In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (Lama guanicoe), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.

Environmental microbes routinely colonize wildlife body surface microbiota. However, animals experience dynamic environmental shifts throughout their daily routine. Yet, the effect of ecological shifts in wildlife body surface microbiota has been poorly explored. Here, we sequenced the hypervariable region V3–V4 of the 16S rRNA gene to characterize the body surface microbiota of wild Magellanic penguins (Spheniscus magellanicus) under two ecological contexts: (1) Penguins walking along the coast and (2) Penguins sheltered underground in their nest, across three subantarctic breeding colonies in the Magellan Strait, Chile. Despite ecological contexts, our results revealed that Moraxellaceae bacteria were the most predominant and abundant taxa associated with penguin body surfaces. Nevertheless, we detected colony‐specific core bacteria associated with penguin bodies. The most abundant were: Deinococcus in the Contramaestre colony, Fusobacterium in the Tuckers 1 colony, and Clostridium sensu stricto 1 in the Tuckers 2 colony. Our results give a new perspective on the niche environmental hypothesis for wild seabirds. First, the ecological characteristics of each colony were associated with the microbial communities from the nest soil and the body surface of penguins inside the nests. For example, in the colonies with heterogenous vegetation cover (i.e. the Tuckers Islets), there was a similar microbial composition between the nest soil and the body surface of penguins. In contrast, on the more arid colony (Contramaestre), we detected differences in the microbial communities between the nest soil and the body surface of penguins.

Coastal food webs are sustained by two contrasting energy channels—a fast pelagic pathway fueled by phytoplankton and a slow benthic pathway built on detrital processing—yet whether these channels remain segregated or become progressively coupled as energy moves toward higher consumers is still poorly resolved, particularly in remote, environmentally variable systems. We tested these competing scenarios—channel compartmentalization versus channel coupling—using carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotopes across a four-level food web in the Francisco Coloane Marine Coastal Protected Area, a subantarctic system in the Strait of Magellan, Chile. Lower-trophic consumers showed strong isotopic differentiation, tracking access to distinct basal resources, but this segregation gave way to substantial niche convergence at intermediate trophic levels, where overlap probabilities exceeded 60%. Macroalgal-derived carbon dominated assimilation across resident consumers (50–80%), while sediment organic matter acted as an integrative pool rather than an independent pathway, blending detrital inputs from multiple sources. The clearest evidence for channel coupling came from the squat lobster Grimothea gregaria: its pelagic and benthic life stages occupied opposite ends of the isotopic gradient, showing that a single species can physically cross channels that appear isotopically segregated at the community level. Together, these results indicate that benthic and pelagic energy pathways in this protected area are not independent but progressively integrated as energy moves up the food web—a pattern with direct implications for how spatial management should treat habitat connectivity in coastal marine reserves.