Toxoplasma gondii Exposure and Dietary Habits of Two Sympatric Carnivores in the Valdivian Temperate Rainforest, Southern Chile.

ABSTRACT: Toxoplasma gondii, a parasitic protozoan, may infect most warm-blooded animals, including humans and carnivores. Our study focused on alien-invasive American minks (Neogale vison) and domestic cats (Felis catus) in the Valdivian Temperate Rainforest, Chile. The main goal was to investigate the relationship between their dietary habits and T. gondii exposure in the Valdivia River watershed. To detect T. gondii exposure, blood serum samples from 49 domestic cats and 40 American minks were analyzed using an ELISA, and stable isotope analysis of δ15N and δ13C from vibrissae was performed to determine the dietary habits of both species. Relationships between T. gondii exposure and dietary habits were explored using generalized linear mixed-effects models. American minks that were T. gondii seropositive exhibited a broader prey range compared to seropositive domestic cats, with minimal dietary overlap between the two groups. Exposure of domestic cats to T. gondii had no significant association with any isotope value or prey item in their diet. In American minks, we found a positive and significant association between the proportion of Domestic chicken (Gallus gallus domesticus) in the diet and high δ15N values with T. gondii exposure. This suggests that domestic species prey related to anthropogenic areas, and the consumption of high-trophic-level prey, may contribute to T. gondii exposure in American minks. Conversely, contrary to previous hypotheses, consumption of rodents showed no significant association with T. gondii exposure in either species. Our findings emphasize the importance of further research to investigate trophic interactions in the transmission dynamics of T. gondii in the Valdivian Temperate Rainforest.

Highly pathogenic avian influenza A (H5N1) in marine mammals and seabirds in Peru.

Highly pathogenic avian influenza (HPAI) A/H5N1 viruses (lineage 2.3.4.4b) are rapidly invading the Americas, threatening wildlife, poultry, and potentially evolving into the next global pandemic. In November 2022 HPAI arrived in Peru, triggering massive pelican and sea lion die-offs. We report genomic characterization of HPAI/H5N1 in five species of marine mammals and seabirds (dolphins, sea lions, sanderlings, pelicans and cormorants). Peruvian viruses belong to lineage 2.3.4.4b, but they are 4:4 reassortants where 4 genomic segments (PA, HA, NA and MP) position within the Eurasian lineage that initially entered North America from Eurasia, while the other 4 genomic segments (PB2, PB1, NP and NS) position within the American lineage (clade C) that circulated in North America. These viruses are rapidly accruing mutations, including mutations of concern, that warrant further examination and highlight an urgent need for active local surveillance to manage outbreaks and limit spillover into other species, including humans.

Rajids ovipositing on marine litter: A potential threat to their survival.

Marine litter is a complex environmental issue threatening the well-being of multiple organisms. In the present study, we present an overlooked pathway by which marine litter interaction with certain ovigerous skates (Family: Rajidae) communities could compromise their survival. We propose that skates from the genus Sympterygia deposit their egg capsules on marine litter substrates by accident, which are then washed ashore still unhatched. We conducted 10 monitoring surveys on three beaches of La Libertad Region, on the north coast of Peru, looking for marine litter conglomerates to determine the presence of egg capsules. We registered a total of 75 marine litter conglomerates, containing 1595 egg capsules, out of which only 15.9 % were presumably hatched, and 15.8 % were still fresh. Fishing materials were identified as the main item in marine litter conglomerates. We conclude that this behavior could contribute to the decline of Sympterygia communities, although further research is needed.

Improving Trapping Efficiency for Control of American Mink (Neovison vison) in Patagonia.

Two main challenges when controlling alien American mink (Neovison vison) in Patagonia are to maximize campaign efficacy and cost-effectiveness and to avoid trapping native species. We designed and tested new variants of collapsible wire box traps, compared the efficacy of a food-based bait and a scent lure and compared catch rates in different seasons of the year. We used the data to model the efficiency rate of the trapping and to determine the trapping effort required to remove 70-90% of the estimated discrete mink population. Between January 2018 and March 2021, we operated 59 trapping transects over 103 three-day trapping periods in southern Chile. Traps were first baited with canned fish, and afterwards with mink anal gland lure. We compared the efficacy of mink capture with that of our previous study. We trapped 196 mink (125 males, 71 females), with most captures in summer. The medium-sized GMV-18 trap caught more male mink, but the more compact GMV-13 caught fewer non-target rodents and no native mammals. The scent lure was more successful than the canned fish when the previous campaign's data were included in the analysis. There was also a significant improvement in the proportion of female mink trapped and reduced labour compared with our previous campaign that used larger traps, fish bait and 400-500 m trap spacings. We caught relatively more females than males after the third night of trapping on a transect. Our data analysis supports the use of the GMV-13 variant of wire cage trap as the best trap size: it is effective on female mink, small, cheap and easy to transport. Combined with mink anal scent lure, it reduces the possibility of trapping native species compared with other traps tested in Chile. As the most efficient method for removing at least 70% of the estimated discrete mink population within the area covered by each trap transect in southern Chile tested to date, we recommend trapping campaigns using GMV-13 during summer, with a 200-m trap spacing, for up to 6 days before moving traps to a new site, with a combination of three days with a female scent gland lure, followed by three days with a male scent gland lure.

Exposure to Toxoplasma gondii in Marine Otters (Lontra felina) and Domestic Cats (Felis catus) in an Arid Environment in Chile.

Toxoplasma gondii is a worldwide-distributed protozoon that infects warm-blooded animals. We determined T. gondii exposure in one marine otter (Lontra felina) and four domestic cats (Felis catus) along the northern and central coast of Chile, indicating a low seroprevalence of 5% (1/19) and 8% (4/50) respectively, likely related to arid environment.

Primer reporte del acantocéfalo Profilicollis altmani en una cigüeñuela de cuello negro Himantopus mexicanus / First report of acanthocephalan Profilicollis altmani on a black-necked stilt Himantopus mexicanus

Se reporta el hallazgo del acantocéfalo Profilicollis altmani, en un individuo de cigüeñuela de cuello negro (Himantopus mexicanus) en la costa norte del Perú. Profilicollis altmani no había sido reportado anteriormente en H. mexicanus, siendo este el primer reporte de este tipo.

We record the presence of the acanthocephalan specie Profilicollis altmani in a black-necked stilt, Himantopus mexicanus, in the Northern coast of Peru. Profilicollis altmani had not been previously reported in H. mexicanus, this being the first report in a new host.