Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2019
Authors
Gunnhild SøgaardAbstract
No abstract has been registered
Authors
Kjell Handeland Rebecca K. Davidson Hildegunn Viljugrein Anders Mossing Erling Meisingset Marianne Heum Olav Strand Ketil IsaksenAbstract
Nematodes of the genera Elaphostrongylus and Dictyocaulus are associated with disease in semi-domesticated tundra reindeer and farmed red deer whereas less knowledge exists in the wild. Their first stage larvae (L1) develop to the infective third stage (L3) in the environment; Elaphostrongylus spp. within intermediate gastropod hosts and Dictyocaulus spp. as free-living larvae. Larval development of Elaphostrongylus is highly temperature dependent with a developmental minimum of 9–10 °C. Larval development of Dictyocaulus spp. may occur at low temperatures (5 °C) but the larvae are sensitive to desiccation. We examined the prevalence and intensity of Elaphostrongylus spp. and Dictyocaulus spp. infections in six wild reindeer and two wild red deer populations in relation to altitude, temperature and rainfall in their respective main summer pasture area over the 5 summers prior to sampling. The parasitological examination was based upon morphological identification of L1 in the faeces of hunted animals. Altitude was calculated from animal position data and temperature and precipitation by means of a nationwide gridded data set. Temperature decreased with increasing altitude, from 13.3 °C for the lowest located red deer population (300 m) to 6.1 °C for the highest located reindeer population (1400 m). No significant relationship between altitude and rainfall was identified. Elaphostrongylus spp. infection decreased in prevalence with increasing altitude, being identified in 89% of investigated samples from the lowest located population and in 3% of samples from the highest. The prevalence of Dictyocaulus spp. infection varied between 28 and 80% and no relationship with altitude was found. The intensity of Elaphostrongylus spp. infection was low in reindeer and moderate in red deer whereas the intensity of Dictyocaulus spp. infection was moderate in both species. Our results indicated that the climatic conditions in all areas studied were suitable for Dictyocaulus spp., whereas summer temperature was a restrictive factor for Elaphostrongylus sp. in reindeer.
Abstract
With climate change, the effect of global warming on snow cover is expected to cause range expansion and enhance habitat suitability for species at their northern distribution limits. However, how this depends on landscape topography and sex in size-dimorphic species remains uncertain, and is further complicated for migratory animals following climate-driven seasonal resource fluctuations across vast landscapes. Using 11 years of data from a partially migratory ungulate at their northern distribution ranges, the red deer (Cervus elaphus), we predicted sex-specific summer and winter habitat suitability in diverse landscapes under medium and severe global warming. We found large increases in future winter habitat suitability, resulting in expansion of winter ranges as currently unsuitable habitat became suitable. Even moderate warming decreased snow cover substantially, with no suitability difference between warming scenarios. Winter ranges will hence not expand linearly with warming, even for species at their northern distribution limits. Although less pronounced than in winter, summer ranges also expanded and more so under severe warming. Summer habitat suitability was positively correlated with landscape topography and ranges expanded more for females than males. Our study highlights the complexity of predicting future habitat suitability for conservation and management of size-dimorphic, migratory species under global warming.
Authors
M. P. G. Hofman M.W. Hayward Morten Heim P. Marchand Christer Moe Rolandsen Jenny Mattisson F. Urbano M. Heurich Atle Mysterud J. Melzheimer N. Morellet U. Voigt B.L. Allen B. Gehr C. Rouco W. Ullmann Øystein Holand Nicolai Hermann Jørgensen Geir Steinheim F. Cagnacci M. Kroeschel Petra Kaczensky B. Buuveibaatar J.C. Payne I. Palmegiani K. Jerina P. Kjellander Ö. Johansson S. LaPoint R. Bayrakcismith John Durrus Linnell M. Zaccaroni M.L.S. Jorge J.E.F. Oshima A. Songhurst C. Fischer R.T. Mc Bride Jr. J.J. Thompson S. Streif R. Sandfort Christophe Bonenfant M. Drouilly M. Klapproth D. Zinner R. Yarnell A. Stronza L. Wilmott Erling Meisingset M. Thaker A.T. Vanak S. Nicoloso R. Graeber S. Saïd M.R. Boudreau A. Devlin R. Hoogesteijn J.A. May-Junior J.C. Nifong John Odden H.B. Quigley F. Tortato D.M. Parker A. Caso J. Perrine C. Tellaeche F. Zieba T. Zwijacz-Kozica C.L. Appel I. Axsom W.T. Bean B. Cristescu S. Périquet K.J. Teichman S. Karpanty A. Licoppe V. Menges K. Black T.L. Scheppers S.C. Schai-Braun F. C. Azevedo F.G. Lemos A. Payne L.H. Swanepoel B.V. Weckworth A. Berger A. Bertassoni G. McCulloch P. Šustr V. Athreya D. Bockmuhl J. Casaer A. Ekori D. Melovski C. Richard-Hansen D. van de Vyver R. Reyna-Hurtado E. Robardet N. Selva A. Sergiel M.S. Farhadinia P. Sunde R. Portas H. Ambarli R. Berzins P.M. Kappeler G.K. Mann L. Pyritz C. Bissett T. Grant R. Steinmetz L. Swedell R.J. Welch D. Armenteras O.R. Bidder T.M. González A. Rosenblatt S. Kachel N. BalkenholAbstract
Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-Depth understanding of the main technological, species-specific and environmental factors that determine the success and failure of satellite tracking devices across species and habitats. Here, we assess the relative influence of such factors on the ability of satellite telemetry units to provide the expected amount and quality of data by analyzing data from over 3,000 devices deployed on 62 terrestrial species in 167 projects worldwide. We evaluate the success rate in obtaining GPS fixes as well as in transferring these fixes to the user and we evaluate failure rates. Average fix success and data transfer rates were high and were generally better predicted by species and unit characteristics, while environmental characteristics influenced the variability of performance. However, 48% of the unit deployments ended prematurely, half of them due to technical failure. Nonetheless, this study shows that the performance of satellite telemetry applications has shown improvements over time, and based on our findings, we provide further recommendations for both users and manufacturers.
Abstract
Ongoing global warming is now affecting migratory cycles in a large variety of taxa in seasonally variable environments. Disruption of migratory systems can cause population decline and affect ecosystem function across the globe. It is therefore urgent to understand the drivers of migration and how the different fitness limitations of the sexes affect migration, but studies seldom considered the full annual cycle. We analysed the annual migration cycle of 237 red deer (Cervus elaphus) in Norway and investigate how different seasonal limitations affected the variation in a suite of migration characteristics. We found fundamental differences in migration phenology between seasons, and migratory traits were much more variable in males. Spring migratory movements were characterized by longer distance roamed, lower speed, lasted longer, more frequent use of stopovers, timing was more synchronized and coincided with onset of plant growth, and with higher daily activity levels. Timing of autumn migration was more variable and not closely related to cease of plant growth. Our study emphasizes the benefits of studying the full annual cycle to gain further insight into the migration process, and how understanding the limitations of the full annual migration process of both sexes is critical for conservation purposes.
Authors
Kamal Atmeh Anne Loison Nicolas Morellet A. J. Mark Hewison P. Marchand Mathieu Garel Erling Johan Solberg Morten Heim Bernt-Erik Sæther Ivar Herfindal Atle Mysterud Erling Meisingset Martin-Hugues St-Laurent Guillaume PéronAbstract
No abstract has been registered
Authors
Kjersti Holt HanssenAbstract
No abstract has been registered
Abstract
Based on data from long-term experimental fields with Norway spruce (Picea abies (L.) H. Karst.), we developed new stem taper and bark functions for Norway. Data was collected from 477 trees in stands across Norway. Three candidate functions which have shown good performance in previous studies (Kozak 02, Kozak 97 and Bi) were fitted to the data as fixed-effects models. The function with the smallest Akaike Information Criterion (AIC) was then chosen for additional analyses, fitting 1) site index-dependent and 2) age-dependent versions of the model, and 3) fitting a mixed-effects model with tree-specific random parameters. Kozak 97 was found to be the function with the smallest AIC, but all three tested taper functions resulted in fairly similar predictions of stem taper. The site index-dependent function reduced AIC and residual standard error and showed that the effect of site index on stem taper is different in small and large trees. The predictions of the age-independent and age-dependent models were very close to each other. Adding tree-specific random parameters to the model clearly reduced AIC and residual variation. However, the results suggest that the mixed-effects model should be used only when it is possible to calibrate it for each tree, otherwise the fixed-effects Kozak 97 model should be used. A model for double bark thickness was also fitted as fixed-effects Kozak 97 model. The model behaved logically, predicting larger relative but smaller absolute bark thickness for small trees.
Abstract
No abstract has been registered
Abstract
No abstract has been registered