Assessing the impact of urban landfills as feeding sites on physiological parameters of a generalist seabird species

The increasing human population and associated urban waste pose a significant threat to wildlife. Our study focused on the Kelp gull (Larus dominicanus), known for opportunistic feeding in anthropogenic areas, particularly urban landfills. We assessed the physiological status of Kelp gulls at a landfill and compared it with gulls from a protected natural site. Results indicate that gulls from the anthropogenic site exhibited lower levels of key physiological parameters linked to diet, including triglycerides, total proteins, uric acid, plasmatic enzyme activity, body condition index, and leukocyte count, in comparison to their counterparts from the natural site. These findings suggest that Kelp gulls experience inferior physical and nutritional conditions when utilizing anthropogenic sites like landfills governmentally managed.

A new species of Maritrema (Trematoda: Microphallidae) parasitizing the Baird's sandpiper Calidris bairdii, and comments about diversity of Microphallidae in two Nearctic shorebirds at Patagonian sites in Argentina

Birds are hosts of a wide diversity of trematodes. Between them, the Microphallidae is a common family with a cosmopolitan distribution. Nevertheless, only 10 Maritrema species have been recorded previously in South America. The aim of the present paper is to describe a new species of Maritrema parasitizing the Nearctic Baird's sandpiper, Calidris bairdii in its wintering areas in Patagonia, Argentina. We also analyze and compare the microphallid diversity in two host species. We collected 44 C. bairdii and 50 Calidris fuscicollis in search of helminths. Trematodes were found only in C. bairdii. A total of 694 trematodes belonging to 4 microphallid species were found parasitizing the intestine and caeca. Four microphallid species were found: Maritrema formicae, Odhneria odhneri, Levinseniella cruzi and Maritrema pichi n. sp. M. formicae showed the highest prevalence, while M. pichi n. sp. was the species with the highest mean intensity and mean abundance. The new species M. pichi n. sp. differs from congeners by the position of the acetabulum that is included within the vitellarium ring, the ovary is anterior to the acetabulum, and the testes are lateral to it. We discuss the parasitological results in relation with the biological and ecological characteristics of both different host species.

Ecotourism effects on health and immunity of Magellanic penguins at two reproductive colonies with disparate touristic regimes and population trends

Negative effects of ecotourism on wildlife are rising worldwide. Conservation physiology can play a major role in protecting wildlife by providing early alerts on changes in the status of individuals exposed to tourist activities. We measured an integrated set of immune and health-state indices to evaluate the effects of ecotourism on Magellanic penguins (Spheniscus magellanicus). We studied two reproductive colonies that differed in the intensity of tourism and population trends: Punta Tombo (higher tourism intensity, declining population) and San Lorenzo (lower tourism intensity, growing population). Within each colony, we compared individuals from an area that was exposed to tourists and a control area where tourism was excluded. Adult penguins exposed to tourism at Punta Tombo, but not at San Lorenzo, showed physiological alterations indicative of chronic stress (higher heterophil to lymphocyte ratios) and parasitic infection (elevated heterophil and eosinophil counts). Penguin chicks exposed to tourism at Punta Tombo, but not at San Lorenzo, also showed physiological alterations indicative of poor immune and general-health condition: lower humoral innate immunity, haematocrit, and glucose levels and higher inflammatory responses likely due to increased prevalence of fleas. Our results indicate that individuals of a declining population exposed to high levels of tourism express physiological indicators of chronic stress and poor health that could make adults and juveniles vulnerable to disease. These effects are expressed despite a long history of exposure and behavioural habituation to human visitation. In contrast, individuals of a growing population exposed to more recent and lower levels of tourism showed no effect. Our study demonstrates how a diverse physiological toolkit within a conservation physiology approach can provide important information for a better comprehension of anthropogenic effects on wild animals in our changing world.