Focus

    Herons and egrets make a comeback

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    The Dombes region, 75 km to the west of Switzerland, currently harbours all nine European herons and egrets as well as Eurasian Spoonbill and, irregularly, Glossy Ibis. © Nidal Issa

    The 2013–2016 atlas not only documents the increase of the Grey Heron population, but also the recovery of the Purple Heron, the first brood of Great White Egrets, and the first breeding attempt by the Little Egret in Switzerland. These events would have been unthinkable just a few years ago and reflect a positive Europe-wide trend.

    Until the mid-20th century, the European populations of many heron and egret species suffered massive losses as wetlands were drained and the birds were persecuted for their plumage. In several of our neighbouring countries, the negative trend was halted when feathers went out of fashion and hunting pressure decreased (herons and egrets were placed under protection in France in 1975). Newly designated, largely undisturbed sanctuaries with vast reedbeds facilitated the recovery of local species and the colonisation by new ones. The development of rice farming in the Camargue and the Po Valley created shallow, inundated areas rich in invertebrates and amphibians, improving the breeding success of herons and egrets and raising the number of wintering birds. The Cattle Egret, for example, has bred in France since 1969 and numbers are growing rapidly. France and Italy together supported more than 20 000 breeding pairs in 2014. The Squacco Heron is also expanding its area of distribution. The Eurasian Spoonbill has bred in France since 1981, and the Glossy Ibis has been a regular breeder since 2006. Somewhat less encouraging are the fluctuating European populations of the Purple Heron and the Black-crowned Night Heron. However, despite the negative long-term prospects, there have been some positive local trends since 2000.

    Trend of the presence index in spring (15 March – 30 June) for four species with the strongest increase in Switzerland. Great White Egret and Little Egret (left axis) as well as Cattle Egret and Squacco Heron (right axis).

    The situation in Switzerland is not comparable with France, as Great White Egret and Black-crowned Night Heron have only bred here occasionally in the past few years, and the Little Egret made a single breeding attempt near Zug in 2014 that was unsuccessful. Apart from the Grey Heron, only the Purple Heron has increased in number in Switzerland, reaching 17 breeding pairs in 2016, the highest level since 1965. Switzerland is not well suited to accommodate large colonies of herons or egrets due to the lack of vast and undisturbed wetlands. The increases in neighbouring countries are therefore primarily reflected in higher numbers of passage migrants and wintering birds. Such is the case of the Great White Egret, a species native to the plains of central and eastern Europe that only began to winter entirely in Switzerland on a regular basis in 1994/1995. The Little Egret is gaining ground as well, and has bred in several areas close to the Swiss border in France and in the province of Varese since 2009. The Cattle Egret is also gradually approaching our borders.

    The history of herons and egrets in Europe is closely associated with large-scale conservation efforts and a positive change in public awareness. There are two ways in which the growing populations in neighbouring countries could have a positive impact in Switzerland: on the one hand, scarce species such as Great White Egret, Little Egret and Black-crowned Night Heron could become regular breeders; on the other hand, new species might breed here for the first time. The long-term conservation of herons and egrets, and all other waterbirds, depends crucially on the maintenance of a dense network of undisturbed wetlands extending across Europe.

    Text: Jérémy Savioz


    Recommended citation of the Atlas online:
    Knaus, P., S. Antoniazza, S. Wechsler, J. Guélat, M. Kéry, N. Strebel & T. Sattler (2018): Swiss Breeding Bird Atlas 2013–2016. Distribution and population trends of birds in Switzerland and Liechtenstein. Swiss Ornithological Institute, Sempach.

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    Species concerned
    Subject
    Waters and wetlands
    Hunting
    New breeding species
    Species on the rise
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