Thor Harald Ringsby
Background and activities
Research
My research interests cover population ecology, life history and conservation biology.
I seek to understand eco-evolutionary mechanisms that causes changes in species distributions and their abundances, which is in the core of population ecology. In order to understand such mechanisms we have to deal with how life history traits vary among individuals, how individuals interact with each other, how they are affected by the environment and how this relates to individual variation in fitness. Understanding and quantifying factors that influence individual variation in fitness is therefore essential in order to predict changes in population sizes over time - which also is central in population ecology.
Variation in time and space
A major part of my research have focused on how populations vary in space and time. It is important to understand how spatial variation in habitat quality among local populations as well as temporal variation in environmental conditions (e.g. variation in climate conditions) influence local variance in life history traits (morphology, survival rates, reproduction, dispersal rates etc) and population dynamics within a species.
Such knowledge is important in order to understand the consequences of habitat fragmentation caused by human activity (intrastructure/forestry/agriculture etc) which is one of the biggest causes of loss of biodiversity today.
I have studied such perspectives empirically in a metapopulation consisting of 18 island populations of House sparrows (Passer domesticus) at the coast of Helgeland in northern Norway since 1993.
The focus in ongoing work covers:
- How does local phenology (e.g. onset of spring, NDVI), spring temperature, and climate change affect the initiation of breeding and the reproductive success
House Sparrows - Density dependent reproductive success; in many bird species nestlings are fed with insects during nest stage (including house sparrows) and in high density populations the competition for insects will be higher; to what extent is the diversity of the local insect fauna (reflecting carrying capacity in the habitat) limiting the reproductive output of house sparrow populations. And, does the spatio-temporal variation (within season variation and among habitats (i.e. islands)) in the insect diversity determine reproductive output
- Spatial and temporal variation in life history traits: the relationship between body size, growth rate and potential role of telomeres as mediators of lifespan and fitness in House Sparrows
- Causes and consequences of variation in egg size in House Sparrows
- Effects of ecto- and endoparasites on variation in individual fitness as well as on population dynamics in House Sparrows
- Predator-prey dynamics
Teaching:
I am program leader for the 2-year interdiciplinary masterprogram in "Natural Resources Management" (on leave Aug 2020-Aug 2021)
Responsibility in courses:
BI1003 - Evolutionary Biology, Ecology and Ethology
BI2033 – Population ecology
BI2034 – Community ecology
RFEL3081 - Natural Resources Management, Interdisciplinary Project (emneansvarlig)
Master projects:
Ask me :-)
Scientific, academic and artistic work
A selection of recent journal publications, artistic productions, books, including book and report excerpts. See all publications in the database
Journal publications
- (2020) Boat disturbance effects on moulting common eiders Somateria mollissima. Marine Biology. vol. 167 (1).
- (2020) Consistent scaling of inbreeding depression in space and time in a house sparrow metapopulation. Proceedings of the National Academy of Sciences of the United States of America. vol. 117 (25).
- (2020) Multi‑generational genetic consequences of reinforcement in a bird metapopulation. Conservation Genetics. vol. 21.
- (2019) Characterizing morphological (co)variation using structural equation models: Body size, allometric relationships and evolvability in a house sparrow metapopulation. Evolution. vol. 73 (3).
- (2019) Parasite prevalence increases with temperature in an avian metapopulation in northern Norway. Parasitology. vol. 146 (8).
- (2018) Offspring fitness and the optimal propagule size in a fluctuating environment. Journal of Avian Biology. vol. 49 (7).
- (2018) Inferences of genetic architecture of bill morphology in house sparrow using a high-density SNP array point to a polygenic basis. Molecular Ecology. vol. 27 (17).
- (2017) Controlling for P-value inflation in allele frequency change in experimental evolution and artificial selection experiments. Molecular Ecology Resources. vol. 17 (4).
- (2017) Reversal of response to artificial selection on body size in a wild passerine bird. Evolution. vol. 71 (8).
- (2017) Demographic influences of translocated individuals on a resident population of house sparrows. Oikos. vol. 126 (10).
- (2017) Insights into the genetic architecture of morphological and sexually selected traits in two passerine bird species. Heredity. vol. 119 (3).
- (2017) Sensitivity analysis of effective population size to demographic parameters in house sparrow populations. Molecular Ecology. vol. 26 (9).
- (2016) Spatial variation in senescence rates in a bird metapopulation. Oecologia. vol. 181 (3).
- (2016) Steroids in house sparrows (Passer domesticus): Effects of POPs and male quality signalling. Science of the Total Environment. vol. 547.
- (2016) Is basal metabolic rate associated with recruit production and survival in free-living house sparrows?. Functional Ecology. vol. 30 (7).
- (2015) Endoparasite infection has both short- and long-term negative effects on reproductive success of female house sparrows, as revealed by faecal parasitic egg counts. PLOS ONE. vol. 10 (5).
- (2015) On being the right size: Increased body size is associated with reduced telomere length under natural conditions. Proceedings of the Royal Society of London. Biological Sciences. vol. 282 (1820).
- (2014) Effects of population characteristics and structure on estimates of effective population size in a house sparrow metapopulation. Molecular Ecology. vol. 23 (11).
- (2014) Lower survival probability of house sparrows severely infected by the gapeworm parasite. Journal of Avian Biology. vol. 45 (4).
- (2013) Temporal and spatial variation in prevalence of the parasite Syngamus trachea in a metapopulation of House Sparrows (Passer domesticus). Parasitology. vol. 140 (10).