Anders Angerbjörn - Academia.edu (original) (raw)

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Papers by Anders Angerbjörn

Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of ... more Most birds incubate their eggs to allow embryo development. This behaviour limits the ability of adults to perform other activities. Hence, incubating adults trade-off incubation and nest protection with foraging to meet their own needs. Parents can either cooperate to sustain this trade-off or incubate alone. The main cause of reproductive failure at this reproductive stage is predation and adults reduce this risk by keeping the nest location secret. Arctic sandpipers are interesting biological models to investigate parental care evolution as they may use several parental care strategies. The three main incubation strategies include both parents sharing incubation duties ("biparental"), one parent incubating alone ("uniparental"), or a flexible strategy with both uniparental and biparental incubation within a population ("mixed"). By monitoring the incubation behaviour in 714 nests of seven sandpiper species across 12 arctic sites, we studied the relat...

Input file to BEAST, for analysing the complete dataset using a mutation rate of 8.9 % per millio... more Input file to BEAST, for analysing the complete dataset using a mutation rate of 8.9 % per million year

Input file to MrBayes for analysing the partial dataset, using Mictotus as an outgrou

Input file to BEAST, for analysing the complete dataset using a mutation rate of 50 % per million... more Input file to BEAST, for analysing the complete dataset using a mutation rate of 50 % per million year

Combined mitochondrial data. Control region: position 1-96; Cytochrome b: position 97-172

Raw data for Naud et al. Ecology and evolution. File includes a data table containing % vegetatio... more Raw data for Naud et al. Ecology and evolution. File includes a data table containing % vegetation cover, plant species richness, plant Shannon evenness, and three distances to centroids (which have been used as measurements of beta diversity on three different spatial scales), as well as a binary presence - absence matrix used for community structure calculations

Current Zoology, 2009

Knowledge of carnivore diets is essential to understand how carnivore populations respond demogra... more Knowledge of carnivore diets is essential to understand how carnivore populations respond demographically to variations in prey abundance. Analysis of stable isotopes is a useful complement to traditional methods of analyzing carnivore diets . We used data on δ13 C and δ15 N in wolverine tissues to investigate patterns of seasonal and annual diet variation in a wolverine Gulo gulo population in the western Brooks Range, Alaska, USA. The stable isotope ratios in wolverine tissues generally reflected that of terrestrial carnivores, corroborating previous diet studies on wolverines. We also found variation in δ13 C and δ15 N both between muscle samples collected over several years and between tissues with different assimilation rates, even after correcting for isotopic fractionation. This suggests both annual and seasonal diet variation. Our results indicate that data on δ13 C and δ15 N holds promise for qualitative assessments of wolverine diet changes over time. Such temporal variati...

Specialist predators per definition show numerical responses to changes in food supply. Numerical... more Specialist predators per definition show numerical responses to changes in food supply. Numerical responses are broadly divided into a reproductive response, where reproductive output increases wit ...

Biodiversity and Conservation, 2003

Journal of Zoology, 2006

The aim of this study was to investigate how the diet of gyrfalcon Falco rusticolus in northern S... more The aim of this study was to investigate how the diet of gyrfalcon Falco rusticolus in northern Sweden was affected by the relative availability of its two main prey species: rock ptarmigan Lagopus mutus and willow ptarmigan Lagopus lagopus. In order to do so, we needed a method to estimate the gyrfalcon's diet proportions of rock and willow ptarmigan from prey remains that we collected from nest sites in separate breeding territories. We also needed a method to calculate the availability of the two prey species in the same breeding territories that the prey remains originated from. We could then compare the diet proportions with prey availability and investigate if the gyrfalcons utilized the two species strictly in relation to their densities, or if they showed a preference for any of the prey species. Morphometric identification to species level from ptarmigan remains was not possible. Therefore, we developed a PCR‐based process of DNA analysis, which could be applied on any ...

Ecography, 1994

The arctic fox Alopex lagopus L population in Sweden is small and its numbers fluctuate widely wi... more The arctic fox Alopex lagopus L population in Sweden is small and its numbers fluctuate widely with food availability, l e rodent populations This fluctuation is mediated through differences in recruitment rates between years The recruitment can be divided into three phases number of litters born, number of cubs per litter and cub survival rates The number of litters and their sizes have been shown to depend on food availability during winter and spring To examine cub survival during the summer and how it relates to food availability, we conducted a feeding experiment m northern Sweden during 1990, a year of low rodent density, involving six occupied arctic fox dens Feeding at dens lowered cub mortality rates However, condition and growth rates of juveniles were not influenced by supplementary feeding at dens, nor were they related to the probability of survival for an individual Thus arctic foxes seem to minimize risks rather than maximize growth The juvenile mortality from weaning...

Archaeometry, 2002

The use of ancient DNA has increased during the past two decades in several scientific discipline... more The use of ancient DNA has increased during the past two decades in several scientific disciplines. However, the underlying mechanisms of DNA degradation in bone tissue are poorly understood. Here we address the importance of hydroxyapatite and collagen for DNA preservation in bone. We used two series of bones and teeth, one set of modern experimentally degraded bovid bones and one set of ancient horse bones/teeth. From these samples, we measured crystallinity, DNA presence and extracted collagen. The mtDNA fragments, parts of cytochrome b and the D–loop were amplified and sequenced. Our results show that presence of DNA was strongly related to the crystallinity in the hydroxyapatite and to the amount of collagen. This suggests that the hypothesis that hydroxyapatite has a crucial role in DNA preservation in calcified tissue is valid; and hydroxyapatite and collagen can be used to indicate whether DNA is present in the material. This is what would be expected if DNA is adsorbed to a...

Microsatellite diversity and fitness : testing the local and general effect hypotheses in an enda... more Microsatellite diversity and fitness : testing the local and general effect hypotheses in an endangered carnivore

The mangrove biotopes in Tanzania are under increasing pressure from domestic uses and changes in... more The mangrove biotopes in Tanzania are under increasing pressure from domestic uses and changes in land-use for aquaculture and solar salt farms. To investigate the impacts of man-made activities on ...

Handbook of the Mammals of Europe, Dec 31, 2022

Science of The Total Environment, 2021