EUROPEAN BEE-EATER (Merops apiaster) - Guêpier d'Europe
Summary
A spectacular bird whose localised populations are expanding in Switzerland. Nesting in colonies they catch their insect prey on the wing as the name implies.
The European Bee-eater is perhaps one of the most beautiful birds in Switzerland with its rich colours and elegant appearance. But as a breeding bird it is a relatively recent addition, being found nesting only since 1991 following a generalised expansion of its range on the northern edge. But since then the population has expanded considerably, and the 2016 survey found 72 pairs in 15 locations, mostly in Western Switzerland but with a few new sites in the North-east (Knaus et al 2018). The nest sites are usually burrows in sand quarries, all of which are below 800m. It is a colonial species and so normally several pairs are found roosting, hunting and breeding together.
This colonial habit means it is quite a vocal bird, calling out as individuals keep contact with their mates or with the larger flock. But their repertoire is rather limited, the basic call is a short "preep" note which can get rolled into a faster series:
When several birds are flocking together this call can turn into a rippling chatter which can carry a surprisingly long distance - here are about 15 birds using a half-dead tree as a base from which to make short sorties out to catch large insects, it was a windy day and you can hear the leaves on the tree rustling:
And here are several pairs active around their nest holes in the Camargue - the sound of cicadas can be heard in the distant forest:
Bee-eaters do not have a "song" as such but when pairs are forming the same basic call becomes rapidly rolled up into a bubbling sequence that undoubtedly serves the same function. Here are several pairs early in the breeding season and if you listen carefully at about 14s and again at 26s you can hear a rolling sequence that has the feel of a song to it:
The expansion of the population in Switzerland is also reflected in similar changes in Germany, Austria and Italy, whilst in their normal stronghold of the French Mediterranean the populations are less stable. This may well be linked to climate change affecting the spring and summer food availability (Knaus et al 2018).
