The common cuckoo is an effective indicator of high bird species richness in Asia and Europe

Federico Morelli,Anders Pape Møller,Emma Nelson,Wei Liang,Yanina Benedetti,Marco Moretti,Piotr Tryjanowski,Petra Šímová

doi:10.1038/s41598-017-04794-3

Abstract

Common cuckoo Cuculus canorus is a charismatic bird species with a dominant presence in human culture: from folklore legends to nowadays there is evidence of cuckoos being a prime candidate as a surrogate of bird diversity. Recent studies demonstrated that the cuckoo can predict hotspots of taxonomic diversity and functional diversity of bird communities in European countries. In this study, we demonstrated that the cuckoo is an excellent bioindicator at multi-spatial scale, extending cuckoo surrogacy from Europe to Asia. Even using three different survey methods (transect, square, point counts), comparing the new findings with results of our research in Europe, sites where the cuckoo is present were characterized by greater species richness, while the cuckoo was absent from sites with low species richness. The goodness of fit of models based on point counts ranged between 71 and 92%. Furthermore, the cuckoo population trend mirrors the average population trend and climate suitability of overall bird communities in Europe. The common cuckoo is therefore a suitable intercontinental bioindicator of hotspots of bird richness, even under climate change scenarios or in areas where the species co-occurs with other cuckoo species, opening a new avenue for standardized citizen science on bird biodiversity surveys worldwide.

Highlights

The most peculiar characteristic of cuckoos leaving its mark on human culture is related to the brood parasitic behavior of the species[4, 5]
Until now nothing was know about common cuckoo predictability in other continents, where the common cuckoo co-occurs in same habitat than other parasite cuckoo species
Sample sites were treated as statistically independent observations because the spatial autocorrelation in all studied countries was not significant (Mantel test, 999 randomizations p > 0.05). In both European and Asian countries common cuckoo occurrence was strongly positively correlated with overall bird species richness (Table 1), with values of bird species richness always being higher in the sample sites where common cuckoos were presents (Fig. 1)

Summary

Introduction

The most peculiar characteristic of cuckoos leaving its mark on human culture is related to the brood parasitic behavior of the species[4, 5]. Because the common cuckoo is a widespread species present in Asia, it is interesting to study if the same pattern found in some European countries, linking the species with bird hotspots, occurs in other continents. Would be necessary to know if the trend of common cuckoo populations follows the overall trend of bird species in different countries, because this condition could make cuckoo a suitable indicator, even under climate change scenarios. We tested the hypothesis that the common cuckoo may serve as an effective surrogate for bird taxonomic diversity in ten European and two Asian countries, comparing the predictive power of the species among countries. A deep understanding of connections linking this indicator species and biodiversity in general will provide new insights useful for addressing action plans for biodiversity conservation and management strategies of ecosystems[21,22,23]

Methods

Results

Conclusion