The great value of these collections is demonstrated by the substantial funding that has been provided by federal, state, and private agencies for their care, as well as by the large scientific literature based on collected specimens. Regulating agencies are often overly enthusiastic in restricting scientific collecting, which is the only kind of mortality that is so highly controlled and yet from which bird species might derive benefits, whereas the same or sister agencies often permit or even encourage activities that are responsible for massive mortality in bird populations. An adequate sample is the minimal number of specimens or other data necessary to ensure investigative and statistical validity. The sample size required for a study depends on the nature of the investigation and the extent of variation in the parameters being studied. Field studies require larger samples than do laboratory studies, because field investigators have less control over the conditions that produce variation, and many studies requiring specimens are studies of variation per se, and thus require large sample sizes.
Computer modelling can help define and sometimes reduce sample size requirements.
The collection of scientific specimens typically has no lasting effect on avian populations. Few ornithologists collect more than 100 individuals in a given year, and the total number of specimens collected annually for research purposes in North America is fewer than 10,000. Back to top C. Methods for Collecting Specimens Humane scientific methods of trapping and shooting are those that kill the bird instantly but avoid injury to the body parts required for the investigation. Shooting is the most effective way to collect many species. Ornithologists who collect birds with a shotgun should be experienced in the proper and safe use of firearms and must comply with laws and regulations governing their use.