Bård G Stokke

• PhD
• Senior Researcher at Norwegian Institute for Nature Research

Predicting coevolutionary outcomes is critical for understanding the consequences of climate change and biodiversity loss. The geographic mosaic theory of coevolution posits that coevolutionary interactions vary among populations, facilitating the persistence of such interactions over evolutionary timescales. Characterisation of geographic mosaics...

Many species are currently experiencing range shifts in response to climate change. The colonisation of new regions can have serious genetic consequences for the shifting population, given that repeated founder events and strong genetic drift are expected to erode genetic variation along the expansion axis. Such a loss of genetic diversity could re...

I arbeidet med konseptutredninga, har ein drøfta i kor stor grad ein skal detaljere beskrivingar av feltmetodikk. Variasjon mellom artar og ulike kartleggingsformål krev variasjon i kartleggingsmetodikk. Konseptutredninga vil ikkje kunne gi detaljerte svar på alle metodiske utfordringar, men gir eit metodisk rammeverk der fleire av elementa vil ver...

Birds migrate over large spatial scales and with complex dynamics which play out over extended time periods, making monitoring of phenology challenging with traditional biodiversity survey approaches. In this study, over a complete spring season, we collected 37,429 hours of audio from 28 networked sensors in forests across the latitudinal extent o...

The expansion of the electric grid is inevitable. Renewable energy is on the rise, and new transmission lines must be built to link new electricity production facilities with the local network. In addition, higher electricity demand due to electrification will lead to the growth of the distribution grid. However, further construction of power lines...

Many mountain species are expected to respond to climate change through upslope shifts of their range limits, but competition may restrict or alter this response. Under traditional range‐limit theory, it is expected that lower‐elevation species are better competitors than closely related higher‐elevation species. However, recent work finds that thi...

Environmental variation among isolated populations can drive genetic differentiation by selection, while isolation alone results primarily in genetic drift. Genetic analyses can aid in identifying genetically isolated populations and population structure of a species across its range. Additionally, such analyses can provide indirect evidence of loc...

Tundra arthropods are of considerable ecological importance as a seasonal food source for many arctic‐breeding birds. Dietary composition and food preferences are rarely known, complicating assessments of ecological interactions in a changing environment. In our field study, we investigated the nestling diet of snow buntings ( Plectrophenax nivalis...

The constant increase in energy consumption has created the necessity of extending the energy transmission and distribution network. Placement of powerlines represent a risk for bird population. Hence, better understanding of deaths induced by powerlines, and the factors behind them are of paramount importance to reduce the impact of powerlines. To...

Range expansion is a common natural phenomenon, which may be intensified by human-induced drivers such as climate change and alterations of habitat. The genetic consequences of range expansion are potentially major, and it is important to study known cases of range expansion to understand how human activities affect contemporary evolution, and to l...

Quantifying the total number of individuals (abundance) of species is the basis for spatial ecology and biodiversity conservation. Abundance data are mostly collected through professional surveys as part of monitoring programs, often at a national level. These surveys rarely follow exactly the same sampling protocol in different countries, which re...

Quantifying species abundance is the basis for spatial ecology and biodiversity conservation. Abundance data are mostly collected through professional surveys as part of monitoring programs, often at a national level. These surveys rarely follow the same sampling protocol in different countries, which represents a challenge for producing abundance...

The ability to track variation in climate is important for species to persist in a given environment. Lack of responses to both long-term changes and inter-annual variation in climate parameters can result in reduced fitness and population decline. Furthermore, migration strategy can influence the ability to track climatic variation due to the pote...

Langtidseffekter av Smøla vindpark på den lokale bestanden av havørn (Haliaeetus albicilla)

While wind energy remains a preferred source of renewable energy, understanding the full spectrum of impacts are vital to balance climate-related benefits against their costs to biodiversity. Environmental impact assessments often fail to assess cumulative effects at larger spatial scales. In this respect, life cycle assessments are better suited,...

Avian brood parasitism is costly for the host, in many cases leading to the evolution of defenses like discrimination of parasitic eggs. The parasite, in turn, may evolve mimetic eggs as a counter-adaptation to host egg rejection. Some generalist parasites have evolved host-specific races (gentes) that may mimic the eggs of their main hosts, while...

It is likely that there will continue to be a substantial increase in the number of wind turbines as we aim to meet global energy demands through renewable sources. However, these structures can have adverse impacts on airborne wildlife, such as posing a potential collision risk with the turbine structure. A range of methods and technologies have b...

Growing human population demands the expansion of the energy transmission grid. Power lines represent a major death hazard for many species, especially birds. Addressing such a human-wildlife conflict requires detailed knowledge of how species use the aerial space and how they react to mitigation measures, such as flight markers. Here, we use a ded...

Wind energy development continues to expand rapidly to meet international climate targets. However, these developments impact biodiversity and associated sustainability targets negatively. Environmental impact assessments (EIA) predominately focus on site-specific impacts; failing to account for cumulative impacts at larger spatial scales. Life cyc...

Human disturbance represents a considerable challenge for the conservation of living organisms and has profound negative impacts globally. There is substantial variation in how species respond to human disturbance. The main aim of the present study is to examine how human activities influence the risk of brood parasitism and nest predation for thre...

As wind energy deployment increases and larger wind‐power plants are considered, bird fatalities through collision with moving turbine rotor blades are expected to increase. However, few (cost‐) effective deterrent or mitigation measures have so far been developed to reduce the risk of collision. Provision of “passive” visual cues may enhance the v...

Summary of a large ecological quantitative impact assessment for alien species in Norway. Additional information and data repository: Sandvik H et al (2020) Data from: Ecological impact assessments of alien species in Norway. Dryad Digital Repository, https://doi.org/10.5061/dryad.8sf7m0cjc

1 . Due to globalisation, trade and transport, the spread of alien species is increasing dramatically. Some alien species become ecologically harmful by threatening native biota. This can lead to irreversible changes in local biodiversity and ecosystem functioning, and, ultimately, to biotic homogenisation. 2 . We risk‐assessed all alien plants, a...

Carrion represents an unpredictable and widely distributed primary food source for vultures and other avian scavengers. Avian scavengers in African savanna ecosystems are reported to rely exclusively on visual stimuli to locate carcasses. However, carnivores’ predation of large mammalian herbivores and subsequent competition for access to the carca...

• Birds colliding with turbine rotor blades is a well‐known negative consequence of wind‐power plants. However, there has been far less attention to the risk of birds colliding with the turbine towers, and how to mitigate this risk. • Based on data from the Smøla wind‐power plant in Central Norway, it seems highly likely that willow ptarmigan (the...

Powerlines are a direct death hazard to birds. We investigate the behavioural responses of birds (flight behaviour) to wire-marking by comparing sections with and without flight diverters on the powerline's wire using a dedicated avian radar in Norway. Our results show a negative correlation between the presence of the marker and (i) the number, (i...

We present the results of an inventory and status assessment of alien species in Norway. The inventory covered all known multicellular neobiota, 2496 in total, 1039 of which were classified as naturalised. The latter constitute c. 3% of all species known to be stably reproducing in Norway. These figures are higher than expected from Norway’s latitu...

This report studies the migration in the outer parts of the Guleslettene wind farm. NINA has done radar mapping during the fall 2018 and spring 2019, and collected audio data both seasons. We have been in the field and mapped the migration, as well as verified radar data. Observations from a previous study have been added, together with data from t...

In the period 2001–2014 we studied Common Cuckoo Cuculus canorus brood parasitism on Meadow Pipits Anthus pratensis in two mountain areas; one located in the eastern and one in the western part of southern Norway. In the total material of 211 Meadow Pipit nests, 14 (6.6%) were parasitized by the cuckoo. The parasitism rate showed considerable varia...

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications...

Our knowledge of avian brood parasitism is primarily based on studies of a few selected species. Recently, researchers have targeted a wider range of host–parasite systems, which has allowed further evaluation of hypotheses derived from well-known study systems but also disclosed adaptations that were previously unknown. Here we present development...

House Crows Corvus splendens lay eggs with bluish-green ground colour and black or brown blotches and only one egg morph was believed to exist. Here, we confirm the existence of an immaculate, spotless blue egg morph that is clearly different from the regular egg morph.

Few species are adapted to high latitudes, and many over-winter in milder climates with migrations involving extensive barrier crossings. By escaping extreme conditions for the majority of the year, physiological and behavioural adaptations presumably need to be less pronounced. The snow bunting Plectrophenax nivalis is the most northerly breeding...

Migration of snow buntings. Migration of snow buntings from breeding grounds to breeding grounds (individuals represented by colour and logger ID). Identified stationary periods represented by solid line (—-) and periods of apparent movement by a dashed line (----), these include directed migration and nomadic behaviour. Breeding site longitude and...

Wintering environmental variables and land use. Environmental variables and land use for the duration of the wintering periods, with 70% Kernel Density Estimation of wintering grounds depicted by black polygon: (a) mean daily mean surface temperature (°C), (b) absolute minimum surface temperature (°C), (c) Percentage crop cover and (d) maximum snow...

Tracked birds deployment information and key timings. Tracked snow bunting deployment information and key timings of significant migration which were used to define Autumn, Winter and Spring periods. Total number of stationary periods (SP) and duration (in days) of wintering stationary periods, defined Autumn and Winter periods, and where known Spr...

Time series of snow buntings. Time series of identified migratory movements, stationary periods and nomadic behaviour. Key migration events are depicted by ▼ southwards and ▲ northwards, and coloured by departure from Svalbard, autumn (red), arrival at wintering grounds (blue), departure from wintering grounds, spring (green) and where known, depar...

Host quality is critical for parasites. The common cuckoo Cuculus canorus is a generalist avian brood parasite, but individual females show strong preference for a specific host species. Here, we use three extensive datasets to investigate different host characteristics determining cuckoo host selection at the species level: (i) 1871 population-spe...

The expansion of wind energy development causes both societal and environmental concerns worldwide. Traditional land use planning approaches however limit addressing such concerns adequately. The scale and complexity of emerging renewable energy construction projects enforce the development of improved plan- and decision support tools that ensure d...

Translocation of individuals from source populations to augment small populations facing risk of extinction is an important conservation tool. Here we examine sex-specific differences between resident and translocated house sparrows Passer domesticus in reproductive success and survival, and the contribution of translocated individuals to the growt...

We all know Cuckoos as the harbingers of spring – whose haunting calls proclaim the birds own name across fields and reedbeds. A bird much more often heard than actually seen, and often mistaken for a hawk or falcon when briefly glimpsed in flight. Cuckoos are also well known, perhaps even infamous, for their habit of laying their own eggs into the...

This chapter deals with adaptations of brood parasitic eggs, which has received a lot of attention by researchers and naturalists for centuries. Both scientists and laymen are intrigued by the sophisticated traits that are enabling parasites to fool or force their hosts into accepting their eggs. A range of brood parasites have evolved mimetic or c...

Being an obligate parasite, juvenile common cuckoos Cuculus canorus are thought to reach their African wintering grounds from Palearctic breeding grounds without guidance from experienced conspecifics but this has not been documented. We used satellite tracking to study naïve migrating common cuckoos. Juvenile cuckoos left breeding sites in Finland...

Number of ringed common cuckoos per country and country where southernmost recovery was obtained. Ringing periods are shown in the country column. Information obtained from European bird ringing atlases. (DOCX)

Tracking Data. (XLSX)

Timing and duration of the autumn migration periods of satellite-tracked juvenile and adult cuckoos in 2010–2014. Dates are given for arrivals and departures and the duration of each stage is given in days. ID = Bird identification with sex (F = female, M = male) followed by satellite-tag ID and last two digits of the tagging year in brackets. Age...

Morphometrics and ages of the young cuckoos. Measured when tagging (N = 13). Tag activation is given as days after tagging. (DOCX)

Location quality of positions included in the study. Number of locations and location quality (LQ A-B, 0–3; CLS 2007–2015) of cuckoos tracked from leaving the breeding areas to arrival on the winter grounds (as the southernmost stationary position) or end of transmission. (DOCX)

Supplementary Wind Analysis. (DOCX)

Fate of tagged cuckoos across studies. Logistic regression (Generalised Linear Model with logit link and binomial error distribution) of Finland post-fledging vs. UK post-fledging: parameter estimate of difference in location: 1.17; SD = 0.70; z = 1.68, P = 0.09. Finland juvenile autumn vs. UK adult autumn: parameter estimate of difference in age/l...

The Plaintive Cuckoo (Cacomantis merulinus) is a widespread brood parasite in Asia, but no data on host species utilization in Bangladesh exist. By searching for nests of all possible host species of the Plaintive Cuckoo at Jahangirnagar university campus, north of Dhaka, we were able to determine which hosts were used in this area. We found that t...

https://www.knnvuitgeverij.nl/NL/webwinkel/0/koekoek/121279

How does behaviour affect biological invasions? Can it explain why some animals are such successful invaders? With contributions from experts in the field, and covering a broad range of animals, this book examines the role of behaviour in biological invasions from the point of view of both invaders and native species. The chapters cover theoretical...

Host specialization evolved in many parasite-host systems. Evolution and maintenance of host specificity may be influenced by host life-history traits, active host selection by the parasite, and host anti-parasite strategies. The relative importance of these factors is poorly understood in situations that offer parasites a choice between hosts with...

We used a four-day program with a pre-test–post-test approach on 355 selected school children to investigate the influence of a wildlife education project on the acquisition of knowledge about large carnivores in Loliondo, Tanzania. After the school program was completed, a significantly higher number of school children correctly identified six car...

Hosts of brood parasites may vary geographically in their ability to resist parasitism. In contrast, geographic variation in defenses, such as egg rejection, is not expected to be present or vary geographically in unsuitable hosts. We examined spatial patterns of resistance in the great tit Parus major, a passerine that is a textbook example of an...

Maternal inheritance via the female-specific W chromosome was long ago proposed as a potential solution to the evolutionary enigma of co-existing host-specific races (or 'gentes') in avian brood parasites. Here we report the first unambiguous evidence for maternal inheritance of egg colouration in the brood-parasitic common cuckoo Cuculus canorus....

Supplementary Figures 1-2, Supplementary Tables 1-10 and Supplementary References

Laying a mimetic egg is important for a brood parasite to succeed in defeating the defenses of a host that can recognize and reject nonmimetic foreign eggs. Several recent studies suggest that common cuckoos (Cuculus canorus) do not lay eggs randomly in their regular hosts’ nests but select host individuals after inspecting their eggs to maximize t...

The evolutionary equilibrium hypothesis was proposed to explain variation in egg rejection rates among individual hosts (intra- and interspecific) of avian brood parasites. Hosts may sometimes mistakenly reject own eggs when they are not parasitized (i.e. make recognition errors). Such errors would incur fitness costs and could counter the evolutio...

Brood parasites and predators pose different threats to passerines that may favour the evolution of enemy-specific defence strategies. Furthermore, potential sex-specific variation in parental investment may be manifested in differences between male and female nest defence behaviour. We investigated these hypotheses in Oriental reed warblers (Acroc...

The evolution of traits in hosts may be influenced by their parasites and vice versa and a coevolutionary arms race often develops between the two. As part of such an arms race, the common cuckoo mimics the eggs of its hosts to avoid egg rejection. Traits related to this arms race may also be influenced by climatic conditions, such as temperature,...

Prey typically respond to potential predators by taking flight. This results in an optimal flight initiation distance (FID) at which the risk of remaining and the cost of flight are equal. Thus, FID is strongly negatively correlated with susceptibility to predation by the sparrowhawk Accipiter nisus across species of small European birds. However,...

Prey typically respond to potential predators by taking flight. This results in an optimal flight initiation distance (FID) at which the risk of remaining and the cost of flight are equal. Thus, FID is strongly negatively correlated with susceptibility to predation by the spar-rowhawk Accipiter nisus across species of small European birds. However,...

Different populations of a host species subject to variable patterns of selection due to cuckoo parasitism provide an optimal situation for studying natural selection and coevolution in action. We compared egg appearance and egg-rejection behavior of 2 common cuckoo (Cuculus canorus) hosts, the ashy-throated parrotbill (Paradoxornis alphonsianus) a...

Global climate change is regarded as one of the major threats to biodiversity. Both local and regional climate parameters can have strong effects on ecological processes affecting the survival and reproduction of plants and animals. High Arctic ecosystems are characterized by low species diversity and the local species have often evolved specific a...

Obligate avian brood parasites lay their eggs in hosts' nests and play no role in the provisioning of the progeny. Many parasites, including Cuculus cuckoos, hatch before their hosts and the altricial chick evicts hosts eggs and nestlings. A hypothesized, but so far untested parasite adaptation is that the embryos of cuckoos develop more quickly th...

Studies of the behavior of animals when confronted with tasks differing in complexity can improve our understanding of animal cognition and learning mechanisms. Coevolutionary interactions between brood parasites and their hosts provide an ideal opportunity for studying animal cognition because egg recognition and rejection are some of the most imp...

Reproductive processes are affected by local and regional climate variation. Birds breeding in the Arctic may experience strong energetic constraints, which will affect their reproductive output. Recent research has emphasized the importance of extra-pair copulation as a means of improving reproductive output. In this paper, we explore ecological a...

Birds are capable of seeing the ultraviolet light (UV) spectrum and as a consequence have evolved UV-reflective structures with signalling functions. Avian eggs also reflect in the UV spectrum but the importance of UV egg matching in egg rejection decisions has been equivocal. Here we conducted egg rejection experiments in the congeneric and sympat...

How do potential hosts escape detrimental interactions with brood parasites? Current consensus is that hole-nesting and granivorous birds avoid brood parasites, like common cuckoos Cuculus canorus, by their inaccessible nest-sites and food unsuitable for parasites, respectively. Any open-nesting insectivorous hosts are believed to remain open to br...

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of th...

In Europe, eggs of the Common Cuckoo (Cuculus canorus) have been found in more than 125 different host species. However, very few species are frequently parasitized. The Cuckoo is divided into several distinct races termed gentes. Females of each gens specialize in parasitizing a particular host species. More than 20 such gentes are recognized in E...