Abstract: The demography and factors affecting the population dynamics of gadfly petrels (Pterodroma spp.) remain poorly known, although they constitute the most diverse genus of Procellariiformes and many species are threaten. Using a long-term individual monitoring dataset over 35 years, this study provides estimates of state-specific demographic parameters of the White-headed Petrel (Pterodroma lessonii) from Mayes Island, Kerguelen archipelago, and tests for the effects of environmental factors. Age at first breeding was 8.7 ± 2.6 years and apparent adult annual survival was 0.941 ± 0.058. Annual breeding probability was 0.356 ± 0.036 for successful breeders and 0.988 ± 0.054 for individuals that took a sabbatical year after a successful breeding event. Successful breeders that bred during two consecutive years had a lower breeding success (0.574 ± 0.048) that individuals that bred after a sabbatical year (0.655 ± 0.036). The realized population growth rate (1.073 ± 0.011) suggested that the population is increasing. There was a slight evidence for a positive effect of the Southern Annular Mode on the breeding probability of successful breeders, but no effect of sea surface temperature, chlorophyll a or wind was detected on demographic parameters. This study revealed that White-headed Petrels had a particularly high adult survival coherent with a quasi-biennial strategy and late age at first breeding. According to life history theory, populations of White-headed Petrel are thus likely to be very sensitive to small variations in adult survival, and anthropogenic factors causing additive mortality such as introduced predators will constitute serious threats for this species.

Abstract: Satellite transmitters and other tracking devices are valuable tools for furthering our understanding of bird movements, and their use has been steadily increasing. Since the necessary handling of birds to deploy transmitters can have deleterious consequences and the transmitter itself can add substantial mass, particularly to small species, or bring discomfort to the individual birds to which they are attached, it is important to quantify the effect such devices on both the behavior and the fitness of equipped animals. Very few studies have focused on the demographic effects of equipping birds with a satellite transmitter, with the vast majority of such studies focusing on short-term behavioral effects. We have assessed the demographic effects of attaching a satellite transmitter to the back of adult breeding Wandering Albatross individuals using long-term demographic data (20 years) and recent developments in capture–recapture methodology. We found no evidence of any negative effects of the attached devices on the probability of survival, breeding, or breeding successfully in the current or following season in either males or females. We conclude that the current satellite transmitters and smaller devices used by researchers are valuable conservation and research tools that do not adversely affect the demographic traits of large albatrosses. Similar tests should be carried out on smaller species, which are more likely to be affected.

Abstract: The study of dispersal or recruitment in long-lived birds using capture–recapture methods is challenging because temporary emigration is often a source of heterogeneity in detection probabilities. To deal with this problem, we introduced unobservable states in the multistate, spatial recruitment model of Lebreton et al. (Oikos 101:253–264, 2003) to study dispersal, recruitment and survival in the Wandering Albatross (Diomedea exulans), a species with a biennial reproduction (individuals skip breeding following a successful reproduction). We highlight some of the limitations and challenges encountered in using this approach. Our dataset came from a 36-year capture–recapture study conducted at three colonies of the Crozet archipelago. The model had five reproductive stages: pre-breeders, successful breeders, failed breeders, and birds in the year after a successful or a failed breeding attempt, which are unobservable. In adults, movements between colonies (i.e. breeding dispersal) were nested within reproductive stages. Several models with different constraints on survival equally fitted the data but had some rank deficiencies (i.e. non-identifiable parameters). Survival estimates were most biologically realistic (from 0.91 to 0.95) when survival was set equal between observable/unobservable states but free to vary between successful/failed breeders and among colonies. Age-specific recruitment probabilities peaked at 9–10 years and appeared well estimated despite limitations in setting the age of constant recruitment probability. Modelling natal dispersal and recruitment required a simplification of the structure of the model due to computer limitations. When applying the complete and reduced versions of the model to the same dataset, we found that survival was well estimated in both cases. Some transition probability estimates were also similar, but transitions from unobservable to observable states were poorly estimated in the simplified version. We conclude that the simplified version of the model should be limited to the estimation of natal dispersal and that the model with a full structure should be used to estimate breeding dispersal.

Abstract:

Abstract. Instrumental seismic observations in northern Finland started in the 1950s. They were originally initiated by the Institute of Seismology of the University of Helsinki (ISUH), but the staff of Sodankylä Geophysical Observatory (SGO) and later geophysicists of the University of Oulu (UO) were involved in the development of seismological observations and research in northern Finland from the very beginning. This close cooperation between seismologists and the technical staff of ISUH, UO, and SGO continued in many significant international projects and enabled a high level of seismological research in Finland. In our paper, we present history and current status of seismic observations and seismological research in northern Finland at the UO and SGO. These include both seismic observations at permanent seismic stations and temporary seismic experiments with portable seismic equipment. We describe the present seismic instrumentation and major research topics of the seismic group at SGO and discuss plans for future development of permanent seismological observations and portable seismic instrumentation at SGO as part of the European Plate Observing System (EPOS) research infrastructure. We also present the research topics of the recently organized Laboratory of Applied Seismology, and show examples of seismic observations performed by new seismic equipment located at this laboratory and selected results of time-lapse seismic body wave travel-time tomography using the data of microseismic monitoring in the Pyhäsalmi Mine (northern Finland).

Abstract: Our aim is to understand the effect of high-speed stream events on the high-latitude ionosphere and more specifically the decrease of the foF2 frequency during the entire day following the impact. First, we have selected one summertime event, for which a large data set was available: Super Dual Auroral Radar Network (SuperDARN) and European Incoherent SCATter (EISCAT) radars, Tromsø and Sodankylä ionosondes, and the CHAllenging Minisatellite Payload (CHAMP) satellite. We modeled with the IPIM model (IRAP Plasmasphere Ionosphere Model) the dynamics of the ionosphere at Tromsø and Sodankylä using inputs derived from the data. The simulations nicely match the measurements made by the EISCAT radar and the ionosondes, and we showed that the decrease of foF2 is associated with a transition from F2 to F1 layer resulting from a decrease of neutral atomic oxygen concentration. Modeling showed that electrodynamics can explain short-term behavior on the scale of a few hours, but long-term behavior on the scale of a few days results from the perturbation induced in the atmosphere. Enhancement of convection is responsible for a sharp increase of the ion temperature by Joule heating, leading through chemistry to an immediate reduction of the F2 layer. Then, ion drag on neutrals is responsible for a rapid heating and expansion of the thermosphere. This expansion affects atomic oxygen through nonthermal upward flow, which results in a decrease of its concentration and amplifies the decrease of [O]/[N2] ratio. This thermospheric change explains long-term extinction of the F2 layer.