Christine Janse

When my MSc-thesis was almost finished, in November/December 2006, I started to look for an interesting internship. I read some internship reports of other students in the library, and searched the internet for ecology-related companies and institutes in the Netherlands. Besides some other possibilities I also came past the website of the Netherlands Institute of Ecology (NIOO-KNAW), and found out that the nearest centre, in Heteren, was also the most interesting one to me: the centre for terrestrial ecology. Because there was a lot of information on the website, including a part called ‘student projects’, I could find out for myself that this would be a nice possibility, and I called the contact person for more information.

In January I started my 4-months project at the Animal Population Biology-department, one of the three Terrestrial Ecology departments in Heteren. At that department one of the questions is the effect of climate change on the reproduction timing of the great tit, studied in the food chain oak-butterfly-tit. Another research species in this question is the pied flycatcher (Ficedula hypoleuca), a long-distance migratory bird species that faces population decline because of mistiming: while the, temperature dependent, caterpillar food peak is advancing due to climate change, the flycatchers appear to be limited in their ability to advance laying date at the same rate, due to the timing of their migration. A previous comparison of different areas in the Netherlands showed that in areas where the peak date is early (there the birds are most mistimed), the population declined the most. My project focused on differences in peak dates within areas, and asked: do flycatchers breeding in parts of the study area (the Hoge Veluwe) with an early food peak show a stronger population decline compared to flycatchers breeding in parts with a late food peak? To answer this question I wanted to make a map of the area with ‘early’ and ‘late’ food peak parts, and I found out that I could use the diameter of oaks as a measure for earliness.

My activities in this internship varied widely: sorting and weighting caterpillar frass, measuring tree diameters at the Hoge Veluwe, using the sixth-tree method for estimating the differences in openness within the area, taking soil samples and preparing them for further analysis, and I also learned to the basics of working with Access, R, and ArcGIS. Just by accident there were two other students doing an internship at the group almost within the same period as I was there; a geodesy student from Delft and a biology student from Wageningen. That was very nice: we could discuss our projects with each other and combine the knowledge of three different study areas.

Besides these activities for my own project I also was involved in the regular meetings and presentations of the group and of the whole centre in Heteren. I have also been to the yearly ‘NIOO-days’, two days of presentations and workshops of the three centres (Heteren, Nieuwersluis, Yerseke) together. I joined the ‘roosting control’ at the Hoge Veluwe: checking the nest boxes on an evening in February, to see which birds use these boxes before the breeding season starts. In the last week of my internship the first pied flycatchers arrived at the Hoge Veluwe, so then I could join a day the person who registrates which flycatcher arrives at what nest box: a very nice final field day at which I could see and hear my study species very well and very often!