Migratory birds are vulnerable to human activities, as they depend on conditions in multiple locations for their success. Many of the large bird migrations are in steep decline or have even disappeared (Wilcove & Wikelski, 2008). For example, bird migrants of the Palearctic-African flyway show a steeper decline in Europe than the resident or short-distance migrant species (Vickery et al., 2013). The most comment treats of humans on migratory birds are climate change, food decline, habitat loss and illegal hunting (Bairlein, 2016). Over decades, these effects must have massively influenced the volume as well as the composition of bird migrations.
In this challenge, you will use bird capture data from Castricum, a bird ringing station along the Dutch coast that has been operating since 1960, operated by the Vogelwerkgroep Midden-Kennemerland (vwgmidden-kennemerland.nl/vogelringstationenglish). It is the oldest and longest-running Dutch ringing station (Van der Meer & Admiraal 2021).
Your task is to analyse and visualize shifts in the volume and composition of bird captures at Castricum over time. You might test for a community shift away from insectivores, away from longer-distance migrants, away from habitat specialists, and towards thermophilic species. Pitfalls include variation in effort and timing, and perhaps in changes in the method of capture. Timing could be accounted for by selecting periods that all years have in common, e.g. August 1 to November 15. For assessing community change, you might consider community trajectory analysis methods such as in Matthews et al. (2013).
You will be given access to an unpublished dataset of bird captures at the Castricum ringing station, compiled by the KNAW Centre for Bird Migration and Demography (vogeltrekstation.nl). You can link this dataset to external datasets that you consider relevant, for example the AVONET dataset on bird traits (Tobias et al. 2022), and bird climate envelopes (Jiguet et al. 2007).
Bairlein, F. (2016). Migratory birds under threat. Science, 354(6312), 547-548.
Jiguet, F., GADOT, A. S., Julliard, R., Newson, S. E., & Couvet, D. (2007). Climate envelope, life history traits and the resilience of birds facing global change. Global Change Biology, 13(8), 1672-1684.
Matthews, W. J., Marsh-Matthews, E., Cashner, R. C., & Gelwick, F. (2013). Disturbance and trajectory of change in a stream fish community over four decades. Oecologia, 173, 955-969.
Tobias, J. A., Sheard, C., Pigot, A. L., Devenish, A. J., Yang, J., Sayol, F., … & Schleuning, M. (2022). AVONET: morphological, ecological and geographical data for all birds. Ecology Letters, 25(3), 581-597.
Van der Meer, T. S., & Admiraal, P. N. (2021). Zestig jaar vogels ringen in Castricum. Tussen Duin & Dijk, 20(1), 12-15.
Vickery, J.A., Smith, K.W., Pain, D.J., Gregory, R.D., Škorpilová, J., Bairlein, F., Ewing, S.R. (2013). The decline of Afro-Palaearctic migrants and an assessment of potential causes. Ibis, 156(1), 1–22.
Wilcove, D. S., & Wikelski, M. (2008). Going, going, gone: is animal migration disappearing. PLoS biology, 6(7), e188.