Henning Heldbjerg

• Aarhus University

Northern European Greylag Goose Anser anser numbers have increased substantially in the last four decades, as birds have adapted to an increasingly agricultural lifestyle year-round. Recent calls for management actions to reduce goose damage to agricultural crops requires contemporary data on foraging distances and habitat use of the species. In th...

The exponential increase in the ‘NW/SW European Greylag Goose population’ (NGGP) has created demands for more precise estimates of the national breeding populations and improved understanding of their movements to support its effective management. Increased NGGP abundance has been associated with a northeast-ward shift in wintering centre of gravit...

As a result of increasingly intensified agricultural practices in Europe over the last century, agroecosystems have experienced severe biodiversity declines. Among the species experiencing negative population trajectories in agricultural habitats are meadow and farmland birds, which have suffered a loss in both habitat and food availability in cult...

We combined data from two independent Danish citizen science time‐series to describe changes in (1) abundance and (2) distribution of 12 wintering populations of geese and swans and tested the hypothesis that increases in national abundance since 2003 correlated with an expansion into formerly unoccupied winter farmland habitat. Five populations sh...

Rooks Corvus frugilegus are common and widespread in urban and agricultural habitats in Denmark. Large numbers are killed annually by derogation shooting to control population growth to reduce noise near populated areas and prevent agricultural damage. Responding to increasing public complaints about noise nuisance from urban rookeries, we investig...

Night-brooding of nestlings in cavity-nesting avian species carries predation risks to parents. Anecdotally, several species are known to shift from constant adult night-brooding behaviour to leaving nestlings unattended at night during offspring development but the timing, speed of change and sex-specific differences between parents, and the facto...

The population of barnacle geese wintering in Denmark has shown a steep increase during the last decades, prompting a parallel escalation of agricultural conflicts. In Denmark, economic compensation to farmers suffering goose damage to crops is not practiced, but despite that the barnacle goose is fully protected, landowners can obtain a permit to...

Abstract The population of barnacle geese wintering in Denmark has shown a steep increase during the last decades, prompting a parallel escalation of agricultural conflicts. In Denmark, economic compensation to farmers suffering goose damage to crops is not practiced, but despite that the barnacle goose is fully protected, landowners can obtain a p...

Most European goose populations have increased exponentially, and this has increasingly brought them into conflict with human activities. To manage this conflict, we used multi-criteria decision analysis to help set population targets for a super-abundant population of greylag geese ( Anser anser ). We relied on expert elicitation to assess the con...

The AEWA European Goose Management Platf orm provides a mechanism for sustainable use and management of goose populations in Europe, based on various monitoring schemes. Most European countries are involved, especially in the northern and western parts. Updated population status reports are published annually and are used for immediate decision-mak...

Global climate change is driving species' distributions towards the poles and mountain tops during both non‐breeding and breeding seasons, leading to changes in the composition of natural communities. However, the degree of season differences in climate‐driven community shifts has not been thoroughly investigated at large spatial scales. We compare...

The greatest loss of biodiversity in the EU has occurred on agricultural land. The Common Starling (Sturnus vulgaris) is one of the many numerous and widespread European farmland breeding bird species showing major population declines linked to European agricultural intensification. Here we present results based on monitoring data collected since 1...

The greatest loss of biodiversity in the EU has occurred on agricultural land. The Common Starling (Sturnus vulgaris) is one of the many numerous and widespread European farmland breeding bird species showing major population declines linked to European agricultural intensification. Here we present results based on monitoring data collected since 1...

The aim and scope of the third Danish bird atlas is to estimate species distribution, density and abundance of common breeding and wintering birds, and assess population estimates for approximately 45 breeding and 30 wintering species. Furthermore, for 18 less common species, to obtain improved population counts. Through the years 2014-2018, 398,38...

Evidence of declines in insect populations has recently received considerable scientific and societal attention. However, the lack of long‐term insect monitoring makes it difficult to assess whether declines are geographically widespread. By contrast, bird populations are well monitored and often used as indicators of environmental change. We compa...

Citizen science is an indispensable means of obtaining the information necessary for maintaining bird monitoring programmes. The aim of this paper is to inspire creative thought and discussion among the ornithological community, scientists and decision makers in Denmark to improve the quality and extent of breeding bird monitoring. We review the st...

The effects of different environmental drivers on the changes in species’ population abundances can be difficult to disentangle as they often act simultaneously. Researchers have built statistical models that include environmental variables (such as annual temperature) or species attributes (such as a species’ temperature preference), which are ass...

The abundant and widespread Common Starling (Sturnus vulgaris) is currently declining across much of Europe due to landscape changes caused by agricultural intensification. The proximate mechanisms causing adverse effects to breeding Starlings are unclear, hampering our ability to implement cost-efficient agri-environmental schemes to restore popul...

Maps of the ringing site and the surrounding fields indicating the different crops and the foraging positions of 17 different tagged Starlings tracked during May 2015 and 2016. (PDF)

Information about the 17 loggers/Starlings showing year, logger, sex, start and length of each logger period, number of foraging positions and registered mean and max distance. (DOCX)

Data set used for analyses of use and selection of habitat categories of GPS-tagged Starlings. (XLSX)

Long-distance migrants are particularly recognized for the distances covered on migration, yet little is known about the distances they cover during the rest of the year. GPS-tracks of 29 Montagu's harriers from breeding areas in France, The Netherlands and Denmark showed that harriers fly between 35 653 and 88 049 km yr 21 , of which on average on...

Over-summering within or near the African wintering range by immature, non-breeding individuals occurs regularly in several species of long-distance migratory raptors, yet the extent of over-summering in Africa by adult birds remains unclear. In this study, we describe a case of an adult Montagu’s Harrier over-summering in Africa, as revealed by GP...

The 2020 EU biodiversity strategy aims to halt the loss of biodiversity and ecosystem services, but this requires effective monitoring to determine whether these aims are achieved. Common bird monitoring continuously assesses changes in the avian community, providing a powerful tool for monitoring temporal changes in the abundance and distribution...

Grundlæggende viden om arters udbredelse og populationsudvikling er nødvendig for forvaltning, lovgivning og beskyttelse af arter og habitater. Indsamling af kvantitative og kvalitative landsdækkende data om arter er samtidig både tids- og ressourcekrævende, når målet er, at resultaterne heraf skal være med en sådan opløsning, at de kan bruges ti...

The Danish breeding Starling population declined at a mean annual rate of −2.24%±0.39 (95% CI) during 1976–2015 (a 60% decline overall). Starling density in the mid-1990s was positively correlated with dairy cattle abundance in 13 local areas. Regional declines in Starling abundance between 2001 and 2014 were positively correlated with loss of high...

Aim Changes in climate and land use practices have been found to affect animal populations in different parts of the world. These studies have typically been conducted during the breeding season, whereas the non‐breeding season (hereafter ‘winter’) has received much less attention. Changes in regional winter abundances could be caused by changes in...

Aim Long‐term monitoring of biodiversity is necessary to identify population declines and to develop conservation management. Because long‐term monitoring is labour‐intensive, resources to implement robust monitoring programmes are lacking in many countries. The increasing availability of citizen science data in online public databases can potentia...

Birds populations allied in abundance Changes in climate can cause populations of species to decline, to increase, or to remain steady. Stephens et al. looked across species of common birds in Europe and the United States. Despite many differences between the two regions, expectations about how a species might respond to climate change did predict...

BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological,...

Analysis of data relating to calling Spotted Crakes Porzana porzana, input to the Danish Citizen Science portal DOFbasen, suggested that on controlling for observer effort, national numbers reported annually have remained reasonably stable during 1981-2013, but with large influxes in a very few years, mostly due to large arrivals late in the season...

Evidence-based conservation of Montagu's Harrier (Circus pygargus) in Denmark The Montagu's Harrier is a rare and threatened breeding bird in Denmark, currently with only 20-25 breeding pairs. Most of the nests are placed in farmland crops and are therefore at risk of being destroyed during harvest. Adults and nestlings might also perish this way....

It has recently been stated that the global goal of halting the loss of biodiversity by 2010 has not been met highlighting the urgent need to monitor trends in biodiversity. Our study suggests that existing indicators of bird biodiversity in Denmark are inaccurate and we present a new objective method for accurately assessing trends in specific hab...

Capsule Long-distance migrant birds show less favourable trends than sedentary/short-distance species. Aims To use breeding bird surveys to contrast population trends amongst common species according to their migration pattern. Methods Changes in abundance of 62 Danish breeding sedentary, short-distance (Europe/North Africa) or long-distance (trans...

Aims To use breeding bird surveys to contrast population trends amongst common species according to their migration pattern. Methods Changes in abundance of 62 Danish breeding sedentary, short-distance (Europe/North Africa) or long-distance (trans-Saharan) migrants were described by fitting log linear regression models to point-count census data ga...

Corn buntings Miliaria calandra were abundant throughout arable agricultural landscapes in Europe, but have catastrophically declined since the mid 1970s with changes in farming practice and now give serious conservation cause for concern. Corn buntings declined in Denmark during 1976–1993, but (almost unique in Europe) have since increased (by up...

Extensive ringing data from Falsterbo, South Sweden, were used to analyse numbers, migration patterns and recoveries in the blue tit Parus caeruleus during 15 yr (1980-94). The ringing totals as well as the totals from the migration counts at Falsterbo showed an overall increase of blue tits during this period. This corresponded with the trends fro...