GAPs in the study of zoo and wild animal welfare.

To investigate the science of animal welfare for zoo and wild animals in the period from 1966 to 2007, we conducted a bibliometric analysis of abstracts downloaded from The Web of Science((c)) database using the keyword combination "Animal welfare, Zoo* and wild" in the topic field. In total we downloaded 1,125 abstracts, which were classified into the following categories: year of publication; environment of the study (e.g., zoo) or theoretical; area of knowledge (e.g., conservation in situ); number of experimental animals used; species; addresses of authors; taxonomic classification; publication language; journal name; number of citations received. Since 1990, there has been a rapid increase in the number of articles published in this area of animal welfare. One worrying result was that published articles were predominately of a theoretical nature (58.65%, N=563). Most of the articles were published by authors either in Europe (47.43%, N=480) or North America (37.65%, N=381) and written in English (87.71%, N=971). The majority of experimental studies were conducted with mammals (75.92%, N=391), and had small sample sizes (N=7 for zoo-based studies). In terms of impact factor (IF), the journals in this study had a median factor equivalent to that for the area of biological sciences (median IF=1.013). Little knowledge cross-over from farm animal welfare was found (only four articles) in this study. In conclusion, zoo and wild animal welfare as a science may benefit from a greater interaction with farm animal welfare.