Literature type: Scientific
Journal: Biological Conservation
Full reference: Marolla, F., Aarvak, T. Hamel, S., Ims, R.A., Kéry, M., Mellard, J.P., Nater, C.R., Schaub, M., Vougioukalou, M., Yoccoz, N.G. & Øien, I.J. 2023. Life-cycle analysis of an endangered migratory goose to assess the impact of conservation actions on population recovery. Biological Conservation 281. https://www.dx.doi.org/10.1016/j.biocon.2023.110028
Evaluating the effectiveness of conservation actions is challenging for migratory species because a population can be impacted anywhere along its route. Conservation actions for the critically endangered Fennoscandian lesser white-fronted goose population include culling of red foxes in the breeding area and habitat improvements and reduction of illegal hunting in the non-breeding areas. One goal of the predator control strategy is to prevent adult birds from using an autumn migration route through western Asia, where mortality is believed to be higher than on the migration route through eastern Europe. We used 23 years of count data obtained at different staging areas to parameterize a seasonal state-space model describing the full-annual cycle dynamics of this population and evaluate whether the recent population recovery was linked to these conservation efforts. The results did not provide evidence that predator control influenced population recovery, as survival on the European route did not appear higher than on the allegedly riskier Asian route. However, adult survival at staging areas on both routes and at wintering sites may have improved in the last decade, suggesting a positive effect of the other conservation initiatives. These results emphasize the importance of including the non-breeding dynamics in population assessments of migratory species and highlight the challenge of evaluating the efficacy of separate conservation actions when a proper experimental design is unfeasible. Our study, which is a unique case of cross-national, coordinated conservation efforts, exemplifies how to model complex population dynamics to assess the influence of costly conservation initiatives.
Literature type: Thesis
Full reference: Markkola, J. 2022. Ecology and conservation of the Lesser White-fronted Goose Anser erythropus. , PhD thesis, Acta Universitatis Ouluensis. A Scientiae Rerum Naturalium 770. Faculty of Science, University of Oulu, Finland.
I studied the rare and threatened lesser white-fronted goose (Anser erythropus), abbreviated LWfG in 1989–1996 in sub-arctic Finnish Lapland (I). The studied subpopulation consisted of 2–15 breeding pairs annually. A total of 30 broods were observed with an average of 2.9 goslings per brood. The 1st year survival of tagged 10 geese was low. Satellite locations, recoveries and resightings were received from NW Russia, Kazakhstan and the Azov Sea area. Cold spells had a negative, and the sum of effective temperatures by 5 July a positive influence on reproduction. Habitat selection (II) was studied in the same area. LWfG preferred the vicinity of water, flat close-range landscape, low forest height and intermediate relative altitudes. LWfG aggregated in the vicinity of conspecifics within the preferred habitats. The averaged RSF model assigned observation and random points correctly with 83.4% success. Locations of historical observations of LWfG matched the predicted distribution of breeding sites. (III) Spring migration patterns on the Bothnian Bay coast of LWfG were examined in 1907–1916 and 1949–2014 and the taiga bean goose (Anser fabalis fabalis) in 1975–2014. Arrival of the short-distance migrant A. fabalis advanced more and earlier than the long-distance migrant A. erythropus, 10.9 days since late 1980’s vs. 5.3 days since the beginning of the 2000’s. In the LWfG, the best model for explaining variation in timing included global and local temperatures, in A. fabalis global and local temperatures and winter NAO. Increasing global temperatures seem to explain trends in both. In the spring staging places of the Bothnian Bay almost all dietary items of the LWfG were Monocotyledons, mostly grasses growing in extensive sea-shore meadows (IV). Only Phragmites, Festuca and possibly Triglochin palustris were preferred. Lesser White-fronts preferred extensive natural meadows. Mowing and grazing benefit the restoration of habitats. Genetic structuring of the LWfG was examined in its whole distribution area from Fennoscandia to East Asia (V). A fragment of the control region of mtDNA was sequenced from 110 individuals. 15 mtDNA haplotypes were assigned to two mtDNA lineages. Molecular variance showed significant structuring among populations: the main western in north-western Russia – Central Siberia, the main eastern in East Asia and the Nordic one, which earns a status as an independent management unit.
Literature type: Thesis
Full reference: Marolla, F. 2020. Understanding and forecasting population dynamics in changing arctic ecosystems. A holistic approach to study the effects of environmental changes on arctic populations of management concern. , Doctoral thesis, Department of Arctic and Marine Biology, The Arctic University of Norway.
Literature type: Scientific
Volume: 155 , Pages: 576–592.
Full reference: Wang, W., Fox, A.D., Cong, P. & Cao, L. 2013. Food constraints explain the restricted distribution of wintering Lesser White-fronted Geese Anser erythropus in China. Ibis 155: 576–592. https://www.dx.doi.org/10.1111/ibi.12039
More than 90% of the Lesser White-fronted Geese Anser erythropus in the Eastern Palearctic flyway population winter at East Dongting Lake, China. To explain this restricted distribution and to understand better the winter feeding ecology and habitat requirements of this poorly known species, we assessed their food availability, diet and energy budgets at this site through two winters. Lesser White-fronted Geese maintained a positive energy budget when feeding on above-ground green production of Eleocharis and Alopecurus in recessional grasslands in autumn and spring to accumulate fat stores. Such food was severely depleted by late November and showed no growth in mid-winter. Geese fed on more extensive old-growth Carex sedge meadows in mid-winter where they were in energy deficit and depleted endogenous fat stores. Geese failed to accumulate autumn fat stores in one year when high water levels prevented the Geese from using recessional grassland feeding areas. Fat stores remained lower throughout that winter and Geese left for breeding areas later in spring than in the previous year, perhaps reflecting the need to gain threshold fat stores for migration. Sedge meadows are widespread at other Yangtze River floodplain wetlands, but recessional grasslands are rare and perhaps restricted to parts of East Dongting Lake, which would explain the highly localized distribution of Lesser White-fronted Geese in China and their heavy use of these habitats at this site. Sympathetic management of water tables is essential to maintain the recessional grasslands in the best condition for Geese. Regular depletion of fat stores whilst grazing sedge meadows in mid-winter also underlines the need to protect the species from unnecessary anthropogenic disturbances that enhance energy expenditure. The specialized diet of the Lesser White-fronted Goose may explain its highly restricted winter distribution and global rarity.
Literature type: Action Plan
Language: Hungarian (In Hungarian with English summary)Download:
Full reference: Bogyó, D., Ecsedi, Z., Tar, J. & Zalai, T. 2013. A kis lilik (Anser erythropus) magyarorszagi fajmegörzesi terve. [Hungarian National Action Plan for Lesser White-fronted Goose (Anser erythropus).] , Ministry of Rural Development, State Secretariat for Environmental Affairs. 93pp.
Literature type: Rep.article
Full reference: Toming, M. & Tolvanen, P. 2009. Restoration and management of the Lesser White-fronted Goose habitats in Matsalu, Estonia. , In: Tolvanen, P., Øien, I.J. & Ruokolainen, K. (eds.). Conservation of Lesser White-fronted Goose on the European migration route. Final report of the EU LIFE-Nature project 2005–2009. WWF Finland Report 27 & NOF Rapportserie Report No 1-2009: pp. 22-23.
Literature type: Rep.article
Full reference: Øien, I.J. & Aarvak, T. 2009. The eff ect of Red Fox culling in the core breeding area for Fennoscandian Lesser White-fronted Geese in 2008. , In: Tolvanen, P., Øien, I.J. & Ruokolainen, K. (eds.). Conservation of Lesser White-fronted Goose on the European migration route. Final report of the EU LIFE-Nature project 2005–2009. WWF Finland Report 27 & NOF Rapportserie Report No 1-2009: pp. 81-82.
Literature type: Thesis
Full reference: Niemelä, M. 2009. Biotic interactions and vegetation management on coastal meadows. , Acta Universitatis Ouluensis. A Scientiae Rerum Naturalium 360. Faculty of Science, University of Oulu, Finland.
Conservation of rare habitats and species are central elements in the management of semi-natural grasslands of high biodiversity. Understanding the impacts of various abiotic and biotic interactions and management methods on threatened species is fundamental to their conservation. In the present study, effects of competition, plant parasitism, grazing and mowing were studied at the community level in Bothnian Bay coastal meadows and in greenhouse. This was the first time when the impacts of various biotic interactions on the critically endangered creeping alkali grass (Puccinellia phryganodes) have been explored in detail in one of its rare occurrences in the boreal vegetation zone in Europe. In addition, questions related to ecological and economical sustainability of cattle grazing on coastal meadows were examined. Puccinellia phryganodes was found to suffer severely from competition with taller graminoids. Simulated and actual grazing by greylag goose, Anser anser, as well as infection by a hemiparasitic plant, Odontites litoralis, were found to indirectly benefit P. phryganodes by decreasing the competitive advantage of its competitors. In spite of the relatively intensive grazing by greylag goose in the field, P. phryganodes experienced a drastic decrease during four years in the grazed experimental quadrats and simultaneously the proportion of the taller graminoids increased substantially. Primary succession of coastal meadow vegetation was found to progress rapidly and continuous formation of suitable open habitats is therefore crucial for the subordinate species. Mowing was found to be an effective management method for some threatened plant species in coastal meadows, but not for P. phryganodes, which would probably benefit more, for example, from livestock grazing. Both lightly and rather intensively managed large open meadows could provide optimal habitats for the critically endangered lesser white fronted goose (Anser erythropus) as well as for the greylag goose. The relatively low and variable yield of the coastal meadow vegetation compared to that of cultivated grasslands sets limits how management by cattle grazing can be implemented. Key factors for both the biodiversity management and livestock production in coastal meadows are timing of the grazing season, intensity of grazing and selection of suitable types of animals.
Literature type: Report
Language: Greek (In Greek with English summary.)Download:
Full reference: Athanasiadis, A., Rigas, Y., Arapis, T. 2005. Restoration and conservation management of Drana lagoon in Evros delta. Final report LIFE 00NAT/GR/7198. [Restoration and conservation management of Drana lagoon in Evros delta. Final report LIFE 00NAT/GR/7198.]
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