POPULATION MONITORING OF NORTHERN FULMARS (FULMARUS GLACIALIS) AND BLACK-LEGGED KITTIWAKES (RISSA TRIDACTYLA) AT SKÁLANES NATURE AND HERITAGE CENTRE
Team project. This project is approved and supervised by Dr Ruedi Nager, Lecturer in the Institute of Biodiversity, Animal Health & Comparative Medicine, School of Life Sciences, University of Glasgow.
Climate change is strongly affecting the temperatures of the Northern Atlantic where sea birds such as the black-legged kittiwake (Rissa tridactyla) and the Northern Fulmar (Fulmarus glacialis) rear their young (Frederiksen et al. 2012). They are both pelagic surface feeding species (OSPAR Commission 2009). The primary constituents of their diet are marine invertebrates and small fish, especially sand eels. Due to high oceanic heat capacity, short term temperature variability is low in oceanic environments, leading to high adaptability to specific thermal environments by many marine ectotherms (Frederiksen et al., 2012). The long-term global temperature increase is negatively affecting many species of pelagic fish, which has caused a decline in piscivorous nesting seabird populations (Frederiksen et al. 2012. Walsh et al., 1995). In addition to climate change, over-fishing in parts of their feeding and nesting range, has been evaluated to be a threat to North Atlantic populations (OSPAR Commission, 2009).
OSPAR, or the Protection of the Marine Environment of the North East Atlantic, has placed the black legged kittiwake on their list of threatened and/or declining species (OSPAR Commission, 2009). Colony sizes varies from less than ten pairs to tens of thousands, often returning to breeding sites for years. The sites of
these colonies can be mixed species, as seen at Skálanes where black-legged kittiwakes and northern fulmars nest on the same cliff front (fig. 5). Kittiwakes tend to lay between 1-3 eggs, as do the fulmars. Breeding and general population decline of the black-legged kittiwake has been observed throughout Norwegian and UK populations (20-29%), as well as in Greenlandic population (19%) (OSPAR Commission, 2009).
According to the OSPAR Commission, more documentation is needed to quantify the overall population decline in cliff-breeding seabirds, particularly the black-legged kittiwake (OSPAR Commission, 2009). It is therefore crucial to carefully monitor the populations of these sea birds at their nesting sites, as a decrease in successful rearing will lead to a global decline of these species (Croxall et al., 2012).
This project aims to monitor colonies of northern fulmars and black-legged kittiwakes present on a cliff side in terms of breeding success, foraging success, and numbers. The data collected will be compared to that of similar studies conducted over previous years. The monitoring is based on an 8-year longitudinal study with a focus on colony size and general population monitoring. The 2019 Iceland Expedition increased the extent of monitoring to include laid eggs, hatching, and fledging success. The marked nests and data collection method will be used to replicate the study to a greater extent than previous years in order to obtain a data set suitable for longitudinal comparison. This will then be shared with the Skálanes and subsequently added to the INTERACT database, contributing to the global initiative of informative population monitoring that can be used to inform future conservation and environmental management efforts.
- Monitoring progress of breeding pairs of black-legged kittiwake (Rissa tridactyla) and northern fulmar (Fulmarus glacialis) with respect to number of eggs, number of hatchlings, and successful fledging.
- Monitoring population size of black-legged kittiwake (Rissa tridactyla) and northern fulmar (Fulmarus glacialis) colonies.
- In line with global trends, the population of both kittiwakes and fulmars is expected to be smaller than recorded in previous years.
- The number of kittiwake nests breeding successfully will be lower than recorded in previous years, following the global trend of decreasing population.
- Cliff plots were established using a photograph (Fig. 5), which is sectioned and labelled for easier nest identification and monitoring. Zones and nest locations will be updated as necessary.
- The occupied nests in each plot will be identified and their location recorded, with reference to previous nest sites from past expeditions to observe possible changes in location.
- The nesting species will be identified per nest and recorded.
- Breeding success will be considered with respect to fledging of the black-legged kittiwakes, and live chicks in the northern fulmar due to extended incubation period. Two people will carry out individual counts using binoculars each observation time, looking at:I. Number of eggs in nest
II. Number of chicks in nest
III. Presence of incubating/rearing adult(s)
General population count:
- Each plot will be observed by an individual counting the number of kittiwakes and fulmars on the plot separately.
- The two observers will carry out the count for every plot using binoculars.
- An average of the two observations will be taken after each session.
- The average number of kittiwakes and fulmars will be noted down at the end of the observational period, taking into account changing numbers in nesting birds throughout the 6-week observation period.
Croxall, J.P, Butchart, S.H.M., Lascelles, B., Stattersfield, A.J. (2012). Seabird conservation status, threats and priority actions: a global assessment. Bird Conservation International. 22(1), pp.1-34.
Frederiksen, M., Anker-Nielsen, T., Beaugrand, G. and Wanless, S. (2012) Climate, copepods and seabird in the boreal Northeast Atlantic – current state and future outlook. Global Change Biology, vol. 19, issue 2. doi: https://doi-org.ezproxy.lib.gla.ac.uk/10.1111/gcb.12072 (20/12/2019)
Walsh, D.J., Halley, M.P., Harris, A., del Nevo, I.M.W., Sim, & M.L. Tasker (1995). Seabird monitoring handbook for Britain and Ireland – A compilation of methods for survey and monitoring of breeding seabirds. JNCC: Peterborough.