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.

PHYSIOLOGIC PARAMETERS AND THEIR RESPONSE TO HANDLING STRESS IN A NEOTROPICAL MIGRATORY SHOREBIRD DURING THE NONBREEDING SEASON.

Physiologic traits are promising indicators of population health in the face of rapidly changing environments. We obtained values of diverse physiologic parameters for Two-banded Plovers (Charadrius falklandicus) in coastal sites in Patagonia, Argentina, with the objectives of determining the timeline in which these parameters become affected by the stress of capture and handling and of obtaining reference values for future monitoring of these populations. We analyzed packed cell volume, white blood cell profile, heterophil/lymphocyte ratio, bacterial agglutination titer, and total protein, glucose, triglyceride, and cholesterol levels in apparently healthy birds. Glucose, total white blood cell count, lymphocytes, and eosinophil levels showed changes with handling times >60 min after capture. The remaining parameters did not manifest significant alterations in response to capture and handling of up to 232 min (average=105.2, SD=56.7). Therefore, although researchers should attempt to obtain blood samples as soon as possible after capture, inclusion of physiologic parameters in monitoring studies of species not easily sampled in a few minutes, such as Two-banded Plovers and other shorebird species during migration, should not be discouraged. Here we provide a physiologic report for the species that can be considered as reference values during the nonbreeding season at Patagonian coastal sites.

MODE OF ATTACHMENT AND PATHOLOGY CAUSED BY PARORCHITES ZEDERI IN THREE SPECIES OF PENGUINS: PYGOSCELIS PAPUA, PYGOSCELIS ADELIAE, AND PYGOSCELIS ANTARCTICA IN ANTARCTICA.

We identified and compared gross and microscopic lesions associated with the cestode, Parorchites zederi, in the digestive tracts of three species of penguins (Spheniscidae): the Chinstrap ( Pygoscelis antarctica ), Gentoo ( Pygoscelis papua ), and Adélie penguins ( Pygoscelis adeliae ). The gastrointestinal tracts of 79 recently dead individuals (71 chicks and eight adults) were collected in locations throughout the Antarctic Peninsula during summer field trips in 2006-09. Parorchites zederi was found in the small intestine of 37 animals (47%), and 23 (62%) of these had parasite-associated lesions. The cestodes were either free in the intestinal lumen, clustered within mucosal ulcers, or deeply embedded in the intestinal wall. Histopathologic changes were most severe in adult Gentoo Penguins and included transmural fibrogranulomatous enteritis, hemorrhage, and edema. This report of pathology associated with P. zederi in the digestive tracts of penguins can serve as reference to monitor health in Antarctic birds associated with environmental changes.

Hematologic and plasma biochemistry values for endangered red knots (Calidris canutus rufa) at wintering and migratory sites in Argentina.

We obtained hematologic and plasma biochemistry values for adult, long-distance migrant Red Knots at their southernmost wintering site in Río Grande (Tierra del Fuego, Argentina) and at the first stopover site in San Antonio Oeste (Río Negro, Argentina). Lymphocytes (L) followed by heterophils (H) were the most abundant leukocytes. H/L ratio and glucose levels were significantly higher at Río Grande, possibly because of the stress of migration and molting. Packed cell volume results ranged widely, probably in response to increased oxygen demand for migration. Protein profiles and lipids were higher at the stopover site and attributable to birds storing reserves for subsequent flights.

Exposure of red knots (Calidris canutus rufa) to select avian pathogens; Patagonia, Argentina.

As part of the shorebird surveillance, Red Knots (Calidris canutus rufa) were sampled in two Patagonian sites in Argentina, Río Grande and San Antonio Oeste, during 2005-2006. Cloacal swabs and serum samples were collected from 156 birds and tested by virus isolation (Newcastle disease virus), polymerase chain reaction (PCR; avian influenza virus and Plasmodium/Hemoproteus), and for antibodies to St. Louis encephalitis virus. All test results were negative.

Assessing pollution in coastal ecosystems: a preliminary survey using the micronucleus test in the mussel Mytilus edulis.

Mussels Mytilus edulis were sampled at increasing distances from urban effluents in two very different locations, Gijon (northern Spain, Europe, 43 degrees N) and Puerto Madryn (Argentina, South America, 43 degrees S), and from an industry effluent in Puerto Madryn. The micronucleus test was performed on branchial cells. For the three situations, a statistically significant negative association was found between the distance of sampling site from the effluent and the mean number of micronuclei per 1000 cell counts, in a range of distances as short as 300m. The micronucleus test in Mytilidae, here revealed to be sensitive enough to monitor urban pollution, is proposed for routine surveys of pollution as a bioindicator of choice for coastal ecosystems.