Abstract

Human observers often are present when researchers record animal behavior, which can create observer effects. These effects are rarely explicitly investigated, often due to the assumption that the study animal is habituated to or unaffected by a human’s presence. We investigated the effect of human pressure gradients on a remote population of large-headed capuchins, Sapajus macrocephalus, looking specifically at the effects of number of observers, distance to observers, and distance to the research base. We conducted this study over 4 months in the Pacaya-Samiria Nature Reserve, Peru, and collected 199 two-minute focal samples of capuchin behavior. We found that capuchin monkeys fed less when human observers were closer to the focal individual, when more observers were present, and when capuchins were closer to the research base. We found no other consistent differences in capuchin monkey behavior across the measured human pressure gradients, although capuchins directed a high proportion of their vigilance toward humans (29% in adults and 47% in infants). Our results support the hypothesis that human pressure gradients influence animal behavior. Given the proportion of human directed vigilance, we recommend that all studies that use human observers to record animal behavior consider human-directed vigilance, record the number of observers, as well as the observer-focal animal distance, to check for these effects.

Highlights

  • Observer effects occur when the behavior of studied organisms changes in response to researcher presence (McDougall, 2012)

  • Different individuals have different tolerances to human presence and different flight initiation distances (Allan et al, 2020). These examples show how human presence can change animal risk perception and animal behavior. These effects could mean that deductions from research using human observers to collect data may not hold true for individuals that are less exposed to humans, for example, in very remote populations

  • We investigated the effect of human pressure gradients and habitat on animal behavior in a remote population of primates

Read more

Summary

Introduction

Observer effects occur when the behavior of studied organisms changes in response to researcher presence (McDougall, 2012) Some researchers mitigate these changes by habituating study animals before data collection takes place (Crofoot et al, 2010; Williamson & Feistner, 2011). Different individuals have different tolerances to human presence and different flight initiation distances (Allan et al, 2020). These examples show how human presence can change animal risk perception and animal behavior. These effects could mean that deductions from research using human observers to collect data may not hold true for individuals that are less exposed to humans, for example, in very remote populations

Objectives
Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call