As I said it depends on the profile of the population. If ESA is a concern, then the NWR management can interpret the regulations as they see fit. This part is the actual regulation: Subpart E—Disturbing Violations: Against Plants and Animals § 27.51 Disturbing, injuring, and damaging plants and animals. (a) Disturbing, injuring, spearing, poisoning, destroying, collecting or attempting to disturb, injure, spear, poison, destroy or collect any plant or animal on any national wildlife refuge is prohibited except by special permit unless otherwise permitted under this subchapter C. This part is an interpretation specific to Prime Hook NWR: “This disturbance includes flushing birds and other wildlife or using electronic calls (or called “taping”) to lure birds closer for observation or photography. Please remember to take only memories and photographs and leave only footprints." This is not a prohibition across the entire NWR system. I don’t know what the profile of the bird population on this particular NWR site, but the wording sounds like almost a word for word from one particular court case involving Endangered Species Act. If a NWR site is home to endangered species or animals on the critical lists, particularly if recordings could disturb those birds, then that would be a reasonable interpretation of the regulation. It is certainly within the pervue of any NWR management decision to take as lax or as proscriptive an interpretation for site rules as needed to manage specific wildlife issues. In some cases observation can and has been disturbance prosecutable under ESA, without flushing or recordings. But there is no specific regulatory prohibition on using recordings, unless there is reason for that interpretation at a specific site. But that is a local decision, not a federal rule. When it is an endangered species, even inadvertant flushing can be proscutable, if it can be shown the observer had reasonable reason to know the bird might be there to be flushed. For instance, if you walk out into the Attwater Prairie Chicken range near a nest and you had warning there were potentially nests in a specific area of the prairie. The flush might be inadvertant, but the observer being there was not. Vicki Crutchfield Live Houston and work in Galveston, TX Cell : 409-789-1178