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.

Behavioural and energetic consequences of competition among three overwintering swan (Cygnus spp.) species

Background Winter numbers of the northwest European population of Bewick’s Swans (Cygnus columbianus bewickii) declined recently by c. 40%. During the same period, numbers of two sympatric and ecologically-similar congeners, the Mute Swan (Cygnus olor) and Whooper Swan (Cygnus cygnus) showed increases or stability. It has been suggested that these opposing population trends could have a causal relationship, as Mute and Whooper Swans are larger and competitively dominant to Bewick’s Swans in foraging situations. If so, effects of competition of Mute and Whooper Swans on Bewick’s Swans should be detectable as measurable impacts on behaviour and energetics. Methods Here, we studied the diurnal behaviour and energetics of 1083 focal adults and first-winter juveniles (“cygnets”) of the three swan species on their winter grounds in eastern England. We analysed video recordings to derive time-activity budgets and these, together with estimates of energy gain and expenditure, were analysed to determine whether individual Bewick’s Swans altered the time spent on key behaviours when sharing feeding habitat with other swan species, and any consequences for their energy expenditure and net energy gain. Results All three swan species spent a small proportion of their total time (0.011) on aggressive interactions, and these were predominantly intraspecific (≥ 0.714). Mixed-effects models indicated that sharing feeding habitat with higher densities of Mute and Whooper Swans increased the likelihood of engaging in aggression for cygnet Bewick’s Swans, but not for adults. Higher levels of interspecific competition decreased the time spent by Bewick’s Swan cygnets on foraging, whilst adults showed the opposite pattern. When among low densities of conspecifics (< c. 200 individuals/km2), individual Bewick’s Swans spent more time on vigilance in the presence of higher densities of Mute and Whooper Swans, whilst individuals within higher density Bewick’s Swan flocks showed the opposite pattern. Crucially, we found no evidence that greater numbers of interspecific competitors affected the net energy gain of either adult or cygnet Bewick’s Swans. Conclusions We found no evidence that Bewick’s Swan net energy gain was affected by sharing agricultural feeding habitat with larger congeners during winter. This was despite some impacts on the aggression, foraging and vigilance behaviours of Bewick’s Swans, especially among cygnets. It is unlikely therefore that competition between Bewick’s Swans and either Mute or Whooper Swans at arable sites in winter has contributed to the observed decline in Bewick’s Swan numbers. Further research is needed, however, to test for competition in other parts of the flyway, including migratory stopover sites and breeding areas.

Biosurveillance of Selected Pathogens with Zoonotic Potential in a Zoo

Monitoring of infectious diseases is one of the most important pillars of preventive medicine in zoos. Screening for parasitic and bacterial infections is important to keep animals and equipment safe from pathogens that may pose a risk to animal and human health. Zoos usually contain many different animal species living in proximity with people and wild animals. As an epidemiological probe, 188 animals (122 mammals, 65 birds, and one reptile) from a zoo in Slovenia were examined for selected pathogens. Antibodies to Toxoplasma gondii and Neospora caninum were detected by ELISA in 38% (46/122) and 3% (4/122) of mammals, and in 0% (0/64) and 2% (1/57) of birds, respectively; the reptile (0/1) was negative. A statistically significant difference in T. gondii prevalence was found in Carnivora compared to Cetartiodactyla and primate antibodies to Encephalitozoon cuniculi were detected by IFAT in 44% (52/118) of mammals and 20% (11/56) of birds, respectively; the reptile (0/1) was negative. Herbivores had a higher chance of being infected with E. cuniculi compared to omnivores. Antibodies to Chlamydia abortus and Coxiella burnetii were not detected in any of the 74 tested zoo animals. The sera of 39 wild rodents found in the zoo were also examined; they were negative for all three parasites. The parasite T. gondii was detected by PCR in the tissue of two mute swans (Cygnus olor), three eastern house mice (Mus musculus), one yellow-necked field mouse (Apodemus flavicollis), and one striped field mouse (A. agrarius). Positive samples were genotyped by a single multiplex PCR assay using 15 microsatellite markers; one sample from a mute swan was characterized as type II. This micro-epidemiological study offers a better understanding of pathogens in zoo animals and an understanding of the role of zoos in biosurveillance.

Biosurveillance of selected pathogens with zoonotic potential in a zoological collection

Monitoring infectious diseases is one of the most important pillars of preventive medicine in zoological collections. Screening for parasitic and bacterial infections is obligatory for keeping animals and equipment safe from pathogens that may pose a risk to animal and human health. Zoological collections usually contain many different animal species, living in close proximity with people and wild animals. As an epidemiological probe, 188 animals (122 mammals, 65 birds, and one reptile) from a zoo in Slovenia were examined for selected pathogens. Antibodies to Toxoplasma gondii and Neospora caninum were detected by ELISA in 37% and 3% of mammals, and in 0% and 3% of birds, respectively; the reptile was negative. A statistically significant difference in T. gondii prevalence was found in Carnivora (78%) compared to Cetartiodactyla (33%, p = 0.0227) and Primates (25%, p = 0.0084). Antibodies to Encephalitozoon cuniculi were detected by IFAT in 55% of mammals and 34% of birds, respectively; the reptile was negative. Herbivores had a higher chance of being infected with E. cuniculi compared to omnivores (p = 0.0015). Antibodies to Chlamydia abortus and Coxiella burnetii were not detected in any of the zoo animals. The sera of 39 wild rodents found in the zoo were also examined; they were negative for all three parasites. The parasite T. gondii was detected by PCR in the tissue of two mute swans (Cygnus olor), one laboratory mouse, two Mus musculus, one Apodemus flavicollis, and one Apodemus agrarius. Positive samples were genotyped by a single multiplex PCR assay using 15 microsatellite markers; one sample from a mute swan was characterized as type II. This micro-epidemiological study offers a better understanding of pathogens in zoo animals and an understanding the role of zoos in biosurveillance.

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.

THE FIRST STUDY OF THE ENDOPARASITIC FAUNA OF MUTE SWANS (CYGNUS OLOR) IN THE NORTHERN PART OF SERBIA

In the Northern part of Serbia, which is part of Pannonian Basin, mute swan (Cygnus olor) population has notably increased over the last few decades. Like other birds from Anatidae family, mute swans are a host of numerous endoparasite species. The aim of this study was to acquire the data on identification and prevalence of endoparasites in mute swans in the Republic of Serbia, as that information is lacking. Individual faecal samples of sixty-eight adult mute swans were examined for the presence of endoparasites. Coprological examination was performed using flotation and sedimentation technique with saturated ZnSO4 solution. The samples were collected from December 2016 to March 2017, during epizootic of highly pathogenic avian influenza H5N8 in the Republic of Serbia. Dead mute swans were collected from twelve different locations in the Northern part of Serbia. Altogether, 39.7% of the examined fecal samples contained different parasites. The endoparasitic fauna was divers and included 3 species of nematodes, 2 cestodes species, one trematode and one protozoan species. Nematodes were the most prevalent helminthes and among these the most frequent nematode species found was Heterakis dispar (17.6%), followed by Echinuria uncinata (5,8%) and Ascaridia spp. (4,4%). Four mixed infections were found, where double infection was the most prevalent. No endoparasites were found in faecal samples of mute swans collected from the locations Sombor and Titel. As this study covers a small population of mute swans, more detailed studies need to be carried out on a larger population in order to gain an insight into the diversity and prevalence of endoparasites in the Republic of Serbia.