© Marcel Burkhardt
Population dynamics of hoopoe and wryneck
We investigate why hoopoes and wrynecks have become rare breeding birds in Switzerland. The results will be used for the conservation of these species.
Breeding populations of hoopoe and wryneck have strongly declined in Switzerland in the last 50 years. Both species are migratory, breed in cavities in farmland areas and feed on specific prey. Suspected reasons for their declines therefore include reduced availability of food and/or cavities in the breeding areas as well as habitat deterioration or loss in the staging and wintering grounds. The relative importance of these factors is unknown, hampering the establishment of efficient conservation strategies for these priority species.
During the last 10 years, approx. 700 nest boxes have been set up in the central Alps (Valais). We document population trends of both species, assess reproductive success and ring young and adult birds. These data will be used in an integrated population model to study the demographic mechanisms potentially causing population declines. To improve our understanding of the whereabouts in the non-breeding period, we apply traditional (ring-recovery analysis) and new methods (stable isotopes, geolocators).
Currently, we examine how environmental conditions during migration and in the wintering grounds affect population trends of the hoopoes (PhD thesis Rien van Wijk). This study is funded by the Swiss National Science Foundation.
Within this project, Thomas Reichlin conducted his PhD thesis. Further aspects have been studied by several master studies at the Universities of Bern and Zurich (Barbara Hildebrandt, Yves Bötsch, Valérie Coudrain, Laura Dafond, Samuel Ehrenbold, Stephanie Geiser, Aline Ioset, Fabio Leippert, Murielle Mermod, Patricia Portner, Michael Schaad, Baptiste Schmid, Matthias Tschumi, Nadja Weisshaupt, Silvia Zingg).
Both species forage on the ground at sites with sparse vegetation cover. A likely reason for the large scale decline of both species may thus be the increased density of grassland vegetation resulting from extensive application of fertilizers.
First results in terms of the identification of wintering areas with light geolocators show that the main wintering area of hoopoes from the Valais is the Sahelian belt. Yet, the individuals from the Valais population do not spend the winter at the same location, as the wintering locations range from Senegal to Niger, indicating a low migratory connectivity. On the other hand, wrynecks from the Valais population spend the winter in southern Spain and northern Morocco – thus, contrary to our expectations, wrynecks are short-distance migrants.
The demographic rates of the two species are surprisingly similar. The hoopoe population increased which was mainly the result of a good breeding success and of substantial immigration of individuals from other populations. The wryneck population fluctuated without showing a trend. The reproductive success of both species depends on the prevailing weather conditions; this link was stronger in hoopoes than in wrynecks.
Wryneck territories are characterised by a considerable amount of bare ground, a high density of ground-nesting ant nests and the presence of breeding cavities. These main resources may occur in different habitats such as wineyards, orchards, parks or even fruit tree plantations, and thus all of them may be suitable habitats for wrynecks. In addition, reproductive success can be promoted by providing suitable nestboxes
Territory occupancy and parental quality as proxies for spatial prioritization of conservation areas.
Conservation through connectivity: can isotopic gradients in Africa reveal winter quarters of a migratory bird?
Modulation of the adrenocortical response to acute stress with respect to brood value, reproductive success and survival in the Eurasian hoopoe.
Short-distance migration of Wrynecks Jynx torquilla from Central European populations.
Breeding Dispersal of Eurasian Hoopoes (Upupa epops) within and between Years in Relation to Reproductive Success, Sex, and Age.
The demographic drivers of local population dynamics in two rare migratory birds.
Bare ground as a crucial habitat feature for a rare terrestrially foraging farmland bird of Central Europe.
Habitat selection by foraging Wrynecks Jynx torquilla during the breeding season: identifying the optimal habitat profile.
Impact of weather and climate variation on Hoopoe reproductive ecology and population growth.
From Publications to Public Actions: When Conservation Biologists Bridge the Gap between Research and Implementation.
Year-Round tracking of small Trans-Saharan migrants using light-level geolocators.
Food or nesting place? Identifying factors limiting Wryneck populations.
Migratory connectivity in a declining bird species: using feather isotopes to inform demographic modelling.
Patches of Bare Ground as a Staple Commodity for Declining Ground-Foraging Insectivorous Farmland Birds.
Nestbox design influences territory occupancy and reproduction in a declining, secondary cavity-breeding bird.
The importance of ant-rich habitats for the persistence of the Wryneck Jynx torquilla on farmland.
Migration patterns of Hoopoe Upupa epops and Wryneck Jynx torquilla: an analysis of European ring recoveries.
Impact of weather variation on feeding behaviour, nestling growth and brood survival in Wrynecks Jynx torquilla.
Wiedehopfpaar zieht Wendehalsnestlinge bis zum Ausfliegen auf.
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