Search results for "General. Including nature conservation"
showing 4 items of 64 documents
Ontogenetic δ15N Trends and Multidecadal Variability in Shells of the Bivalve Mollusk, Arctica islandica
2021
Bulk stable nitrogen isotope values of the carbonate-bound organic matrix in bivalve shells (δ15NCBOM) are increasingly used to assess past food web dynamics, track anthropogenic nitrogen pollution and reconstruct hydrographic changes. However, it remains unresolved if the δ15NCBOM values are also affected by directed ontogenetic trends which can bias ecological and environmental interpretations. This very aspect is tested here with modern and fossil specimens of the long-lived ocean quahog, Arctica islandica, collected from different sites and water depths in the NE Atlantic Ocean. As demonstrated, δ15NCBOM values from the long chronologies show a general decrease through lifetime by −0.00…
Chimpanzees surviving in a fragmented high‐altitude forest landscape of the Congolese Albertine Rift
2021
This paper documents a community of eastern chimpanzees (Pan troglodytes schweinfurthii Giglioli, 1872) inhabiting three relict forest fragments situated on the Lake Albert escarpment, down the Ituri highlands, of eastern Democratic Republic of the Congo (DRC). The area explored had a combined forested surface of ±18.15 km2 in 2017, shrinking by 1.2% per year between 2010 and 2015. Between 2015 and 2017, we found 160 chimpanzee nests along 37.6 km of pilot walks, some up to 2,000 m altitude. Another 123 nests logged along 6.7 km transects led to an estimate of chimpanzee density of 4.62 weaned individuals per square kilometer of forest habitat. Camera‐trap images and direct observations rev…
Verifying the predicted risk of extinction based on ecological characteristics
2021
Red List status of species should reflect species extinction risk. Because data are limited and species response has a time lag, species may be threatened by extinction even if they are not Red‐Listed. The ability to predict species risk of extinction from ecological characteristics holds promises for proactively targeting conservation measures to species at high risk. In 2005, the risk of extinction from ecological characteristics was predicted for 81 species of Finnish butterflies. Now, after 15 years and two additional national Red List assessments, these predictions are verified. Species with a higher risk of extinction according to the original ecological extinction risk rank (EERR) ha…
Long-Term Data Reveal the Associations of the Egg Quality With Abiotic Factors and Female Traits in the Baltic Herring Under Variable Environmental C…
2021
In fish, the lipid resources of the female form a link between the environment and progeny, contributing to the contents of the egg yolk. Variation of the environmental conditions is therefore expected to affect the egg quality via maternal pathways, reflecting the female’s response to the environmental factors before spawning. We investigated the content of lipids and thyroid hormones in the ovary and eggs of the Baltic herring during 1988–2019, when salinity of the Baltic Sea first declined and then stabilized to a lower level, and winters varied between severe and mild. The total lipid resources of spawning females decreased by 40–50% during the study, and the ovarian lipid concentration…