Stories tagged nest monitoring

Dec
10
2008

As biologists we spend a lot of time observing our focal species but we try to minimize any disturbance our activities might cause. However, sometimes we cannot get the data we need without intruding on the lives of our study species. For example, to determine the number of eggs laid in a nest or to determine when egg laying begins, we need to look inside the nest and doing so could have the potential to disrupt normal bird activity.
Common pheasant's nest: Does the very act of checking to make sure there are eggs in this nest make the eggs vulnerable?
Common pheasant's nest: Does the very act of checking to make sure there are eggs in this nest make the eggs vulnerable?Courtesy Jarosław Pocztarski

In the field of ornithology there has been some concern that nest monitoring could either increase or decrease the risk of nest predation. An increase or decrease in the risk of nest predation could occur for several reasons (1) we are leaving human scent trails to the nest that predators follow, (2) predators are watching us and follow us to the nest, (3) we disrupt the incubation process causing the female to stay off the nest longer or (4) our activity at the nest deters predators.
A study was just published in the AUK (a journal of the American Ornithologists Union - http://www.aou.org/) trying to determine if nest monitoring affects the risk of nest predation in 11 species of birds in the Czech Republic. Using temperature data loggers placed inside each nest to determine when females were present or absent from the nest, Karel Weidinger found that activity at the nest as a result of nest monitoring does not increase the risk of nest predation. However, she did find that the risk of nest predation was slightly lower two hours following observer activity at the nest but this reduced risk did not change overall nesting success. This work supports previous research suggesting that nest monitoring activities do not affect the risk of predation. This is great news for biologists because now we can be more confident that monitoring bird nests does not increase the risk of predation.