Comparative Genomics Supports Ecologically Induced Selection as a Putative Driver of Banded Penguin Diversification.

The relative importance of genetic drift and local adaptation in facilitating speciation remains unclear. This is particularly true for seabirds, which can disperse over large geographic distances, providing opportunities for intermittent gene flow among distant colonies that span the temperature and salinity gradients of the oceans. Here, we delve into the genomic basis of adaptation and speciation of banded penguins, Galápagos (Spheniscus mendiculus), Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), and African penguins (Spheniscus demersus), by analyzing 114 genomes from the main 16 breeding colonies. We aim to identify the molecular mechanism and genomic adaptive traits that have facilitated their diversifications. Through positive selection and gene family expansion analyses, we identified candidate genes that may be related to reproductive isolation processes mediated by ecological thermal niche divergence. We recover signals of positive selection on key loci associated with spermatogenesis, especially during the recent peripatric divergence of the Galápagos penguin from the Humboldt penguin. High temperatures in tropical habitats may have favored selection on loci associated with spermatogenesis to maintain sperm viability, leading to reproductive isolation among young species. Our results suggest that genome-wide selection on loci associated with molecular pathways that underpin thermoregulation, osmoregulation, hypoxia, and social behavior appears to have been crucial in local adaptation of banded penguins. Overall, these results contribute to our understanding of how the complexity of biotic, but especially abiotic, factors, along with the high dispersal capabilities of these marine species, may promote both neutral and adaptive lineage divergence even in the presence of gene flow.

Detection of Mycoplasma spp. in free-living seabirds.

This study aimed to investigate the presence of Mycoplasma spp. and identify the species of mycoplasma isolates obtained from seabirds found on Brazilian coastal beaches. Tracheal and cloacal swab samples were collected from 50 seabirds rescued by three conservation and marine animal rehabilitation centers located in Brazil. The tracheal and cloacal samples were subjected to mycoplasma culture and the isolates were identified through PCR. A "Mollicutes-specific" 16S rRNA PCR reaction was employed for triage. Four species-specific PCR reactions were used to detect Mycoplasma gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis, or M. gallinarum. The Mollicutes positive and species negative samples were submitted do 16S rRNA sequencing. Eighteen (36%) of 50 seabirds tested positive for mycoplasma by culture. In the PCR for the genus, 28 (56%) of 50 seabirds were positive for Mycoplasma spp., with 13 (26%) detected in the trachea, one (2%) in the cloaca, and 14 (28%) in both sites. In the species-specific PCR, M. gallisepticum was detected in 17.8%, and M. meleagridis in 17.8%. Both species were detected in 14.3%. Of the isolates not characterized at species level, we obtained ten sequences and they were divided into three clusters. The first cluster was closely related to M. meleagridis, the second to M. synoviae, and the third grouped M. tully, M. gallisepticum, and M. imitans. Four and five of nine species of seabirds studied had mycoplasma detected by culture or PCR, respectively. Mycoplasmas were found in the majority of the animals studied, with the highest prevalence proportionally found in Sula leucogaster, and the lowest in Fregata magnificens. The phylogenetic analysis identified Mycoplasma spp. adapted to aquatic birds.

Pathogenic potential of an environmental Aspergillus fumigatus strain recovered from soil of Pygoscelis papua (Gentoo penguins) colony in Antarctica.

Aspergillus fumigatus is a common opportunistic pathogen in different animals, including birds such as penguins. For the first time, a fungal strain identified as A. fumigatus was isolated from soil in the nests of gentoo penguins, Pygoscelis papua, on Livingston Island, South Shetland Islands (maritime Antarctica). This isolate (A. fumigatus UFMGCB 11829) displayed a series of potentially pathogenic characteristics in vitro. We evaluated its detailed molecular taxonomy and submitted the A. fumigatus UFMGCB 11829 Antarctic strain to in vivo pathogenic modelling. The isolate was confirmed to represent A. fumigatus morphological and phylogenetic analysis showed that it was closely related to A. fumigatus sequences reported from animals, immunosuppressed humans, storage grains, plants and soils. The strain displayed the best mycelial growth and conidia production at 37 ºC; however, it was also able to grow and produce conidia at 15º, demonstrating its capability to survive and colonize penguin nest at least in the summer season in maritime Antarctica. In pathogenicity tests, healthy mice did not showed symptoms of infection; however, 50% lethality was observed in immunosuppressed mice that were inoculated with 106 and 107 spores. Lethality increased to 100% when inoculated with 108 spores. Our data highlight the potential pathogenicity of opportunistic A. fumigatus that may be present in the Antarctic, and the risks of both their further transfer within Antarctica and outwards to other continents, risks which may be exacerbated due global climatic changes.

Phylogenetic Analyses of Lizards from the Chilean Humboldt Archipelago Reveal a New Species for the Chañaral Island (Squamata: Liolaemidae).

The Humboldt Archipelago, situated on Chile's north-central coast, is renowned for its exceptional biodiversity. However, lizards of the Liolaemus genus are a particularly understudied group in this archipelago. Liolaemus genus is divided into two clades: chiliensis and nigromaculatus. Within the nigromaculatus clade the zapallarensis group is restricted to the semi-arid and arid coastal habitats of the Atacama Desert in north-central Chile. While it has been reported that lizards from the zapallarensis group inhabit various islands within the Humboldt Archipelago, there has been limited knowledge regarding their specific species identification. To identify the lizard species inhabiting these islands, we conducted phylogenetic analyses using a mitochondrial gene and examined morphological characteristics. Our findings reveal that lizards from the Damas, Choros, and Gaviota islands belong to Liolaemus silvai. In contrast, the lizards on Chañaral Island form a distinct and previously unrecognised group, clearly distinguishable from Liolaemus silvai. In conclusion, our study not only confirms the presence of L. silvai on the Damas, Choros, and Gaviota islands but also describes a new lizard species on Chañaral Island named Liolaemus carezzae sp. nov. These findings contribute valuable insights into the biodiversity of these islands and introduce a newly discovered endemic taxon to the region, enriching our understanding of Chile's unique island ecosystems.

Ingestion of marine debris by juvenile Magellanic penguins (Spheniscus magellanicus) in wintering grounds of coastal Argentina.

The occurrence of marine debris in the stomach contents of young male and female Spheniscus magellanicus stranded along the Atlantic coast of northern Argentina during its post-breeding exodus is reported for the first time. Marine debris was found in 15.5 % of 148 dead penguins, with a higher proportion of debris found in females when compared to males. A total of 81 debris items was recorded; plastic and paper each contributed with an equal number of debris whereas rubber contributed with a single item. Chemical identification performed using FTIR/ATR revealed that plastic items were largely LDPE and PA; other polymers included HDPE, PP and PS. The average length of fragmented plastic debris are in line with those reported from penguins stranded along the southern Brazilian coasts. Our study indicates that loads of ingested marine debris were roughly five times lower when compared to the estimates for the species in Brazilian beaches.

Changing course: Relocating commercial tanker lanes significantly reduces threat of chronic oiling for a top marine predator.

A goal for conservation biologists is to show that policies enacted on behalf of an imperiled species results in direct benefits for it. In Argentina, tens of thousands of Magellanic penguins (Spheniscus magellanicus) were estimated to have died from chronic oil pollution each year through the early 1980s. From 1982 to 1990, surveys at sites along approximately 900 km of Chubut Province coastline found that >60 % of penguin carcasses had evidence of oiling in some years. In response to these findings, as well as pressure from non-governmental organizations and the public, provincial and federal authorities in Chubut moved the commercial tanker lanes 20 nautical miles farther offshore in 1997 and required oil tankers to have double hulls. During a second round of surveys in 2001, using most of the same sites as the first survey period, the number of dead and oiled penguins dropped effectively to zero. A policy change not only led to fewer oiled penguins, but also likely increased the survival of adult Magellanic penguins near some of their most significant breeding colonies in Argentina.

Flavobacterium pygoscelis sp. nov., isolated from a chinstrap penguin chick (Pygoscelis antarcticus).

Strain I-SCBP12nT, a novel Gram-stain-negative, aerobic, non-spore-forming, motile-by-gliding and rod-shaped bacterium, was isolated from a chinstrap penguin chick (Pygoscelis antarcticus) during a 2015 expedition to the Chilean Antarctic territory. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that strain I-SCBP12nT belonged to the genus Flavobacterium, being closely related to strains Flavobacterium chryseum P3160T (98.52 %), Flavobacterium hercynium WB 4.2-33T (98.47 %) and Flavobacterium chilense LM-19-FpT (98.47 %). The genome size of strain I-SCBP12nT was 3.69 Mb with DNA G+C content 31.95 mol%. Genomic comparisons of strain I-SCBP12nT with type species in the genus Flavobacterium were performed, with obtained average values near 75.17 and 84.33 % for the blast and MUMer analyses of average nucleotide identity, respectively, and 0.86 for the tetranucleotides frequency analysis. These values are far from the accepted species cut-off values. Strain I-SCBP12nT contained MK-6 as the predominant menaquinone and the major polar lipids were aminophospholipid, an unidentified aminolipid and unidentified lipids. The predominant fatty acids (> 5 %) were iso-C14 : 0, iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C16 : 1, iso-C16 : 0 3-OH, C15 : 1 ω6c and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c). Phenotypic, chemotaxonomic and genomic data supported the assignment of strain I-SCBP12nT (=CECT 30404T=RGM 3223T) to a novel species of Flavobacterium, for which the name Flavobacterium pygoscelis sp. nov.is proposed.

H6N8 avian influenza virus in Antarctic seabirds demonstrates connectivity between South America and Antarctica.

Wild aquatic birds are the natural reservoirs of avian influenza viruses (AIVs). It is estimated that 100 million seabirds live in the Antarctic Peninsula and adjacent islands, regularly encountering migratory birds that use the islands to nest. Between 2010 and 2013, we collected samples from 865 seabirds in Elephant, King George and Livingston islands, around Antarctica Peninsula: chinstrap penguin (n = 143); gentoo penguin (n = 208); Adelie penguin (n = 46); brown skua (n = 90); Cape petrel (n = 115) and southern giant petrel (n = 263). Serum (n = 673) samples were analysed by competitive ELISA and swabs (n = 614) were tested by one step real-time RT-PCR for avian influenza virus (AIV). Sera from 30 chinstrap penguins, 76 brown skuas and a single Adelie penguin were seropositive for AIV. Thirteen swab samples were AIV positive by RT-PCR, and complete genome sequences of H6N8 AIVs isolated from brown skua and chinstrap penguin in 2011 were obtained. Phylogenetic analyses indicated that all gene segments of the H6N8 viruses were closely related to Argentinian and Chilean AIVs. The prevalence with which we identified evidence for AIVs infection in various Antarctic seabirds suggest viral circulation in Antarctic avifauna and interspecies viral transmission in the sub-Antarctic region.

Influenza A(H11N2) Virus Detection in Fecal Samples from Adélie (Pygoscelis adeliae) and Chinstrap (Pygoscelis antarcticus) Penguins, Penguin Island, Antarctica.

Influenza A viruses infect a range of host species, including a large variety of mammals and more than a hundred species of birds. A total of 95 avian fecal samples were collected from penguin colonies in the South Shetland Islands, close to the Antarctic Peninsula, and tested by reverse transcription-PCR (RT-PCR) to detect avian influenza viruses (AIVs). Five out of seven samples collected from Penguin Island were positive for AIVs. Analysis of the genomes recovered from four samples revealed the detection of influenza A(H11N2) virus in fecal samples from Adélie penguins (Pygoscelis adeliae) and from a colony of chinstrap penguins (Pygoscelis antarcticus). Bayesian phylogeographic analysis revealed the clustering of all currently available H11N2 samples from Antarctica's avifauna in a single cluster that emerged at least in the early 2010s, suggesting its continued circulation on the continent. Our results reinforce the need for continuous surveillance of avian influenza on the Antarctic continent. IMPORTANCE Although wild birds play a role in the transmission and ecology of avian influenza viruses (AIVs) across the globe, there are significant gaps in our understanding of the worldwide distribution of these viruses in polar environments. In this study, using molecular analysis and full-genome sequencing, we describe the detection of distinct influenza A(H11N2) viruses in fecal samples of penguins in the Southern Shetland Islands, Antarctica. We emphasize the need for virus monitoring as AIVs may have implications for the health of endemic fauna and the potential risk of the introduction of highly pathogenic AIVs to the continent.

Feather mercury levels in beached Magellanic penguin (Spheniscus magellanicus) in northern Argentina during the non-breeding season.

Mercury (Hg) is a great concern for marine environments. Bird feathers have been widely used to assess Hg pollution. In this study, we determine mercury concentrations in body feathers of juvenile Magellanic penguins (Spheniscus magellanicus) from the southeastern sector of Buenos Aires province, Argentina, during a non-breeding season, considering both sexes. Hg levels, considering both females and males together, ranged between 265.5 and 1515.52 ng/g. These levels are well below the concentrations in feathers suggested for taking actions focused on the protection of seabirds. Non-significant differences between sexes regarding Hg levels were found, probably because juveniles were sexually immature and females did not excrete Hg by egg laying yet. Hg concentrations found in this study were an order of magnitude higher than those reported 10 years ago for the species in breeding areas on the Argentine coast. Thus, the present study provides relevant information indicating a possible increase of Hg pollution in the southwestern region of the Atlantic Ocean and thus trigger for the development of monitoring programs and regional strategies to improve the conservation status of this species.

Escherichia coli carrying blaNDM-1 obtained from a migratory penguin (Spheniscus magellanicus) in the Brazilian seacoast.

The reservoirs for NDM-producing Enterobacterales are increasing, not only in hospitals, but also in the environment and in the community, challenging the therapeutic efficacy of carbapenems. We aimed to characterize an isolate of Escherichia coli harboring the blaNDM-1 gene recovered from the bloodstream of a penguin (Spheniscus magellanicus) in Southern Brazil. A total of 74 bacterial isolates recovered from arterial blood samples from dead birds were submitted to species identification and antibiotic susceptibility evaluation. One isolate presented resistance to carbapenems (E. coli 89PenNDM) and proved to harbor the blaNDM-1 gene by multiplex high-resolution melting real-time PCR (PCR-HRM). Conjugation experiments indicated that the blaNDM-1 was transmissible to E. coli J53. Whole genome sequencing (WGS) confirmed the presence of the blaNDM-1 gene in a conjugative plasmid (IncA/C2 plasmid) in both the E. coli 89PenNDM and its transconjugants. The isolate was classified as ST 156 and many other resistance genes (e.g., sul1, sul,2, strA, floR, tet(A)) were identified, all carried in the same IncA/C2 plasmid. This is the first report of blaNDM-1-producing E. coli isolated from a penguin in the Brazilian seacoast. The presence of a carbapenemase gene in wildlife animals is of concern as they may become reservoirs of multidrug-resistant bacteria and disseminate them to the environment.

Ingestion of plastics and other debris by coastal and pelagic birds along the coast of Espírito Santo, Eastern Brazil.

Although the ingestion of plastics and other anthropogenic debris by seabirds is a global problem, few studies have employed standardized protocols to quantify and classify the debris ingested by seabirds in the Southwest Atlantic. We evaluated the ingestion of marine debris (items >0.1 mm) by 126 coastal and pelagic birds (19 species) along the coast of Espírito Santo, Eastern Brazil. Debris were found in 30% of birds examined (11 species). Particles <1 mm accounted for 35% of all debris items. Most ingested debris were plastics (97%). Ingestion of >0.1 g of plastic debris was recorded in five species: Atlantic yellow-nosed albatrosses (Thalassarche chlororhynchos), Cory's shearwaters (Calonectris borealis), Manx shearwaters (Puffinus puffinus), brown boobies (Sula leucogaster), and Magellanic penguins (Spheniscus magellanicus). Our findings suggest that the ingestion of marine debris, especially plastics, is a common problem for coastal and pelagic birds in tropical Southwest Atlantic waters.

Adenovirus Diversity in Fur Seal and Penguin Colonies of South America.

Adenoviruses are medium size nonenveloped viruses with a trend of coevolution with their hosts. We surveyed South American fur seals (Arctocephalus australis) and Humboldt penguins (Spheniscus humboldti) for adenoviruses at two sites from 2009 to 2012. Despite the common pattern of host specificity, some of the adenoviruses in our study were present in samples from unexpected host species. We identified mastadenoviruses, aviadenoviruses, and siadenoviruses in A. australis from Peru and Chile and in S. humboldti from Peru. The El Niño Southern Oscillation (ENSO) significantly reduces the productivity of the Humboldt upwelling system, which can change trophic and other ecological interactions, facilitating exposure to new pathogens. One aviadenovirus was detected in both the penguins and the fur seals, an interclass distance. This finding occurred only during the 2009 ENSO and not in 2010 or 2012. Further studies of viral diversity in sites with high-density mixed species populations are necessary to better understand viral evolution and the effect of environmental change on viral evolution and host specificity.

Consequences of phenological shifts and a compressed breeding period in Magellanic penguins.

Phenological shifts may ameliorate negative effects of climate change or create carryover effects and mismatches that decrease fitness. Identifying how phenological shifts affect performance is critical for understanding how individuals and populations will respond to climate change, but requires long-term, longitudinal data. Using 34 yr of data from the Magellanic penguin (Spheniscus magellanicus) colony at Punta Tombo, Argentina, we examined the consequences of the delayed onset of breeding (i.e., arrival and egg-laying dates) that has occurred at the colony since 1983. To understand how the delay propagates through the rest of the reproductive cycle, we identified phenological trends in hatch and fledge dates. Median hatch dates were 0.29 d later each year, amounting to a 10-d shift over the course of the study. Median fledge dates did not shift over the 34-yr period, however, thus shortening the median nestling period duration by 14%. We tested several predictions regarding performance outcomes of the compressed nestling period, finding that later-hatched chicks fledged significantly younger than earlier-hatched chicks, and that younger fledglings left the colony with smaller bills and with more chick down. Interestingly, although younger chicks fledged significantly lighter and in worse body condition than older fledglings early in the study, this trend reversed over time, with younger chicks actually fledging heavier and in better body condition in more recent years. Smaller and lighter fledglings were less likely to recruit to the colony as adults. We find that delayed breeding has significantly compressed nestling periods at Punta Tombo, influencing chick growth and fledgling condition. These findings highlight the importance of studying phenology across multiple life events to understand the consequences of phenological shifts for organismal fitness.

Occurrence and Quantification of Antimicrobial Resistance Genes in the Gastrointestinal Microbiome of Two Wild Seabird Species With Contrasting Behaviors.

Antimicrobial resistance genes (ARGs) are environmental pollutants and anthropization indicators. We evaluated human interference in the marine ecosystem through the ocurrence and quantification (real-time PCRs) of 21 plasmid-mediated ARGs in enema samples of 25 wild seabirds, upon admission into rehabilitation: kelp gull (Larus dominicanus, n = 14) and Magellanic penguin (Spheniscus magellanicus, n = 11). Overall, higher resistance values were observed in kelp gulls (non-migratory coastal synanthropic) in comparison with Magellanic penguins (migratory pelagic non-synanthropic). There were significant differences between species (respectively, kelp gull and Magellanic penguin): ARGs occurrence (bla TEM [p = 0.032]; tetM [p = 0.015]; tetA [p = 0.003]; and sulII [p = 0.007]), mean number of ARGs per sample (p = 0.031), ARGs mean load percentage (aadA [p = 0.045], tetA [p = 0.031], tetM [p = 0.016], bla TEM [p = 0.032], sulII [p = 0.008]), percentage of genes conferring resistance to an antimicrobial class (betalactams [p = 0.036] and sulfonamides [p = 0.033]), mean number of genes conferring resistance to one or more antimicrobial classes (p = 0.024]), percentage of multiresistant microbiomes (p = 0.032), and clustering (p = 0.006). These differences are likely due to these species' contrasting biology and ecology - key factors in the epidemiology of ARGs in seabirds. Additionally, this is the first report of mecA in seabirds in the Americas. Further studies are necessary to clarify the occurrence and diversity of ARGs in seabirds, and their role as potential sources of infection and dispersal within the One Health chain of ARGs.

Antarctic krill fishery effects over penguin populations under adverse climate conditions: Implications for the management of fishing practices.

Fast climate changes in the western Antarctic Peninsula are reducing krill density, which along with increased fishing activities in recent decades, may have had synergistic effects on penguin populations. We tested that assumption by crossing data on fishing activities and Southern Annular Mode (an indicator of climate change in Antarctica) with penguin population data. Increases in fishing catch during the non-breeding period were likely to result in impacts on both chinstrap (Pygoscelis antarcticus) and gentoo (P. papua) populations. Catches and climate change together elevated the probability of negative population growth rates: very high fishing catch on years with warm winters and low sea ice (associated with negative Southern Annular Mode values) implied a decrease in population size in the following year. The current management of krill fishery in the Southern Ocean takes into account an arbitrary and fixed catch limit that does not reflect the variability of the krill population under effects of climate change, therefore affecting penguin populations when the environmental conditions were not favorable.

Enterococci from Wild Magellanic Penguins (Spheniscus magellanicus) as an Indicator of Marine Ecosystem Health and Human Impact.

Enterococci are commensals that proliferated as animals crawled ashore hundreds of millions of years ago. They are also leading causes of multidrug-resistant hospital-acquired infections. While most studies are driven by clinical interest, comparatively little is known about enterococci in the wild or the effect of human activity on them. Pharmaceutical pollution and runoff from other human activities are encroaching widely into natural habitats. To assess their reach into remote habitats, we investigated the identity, genetic relatedness, and presence of specific traits among 172 enterococcal isolates from wild Magellanic penguins. Four enterococcal species, 18 lineage groups, and different colonization patterns were identified. One Enterococcus faecalis lineage, sequence type 475 (ST475), was isolated from three different penguins, making it of special interest. Its genome was compared to those of other E. faecalis sequence types (ST116 and ST242) recovered from Magellanic penguins, as well as to an existing phylogeny of E. faecalis isolated from diverse origins over the past 100 years. No penguin-derived E. faecalis strains were closely related to dominant clinical lineages. Most possessed intact CRISPR defenses, few mobile elements, and antibiotic resistances limited to those intrinsic to the species and lacked pathogenic features conveyed by mobile elements. Interestingly, plasmids were identified in penguin isolates that also had been reported for other marine mammals. Enterococci isolated from penguins showed limited anthropogenic impact, indicating that they are likely representative of those naturally circulating in the ecosystem inhabited by the penguins. These findings establish an important baseline for detecting the encroachment of human activity into remote planetary environments.IMPORTANCE Enterococci are host-associated microbes that have an unusually broad range, from the built hospital environment to the guts of insects and other animals in remote locations. Despite their occurrence in the guts of animals for hundreds of millions of years, we know little about the properties that confer this range or how anthropogenic activities may be introducing new selective forces. Magellanic penguins live at the periphery of human habitation. It was of interest to examine enterococci from these animals for the presence of antibiotic resistance and other markers reflective of anthropogenic selection. Diverse enterococcal lineages found discount the existence of a single well-adapted intrinsic penguin-specific species. Instead, they appear to be influenced by a carnivorous lifestyle and enterococci present in the coastal sea life consumed. These results indicate that currently, the penguin habitat remains relatively free of pollutants that select for adaptation to human-derived stressors.

Atrophic Proventriculitis Associated with Gravid Females of Tetrameres sp. (Nematoda: Tetrameridae) in the Magellanic Penguin (Spheniscus magellanicus) on the Coast of Brazil.

The present study offers the first description of proventriculitis associated with the presence of gravid female nematodes of the genus Tetrameres (Nematoda: Tetrameridae) in 3 juvenile Magellanic penguins (Spheniscus magellanicus) found dead on the coast of Brazil. This study broadens knowledge on parasites associated with these hosts and the real impact of this association.

HEMATOLOGY AND PLASMA CHEMISTRY VALUES IN BEACHED MAGELLANIC PENGUIN (SPHENISCUS MAGELLANICUS) IN NORTHERN ARGENTINA DURING THE NONBREEDING SEASON.

Seabirds have been widely used for monitoring the health of the oceans in diverse marine regions. Among low-cost survey strategies, systematic surveys of seabirds beached on coasts have been developed since the 20th century. However, these studies do not always address blood aspects. The assessment of the health status of birds based on the analysis of hematological and plasma chemistry is crucial to evaluate the overall health status profile of live organisms. Here, the authors study the variability of blood parameters by sex, age class, and year of beached Magellanic Penguin during the nonreproductive period in northern Argentina. Of 44 penguins, 77% were categorized as younger juveniles and the rest as older juveniles, and were captured and studied in coastal areas of Buenos Aires Province during the summers of 2017 and 2018. The mean body weight of beached penguins was affected by the age class of the individuals; most of the younger juveniles showed poor condition in terms of body mass (1,761 ± 235 g). No significant differences were observed in body weight between years and sex. Still, there were significant differences between years for alkaline phosphatase (ALP) and creatine phosphokinase (CPK) values. Twelve of the 20 blood parameters analyzed differ significantly with the age class of the beached penguins; younger juveniles were in a state of inanition. Our results may serve as a necessary first step in improving the conservation status of the Magellanic Penguin in nonbreeding grounds of Argentina, and call for a better knowledge of the health status of the species along its annual cycle.

SEROLOGICAL SURVEY FOR SELECT INFECTIOUS AGENTS IN WILD MAGELLANIC PENGUINS (SPHENISCUS MAGELLANICUS) IN ARGENTINA, 1994-2008.

Despite being the most numerous penguin species in South America, exposure of the Magellanic Penguin (Spheniscus magellanicus) to pathogens has not yet been thoroughly assessed. We collected serum from 1,058 Magellanic Penguins at 10 breeding colonies along the entire latitudinal range of this species in Argentina. The work spanned 10 breeding seasons over 15 yr (1994-2008). Sera were tested for antibodies to select infectious agents. Antibodies reacting against 16 pathogens were detected (seroprevalence): Aspergillus sp. (15.1%), Chlamydia psittaci (6.5%), Salmonella Pullorum (3.1%), Salmonella Typhimurium (81.3%), Aviadenovirus sp. (18.1%), Duck atadenovirus A (23.6%), Anatid herpesvirus 1 (0.7%), Avian orthoreovirus (3.3%), Avian coronavirus M41 (43.5%), Avian coronavirus C46 (59.8%), Avian coronavirus A99 (37.4%), Avian coronavirus JMK (40.2%), Tremovirus A (0.3%), Avian avulavirus 1 (44.0%), Avian avulavirus 2 (43.8%), and Avian avulavirus 3 (46.6%). No antibodies were detected against nine infectious agents: Gallid alphaherpesvirus 1, Gallid alphaherpesvirus 2, Infectious bursal disease virus, Avastrovirus 2, West Nile virus, Eastern equine encephalitis virus, Venezuelan equine encephalitis virus, Western equine encephalitis virus, and Influenza A virus. While restricted by limitations inherent to serological methods, our results provide baseline knowledge for a key species in the South Atlantic Ocean. This information is valuable for adaptive conservation management in a time of increasing environmental stressors affecting the Patagonian Sea, one of the world's richest pelagic seabird communities.