https://rdi.uncoma.edu.ar/handle/uncomaid/15887 2026-07-08T06:16:47Z https://rdi.uncoma.edu.ar/handle/uncomaid/19516 Autotomy in Achala copper lizard: do sex and body size traits influence tail loss and regeneration? Autotomy in animals, the voluntary loss of a body part at a specific location, is a widespread behaviour observed across various groups. This mechanism provides several advantages, such as predator evasion, escape from entrapments, and even reduced injury costs from agonistic interactions. Lizards display tail autotomy in response to predation and intraspecific aggression. Moreover, it is common for these reptiles to have sexually dimorphic traits, such as colouration and body size, which may influence predation risk and consequently their antipredatory strategies. This study focuses on the Achala copper lizard (Pristidactylus achalensis) which inhabits an isolated highland ecosystem in central Argentina. This species is an ideal study model due to its territorial and aggressive behaviour, high intraspecific competition and sexual dichromatism. The aims of this study were to determine the influence of sex and body size on the occurrence of tail autotomy in P. achalensis. Additionally, we assessed the cost of autotomy by analysing the distance between the vent and the tail cut. Furthermore, we investigated the possibility of repeated tail autotomy by a single individual. Our results showed that in P. achalensis, sex and body size interacted significantly resulting in different patterns of tail autotomy. In females, the frequency of autotomy increased gradually with body size, whereas in males it increased more abruptly and reached its maximum frequency at smaller body sizes than in females. Males presented higher autotomy frequencies than females, likely because they are more likely to be perceived by avian predators than cryptic females. The findings of this study contribute to broadening the knowledge of lizard behaviour, shedding light on the complex interplay between predation, intraspecific competition and reproductive dynamics in this unique species. https://rdi.uncoma.edu.ar/handle/uncomaid/19503 Synthesizing the Impacts of Natural Disturbances and Climate on Patagonian Semiarid Grasslands: Insights From an 18-Year Long-Term Monitoring Study Question: How does the vegetation of northwestern Patagonia grasslands respond to climate fluctuations and disturbances? Location: Northwestern Patagonia, Argentina. Methods: Our study was carried out in livestock- grazed grasslands affected by drought (1998), wildfire (1999), and volcanic ash deposition (2011). We analyzed annual precipitation trends, rainfall-use efficiency, and the relationship between ENSO events and seasonal climate. Before a severe drought, we monitored vegetation at three sites over 18 years (1999–2017). Only the North and South sites were affected by fire, while the unburned Control site was impacted by grazing and volcanic ash deposition. We used linear mixed-effects models to assess the relationships between vegetation cover and species richness with precipitation, temperature, and disturbances. We calculated species turnover, diversity, evenness, and similarity, and constructed a native reference community. Results: Precipitation showed a negative trend from 1991 to 2018. Rainfall-use efficiency was low in 2006 and high in 2016. ENSO signals were stronger in spring than in winter. Spring precipitation and temperature enhanced both cover and richness. Annual species responded positively to annual and spring precipitation. In the Control site, plant cover recovered faster post- drought than post-eruption, whereas species richness showed the opposite pattern. Grassland recovers fast after fire compared to other disturbances. Species turnover was lowest 8 years post-drought and 6 years post-eruption. Diversity and evenness increased over time, and were higher in burned sites compared to the Control. The community most similar to the native reference com- munity was the recently burned grassland. Conclusions: Our long-term study shows that seasonal climate and disturbances shape grassland dynamics, which can be interpreted within the framework of Mediterranean-climate grassland ecology. Grassland managers in northwestern Patagonia could benefit from our findings by adapting livestock management practices to enhance grassland post- disturbance recovery and reduce the invasion of opportunistic species. https://rdi.uncoma.edu.ar/handle/uncomaid/19469 Exploring mitochondrial diversity in the species-rich genus Liolaemus: the interplay between isolation by distance and environmental thermal variability Intraspecific genetic variation enhances a species´ capacity to endure diverse environments. Such variation can drive genetic divergence among populations, often manifesting as isolation by distance (IBD). Here, we investigated how ecological, environmental, life-history, body size, and phylogenetic factors shape IBD and nucleotide diversity (π) using two mitochondrial genes in Liolaemus lizards. From GenBank database, we examined two genes: Cytochrome b (Cytb; 88 species) and 12S ribosomal RNA (12S rRNA; 37 species), integrating them with geographic information of each species. We then estimated Mantel’s correlation coefficient (r), isolation-by-distance slope (βIBD), and π for each genetic marker, then evaluated the relationship between βIBD and π. IBD was present in 55.40% of species for Cytb and 42.42% for 12S rRNA. Species from higher altitudes were associated with steeper βIBD in Cytb, whereas larger species showed a weaker βIBD-Cytb effect. Bayesian generalized linear mixed models indicated that IBD positively explained π for both genes. In Cytb, π declined with increasing variability in environmental temperature and larger body size, whereas π in 12S rRNA was negatively associated with annual mean temperature. Our results suggest that, although IBD and environmental temperature may generate shared patterns influencing mitochondrial genetic diversity in Liolaemus lizards, the two mitochondrial markers also exhibit distinct trends in how they shape genetic structure and diversity. This study represents an initial step toward understanding how mitochondrial genetic diversity may be maintained and structured within this species-rich genus. https://rdi.uncoma.edu.ar/handle/uncomaid/19195 Honeydew-mediated indirect interactions: magnet and spillover effects of an invasive willow–aphid complex. Abundance and richness of insect pollinators that fed on or collected the honeydew excreted by the giant willow aphid on invaded willows. Then, to assess associational effects, we compared the abundance and species richness of floral visitors with a potential pollinator role (hereafter pollinators) on S. chilensis located near and far away from the willow-aphid complex.