Human disturbance alters endocrine and immune responses in the Galapagos marine iguana (Amblyrhynchus cristatus).
Anthropogenic disturbance is a relevant and widespread facilitator of environmental change and there is clear evidence that it impacts natural populations. While population-level responses to major anthropogenic changes have been well studied, individual physiological responses to mild disturbance can be equally critical to the long-term survival of a species, yet they remain largely unexamined. The current study investigated the impact of seemingly low-level anthropogenic disturbance (ecotourism) on stress responsiveness and specific fitness-related immune measures in different breeding stages of the marine iguana (Amblyrhynchus cristatus). Specifically, we found stress-induced elevations in plasma corticosterone among tourist-exposed populations relative to undisturbed populations. We also found changes in multiple immunological responses associated with stress-related effects of human disturbance, including bacterial killing ability, cutaneous wound healing, and hemolytic complement activity, and the responses varied according to reproductive state. By identifying health-related consequences of human disturbance, this study provides critical insight into the conservation of a well-known species that has a very distinct ecology. The study also broadens the foundation of knowledge needed to understand the global significance of various levels of human disturbance.
French
Susannah S
SS
Department of Biology, Utah State University, Logan, UT 84322, USA. sfrench@biology.usu.edu
DeNardo
Dale F
DF
Greives
Timothy J
TJ
Strand
Christine R
CR
Demas
Gregory E
GE
D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology; D001770:Blood Bactericidal Activity / Q000502:physiology; D003165:Complement System Proteins / Q000378:metabolism; D003345:Corticosterone / Q000097:blood / Q000378:metabolism; D004484:Ecuador; D004703:Endocrine System / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006802:Human Activities; D006801:Humans; D007076:Iguanas / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D007107:Immune System / Q000378:metabolism / Q000502:physiology*; D008297:Male; D013315:Stress, Psychological / Q000097:blood / Q000503:physiopathology; D013739:Testosterone / Q000097:blood; D014945:Wound Healing / Q000502:physiology
D013739:Testosterone; D003165:Complement System Proteins; D003345:Corticosterone