The Effects of Human Disturbance on Trumpeter Swan Breeding Behavior
Henson P and Grant TA. 1991. The Effects of Human Disturbance on Trumpeter Swan Breeding Behavior. Wildlife Society Bulletin. 19(3):248-257
We studied the response of breeding trumpeter swans to human disturbance occurring along the Copper River Highway, near Cordova, Alaska. Except for incidental disturbance caused by researchers, disturbances were normally occurring and were not experimentally applied or controlled. Regular aircraft overflights and passing road traffic alerted birds but did not cause incubating females to leave the nest. Swans were more sensitive to the noise and visible presence of stopped vehicles, pedestrians, and researchers. Such disturbances led to frequent recesses by incubating females, to uncharacteristic brood movements, and to significant behavioral changes. Undisturbed swans always covered eggs with nesting material prior to recessing, whereas disturbed females failed to do so on 26 of 28 occasions. Females took longer recesses when disturbed and spent less time feeding and preening. These responses may lead to a decrease in productivity due to increases in egg and hatchling mortality and additional stress on an already energetically stressed female.
- Type
- Journal Article
- Authors
- Henson, Paul; Grant, Todd
- Units
- CAKN , DENA , WRST
- Keywords
- Alnus sinuata, Copper River Delta, Corvus corax, Cygnus buccinator, Disturbances, Effects, Haliaeetus leucocephalus, Human, Pica pica, Picea sitchensis, Reproduction, Salix spp., Sterna paradisaea, Tsuga heterophylla