Human and vehicle disturbance reduces nest attendance in migratory birds during pipeline construction activities

Abstract Incidental take, the unintended harm or mortality of birds from human activities, can negatively impact avian populations, particularly during periods like nesting. Understanding the influence of anthropogenic disturbances on nesting bird behavior is therefore important for developing effective mitigation and conservation strategies. We investigated the effects of noise, human presence, and vehicle activity/proximity on parental behavior at 83 nests of 30 migratory bird species during pipeline construction in Alberta and British Columbia, Canada. Using generalized linear mixed models, we analyzed behavioral responses to these disturbances. When birds were present on their nests, construction activity did not increase their likelihood of departure. Instead, nest stage was the primary factor influencing this behavior, with parents departing more frequently from nests containing nestlings than from those with eggs. However, when away from the nest, an increased number of light-duty vehicles reduced the probability of a parent returning to its nest within a 15-min observation window. Noise levels also influenced parental return and visitation, with the strongest negative effect observed for nests located in open ecosites. Furthermore, increased human presence reduced the frequency of parental visits to nests. These findings emphasize that nesting migratory birds are sensitive to human and vehicle activity when they are away from the nest. Therefore, implementing targeted conservation measures, such as establishing setbacks to minimize disturbances especially in open ecosites and limiting non-essential vehicle and human traffic near active nests seems to be particularly important at reducing the impacts of construction on nesting birds.