Browsing by Author "Infante, Jose"

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    Altered fire regimes modify lizard communities in globally endangered Araucaria forests of the southern Andes
    (NATURE PORTFOLIO, 2021) Infante, Jose; Novoa, Fernando J.; Ibarra Eliessetch, José Tomás; Melnick, Don J.; Griffin, Kevin L.; Bonacic, Cristian
    Wildfire regimes are being altered in ecosystems worldwide. The density of reptiles responds to fires and changes to habitat structure. Some of the most vulnerable ecosystems to human-increased fire frequency are old-growth Araucaria araucana forests of the southern Andes. We investigated the effects of wildfires on the density and richness of a lizard community in these ecosystems, considering fire frequency and elapsed time since last fire. During the 2018/2019 southern summer season, we conducted 71 distance sampling transects to detect lizards in Araucaria forests of Chile in four fire "treatments": (1) unburned control, (2) long-term recovery, (3) short-term recovery, and (4) burned twice. We detected 713 lizards from 7 species. We found that the density and richness of lizards are impacted by wildfire frequency and time of recovery, mediated by the modification of habitat structure. The lizard community varied from a dominant arboreal species (L. pictus) in unburned and long-recovered stands, to a combination of ground-dwelling species (L. lemniscatus and L. araucaniensis) in areas affected by two fires. Araucaria forests provided key habitat features to forest reptiles after fires, but the persistence of these old-growth forests and associated biodiversity may be threatened given the increase in fire frequency.
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    Is tourism impacting pumas in the Torres del Paine UNESCO Biosphere Reserve in southern Chile?
    (2023) Cifuentes-Ibarra, Mauricio; Elbroch, L. Mark; Ohrens, Omar; Infante, Jose; Bonacic, Cristian
    Ecotourism generates $7.6 trillion annually and supports 292 million jobs around the world, and because of these benefits, it has been emphasized as a conservation strategy. Ecotourism, how-ever, is not the solution for every community, and there is growing evidence that tourism can have unintended consequences for local people and wildlife, unless well managed. Here, we assessed the relative impacts of anthropogenic activities related to tourism (e.g. road density, distance to ranches and camping areas) and prey distributions on puma occupancy and abun-dance in the open steppe habitat of the southeast portions of the Torres del Paine UNESCO Biosphere Reserve, where pumas are protected. In winter, puma abundance and occupancy were explained by both prey and anthropogenic metrics. In summer, puma abundance was explained by both prey and anthropogenic metrics, but occupancy only by anthropogenic metrics. Across both periods, puma abundance was only explained by anthropogenic metrics, and occupancy was explained by both prey and anthropogenic metrics. Guanacos, the most important prey species for local pumas, never appeared in any top model, except in summer, during which puma abundance was explained by lower not higher guanaco abundance. Not unexpectedly, puma abundance and occupancy were negatively correlated with trail and road density across all analyses. In the high tourism season of summer, roads had 2-3 times the impact on puma abundance than prey metrics in top models. During our study, the average number of monthly visitors per month in summer (November-January) was 892 % higher than winter (May-July). As a whole, we believe our analyses suggest that tourism may be negatively impacting pumas, but the severity of this impact remains questionable. Future work should include studying stress in puma populations experi-encing heavy tourism, simultaneous with the work needed to understand relative thresholds of impact on puma fitness metrics (e.g. survival, hunting success). We believe our work also high-lights the need for standards and guidelines to be created and adopted among those involved in puma tourism in Torres del Paine and beyond.
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    Land use intensification coupled with free-roaming dogs as potential defaunation drivers of mesocarnivores in agricultural landscapes
    (WILEY, 2021) Galvez, Nicolas; Infante, Jose; Fernandez, Adrian; Diaz, Jesus; Petracca, Lisanne
    Land use intensification, by which habitat loss, habitat fragmentation and increased land ownership subdivision occurs, represents one of the largest threats to biodiversity. The extent to which land use intensification affects the presence of native mesocarnivores is largely unexplored, with great implications for all working landscapes where agriculture and native wildlife co-occur. We obtained mesocarnivore detection/non-detection data from 180 4-km(2) sampling units in agricultural landscapes of southern Chile from January to April 2019. We used these data to (a) investigate the associations of private land ownership subdivision, forest fragmentation and forest loss with the occurrence of mesocarnivores using single-species occupancy models, (b) assess patterns of mesocarnivore co-occurrence with free-roaming domestic mesocarnivores (e.g. cats and dogs) using two-species occupancy models and (c) determine whether co-occurrence of native and domestic mesocarnivores led to alterations in species' temporal activity. Land ownership subdivision, rather than habitat loss or fragmentation, had the greatest impact on native mesocarnivore occurrence, with some influence of domestic dogs. Mesocarnivore community occurrence varied from a native to domestic species composition as private land ownership subdivision increased. Native mesocarnivores altered their behaviour temporally when co-occurring with domestics. Lastly, the presence of domestic dogs was associated with an absence of native mesocarnivores, which merits further investigation into the contribution of domestic dogs to a defaunation process in agricultural areas. Policy implications. Our evidence supports focusing efforts in three key dimensions to advance biodiversity conservation in agricultural landscapes. First, private land subdivision represents a robust proxy for measuring anthropogenic impacts on mesocarnivores, and we advocate its use to inform agricultural policy to mitigate a potential defaunation process. Second, there is a need to further engage with landowners and evaluate values, motivation, willingness and action to protect remnant native vegetation and slow land use change. And, lastly, improvements to legislation and conservation marketing strategies on responsible pet ownership are critical to ameliorating the negative impacts of dogs on native wildlife species.
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    Response of mesocarnivores to anthropogenic landscape intensification: activity patterns and guild temporal interactions
    (OXFORD UNIV PRESS INC, 2021) Galvez, Nicolas; Meniconi, Paola; Infante, Jose; Bonacic, Cristian
    Carnivores face important anthropogenic threats in agricultural areas from habitat loss and fragmentation, disturbance by domestic free-roaming dogs and cats, and direct hunting by humans. Anthropogenic disturbances are shifting the activity patterns of wild animals, likely modifying species interactions. We estimated changes in the activity patterns of the mesocarnivore guild of agricultural landscapes of the La Araucania region in southern Chile in response to land-use intensification, comparing intra- and interspecific activity patterns at low and high levels of forest cover, fragmentation, and land ownership subdivision. Our focal species comprise the guina or kod-kod (Leopardus guigna), two fox species (Lycalopex culpaeus and L. griseus), a skunk (Conepatus chinga), and one native mustelid (Galictis cuja), in addition to free-roaming dogs (Canis lupus familiaris) and cats (Felis catus) and their main mammalian prey species (i.e., Rodentia and Lagomorpha). In 23,373 trap nights, we totaled 21,729 independent records of our focal species. Our results show tendencies toward nocturnality at high land-use intensification, with potential impacts on species fitness. Nocturnal mesocarnivores decreased their diurnal/crepuscular activity, while cathemeral activity shifted to nocturnal activity at high land-use intensification, but only when in sympatry with a competitor. High land-use intensification decreased the activity overlap between native and domestic mesocarnivores but increased the overlap between native mesocarnivores. High intensification also reduced overlap with prey species. Notably, foxes displayed peaks of activity opposing those of dogs, and plasticity in activity pattern when in sympatry with dogs, such as strategies to avoid encounters. We stress the need to suppress the free-roaming and unsupervised activity of dogs to mitigate impacts of high land-use intensification on mesocarnivores.