Citation: Sandvik, H. (2004) Life-history and breeding biology of
seabirds in a changing environment: a comparative approach. –
Doctor scientiarum thesis, Institutt for biologi,
Universitetet i Tromsø, Tromsø, Norway. 131 pages.
Preface, . . . 4
Abstract, . . . 6
Introduction, . . . 7
Paper I, . . . 29
Paper II, . . . 57
Paper III, . . . 91
Abstract: The climate of the earth has started
to change as a result of human activity, and further changes in the means and
variances of meteorological and climatological parameters have been predicted.
Effects of both natural and anthropogenic climatic variability have also been
documented in many biological species at all trophic levels. Seabirds constitute
a group of marine top-predators with life-history characteristics that make them
especially vulnerable for environmental changes: they are comparatively long-lived
and have low fecundity. This means that even small changes in adult survival can
drastically reduce life-time reproductive success. In the analyses presented in
this thesis, I attempted to go beyond simply enumerating the species affected. If
there are any characteristics in the ecology or life history of species that
predisposes them to respond more strongly to climate variability than other
species, those characters can only be revealed by interspecific analyses.
The articles that are part of this thesis include one theoretical
and two empirical papers, the first of which is a case study carried out at a
seabird colony in the Barents Sea, and the latter of which is a comparative
analysis of the data available on all North Atlantic seabirds. The theoretical
paper contributes to the methodology of phylogenetic-comparative analyses, which
is the tool used by biologists to reveal lawfulness in nature.
The case study from Hornøya is the first to document an effect of
climatic variability on the adult survival of North Atlantic seabirds. Especially
alarming was the clearly negative effect of warm seawater conditions, a situation
that will become more common in the future.
Effects of climate were also widespread in the interspecific data
base analysed. While climatic responsiveness in population size was not accounted
for by any of the explanatory variables investigated, comparative analyses showed
that responsiveness of offspring production and adult survival to climatic
variability exhibit patterns that are compatible with life-history theory:
responsiveness tended to be higher in species with higher fecundity and/or
lower survival. The bearings of these findings and proposals for future research
Full text: © 2004 Hanno Sandvik.
If you agree to make printouts on recycled paper,
you may download the introduction here (pdf, 2.5 MB).
Media coverage: the PhD disuptation has resulted in the following interviews/articles (in Norwegian),
– Solhaug, R. H. (2004) Dør av drivhuseffekt [Die from greenhouse effect]. URL http://www.forskning.no/Artikler/2004/september/1093958791.83. forskning.no, Oslo.
– Horn, K.-S. (2004) Varmere hav dreper sjøfuglene [Warmer sea kills seabirds]. Radio interview and TV notice broadcasted on 31 August in Nordnytt. NRK Troms & Finnmark, Tromsø.
– Kjos, E. (2004) Drivhuseffekt truer sjøfugl [Global warming threatens seabirds]. Radio interview broadcasted on 2 September in Kveldsåpent. NRK P1, Trondheim.
– Eli, O. K. (2004) Drivhuseffekt truer sjøfugl [Global warming threatens seabirds]. Radio interview broadcasted on 3 September. Radio Mosjøen, Mosjøen.
– Wiggen, T. M. (2004) Drivhuseffekten dreper sjøfuglene [Global warming kills seabirds]. Altaposten (Alta), 9. september, 21.
– Kaarbø, A. (2004) Klimaendringer truer sjøfugl i nord [Climatic change threatens seabirds in the north]. Aftenposten (Oslo), 12. september, 4.
– Tarjem, G. (2004) Drivhuseffekt truer sjøfugl [Global warming threatens seabirds]. Radio interview broadcasted on 29 September in Verdt å vite. NRK P2, Oslo.
– Laukøy, E. (2004) Sjøfugl tåler ikke varmere vann [Seabirds cannot cope with warmer water]. TV interview broadcasted on 30 September in Schrödingers katt. NRK 1, Trondheim.
– [Gunnerød, T. B., H. G. Jürgens, and H. Sandvik] (2004) Drivhuseffekten er med på å drepe sjøfuglene. NINA Fakta 25(5), 1–2.
– Jensen, H. H. (2005) Utrydningstruet [threatened by extinction]. TV interview broadcasted on 15 December in Aktuelt Trøndelag. TVTrøndelag, Trondheim.