Wildlife Conservation Society Argentina

Abstract Gulls are opportunistic birds that take advantage of anthropogenic food subsidies, often leading to conflicts with human populations. In Argentina, the Kelp Gull ( Larus dominicanus ) is distributed along the Atlantic coast and in some freshwater environments. We evaluated the trophic ecology of a population nesting in Nahuel Huapi Lake, with access to anthropogenic food subsidies. We used complementary methodologies (pellets, stomach contents, stable isotopes) to determine their diet during the incubation and chick‐rearing periods in 2019 and 2020, in two colonies (~261 and 314 nests) located close to urban areas. Pellets showed a relatively high percentage of anthropogenic food resources (>40%) and terrestrial arthropod remains (>40%) in all breeding stages and years, except during incubation in 2019, when >70% of rodent remains were recorded. Stomach contents also showed a high percentage of garbage in both years (40–80% incubating adults, 30–40% chicks) and of terrestrial arthropods (30–60%). Isotopic niche width differed between years, and the isotopic composition ( δ 13 C and δ 15 N) of adult and chick red blood cells showed a significant proportion of terrestrial resource (natural and anthropogenic items combined) consumption in all stages and years and a lower proportion of garbage in 2019. This study shows the generalist and opportunistic habits of Kelp Gulls at the Nahuel Huapi Lake colonies, evidenced by the wide variety of food consumed and the ability to take advantage of the food that becomes available in the natural environment (e.g., rodent outbreak throughout 2019). This study of the trophic ecology of the Kelp Gulls in the Nahuel Huapi Lake provides essential baseline information for future assessments of the gulls' demographic behaviour and their role within the urban‐lake‐terrestrial ecosystem. Further studies to understand the use of resources during the non‐breeding season are recommended.

IntroductionMarket-driven poaching and unsustainable wildlife harvest are significant drivers of population decline for numerous plant and animal species, including high-profile species like Asian and African elephants, wild cats, sharks and rays, and pangolins. This publication reviews the emerging role of conservation technology in combating this trade.Technologies and applicationsWe showcase how innovative technological tools are revolutionizing the detection and disruption of illegal and unsustainable wildlife trade, with a focus on those available to frontline staff working to prevent poaching and trafficking from source sites. We consider a diverse array of deployed technologies ranging from open-source software platforms, AI, and mobile apps to cutting-edge hardware, including camera traps, acoustic sensors, and remote sensing tools.Case studiesTo demonstrate the complex threats posed by IUWT to wildlife and the consequent need for tailored solutions, we present two case studies, one terrestrial and one marine, showcasing the importance of appropriate suites of technology tools for conservation implementation.DiscussionTechnology has potential to empower rangers, park staff, wildlife and fisheries inspectors, customs officials, police, and conservation practitioners with unprecedented capabilities to monitor threatened wildlife, detect illegal activities, gather evidence, and support law enforcement interventions.

ABSTRACTAimTo understand the influence of Andean uplifts and glacial cycles on South American biodiversity, we delve into the population genetics and evolutionary history of a unique subantarctic island raptor specialised in exploiting marine food webs.LocationIslands in Tierra del Fuego and Malvinas/Falklands.Time periodLast glacial period to the present.Taxon Phalcoboenus australis. MethodsWe used RAD sequencing to assess genetic diversity, population structure and to model demographic history through descriptive and hypothesis‐based evolutionary methods.ResultsWe found evidence of two independent lineages: one inhabiting the Fuegian archipelago and the other one occurring in the Islas Malvinas/Falkland Islands, with the latter presenting higher genetic diversity and evidence of finer‐scale population structure. The best supported demographic scenario places the divergence time of these lineages during the last glacial period (ca. 50,000 years ago), with the occurrence of gene flow during the first 27,000 years after their divergence. Recent demographic modelling supports the general pattern of increasing genetic variability as landmasses were uncovered following the glacial period (i.e., the Fuegian archipelago) in contrast with a decrease in genetic diversity associated to island fragmentation (i.e., in the Islas Malvinas/Falkland Islands).Main ConclusionsWe propose that post‐glacial sea level rise and the subsequent isolation across the submerging Patagonian Shelf have driven population fragmentation and recent genetic structure in this species. Our findings advocate for recognising the two identified divergent lineages as distinct conservation units. We highlight the intricate interplay of ecological factors, glacial cycles and population dynamics in shaping the evolutionary trajectory of this unique and threatened raptor species in southern South America.

Las aves marinas son uno de los grupos de aves más amenazados a nivel global. Sin embargo, varias actividades humanas también proveen recursos que estas aves pueden utilizar en su beneficio. Se presenta una síntesis del conocimiento sobre el uso de recursos antrópicos por parte de las aves marinas que se reproducen en el litoral patagónico argentino. Las investigaciones realizadas indican que un total de quince especies utilizan recursos antrópicos para su alimentación y/o nidificación durante los meses de la temporada reproductiva. De los diferentes recursos de alimento de origen antrópico identificados, el provisto por la pesca comercial durante las operaciones en el mar es utilizado por el mayor número de especies (doce) y el que representa la oferta de mayor extensión geográfica. Un menor número de especies hacen uso de residuos urbanos (cuatro) y de recursos derivados de la pesca recreativa (tres) y la actividad agrícola-ganadera (seis). En relación a los recursos antrópicos para nidificar, la información disponible es mayormente anecdótica, e indica que seis especies aprovechan ambientes y/o estructuras antrópicas para construir sus nidos, y siete incorporan materiales antrópicos en los mismos. Se discuten los posibles beneficios y costos asociados a dicho uso, y se consideran los posibles conflictos derivados en relación a otras especies y las poblaciones humanas. Se espera que esta síntesis de conocimiento, identificando limitaciones de estudios previos y vacíos de información, contribuya a la definición de prioridades de investigación y al desarrollo de recomendaciones para el monitoreo de las interacciones entre aves marinas reproductoras y actividades humanas.