Talvituvate lindude rahvusvaheline lennuloendus

Enamus Kirde-Euroopas sh Eesti merealal esinevatest linnuliikidest on rändelised, seetõttu mõjutavad liikide levikut ja arvukust oluliselt tingimused väljaspool Eestit. Arvukuse muutuste põhjuseks võivad olla liikide pesitsemistingimused Siberi tundraaladel, mõjud rändepeatuspaikades või talvitusaladel Lääne- Euroopas või Aafrikas. Eestis talvel koonduvate liikide arvukust mõjutab talvine kliima – alates 1990.a. on sagenenud nn pehmed talved, mistõttu üha enam linde jääb Eesti vetesse talvituma, selle asemel, et rännata Läänemere lõunaossa või Põhjamerre. Samuti kahandavad lindude talvist arvukust massiline suremus pakase või haiguste tõttu. Looduslikuks „müraks“ on ka merelindudel esinev nii mereliste kui ka maismaa elupaikade rööbiti kasutamine aastatsükli või pesitsusperioodi vältel (Eestis pesitsevatest liikidest n. merikotkas, hallhani, laululuik), mistõttu survetegurite allikat asurkonnale pole alati võimalik tuvastada. Seega on linnuasurkondade puhul tulemuslikum regionaalsete ja globaalsete seisundi ja staatuse hinnangute perioodiline korraldamine. Läänemere piirkonnas on talvituvate merelindude asurkondade seisundi hindamist läbi viidud kolmel korral. Esimesel korral, 1992-1993 viidi läbi Läänemereülesed laeva- ning lennuloendused, mis andsid esmakordselt tervikpildi talvel toimuvast (Durinck et al., 1994). Miinuseks oli see et välitööd kestsid kaks talve (joonis 1). Aastal 2011 ilmus teine Läänemere kokkuvõte, kus kasutati suures osas kesktalvise veelinnuloenduse materjale (Skov et al., 2011) (joonis 1,2.). Koordineerituim loendus Läänemerel viidi läbi 2016.a. Projektist võtsid osa kõik Läänemereäärsed maad, va. Venemaa. Valdavalt kasutati loenduseks lennukeid, laevaloendused toimusid vaid osaliselt Saksamaal ning täies mahus Poolas ja Leedus (joonis 3).Töö rahastamine toimub perioodi 2014–2020 struktuuritoetuse prioriteetse suuna nr 8 „Roheline infrastruktuur ja hädaolukordadeks valmisoleku suurendamine“ meetme tegevuse 8.1.6 “Kaitstavate liikide ja elupaikade inventuurid ja andmehõive” eelarvest

Talvitavate veelindudel rahvusvaheline lennuloendus Eesti rannikumerel 2021

Enamus Kirde-Euroopas sh Eesti merealal esinevatest linnuliikidest on rändelised, seetõttu mõjutavad liikide levikut ja arvukust oluliselt tingimused väljaspool Eestit. Arvukuse muutuste põhjuseks võivad olla liikide pesitsemistingimused Siberi tundraaladel, mõjud rändepeatuspaikades või talvitusaladel Lääne- Euroopas või Aafrikas. Eestis talvel koonduvate liikide arvukust mõjutab talvine kliima – alates 1990.a. on sagenenud nn pehmed talved, mistõttu üha enam linde jääb Eesti vetesse talvituma, selle asemel, et rännata Läänemere lõunaossa või Põhjamerre. Samuti kahandavad lindude talvist arvukust massiline suremus pakase või haiguste tõttu. Looduslikuks „müraks“ on ka merelindudel esinev nii mereliste kui ka maismaa elupaikade rööbiti kasutamine aastatsükli või pesitsusperioodi vältel (Eestis pesitsevatest liikidest n. merikotkas, hallhani, laululuik), mistõttu survetegurite allikat asurkonnale pole alati võimalik tuvastada. Seega on linnuasurkondade puhul tulemuslikum regionaalsete ja globaalsete seisundi ja staatuse hinnangute perioodiline korraldamine. Läänemere piirkonnas on talvituvate merelindude asurkondade seisundi hindamist läbi viidud kolmel korral. Esimesel korral, 1992-1993 viidi läbi Läänemereülesed laeva- ning lennuloendused, mis andsid esmakordselt tervikpildi talvel toimuvast (Durinck et al., 1994). Miinuseks oli see et välitööd kestsid kaks talve (joonis 1). Aastal 2011 ilmus teine Läänemere kokkuvõte, kus kasutati suures osas kesktalvise veelinnuloenduse materjale (Skov et al., 2000, Skov et al., 2011) (joonis 1, 2.). Järgmine koordineerituim loendus Läänemerel viidi läbi 2016.a. Projektist võtsid osa kõik Läänemereäärsed maad, va. Venemaa. Valdavalt kasutati loenduseks lennukeid, laevaloendused toimusid vaid osaliselt Saksamaal ning täies mahus Poolas ja Leedus (joonis 3). Viimane Läänemereülene talvitavate veelindude loendus viidi läbi 2020.a. talvel, kus osalesid kõik Läänemeremaad, välja arvatud Läti ja Eesti. Selle põhjuseks oli lennuloendusteks sobiva ilma puudumine, mistõttu viidi loendused läbi 2021.a. jaanuaris ja veebruaris.Keskkonnainvesteeringute Kesku

Protected area characteristics that help waterbirds respond to climate warming

Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation-relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) changed in response to increases in temperature over 25 years in 26 European countries. We measured community reshuffling based on abundance time series collected under the International Waterbird Census relative to N2K sites' conservation targets, funding, designation period, and management plan status. Waterbird community composition in sites explicitly designated to protect them and with management plans changed more quickly in response to climate warming than in other N2K sites. Temporal community changes were not affected by the designation period despite greater exposure to temperature increase inside late-designated N2K sites. Sites funded under the LIFE program had lower climate-driven community changes than sites that did not received LIFE funding. Our findings imply that efficient conservation policy that helps waterbird communities respond to climate warming is associated with sites specifically managed for waterbirds

Factors affecting the flight altitude of migrating waterbirds in Western Estonia

The article examines the effects of weather, temporal factors and distance to coast on the flight altitude of migrating waterbirds in Western Estonia. A laser range finder and marine surveillance radar were used to measure flight altitudes. Visible effects on avian flight altitude due to weather conditions such as wind conditions, visibility and cloud cover were identified. Tailwinds were found to be associated with elevated flight altitude, while reductions in altitude were reportedly due to high wind speed. It was noted that behavioural and physical adaptations to the environment also helped in specific flight altitude selection

Coastal grassland wader abundance in relation to breeding habitat characteristics in Matsalu Bay, Estonia

Wader populations have been declining worldwide, providing a fundamental question as to which environmental factors limit population growth. Many studies have focused on the effects of habitat change on wader populations as a result of climate change, agricul-tural intensification or abandonment of arable land. However, there are few studies inves-tigating the relationship between wader distribution/abundance and prey abundance. This study focused on the relationship between breeding wader abundance, habitat character-istics and prey abundance on different types of coastal and floodplain grasslands. The study was carried out in the Matsalu Bay area, Western Estonia between 2001 and 2005. Results showed that most wader species were strongly related to habitat flooding type but not to plant species richness or evenness or mean vegetation coverage. Abundance of epigeic earthworms at a site was positively correlated with wader species diversity and abundance, as well as at the individual species level for abundance of Northern Lapwing Vanellus vanellus, Black-tailed Godwit Limosa limosa and Redshank Tringa totanus

Long-term population trends and shifts in distribution of Bewick's swans cygnus columbianus bewickii wintering in northwest Europe

Coordinated international censuses of the Northwest European Bewick's Swan Cygnus columbianus bewickii population have been undertaken across the swans' wintering range at c. 5-year intervals since 1984. During the early years of the study, numbers increased steadily to a peak of 29,780 individuals in January 1995, but then declined by 39.4% to 18,057 swans counted in January 2010 before showing a partial recovery to 20,149 recorded in January 2015. Changes in distribution across the wintering range were also recorded; a higher proportion of the population now remains in more easterly countries (notably Germany) in mid-winter, whilst only a handful of birds migrated to Ireland (at the western edge of the range) during the 2000s compared to >1,000 wintering there at the start of the study. Variation between censuses in the proportion of swans recorded in different parts of the range were attributable to weather conditions, with more swans wintering further north in warmer years. The overall percentage of cygnets recorded in each of the census years ranged from 9.6% in 2010 to 13.2% in 2005, with no obvious consistency over time in the distribution of cygnets across the wintering range. There were however changes between 1990 and 2015 in the swans' use of feeding habitats, with a decline in the proportion of birds on pasture and a corresponding increase in those on arable land. Decreases in the total population size and changes in distribution in the 21st century have implications for the designation and resultant protection of sites of international importance for the species

Protected area characteristics that help waterbirds respond to climate warming

Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation-relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) changed in response to increases in temperature over 25 years in 26 European countries. We measured community reshuffling based on abundance time series collected under the International Waterbird Census relative to N2K sites’ conservation targets, funding, designation period, and management plan status. Waterbird community composition in sites explicitly designated to protect them and with management plans changed more quickly in response to climate warming than in other N2K sites. Temporal community changes were not affected by the designation period despite greater exposure to temperature increase inside late-designated N2K sites. Sites funded under the LIFE program had lower climate-driven community changes than sites that did not received LIFE funding. Our findings imply that efficient conservation policy that helps waterbird communities respond to climate warming is associated with sites specifically managed for waterbirds

Protected area characteristics that help waterbirds respond to climate warming

Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation-relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) changed in response to increases in temperature over 25 years in 26 European countries. We measured community reshuffling based on abundance time series collected under the International Waterbird Census relative to N2K sites’ conservation targets, funding, designation period, and management plan status. Waterbird community composition in sites explicitly designated to protect them and with management plans changed more quickly in response to climate warming than in other N2K sites. Temporal community changes were not affected by the designation period despite greater exposure to temperature increase inside late-designated N2K sites. Sites funded under the LIFE program had lower climate-driven community changes than sites that did not received LIFE funding. Our findings imply that efficient conservation policy that helps waterbird communities respond to climate warming is associated with sites specifically managed for waterbirds