The role of voucher specimens in validating faunistic and ecological research
- What Constitutes a Voucher Specimen?
- Preparation and Deposition of Vouchers
- Current Requirements, Policies and Recommendations on Vouchers
- How Many Specimens? Guidelines on Depositing Vouchers
- The Benefits of Depositing Vouchers (and the costs of not doing so)
- Deposition of vouchers permits long term studies
- Deposition of vouchers permits correction of published errors
- Deposition of vouchers permits resolution of species limits
- Lack of vouchers renders published results unverifiable
What Constitutes a Voucher Specimen?
Although specimens used in faunistic and ecological studies range in size from whales to viruses, and in abundance from houseflies to critically endangered species, this brief focuses primarily on terrestrial arthropods. Voucher specimens generally are entire preserved specimens, in accordance with the usual methods of collection and preservation of invertebrates. However, under certain situations (such as studies of rare or endangered species), acceptable vouchers may also be preserved tissue samples, photographs or even sound recordings.
Designation of voucher specimens is a long-established practice in systematic research, through the designation of type specimens of newly described species. The requirement for a one-to-one correspondence between a scientific name and a real organism is undoubtedly responsible for the convention in systematics of depositing authoritatively identified specimens from a study in a research collection, whether the specimens are types or not.
The advent of molecular systematics has led to the use of another type of taxonomic voucher specimen, in which DNA sequences are deposited in widely accessible electronic databases such as GenBank (but see Ruedas et al. (2000) for a discussion of the unsuitability of sequence data alone as voucher specimens and Harris (2003) for a sobering example of error rates in published GenBank sequences).
One of the differences between systematic studies and faunistic or ecological studies is that the latter may accumulate many more specimens (up to hundreds of thousands in some large scale biodiversity inventories) and many more species. However, correct identification of taxa is just as important and, thus, specimens should be available so that other workers can confirm the identity of the study organisms. Voucher specimens in faunistic and ecological research should be prepared in the same way and accompanied by the same data as specimens collected for systematic research. The number of specimens that should be deposited as vouchers from such studies is an additional consideration, discussed below.
Page updated on Feb 23, 2014