130 research outputs found
Environmental factors affecting numbers of pink-footed geese Anser brachyrhynchus utilising an autumn stopover site
NorwayFor
huntable waterbird species, the autumn migration strategy may be important for their fitness, as their behaviour and
environmental factors may influence their exposure to hunting mortality. Hunting activity may also reduce the access to
food resources which may be limited in the wintering areas, thereby affecting winter survival. In this study we assessed the
possible influence of food resources, weather conditions, inter-specific competition and hunting intensity (as a measure
of possible disturbance) on abundance and distribution of pink-footed geese Anser brachyrhynchus at their main autumn
stopover site in Norway. The results show that food resources in term of spilt cereal grain were abundant, even by the time
the geese had moved on. Snow cover did not limit the food availability during the main migratory period. Inter-specific
competition with greylag geese Anser anser reduced food supplies locally and appeared to be increasing. Goose hunting
intensity varied among sites and our data indicate a negative relationship between hunting intensity and the rate at which
geese consumed the food resources. Collectively, our results suggest that the majority of pink-footed geese leave the stopover
area earlier than they would otherwise, when hunting intensities are high. In the case of pink-footed geese, population
consequences of disturbance is not a concern at present; however, an international species management plan calls for 1)
keeping disturbance low in areas where geese do not cause conflicts with agriculture to prevent them being pushed to areas
with problems, and 2) increased harvest to reduce and stabilise the population size. Both objectives can be met by reducing
hunting disturbance in mid-Norway and it is recommended that a better local organisation of hunting is implemented
Stakeholder involvement in adaptive goose management; case studies and experiences from Norway
Two Svalbard-breeding goose populations, the pink-footed goose Anser brachyrhynchus and the barnacle goose Branta leucopsis, have, over the last decades, increased in numbers and expanded in distribution. At spring-staging sites in Norway, conflicts with agriculture are significant as the geese feed on cultivated fields, with negative consequences for the farmers. In the present paper we give an overview of relevant stakeholders in these goose-agriculture conflicts and share some of our experiences when involving stakeholders and users in a dynamic and adaptive process. The paper demonstrates how researchers can engage in the management process at different levels, in order to facilitate a process towards an adaptive co-management in an environment of conflicting interests. The framework described may be used for threatened bird species and situations where there are conflicts between wildlife stakeholders such as management agencies, conservation interests, hunting and agriculture.Two Svalbard-breeding goose populations, the pink-footed goose Anser brachyrhynchus and the barnacle goose Branta leucopsis, have, over the last decades, increased in numbers and expanded in distribution. At spring-staging sites in Norway, conflicts with agriculture are significant as the geese feed on cultivated fields, with negative consequences for the farmers. In the present paper we give an overview of relevant stakeholders in these goose-agriculture conflicts and share some of our experiences when involving stakeholders and users in a dynamic and adaptive process. The paper demonstrates how researchers can engage in the management process at different levels, in order to facilitate a process towards an adaptive co-management in an environment of conflicting interests. The framework described may be used for threatened bird species and situations where there are conflicts between wildlife stakeholders such as management agencies, conservation interests, hunting and agriculture
Selection of a diversionary field and other habitats by large grazing birds in a landscape managed for agriculture and wetland biodiversity
1. Several populations of cranes, geese, and swans are thriving and increasing in modern agricultural landscapes. Abundant populations are causing conservation conflicts, as they may affect agricultural production and biodiversity negatively. 2. Management strategies involving provisioning of attractive diversionary fields where birds are tolerated can be used to reduce negative impact to growing crops. To improve such strategies, knowledge of how the birds interact with the landscape and respond to current management interventions is key. 3. We used GPS locations from tagged common cranes (Grus grus) and greylag geese (Anser anser) to assess how they use and select differentially managed habitats, such as diversionary fields to decrease impact on agriculture and wetlands pro-tected for biodiversity conservation. 4. Our findings show a high probability of presence of common cranes and grey-lag geese in the protected area and in the diversionary field, but also on arable fields, potentially causing negative impact on agricultural production and wetland biodiversity. 5. We outline recommendations for how to improve the practice of diversionary fields and complementary management to reduce risk of negative impact of large grazing birds in landscapes tailored for both conservation and conventional agriculture. adaptive management, Anser anser, common crane, conservation conflict, diversionary field, greylag goose, Grus grus, protected area, resource selection function, supplemental feedingpublishedVersio
Population control by means of organised hunting effort : Experiences from a voluntary goose hunting arrangement
Implementing management objectives may be challenging when decisions are made at different scales than where they are supposed to be carried out. In this study we present a situation where local goose hunting arrangements respond to objectives in an international management plan for pink-footed geese (Anser brachyrhynchus) and a local wish to reduce goose numbers as means to reduce grazing damage on farmland. A unique ten-year dataset provides an evaluation of the efficiency of voluntary actions at a local scale for implementing a policy of population control of geese, and general lessons are drawn for collaboration and coproduction of knowledge for adaptive management. The study demonstrates how both the hunters and geese adapt in a situation where increasing the harvest of geese is the main objective. Introducing hunting-free days and safe foraging areas significantly increased goose numbers in the study area, with a corresponding increase in hunting success in terms of number of harvested geese. The geeseâs behavioural response to hunting also triggered the hunters to adapt accordingly by optimal timing and placement in the landscape. Based on the results of the present study we suggest a framework for local implementation of management actions. Bringing end-users on board, facilitates processes and strengthens the achievements, as they represent the actors where implementation occurs. Specifically, our findings demonstrate how optimal goose hunting can be practiced by the use of an adaptive framework with active stakeholder participation. Adaptive framework Geese Local engagement Management implementation Optimal hunting arrangements Recreational huntingpublishedVersio
Stakeholder involvement in adaptive goose management; case studies and experiences from Norway
Two Svalbard-breeding goose populations, the pink-footed goose Anser brachyrhynchus and the barnacle goose Branta leucopsis, have, over the last decades, increased in numbers and expanded in distribution. At spring-staging sites in Norway, conflicts with agriculture are significant as the geese feed on cultivated fields, with negative consequences for the farmers. In the present paper we give an overview of relevant stakeholders in these goose-agriculture conflicts and share some of our experiences when involving stakeholders and users in a dynamic and adaptive process. The paper demonstrates how researchers can engage in the management process at different levels, in order to facilitate a process towards an adaptive co-management in an environment of conflicting interests. The framework described may be used for threatened bird species and situations where there are conflicts between wildlife stakeholders such as management agencies, conservation interests, hunting and agriculture.Two Svalbard-breeding goose populations, the pink-footed goose Anser brachyrhynchus and the barnacle goose Branta leucopsis, have, over the last decades, increased in numbers and expanded in distribution. At spring-staging sites in Norway, conflicts with agriculture are significant as the geese feed on cultivated fields, with negative consequences for the farmers. In the present paper we give an overview of relevant stakeholders in these goose-agriculture conflicts and share some of our experiences when involving stakeholders and users in a dynamic and adaptive process. The paper demonstrates how researchers can engage in the management process at different levels, in order to facilitate a process towards an adaptive co-management in an environment of conflicting interests. The framework described may be used for threatened bird species and situations where there are conflicts between wildlife stakeholders such as management agencies, conservation interests, hunting and agriculture
Effekten av skadefelling av grÄgÄs (Anser anser) for grovfÎr-produksjonen pÄ et nordnorsk gÄrdsbruk
Beiteskader fra gÄs, her grÄgÄs (Anser anser), er et Þkende problem for smÄ, mellomstore og store Ärdsbruk flere steder i Norge. Beiteskadene har Þkt i takt med den Þkende bestanden av grÄgÄs de siste tiÄr, som kan skyldes en rekke faktorer, blant annet klimaendringer. Beiteskader fra gÄs kan deles inn i 1) tap av grovfÎr (gress), 2) tap av spirer og sÄkorn, 3) store mengder avfÞring som reduserer kvaliteten pÄ innhÞstet fÎr, 4) nedtrÄkking av gress/spirer og 5) spredning av frÞ fra uÞnskete planter og vekster. I dette prosjektet har vi kartlagt omfanget av beiteskader pÄ grovfÎrproduksjon pÄ MusvÊr og estimert det Þkonomiske tapet gÄrdsdriften pÄfÞres. MusvÊr er en Þygruppe som ligger ytterst mot havet, vest for KvalÞya i Troms. GÄrdsdriften pÄ MusvÊr har i de siste Ärene blitt mer pÄvirket av gÄsebeiting. Som et avbÞtende tiltak mot beiteskader har prosjektet sett pÄ effekten av skadefelling av grÄgÄs, gjennomfÞrt etter en detaljert plan. Vi Þnsket Ä estimere antallet grÄgÄs som minimum mÄ felles for Ä oppnÄ en avbÞtende effekt. Prosjektet konkluderer med at grÄgÄsa pÄ MusvÊr kan spise opp mot halvparten av gresset pÄ et jorde og legge igjen betydelig mengder med ekskrementer om gjessene tillates Ä beite fritt. Et testforsÞk viste at ekskrementer fra grÄgÄs kan ligge uberÞrt pÄ et jorde i opptil 2 mÄneder og vil derfor kunne komme med i bÄde fÞrste og andre slÄtt. Tapet av grovfÎr pÄ det hardest beitede jordet utgjorde ca. NOK 30 000 estimert fra fÞrste og andre slÄtt tilsammen, beregnet nÄr det mÄ erstattes med innkjÞp av fullgodt erstatningsfÎr. Siden dette jordet var sÄ tilgriset av ekskrementer fra grÄgÄs at bÞndene ikke vil hÞste det som fÎr til husdyra sine, og jordet ansees som tapt, er det reelle tapet betydelig hÞyere. Uten skadefelling pÄ nÊrliggende arealer vil antall gjess som beitet pÄ dette arealet antakelig vÊrt stÞrre og tapene enda stÞrre.....publishedVersio
Young birds switch but old birds lead : how barnacle geese adjust migratory habits to environmental change
This research was funded by a grant from the Netherlands Organization for Scientific Research awarded to TO (ref 019.172EN.011).Long-distance migratory animals must contend with global climate change, but they differ greatly in whether and how they adjust. Species that socially learn their migration routes may have an advantage in this process compared to other species, as learned changes that are passed on to the next generation can speed up adjustment. However, evidence from the wild that social learning helps migrants adjust to environmental change is absent. Here, we study the behavioral processes by which barnacle geese (Branta leucopsis) adjust spring-staging site choice along the Norwegian coast, which appears to be a response to climate change and population growth. We compared individual-based models to an empirical description of geese colonizing a new staging site in the 1990s. The data included 43 years of estimated annual food conditions and goose numbers at both staging sites (1975â2017), as well as annual age-dependent switching events between the two staging sites from one year to the next (2000â2017). Using Approximate Bayesian Computation, we assessed the relative likelihood of models with different âdecision rulesâ, which define how individuals choose a staging site. In the best performing model, individuals traveled in groups and staging site choice was made by the oldest group member. Groups normally returned to the same staging site each year, but exhibited a higher probability of switching staging site in years with larger numbers of geese at the staging site. The decision did not depend on food availability in the current year. Switching rates between staging sites decreased with age, which was best explained by a higher probability of switching between groups by younger geese, and not by young geese being more responsive to current conditions. We found no evidence that the experienced foraging conditions in previous years affected staging site choice. Our findings demonstrate that copying behavior and density-dependent group decisions explain how geese adjust their migratory habits rapidly in response to changes in food availability and competition. We conclude that considering social processes can be essential to understand how migratory animals respond to changing environments.Publisher PDFPeer reviewe
Evaluering av norsk handlingsplan for dverggÄs
Kvalnes, T., Follestad, A., Krange, O. & Tombre, I.M. 2023. Evaluering av norsk handlingsplan for dverggÄs. NINA Rapport 2349. Norsk institutt for naturforskning.
DverggÄsa (Anser erythropus) er en kritisk truet art i Norge, den har gÄtt fra Ä vÊre en tallrik fugl pÄ 1940-tallet til Ä ha en hekkebestand som de siste tre generasjonene gjentatte ganger har vÊrt fÊrre enn 50 reproduserende individer. Den norske hekkebestanden utgjÞr nesten hele den gjenvÊrende fennoskandiske bestanden av arten. Dette har gjort at dverggÄsa har blitt utpekt som en prioritert art med egen forskrift. BirdLife Norge (tidligere Norsk Ornitologisk Forening) har siden 1985 gjennomfÞrt Ärlige prosjekter i Finnmark, for Ä kartlegge og overvÄke bestanden. Gjennom blant annet merking med halsringer, fotringer og GPS-loggere har de kartlagt trekkrutene fra Norge til overvintringsomrÄdene i Hellas. NINA har pÄ oppdrag fra MiljÞdirektoratet foretatt en samlet evaluering av aktivitetene i den norske handlingsplanen for dverggÄs som ble publisert i 2009.
MÄlene med evalueringen var 1) Ä evaluere mÄloppnÄelse i forhold til handlingsplanen, 2) Ä evaluere hvorvidt kunnskap fra overvÄkningen blir tilrettelagt og formidlet for videre bruk, 3) Ä evaluere organisering og finansiering av tiltak og 4) Ä gi innspill til videre kunnskapsinnhenting og tiltak i det framtidige arbeidet. Evalueringen er basert pÄ en gjennomgang av relevante publiserte resultater, slik som rapporter fra BirdLife Norge og vitenskapelige artikler, og annen informasjon som er laget i tilknytning til prosjektet. Dette for Ä fÄ en oversikt over nÄvÊrende kunnskap om bestanden. Vi har intervjuet informanter som representerer en rekke interessegrupper og brukere av informasjon fra arbeidet med dverggÄsa. I tillegg har vi, ved bruk av den sÄkalte rÞd til grÞnn metoden, vurdert behovet for kunnskapsinnhenting og tiltak pÄ veien videre.
MÄlene i handlingsplanen var 1) Ä stanse den pÄgÄende bestandsnedgangen innen 2015 og 2) Þke den fennoskandiske bestanden til 1000 individer pÄ lengre sikt. MÄl nummer to har ikke blitt oppnÄdd enda. Bestandsnedgangen er imidlertid stanset og bestanden har utvist en svak vekst, slik at det fÞrste mÄlet dermed er nÄdd. Dette vurderes i stor grad som en effekt av de samlede tiltakene som er igangsatt for Ä bevare arten. En revidering av handlingsplanen anbefales. Nye bestandsmÄl bÞr defineres som steg pÄ veien mot Ä sikre en levedyktig bestand. Dette kan operasjonaliseres ved Ä benytte rÞdlistekriteriene til Ä definere mÄl og informere valg av tiltak.
Tiltakene som er igangsatt har hatt som formĂ„l Ă„ redusere voksendĂždelighet og Ăžke ungeproduksjonen. Det har vĂŠrt innfĂžrt ferdselsforbud i viktige rasteomrĂ„der, som pĂ„ Valdakmyra i Porsanger kommune og RĂžrholmen i Alta kommune. Ă
rlig uttak av rÞdrev (Vulpes vulpes) har vÊrt gjennomfÞrt i og rundt hekkeomrÄdet. Det er innfÞrt jaktforbud pÄ grÄgÄs (Anser anser) i store deler av Finnmark for Ä unngÄ at dverggjess blir felt ved en feiltakelse. Utstrakt internasjonalt samarbeid med Finland, Russland og andre land har vÊrt viktig for Ä overvÄke, redusere ulovlig jakt og sikre viktige funksjonsomrÄder langs trekkrutene og i vinteromrÄdene.
Tiltakene har generelt god stÞtte blant informantene. De uttrykker at folk er opptatt av at en skal ta vare pÄ dverggÄsa. Personer i forvaltningen og museumsansatte benytter i stor grad kunnskapen som genereres av overvÄkingen og ulike forskningsprosjekter. Det er imidlertid en mangel pÄ kunnskap om arbeidet med dverggÄsa blant andre folk som bruker funksjonsomrÄdene og vi har observert et Þnske om at kunnskapen i stÞrre grad formidles. Det er informanter som forteller at flere interessenter ikke er enige i jaktforbudet, sÊrlig gjelder det de etablerte grensene for hvor jaktforbudet skal gjelde. Det er ogsÄ en misnÞye blant noen interessenter som uttrykker at jegerstanden undervurderes nÄr forvaltningen tar som utgangspunkt at de ikke kan skille dverggÄs fra grÄgÄs under jakten. Her anbefales det at forvaltningen gÄr i dialog med interessegrupper (bÞnder og jegere) for Ä se om det kan vÊre mulig Ä gjÞre tilpasninger som mÞter deres behov eller sikrer bedre informasjonsflyt og kommunikasjon samtidig som en forhindrer Þkt risiko for dverggÄsa. En diskusjon om justering av grensene for jaktforbudet bÞr vÊre en del av en slik dialog.
VÄr evaluering tilsier at mye av arbeidet som har vÊrt gjennomfÞrt gjennom mange Är har vÊrt viktig og bÞr fortsette i Ärene framover. Nye mÄl for arten og noen nye tiltak foreslÄs innfÞrt. Men dverggÄsa trekker over store avstander og mange land. Det er begrenset hva man kan oppnÄ med nasjonale tiltak i Norge. For Ä sikre stÞrst mulig sannsynlighet for Ä lykkes vil det vÊre ytterst viktig at det internasjonale arbeidet prioriteres i tiden framover. Evalueringen avdekker ogsÄ noen kunnskapsmangler som vil vÊre viktig Ä dekke slik at mer skreddersydde tiltak kan iverksettes og effekten av tiltak slik som rÞdrev uttak kan evalueres med mer detaljert kunnskap om predasjon. Internasjonalt er det spesielt viktig Ä sikre omrÄdene som benyttes under trekket og overvintringen mot ulovlig jakt, nedbygging og forstyrrelser. En fortsatt overvÄking pÄ overvintring, langs trekkruta og pÄ rasteplass i Norge er vesentlig for Ä kunne evaluere effekten av de ulike tiltakene. Basert pÄ informasjon fra intervjuene kan det ogsÄ vurderes om det skal etableres en form for ressursgruppe, der representanter for ulike involverte og berÞrte aktÞrer kan mÞtes. Et slikt fora vil Äpne for tettere dialog, erfaring- og kunnskapsutvikling og vil sannsynligvis ogsÄ bidra til en Þkt forstÄelse og aksept for ulike tiltak. Dermed kan det ogsÄ bidra til Ä nÄ forvaltningsmÄlene
Spatio-temporal patterns of crop damage caused by geese, swans and cranes-Implications for crop damage prevention
European populations of geese, swans and cranes have increased considerably since the 1970s raising conflicts between conservation and farming interests. Crop damage caused by geese, swans and cranes across the national scale needs a trans-boundary approach that captures the site-specific characteristics of crop damage at a more refined spatial scale, to deal with the high spatio-temporal variation inherent in the system and to avoid conflict displacement. In the present study we use long-term crop damage data (2000-2015) in Sweden to evaluate seasonal and annual patterns of crop damage. We show that crop damage increased over years but followed a fairly consistent seasonal pattern during the later parts of the study period. We show how these seasonal patterns differ across the country such that trans-boundary regions with similar patterns of crop damage, relating to different nuisance species and damaged crops, can be identified. These findings about spatio-temporal variation of damage can be used to find appropriate scales of management units (e.g. areas with similar conditions), and to adapt damage mitigation strategies to temporal and spatial-specific conditions, e.g. guidance of when and where certain crop may be suitable as sacrificial crops
The connectivity of spring stopover sites for geese heading to arctic breeding grounds
During the spring migration arctic-breeding geese pause in temperate and sub-arctic staging areas in order to deposit body reserves for breeding. Focusing on a single arctic stopover site in West-Spitsbergen, Svalbard, Norway (Varsol-bukta, 77 degrees 45'N, 14 degrees 24'E), behavioural strategies of Barnacle Geese Branta leucopsis were investigated and body condition and presence of individually marked birds recorded. Individuals using different staging areas earlier along the migration route (Helgeland and Vesteralen on the Norwegian mainland) and heading to different breeding colonies (the close-by Nordenskioldkysten, and the distant Kongsfjorden) were compared during springs 2003-05. Birds in Vesteralen left the staging area earlier than those in Helgeland, and arrived earlier in Varsolbukta as well. In Varsolbukta, females gained body condition at a similar rate regardless of their colony affiliation, whereas males from Nordenskioldkysten exhibited a smaller overall increase in condition compared to males from Kongsfjorden. The Kongsfjorden birds stayed for a shorter period (average 2.8 days) than those from Nordenskioldkysten (average 4.0 days). Nordenskioldkysten birds frequently left Varsolbukta for short periods presumably visiting the breeding area in order to optimise nest initiation with respect to prevailing snow conditions. The date of final departure was also correlated with nest initiation date at Nordenskioldkysten. No such relationship for the Kongsfjorden birds was found. We suggest that the geese adopt a 'hopping' strategy, using a network of stopover sites in Svalbard during spring with a last stopover at a buffer area in the proximity to the breeding area. For this vulnerable population it is important to identify the sites forming the links in this chain, and to establish their function and utilisation by geese during the vital prebreeding period
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