Knud Falk

Knud Falk
Independent Researcher

PhD

About

82
Publications
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Publications

Publications (82)
Article
Full-text available
While collating contributions and comments from 36 researchers, the coordinating authors accidentally omitted Dr. Suzanne Carrière from the list of contributing co-authors. Dr. Carrière's data are described in Tables 1 and 3, Figure 2 and several places in the narrative.The new author list is thus updated in this article.
Article
Full-text available
The Arctic is undergoing biological and environmental changes, and a coordinated effort to monitor is critical to detect these changes. The Circumpolar Biodiversity Monitoring Programme (CBMP) of the Arctic Council biodiversity working group, Conservation of Arctic Flora and Fauna (CAFF), has developed pan-Arctic biodiversity monitoring plans that...
Article
Full-text available
Tundra-breeding birds face diverse conservation challenges, from accelerated rates of Arctic climate change to threats associated with highly migratory life histories. Here we summarise the status and trends of Arctic terrestrial birds (88 species, 228 subspecies or distinct flyway populations) across guilds/regions, derived from published sources,...
Article
This review provides a synopsis of the main findings of individual papers in the special issue Terrestrial Biodiversity in a Rapidly Changing Arctic. The special issue was developed to inform the State of the Arctic Terrestrial Biodiversity Report developed by the Circumpolar Biodiversity Monitoring Program (CBMP) of the Conservation of Arctic Flor...
Article
Full-text available
The peregrine falcon (Falco peregrinus) and the gyrfalcon (Falco rusticolus) are top avian predators of Arctic ecosystems. Although existing monitoring efforts are well established for both species, collaboration of activities among Arctic scientists actively involved in research of large falcons in the Nearctic and Palearctic has been poorly coord...
Article
Full-text available
The peregrine falcon (Falco peregrinus) and the gyrfalcon (Falco rusticolus) are top avian predators of Arctic ecosystems. Although existing monitoring efforts are well established for both species, collaboration of activities among Arctic scientists actively involved in research of large falcons in the Nearctic and Palearctic has been poorly coord...
Article
Full-text available
Denmark being a country with only a few suitable steep nesting cliffs has only harboured a small population of Peregrine Falcons (Falco peregrinus) in historic time. In the previous century, the population gradually declined due to persecution, egg and young collection, and pollution. The last breeding attempt in the 20 th century occurred in 1972...
Article
Full-text available
The DDT-induced effects, eggshell thinning and breeding failure in Peregrine Falcon (Falco peregrinus) populations were reverted with restrictions on the use of the compound from the 1970s, and in most studied populations, the eggshell thickness is back to normal. In Greenland, a previous study of eggshell thinning in Peregrines found that shells h...
Preprint
Full-text available
In order to better understand the potential effects of climate change on the Peregrine Falcon, we investigated the relationship between extreme weather events and Peregrines’ breeding success in South Greenland. We defined three variables – number of days with extremely low temperatures, extreme precipitation, consecutive rainy days – and an additi...
Article
A suite of perfluoroalkyl substances (PFASs) and polychlorinated naphthalenes (PCNs) were determined in 41 peregrine falcon eggs collected in South Greenland between 1986 and 2014. Median concentrations of perfluorinated sulfonic acids (ΣPFSA) and perfluorinated carboxylic acids (ΣPFCA) were 303 ng/g dry weight (dw) (58 ng/g wet weight, ww) and 100...
Article
Median levels of regulated flame retardants, i.e. polybrominated diphenyl ethers (PBDEs), brominated biphenyl (BB) 153 and hexabromocyclododecane (HBCD) in 33-48 eggs of peregrine falcons (Falco peregrinus) from Greenland were 1900, 359 and 5.98 ng/g lipid weight (lw) and generally intermediate to levels in North America and Europe. Unregulated fla...
Article
Ritenbenk/Innaq in Disko Bay is the only remaining Thick-billed Murre colony in central West Greenland. It has declined by 72% since 1980 and now (2012) holds c.1,100 breeding pairs. In 2005–2006 and 2011–2012, a number of studies were carried out in this colony to improve our understanding of the population decline and its causes. Hunting has prev...
Technical Report
Full-text available
As part of the environmental studies in connection with oil exploration in Baffin Bay, baseline studies of seabird ecology were carried out at colonies north of Upernavik during the summers of 2008-13. The main study species were thick-billed murre and black-legged kittiwake. GPS tracking of both species showed that important foraging areas during...
Article
Large population declines were reported for the thick-billed murre (Uria lomvia) in Greenland for the period 1930s–1980s, but no national status has been published for the past 20 years. Meanwhile, the murres have gained more protection and several human-induced mortality factors have been markedly reduced. Here, we give an updated status based on...
Article
Full-text available
Leg-mounted loggers are increasingly used in seabird activity studies, but few studies have validated the information obtained about bird behaviour with independent data. Using Brünnich’s Guillemot Uria lomvia as a study species, we show by comparing interpretations of time–depth recorder (TDR) data with visual observations that activity budgets in...
Article
Peregrine falcon eggs were collected in South Greenland between 1986 and 2003 and analysed for 6 congeners of toxaphene and 5 chlordane-related pesticides (cis-chlordane, trans-chlordane, cis-nonachlor, trans-nonachlor and oxychlordane). Oxychlordane had the highest median concentration of 1448ng/g lipid weight (lw) or 79ng/g wet weight (ww) of all...
Technical Report
Full-text available
The Danish Ministry of the Environment has requested DCE – Danish Centre for Environment and Energy (DCE), Aarhus University, to develop a technical report identifying ecologically valuable and sensitive marine areas in relation to increased shipping activities in Greenlandic waters. The report is used as the basis for the work in the national work...
Article
The diet of thick-billed murres (Uria lomvia) wintering in coastal western Greenland was studied by analyzing the stomach contents of 202 birds supplied by local hunters in four regions, from October 1988 to March 1989. Fish and crustaceans were present in 68 and 71% (frequency of occurrence), respectively, of all stomachs containing prey remains (...
Article
Abdim's Stork is a common breeding bird in most human settlements across the Sahel. However, very few studies have surveyed the population and described its breeding and feeding ecology during the breeding season. We identified the breeding range in Niger, surveyed nests in 23 villages/towns and, based on the number of villages and towns in the bre...
Article
This paper presents the results of a satellite tracking study of seven adult Abdim's Storks Ciconia abdimii that were followed from the nesting areas in southern Niger across the equator to the non-breeding range and back. Post-breeding migration started between early November and early December when all birds migrated directly to an area south of...
Technical Report
Full-text available
Studies of Thick-billed Murre were carried out in the colony at Ritenbenk/Innaq which has declined severely and is estimated to 2447 birds in 2006. This report includes studies of colony attendance, population estimate, population modelling and sustainable harvest modelling, chick feeding and foraging activities and migration based on ringing recov...
Article
Full-text available
Abdim’s Storks Ciconia abdimii were studied in a post-breeding staging area dominated by Sahelian grasslands in southeastern Niger. In late September 2003, a total of 5,763 birds was recorded on systematic transect counts. The estimated density was 5.66 per km2, equivalent to a total of c. 17,000 Abdim’s Stork within the utilized area of 3,000 km2....
Article
Although the Abdim's Stork (Ciconia abdimii) is a common breeder in the Sahel zone across Africa, its diet during the breeding season has never been studied. Chick meals were sampled in stork nests in West and Central Niger during early July and late August, representing early and mid rainy seasons in the area. The diet consisted of amphibians (Buf...
Article
Full-text available
We used δ15N and δ13C analyses of blood, muscle, and liver tissues to evaluate similarity of diet among five seabird species: Black Guillemot (Cepphus grylle), Black-legged Kittiwake (Rissa tridactyla), Dovekie (Alle alle), Glaucous Gull (Larus hyperboreus), and Thick-billed Murre (Uria lomvia) nesting at Coburg Island on the west and Hakluyt Islan...
Article
Thirty-seven addled peregrine falcon eggs collected in South Greenland between 1986 and 2003 were analysed for their content of the organochlorine compounds polychlorinated biphenyls (PCBs), dichlorodiphenyl tricloroethane (DDT) and its degradation products, hexachlorocyclohexane (HCH) isomers and hexachlorobenzene (HCB). PCBs and DDT (including me...
Article
Full-text available
We found that synchronous fluctuations of two congeneric seabird species across the entire Arctic and sub-Arctic regions were associated with changes in sea surface temperatures (SST) that were linked to two climate shifts, in 1977 and again in 1989. As the SST changes linked to climate shifts were congruent at the scale of ocean basins, fluctuatio...
Article
Data-loggers were used to measure the flight and diving activity of Brunnich's Guillemots Uria lomvia breeding in a colony in the North Water polynya. During a total of 51.1 bird-days the birds spent an average of 16.6% (4.0 h/day) of their time underwater, 7.1% in flight (1.7 h/day), 25.4% surface swimming and 50.9% on nest attendance. At-sea time...
Article
In this study of thick- billed murres in high- arctic Greenland we used electronic data loggers and satellite transmitters (PTTs) to identify the foraging areas of chick-rearing adults, and to map the routes and staging areas of adults accompanying post-fledging chicks during their swimming migration within the North Water (NOW) polynya. During the...
Article
Full-text available
Coastal and offshore waters of Southwest Greenland are internationally important wintering areas for king eiders (Somateria spectabilis) breeding in eastern Canadian Arctic and in northwestern Greenland. This paper presents the first assessment of their winter diet. Based on esophageal-proventricular samples from 26 females (13 juveniles and 13 old...
Article
Full-text available
Southwest Greenland provides wintering grounds for 70% (∼460,000) of the northern common eider (Somateria mollissima borealis) population. From 241 gullet samples (esophagus and proventriculus content) collected over three winters (1999–2002) near Nuuk, we identified 39 species consumed by the eiders. In contrast to studies elsewhere, fresh mass of...
Article
During waterfowl hunting a large number of birds are shot but not instantly killed. Some will die within a few days as a direct consequence of heavy injuries, whereas another proportion is only lightly injured and will survive for an extended period of time although their survival may still be affected. We predicted that embedded body shot (when no...
Article
Full-text available
We examined local movements, home ranges and body condition of wintering Northern Common Eiders Somateria mollissima borealis in Southwest Greenland from late winter until spring migration in 2000 and 2001. At key marine habitats at coastal areas and in the inner fjord system of Nuuk, we implanted 33 Eiders with satellite transmitters and collected...
Article
Temporal trends of mercury (Hg) in West Greenland gyrfalcons, peregrine falcons, and white-tailed eagles were determined over 150 years from 1851 to 2003. Hg was measured in the fifth primary feather. Results showed that Hg increased in the order gyrfalcon (lowest) < peregrine falcon (intermediate) < white-tailed eagle (highest). All species showed...
Article
Temporal trends of mercury (Hg) in West Greenland gyrfalcons, peregrine falcons, and white-tailed eagles were determined over 150 years from 1851 to 2003. Hg was measured in the fifth primary feather. Results showed that Hg increased in the order gyrfalcon (lowest) < peregrine falcon (intermediate) < white-tailed eagle (highest). All species showed...
Article
Full-text available
The large numbers of common eiders Somateria mollissima and king eiders S. spectabilis wintering in southwest Greenland are subject to intensive hunting, and in addition to direct harvest an unknown number of birds are wounded and become carriers of embedded lead shot. We conducted the first assessment of the magnitude of this undesirable side effe...
Article
Full-text available
Endogenous reserves influence both survival and reproduction of many waterfowl species, but little is known about reserve levels of most species during the nonbreeding season, particularly those wintering at high latitudes. We investigated whether age, sex, and season were related to carcass composition of northern common eiders (Somateria mollissi...
Article
Full-text available
To examine how endogenous reserves may influence avian life history, it is often necessary to quantify carcass composition. However, proximate analyses are expensive, time-consuming and difficult to perform under field conditions. Consequently, carcass composition is often estimated from easily measured data. We evaluate methods of estimating carca...
Article
Thickness of eggshell fragments and whole eggs from the Peregrine Falcon Falco peregrinus collected in South and West Greenland between 1972 and 2003 was measured and compared to shell thickness of pre-DDT eggs, also collected in Greenland. Linear regression yields a significant increase in the average thickness of eggshells over the period of 0.19...
Article
A time trend between 1986 and 2003 was found for brominated flame retardants in peregrine falcon eggs from South Greenland, with significantly increasing concentrations of the polybrominated diphenyl ethers (PBDEs) 99, 100, 153, 154, and 209. For BDE-99 and -100, the concentration increased approximately 10% per year. The concentrations of PBDEs we...
Technical Report
Full-text available
On the 2nd ENVINET meeting in Interlaken it was suggested to establish a Station Manager Forum for exchange of experience among station managers. On the 3rd ENVINET meeting in Oban it was decided to go further with this project as an ENVINET Technical Task named “Site Management at ENVINET stations” (see appendix 1.1 for project proposal). The aim...
Article
Bird-borne data loggers were used to investigate the foraging strategies of Brnnich's guillemots breeding in a colony in the North Water Polynya: the flight performance and diving activity of incubating birds were compared to those of chick-rearing individuals. No significant differences were recorded between the bird groups in the potential foragi...
Article
Full-text available
The North Water polynya is an area of open water that occurs year round between northwest Greenland and Canada. Oceanographic conditions differ between the western ('latent heat' polynya type) and extreme eastern ('sensible heat' polynya type) sectors of the polynya, and the effects of this variation on prey availability and foraging conditions for...
Article
Full-text available
We used δ15N and δ13C analyses of blood, muscle, and liver tissues to evaluate similarity of diet among five seabird species: Black Guillemot (Cepphus grylle), Black-legged Kittiwake (Rissa tridactyla), Dovekie (Alle alle), Glaucous Gull (Larus hyperboreus), and Thick-billed Murre (Uria lomvia) nesting at Coburg Island on the west and Hakluyt Islan...
Article
Late in the summers of 1997 and 1998 surveys of common eider (Somateria mollissima) colonies were conducted throughout Avanersuaq Municipality in north-west Greenland. Although old information from eider colonies was available, these surveys provided the first almost all colonies in the district, thereby improving the baseline data for assessing fu...
Article
Late in the summers of 1997 and 1998 surveys of common eider (Somateria mollissima) colonies were conducted throughout Avanersuaq Municipality in north-west Greenland. Although old information from eider colonies was available, these surveys provided the first almost all colonies in the district, thereby improving the baseline data for assessing fu...
Article
This paper reports the results of an investigation of dovekies (Alle alle) breeding at Hakluyt Island in the Thule District, Northwest Greenland. The paper presents a comprehensive examination of the chick diet of dovekies in the species' most important breeding area. Food delivered to nestlings consisted primarily of copepods Calanus hyperboreus a...
Article
The little auk population of the Thule district in Greenland is generally believed to be the largest anywhere and to comprise more than half of the world population, although published numbers have largely been conjectural. In 1996/1997 we estimated breeding density of little auks at Hakluyt Island in this district by colour-marking a number of bir...
Article
Full-text available
CONTENTS 1. Introduction 2. National reports 2.1 Incidental mortality of seabirds in Alaska 2.1.1 Introduction 2.1.2 Types of fisheries in Alaska monitored for incidental mortality of seabirds 2.1.3 Fisheries observer program in Alaska 2.1.4 Incidental mortality of seabirds 2.1.5 Management recommendations 2.2 Review of the seabird bycatch problem...
Article
An eight year old Thick-billed Murre (Uria lomvia) identified in 1997 at Hakluyt Island, Thule, Greenland, where it was apparently breeding, had been banded as a chick on Coats Island in Hudson Bay, Canada. This is the first known case of colony interchange in the species, which is normally considered to exhibit a very high degree of colony philopa...
Article
The breeding ecology of the Fulmar Fulmarus glacialis and the Kittiwake Rissa tridactyla in the high Arctic was studied in relation to the occurrence of the northeast water polynya in northeasternmost Greenland (80 degrees N). Mean laying dates were 31 May in the Fulmar and 18 June in the Kittiwake; the total nesting season for the Fulmar just matc...
Article
A small seabird community depends on the resources of the Northeast Water (NEW) polynya. In spring, at least 1000 King Eiders and 2500 Common Eiders form pre-breeding congregations at Ob Bank before dispersing in mid June to breeding areas. The most abundant species is the Fulmar, which breeds in six colonies with a total of 2550 “apparently occupi...
Article
Ship-based surveys of seabirds were carried out off southwestern Greenland in the autumn of 1988 and winter of 1989. The results provide the first quantitative information on seabird distribution and numbers for single seasons and estimates for one particular area in winter. Some oceanographic habitat characteristics important for seabird distribut...
Article
Three northern fulmars (Fulmarus glacialis) were tracked with satellite transmitters while they dispersed from a colony at the North East Water polynya in high-arctic Greenland after breeding failure. The longest cumulative distance recorded was 2043 km in 14 days, giving an average daily movement of 143 km, and the maximum distance covered in 1 da...
Article
Across the Danish–German border in the Wadden Sea, a new dike was completed in 1981, enclosing formerly productive tidal flats and marsh areas which were most important as feeding grounds to breeding and migrant waterbirds. The bird populations responded immediately by a 50% or more reduction in numbers of resting birds and breeding pairs of most s...