Flight initiation by Ferruginous Hawks depends on disturbance type, experience, and the anthropogenic landscape

PLoS One. 2017 May 18;12(5):e0177584. doi: 10.1371/journal.pone.0177584. eCollection 2017.

Abstract

The expansion of humans and their related infrastructure is increasing the likelihood that wildlife will interact with humans. When disturbed by humans, animals often change their behaviour, which can result in time and energetic costs to that animal. An animal's decision to change behaviour is likely related to the type of disturbance, the individual's past experience with disturbance, and the landscape in which the disturbance occurs. In southern Alberta and Saskatchewan, we quantified probability of flight initiation from the nest by Ferruginous Hawks (Buteo regalis) during approaches to nests by investigators. We tested if probability of flight was related to different disturbance types, previous experience, and the anthropogenic landscape in which individual Ferruginous Hawks nested. Probability of flight was related to the type of approach by the investigator, the number of previous visits by investigators, and the vehicular traffic around the nest. Approaches by humans on foot resulted in a greater probability of flight than those in a vehicle. Approaches in a vehicle via low traffic volume access roads were related to increased probability of flight relative to other road types. The number of previous investigator approaches to the nest increased the probability of flight. Overall, we found support that Ferruginous Hawks show habituation to vehicles and the positive reinforcement hypotheses as probability of flight was negatively related to an index of traffic activity near the nest. Our work emphasizes that complex, dynamic processes drive the decision to initiate flight from the nest, and contributes to the growing body of work explaining how responses to humans vary within species.

MeSH terms

  • Animals
  • Behavior, Animal*
  • Conservation of Natural Resources
  • Hawks*
  • Human Activities*
  • Nesting Behavior
  • Probability

Grants and funding

The authors were supported by operating grants from Environment Canada to T.I.W., Alberta Environment and Parks (AEP), Canadian Department of National Defence, and the Saskatchewan Ministry of Environment, Agriculture and Agri-food Canada (AAFC). Additional financial support was obtained from grants awarded by the National Science and Engineering Research Council (NSERC) to E.M.B., Conservation Funds from the Alberta Conservation Association to E.M.B., the Queen Elizabeth II Graduate Scholarship (University of Alberta), Alberta Sports and Recreation, and the Climate Change Emissions Management Corporation. Industrial partners included Nexen Inc., AltaLink, L.P., Cenovus Energy, Suncor Energy, and the Petroleum Technology Alliance of Canada.