Habitat-, age-, and sex-related alterations in oxidative stress biomarkers in the blood of mute swans (Cygnus olor) inhabiting pomeranian coastal areas (Northern Poland)

The mute swan (Cygnus olor) can be considered a representative species of birds associated with the aquatic environment and responding very clearly to changes in the environment. Assuming that the condition of the mute swan population well reflects the state of the environment, this species was used in our research as a bioindicative species. Thus, the aim of our study was to elucidate the association between metal contents in soil samples collected from a habitat of mute swans and element contents in their feathers as well as the levels of biomarkers of lipid peroxidation, oxidatively modified proteins, and total antioxidant capacity in the blood of mute swans living in three agglomerations in coastal areas in the southern part of the Baltic Sea (Pomeranian region, northern Poland). We compared the effects of inhabitation, age, and sex on the ecophysiological accumulation of metals in three wintering populations of the mute swan from coastal areas of northern Poland, i.e., Słupsk, Gdynia, and Sopot. In Słupsk, the anthropogenic pressure was related predominantly to the level of Al and, to a lesser extent, to the content of Rh and Ru. We found maximum levels of lipid peroxidation biomarkers in the blood of the mute swans from Gdynia (38.20 ± 6.35 nmol MDA·mL−1). At the same time, maximum levels of aldehydic and ketonic derivatives of oxidatively modified proteins were noted in the blood of swans from Sopot compared to the values obtained in mute swans from Słupsk and Gdynia. This trend suggesting high levels of oxidative stress biomarkers was also confirmed by a decrease in the total antioxidant capacity in these groups.

New record of the Mute swan Cygnus olor (Gmelin, 1789) from the Transfiguration Island (Laptev Sea)

In this article new record of the Mute swan Cygnus olor (Gmelin, 1789) from the Transfiguration Island (Laptev Sea) is given.

Age-related differences in reproductive success support the selection hypothesis in a Mute Swan population

In many bird species, we observe age-related differences in reproductive success, which usually increases early in life and later decreases due to senescence. At the individual level, an early-life improvement in breeding performance may be associated with experience acquired during early reproductive events (experience hypothesis). At the population level, higher average reproductive success of older age cohorts can result from a disappearance of low-quality individuals from the population (selection hypothesis). Here, we tested these hypotheses in a wild population of the Mute Swan Cygnus olor from central Poland. In 1996–2016, we collected information on breeding success of 150 marked individuals (70 females and 80 males; 590 breeding attempts). At the population level, there was an initial increase in reproductive success (1–5 years), followed by a plateau (5–8 years), and then by a decrease in older age classes. Both within- and between-individual age variation contributed to the linear increase in reproductive success at the population level, but the latter effect was much more apparent. Short-term breeders (≤ 2 breeding events) had significantly lower reproductive success than long-term breeders (≥ 3 breeding events) during their first two breeding attempts, providing support for selection hypothesis and disappearance of low-quality phenotypes. After exclusion of short-term breeders, a positive age-related increase in reproductive success lost significance, suggesting that under-specific condition (rapid population growth and strong human disturbance) experience may have a limited effect on reproductive success in long-lived species with strong pair bonds, such as the Mute Swan.

Mute Swan (Cygnus olor Gmelin, 1789).

This chapter describes the terminology, nomenclature, morphology, geographical distribution, diet, physiology, reproduction, behaviour, ecology, habitats, invasion patterns, environmental impact, control and human use of the mute swan (Cygnus olor).