Dr. Henk van der Jeugd

Understanding the role of migratory birds as vectors of zoonotic arthropod-borne diseases

Many arthropod-borne diseases are expanding their distribution areas, and are associated with an increase in number of reported cases. These vector borne diseases benefit from the increase in global temperatures, increased global travelling and transportation, and an increase in vector densities, such as mosquitos and ticks. We combine widespread surveillance of arboviruses in avian hosts (using trained citizen scientist) and arthropod vectors, with in-depth virological and ecological studies to investigate the probability of introduction and establishment of novel diseases, the impact of these diseases on host population dynamics and the role of novel, local arthropod vectors on disease transmission. We us the recent emergence of Usutu virus in the Netherlands as a model to study the implications of the establishment of a novel tropical virus in the temperate zone. This project is part of the ZonMw program Eco-alert.

ALW Meerwaarde project: 'Towards an early warning system for the protection of birds, based on insights from population modeling'

The conservation of birds is hampered by ambiguous interpretation of trend data on numbers of birds. Knowledge is currently lacking to separate clear ‘early warning’ signals of significant declines from more natural fluctuations. Using long-term data on population numbers, survival and reproduction population models are constructed for bird species with a range of life cycles. Model analyses will reveal the significance of recent declines for the persistence of the bird populations. In close cooperation with BirdLife International Netherlands we will develop a protocol for an ‘early warning system’ to identify truly vulnerable bird species (Red List).

Project: 'Is plasticity in timing important for population trends of passerine birds in a warming Europe?'

Climate change is a key factor affecting the population dynamics of passerine birds. We model reproduction and survival of the 30 most abundant passerine species ringed within the framework of the Europe-wide Constant Effort Site schemes over a period of more than 20 years in ten countries. Specifically, the following hypotheses will be examined: (1) Species with a higher phenological plasticity maintain reproductive success in early springs while less plastic species experience a resource mismatch and lower reproductive success; (2) first-winter survival counteracts the effects of differential reproduction thus nullifying any potential link between poor breeding success and population size.

Brent geese Branta bernicla ssp. are herbivores, and Eelgrass, Zostera spec. is an important food source for all populations in the circumpolar breeding range. Ecosystems dominated by eelgrass are now among the most endangered habitats in the world. This is an immediate threat to the existence of populations of the Brent goose. In this research project, we aim to investigate the link between habitat use, fitness and population dynamics of Brent geese, and we will study the intricate link between Brent grazing, sedimentation and eelgrass recovery. We make extensive use of state of the art tracking devices to determine year-round habitat use.