2015
Recent impact of DDT contamination on Black Stork eggs.
... Since the Black Stork has so far not been mentioned as a species affected by DDT we do not have information about its critical contamination effect levels. However, we also present data suggesting that DDT contamination might have affected Black Stork historically. Current data suggest that the reduction of eggshell thickness has not (yet) reached the levels described as critical for other affected species. However, we found a significant reduction of egg volumes,which in turn negatively affects hatching, as eggs below a threshold size fail to hatch. The ratio of small eggs versus normal eggs has increased by almost 10 % in recent years and is strikingly higher as compared to the pre-DDT period. There is also a significant correlation between eggs of reduced size and their respective DDE (1,1-bis(4-chlor-ophenyl)-2,2-dichloroethene) values.
- it could be argued that Black Storks become contaminated at stop-over locations during migration and/ or on the wintering grounds, most likely in East Africa
- some recent studies of distribution and longevity of DDT breakage products in the environment confirm that there might be local sources of DDT where it has not been applied for a very long time. This likelihood is strengthened by the ability of earthworms to bio-concentrate DDE from soil. Since juvenile Black Storks are regularly observed foraging on earthworms on fresh tilths before their first migration (our data), this may increase DDT/E concentration in juvenile birds and subsequently reduce their survival. Preliminary data from GPS-tracked juvenile storks which did not reach Africa imply that at least some non-African sources of DDT/E may be involved, but currently specific examinations of relevant areas are lacking. In future, the presence and possible impact of other contaminants, such as mercury, shall also be included in this ongoing study
Strazds, M. (2015). Recent impact of DDT contamination on Black Stork eggs. Journal of Ornithology, vol. 156, no. 1, pp. 187-198, 2015.
https://www.academia.edu/87806524/Recen ... =swp_share
Other treaths
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marika.solo
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Re: other treaths
2021
Assessing mercury pollution using black stork eggshells
- The black stork (Ciconia nigra) is predominantly a fish-eating bird and forages primarily in streams, fish ponds, and similar aquatic environments. They usually lay eggs with an interval of two days. The time frame between the arrival of females on the breeding grounds in Latvia and the laying of their first eggs varies from four to fourteen days (mean = 7). Consequently, the contaminants that are transferred from the mother to her eggs likely represent the contaminants that are present around the nesting site at the time of egg laying.
- ... our results indicate some, although not very high, presence of mercury in the surrounding environment (marika: Latvia)
- Possible local sources of mercury include anthropogenic activity such as peat extraction, forestry, cement production [23], illegal dumps and waste incineration, and historical presence of military forces from World War I and II. Possible natural sources of mercury include beaver ponds. (marika: local exposure by food)
- Another possible source of contamination is connected with female choice of wintering locations and/or staging grounds on the way back to the breeding grounds. In this case, mercury might be “imported” from another country. (marika: maternal transfer from wintering and stopover areas)
Abola, A., Strazds, M., Gavare, Z., & Veilande, R. (2021). ASSESSING MERCURY POLLUTION USING BLACK STORK EGGSHELLS. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, 1, 12-16. https://doi.org/10.17770/etr2021vol1.6528
https://journals.rta.lv/index.php/ETR/a ... /6528/5395
Assessing mercury pollution using black stork eggshells
- The black stork (Ciconia nigra) is predominantly a fish-eating bird and forages primarily in streams, fish ponds, and similar aquatic environments. They usually lay eggs with an interval of two days. The time frame between the arrival of females on the breeding grounds in Latvia and the laying of their first eggs varies from four to fourteen days (mean = 7). Consequently, the contaminants that are transferred from the mother to her eggs likely represent the contaminants that are present around the nesting site at the time of egg laying.
- ... our results indicate some, although not very high, presence of mercury in the surrounding environment (marika: Latvia)
- Possible local sources of mercury include anthropogenic activity such as peat extraction, forestry, cement production [23], illegal dumps and waste incineration, and historical presence of military forces from World War I and II. Possible natural sources of mercury include beaver ponds. (marika: local exposure by food)
- Another possible source of contamination is connected with female choice of wintering locations and/or staging grounds on the way back to the breeding grounds. In this case, mercury might be “imported” from another country. (marika: maternal transfer from wintering and stopover areas)
Abola, A., Strazds, M., Gavare, Z., & Veilande, R. (2021). ASSESSING MERCURY POLLUTION USING BLACK STORK EGGSHELLS. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, 1, 12-16. https://doi.org/10.17770/etr2021vol1.6528
https://journals.rta.lv/index.php/ETR/a ... /6528/5395
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marika.solo
- Site Admin
- Posts: 11216
- Joined: 29 Sep 2021, 09:38
Re: other treaths
2020
Wind energy development and wildlife conservation in Lithuania: A mapping tool for conflict assessment
The paper presents a mapping tool aiming to identify and minimise potential conflicts between onshore wind energy development and wildlife conservation in Lithuania. It merges current information on the distribution, conservation status and sensitivity of birds and bats to wind power with an integrated evaluation of wind resources (modelled wind speed), special planning status and technical perspectives of wind energy development.
- Breeding Black and White Storks, birds of prey and colonies of terns and gulls were considered to have the highest scores of sensitivity to the different effects of wind power among breeding bird species.
- Storks, Great White Egret, White-tailed Eagle, Lesser Spotted Eagle, Common Buzzard and Common Crane had the highest scores during the migration period.
- Wildlife in the western part of the country in the Curonian Lagoon region, as well as the municipalities of Varėna, Biržai and Anykščiai were characterized as highly sensitive to wind power.
- Considering the installed wind power (by MW), 27% of installed wind power in 2017 was located in the high conflict zones, 26% in the medium conflict zones, while 47% of installed energy was located in low conflict zones.
Morkūnė R, Marčiukaitis M, Jurkin V, Gecevičius G, Morkūnas J, Raudonikis L, et al. (2020) Wind energy development and wildlife conservation in Lithuania: A mapping tool for conflict assessment. PLoS ONE 15(1): e0227735. https://doi.org/10.1371/journal.pone.0227735
https://journals.plos.org/plosone/artic ... ne.0227735
Wind energy development and wildlife conservation in Lithuania: A mapping tool for conflict assessment
The paper presents a mapping tool aiming to identify and minimise potential conflicts between onshore wind energy development and wildlife conservation in Lithuania. It merges current information on the distribution, conservation status and sensitivity of birds and bats to wind power with an integrated evaluation of wind resources (modelled wind speed), special planning status and technical perspectives of wind energy development.
- Breeding Black and White Storks, birds of prey and colonies of terns and gulls were considered to have the highest scores of sensitivity to the different effects of wind power among breeding bird species.
- Storks, Great White Egret, White-tailed Eagle, Lesser Spotted Eagle, Common Buzzard and Common Crane had the highest scores during the migration period.
- Wildlife in the western part of the country in the Curonian Lagoon region, as well as the municipalities of Varėna, Biržai and Anykščiai were characterized as highly sensitive to wind power.
- Considering the installed wind power (by MW), 27% of installed wind power in 2017 was located in the high conflict zones, 26% in the medium conflict zones, while 47% of installed energy was located in low conflict zones.
Morkūnė R, Marčiukaitis M, Jurkin V, Gecevičius G, Morkūnas J, Raudonikis L, et al. (2020) Wind energy development and wildlife conservation in Lithuania: A mapping tool for conflict assessment. PLoS ONE 15(1): e0227735. https://doi.org/10.1371/journal.pone.0227735
https://journals.plos.org/plosone/artic ... ne.0227735
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marika.solo
- Site Admin
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Re: Other treaths
2024
Low juvenile survival threatens the Black Stork Ciconia nigra in northern Europe.
Summary
Detecting factors causing the decline of wildlife populations provides essential knowledge for their effective conservation. Populations of Black Stork Ciconia nigra are decreasing in northern Europe; however, there are no detailed analyses of its survival, which frequently is a key demographic parameter affecting population dynamics in long-lived species. We used long-term data from re-sighted colour-ringed birds and satellite-tracked birds to estimate age- and sex-specific survival in a rapidly declining Black Stork population in the Baltic region at the northern end of the European range. Apparent survival (0.89) among colour-ringed birds older than one year was not significantly different from the previously reported estimates in Central Europe and the estimated real survival of GPS-tracked birds (0.77). However, the apparent survival of first-year (1y) birds was only 0.04, which is remarkably lower than earlier estimates in Central Europe. The real survival of GPS-tracked 1y birds was somewhat higher (0.11), but still much lower than estimates in other long-lived species. Apparent survival was three times lower in 1y females (0.013) than 1y males (0.045); this could be explained in part by a higher mean natal dispersal of females (189.1 km), compared with that of males (72.0 km), as well as by sex-specific mortality due to poor foraging conditions. There were no significant differences in apparent survival between the male and female storks older than one year. To better address the population decline, further research is needed to determine the factors causing low survival in young Black Storks, including the roles of food availability and climate change.
Väli, Ü., Strazds, M., Kaldma, K., & Treinys, R. (2024). Low juvenile survival threatens the Black Stork Ciconia nigra in northern Europe. Bird Conservation International, 34, e10. doi:10.1017/S0959270924000042
https://www.cambridge.org/core/journals ... 5D90FA57C5
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the discussion is very interesting
Low juvenile survival threatens the Black Stork Ciconia nigra in northern Europe.
Summary
Detecting factors causing the decline of wildlife populations provides essential knowledge for their effective conservation. Populations of Black Stork Ciconia nigra are decreasing in northern Europe; however, there are no detailed analyses of its survival, which frequently is a key demographic parameter affecting population dynamics in long-lived species. We used long-term data from re-sighted colour-ringed birds and satellite-tracked birds to estimate age- and sex-specific survival in a rapidly declining Black Stork population in the Baltic region at the northern end of the European range. Apparent survival (0.89) among colour-ringed birds older than one year was not significantly different from the previously reported estimates in Central Europe and the estimated real survival of GPS-tracked birds (0.77). However, the apparent survival of first-year (1y) birds was only 0.04, which is remarkably lower than earlier estimates in Central Europe. The real survival of GPS-tracked 1y birds was somewhat higher (0.11), but still much lower than estimates in other long-lived species. Apparent survival was three times lower in 1y females (0.013) than 1y males (0.045); this could be explained in part by a higher mean natal dispersal of females (189.1 km), compared with that of males (72.0 km), as well as by sex-specific mortality due to poor foraging conditions. There were no significant differences in apparent survival between the male and female storks older than one year. To better address the population decline, further research is needed to determine the factors causing low survival in young Black Storks, including the roles of food availability and climate change.
Väli, Ü., Strazds, M., Kaldma, K., & Treinys, R. (2024). Low juvenile survival threatens the Black Stork Ciconia nigra in northern Europe. Bird Conservation International, 34, e10. doi:10.1017/S0959270924000042
https://www.cambridge.org/core/journals ... 5D90FA57C5
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the discussion is very interesting