biodiversity surveys, but using volunteers to carry out a scientifically sound project is not an easy option, and should only be implemented when volunteers would make a meaningful contribution and enable an otherwise impossible project.

Sharing biodiversity data: citizen scientists’ concerns and motivations

“…In addition, participation can be inspired by the desire to contribute to conservation science or management. With the literature discussing many examples of the contribution of citizen science to research and management (Dickinson et al 2010;Lovell et al 2009;Shirk et al 2012), many authors also stress the importance of communicating with volunteers about the impact of their work, as the awareness of making a concrete contribution is an important motivator for investing time and effort (e.g., Bonney et al 2009;Gouveia et al 2004). …”

Quantifying the sampling error in tree census measurements by volunteers and its effect on carbon stock estimates

“…This is not a new development; for example, the United Kingdom-based Royal Society for the Protection of Bird's ''Big Garden Watch'' has been running for over 30 years and in 2011 more than 600 000 people took part (RSPB 2011; see also Dickinson et al 2010), but recent years have seen an increase in the variety of studies that utilize citizen scientists. The societal benefits of nonprofessional engagement in such environmental research are welldocumented, and range from raising awareness of environmental issues at both project-specific and wider levels to realizing or intensifying personal relationships with nature and communicating knowledge and experience to others (Newman et al 2003, Lovell et al 2009). …”

“…In situations where large amounts of data need to be collected over large areas to provide both baseline data (for example, for national forest inventories) and repeated survey data (re-census data to estimate change), and governments or agencies do not have large financial resources for this, citizen science can play a valuable role in the type of ecological research that is usually costly, time-consuming, and labor-intensive (Newman et al 2003, Lovell et al 2009). However, there are concerns over the reliability of data collected by unskilled volunteers (Darwall andDulvy 1996, Foster-Smith andEvans 2003).…”

“…Recently, for instance, Fitzpatrick et al (2009) reported that volunteers failed to identify small infestation occurrences of an insect pest in hemlock forests, while Milberg et al (2008) found that during a vegetation surveying exercise up to 30% of presence frequency data were missed by nonexperts, but that the bias in percent cover estimate was relatively low. Techniques such as active collecting and capture of moving invertebrates and specimen recognition and identification are methods that present particular difficulties for nonspecialist volunteers, but studies suggest that if the survey techniques are kept simple, and the subjectivity of the methods minimized, volunteers could be almost as good as experienced experts (Lovell et al 2009). Measurement of tree diameters, a relatively nonsubjective method on a stationary object, should present fewer problems for inexperienced volunteers.…”

Linee Guida per il monitoraggio dei coleotteri saproxilici protetti in Europa

“…In accordo con le raccomandazioni di Lovell et al (2009) si è cercato di minimizzare le componenti soggettive richiedendo obbligatoriamente la foto dell'esemplare da sottoporre allo specialista MIPP per validazione. I reperti non fotografati di norma non sono stati presi in considerazione.…”