The Cuckoo As A Canary In The Conservation Coal Mine
Currently, one of the hot topics in conservation circles is “coevolution.” That is, how certain species may act as surrogates and indicators of the level of biodiversity in a particular system. Using this phenomenon of surrogates to inform priorities, conservationists try to gauge the abundance of certain species as proxies for the health of the ecosystem as a whole. We’ve discussed surrogate species in a previous article and some have called surrogates the “holy grail of conservation.” But verifying the effectiveness of the approach and identifying species that make appropriate surrogates are not exact sciences.
According to the authors of this study, there are five characteristics that make surrogates reliable. They must be:
(1) sufficiently sensitive to provide an early warning of change; (2) widely applicable in nature; (3) capable of providing a continuous assessment over a wide range of perturbed environmental conditions; (4) independent of sample size; and (5) easy and cost-effective to measure, collect, assay, and calculate.
Based on these characteristics, the authors suggest that the Cuckoo bird is a potentially good candidate as an indicator for biodiversity across Europe. This is in part because the Cuckoo “is widespread and common in European agroecosystems.” Cuckoos, they say, are even better surrogates than top predators, who are more commonly used by scientists. The goal of this study was to assess the suitability of Cuckoos as surrogates. Over four years of sampling 59 sites throughout Poland, the authors found that the occurrence of Cuckoos was 27% more effective in predicting biodiversity health than using predators. The presence of Cuckoos is “is a prime indicator of avian diversity at a local scale.”
The authors note that top predators may have more “charismatic value” for conservation projects, but that selecting the best possible surrogates should be the priority. In this case, statistical models using top predators showed an overall reliability of 59%. The same models based on Cuckoo occurrence improved the reliability to more than 75%. For animal advocates and especially conservationists, this finding suggests that we can find new ways to do our work much more efficiently.