Effect of human disturbance on long-term habitat use and breeding success of the European Nightjar, Caprimulgus europaeus

Land managers often respond to declining numbers of target species by creating additional areas of habitat. If these habitats are also subject to human disturbance, then their efforts may be wasted. The European Nightjar (Caprimulgus europaeus) is a ground-nesting bird that is listed as a species of European Conservation Concern. It appears to be susceptible to human disturbance during the breeding season. We examined habitat use and reproductive success over 10 years in a breeding population on 1335 ha of managed land in Nottinghamshire, England. The study site was divided into a heavily disturbed section and a less disturbed section of equal habitat availability, forming a natural long-term experiment. The site is open to the public, and visitor numbers approximately doubled during the study. We found that overall Nightjar density was significantly lower and there were significantly fewer breeding pairs in the heavily disturbed habitat compared with the less disturbed habitat. However, average breeding success per pair, in terms of eggs and fledglings produced, was not significantly different between the two sections across years. Our findings suggest that human recreational disturbance may drastically alter settlement patterns and nest site selection of arriving females in some migratory ground-nesting species and may reduce the utility of apparently suitable patches of remnant and created habitat. Land managers should bear this in mind when creating new areas of habitat that will also be accessible to the public. Our study also highlights the value of long-term population monitoring, which can detect trends that short-term studies may miss.

Flight initiation distances of nesting Piping Plovers (Charadrius melodus) in response to human disturbance

Birds frequently interact with people when they occur in coupled human-ecological or anthropogenic environments, which makes the protection of legally protected species a challenge. Flight initiation distances (FIDs) are often used to inform development of appropriate buffer distances required for human exclusion zones used to protect birds nesting in anthropogenic landscapes. Piping Plovers (Charadrius melodus) are protected by the Endangered Species Act in the United States and often nest in areas used by humans. Studies evaluating Piping Plover FIDs are limited and implementation of exclusion zones has been inconsistent across the species’ range. We measured Piping Plover response and FIDs to naturally occurring stimuli on public beaches at Lake McConaughy, Nebraska, USA. Piping Plover FIDs differed most by stimulus class (vehicle, human, dog, human with dog), Julian day, and hour of day. Piping Plover FIDs were greatest for dog and human with dog compared to humans and vehicles. For all types of stimuli, Piping Plover FIDs decreased over time during the nesting season and increased slightly during each day. In the majority of instances in which Piping Plovers left their nests, return times to the nest were relatively short (less than three minutes). These results suggest Piping Plovers become habituated to the presence of human-related stimuli over the course of a nesting season, but other explanations such as parental investment and risk allocation cannot be excluded. Additional research and improved guidance regarding the implementation of exclusion zones is needed so managers can implement effective protection programs in anthropogenic landscapes.