Gerardo Soto

The avifauna of Mocha Island is analysed according to species richness, habitat use, and reproductive status, and the first quantitative population estimates of forest landbirds are presented basing on unbiased survey data as a basis for conservation. We recorded a total of 100 species, including non-breeders. Among all recorded taxa, landbirds (n = 48 spp. or 48 %) exhibit higher species numbers when compared to shore-and seabirds (38), and freshwater birds (14). Within the documented breeding avifauna (n = 54 spp.) landbirds take an even relative higher value, amounting to 88 % (or 42 spp.). Austral and Neotropical species are most numerous within the landbird assemblage, reflecting the closest biogeographical realm. When comparing different Chilean avifaunas, southern mainland ecosystems show the highest landbird richness (90), followed by Chiloe Island (61), Mocha Island (42), and remote Juan Fernandez Islands (11). From line transects surveyed, 884 bird individuals belonging to 18 resident forest landbird species were recorded (averaging 10.3 ind/ha). We calculated the total population size of forest landbirds in the reserve (2300 ha) being 23,681 individuals. Two of the three endemic taxa (Mocha Rayadito and Mocha Chucao) show relatively high population sizes of about 4,100 and 3,700 individuals, respectively. The Mocha Thrush shows a population of about 670 individuals in forests, but is equally abundant in anthropogenic pastures around. Future conservation management of Mocha Island should consider richness, composition, and abundance of landbirds reported in this study, with emphasis on breeding ecology of the three mentioned endemics. Priority should be put on controlling illegal timber extraction, bird hunting and chick collecting, as well as on sensitization of local people to avoid introducing alien species.

Context Interactions between landscape-scale processes and fine-grained habitat heterogeneity are usually invoked to explain species occupancy in fragmented landscapes. In variegated landscapes, however, organisms face continuous variation in micro-habitat features, which makes necessary to consider ecologically meaningful estimates of habitat quality at different spatial scales. Objectives We evaluated the spatial scales at which forest cover and tree quality make the greatest contribution to the occupancy of the long-horned beetle Microplophorus magellanicus (Coleoptera: Cerambycidae) in a variegated forest landscape. Methods We used averaged data of tree quality (as derived from remote sensing estimates of the decay stage of single trees) and spatially independent pheromone-baited traps to model the occurrence probability as a function of multiple cross-scale combinations between forest cover and tree quality (with scales ranging between 50 and 400 m). Results Model support and performance increased monotonically with the increasing scale at which tree quality was measured. Forest cover was not significant , and did not exhibit scale-specific effects on the occurrence probability of M. magellanicus. The interactive effect between tree quality and forest cover was stronger than the independent (additive) effects of tree quality and particularly forest cover. Significant interactions included tree quality measured at spatial scales C200 m, but cross-scale interactions occurred only in four of the seven best-supported models. Conclusions M. magellanicus respond to the high-quality trees available in the landscape rather than to the amount of forest per se. Conservation of viable metapopulations of M. magellanicus should consider the quality of trees at spatial scales [200 m.

Theoretical models predict that animals should make foraging decisions after assessing the quality of available habitat, but most models fail to consider the spatio-temporal scales at which animals perceive habitat availability. We tested three foraging strategies that explain how Magellanic woodpeckers (Campephilus magellanicus) assess the relative quality of trees: 1) Woodpeckers with local knowledge select trees based on the available trees in the immediate vicinity. 2) Woodpeckers lacking local knowledge select trees based on their availability at previously visited locations. 3) Woodpeckers using information from long-term memory select trees based on knowledge about trees available within the entire landscape. We observed foraging woodpeckers and used a Brownian Bridge Movement Model to identify trees available to woodpeckers along foraging routes. Woodpeckers selected trees with a later decay stage than available trees. Selection models indicated that preferences of Magellanic woodpeckers were based on clusters of trees near the most recently visited trees, thus suggesting that woodpeckers use visual cues from neighboring trees. In a second analysis, Cox's proportional hazards models showed that woodpeckers used information consolidated across broader spatial scales to adjust tree residence times. Specifically, woodpeckers spent more time at trees with larger diameters and in a more advanced stage of decay than trees available along their routes. These results suggest that Magellanic woodpeckers make foraging decisions based on the relative quality of trees that they perceive and memorize information at different spatio-temporal scales.

Accurate estimates of the quality and quantity of remnant habitats is critical for planning management activities for the conservation of threatened species. Although habitat quality usually is understood from a multidimen-sional niche space approach, the availability of foraging substrates can be a suitable and more proximate index of habitat quality for species with specialized habitat requirements, like woodpeckers that feed almost exclusively on larvae of wood-boring beetles in the trunks and branches of infested trees. Recent approaches use simple mathematical algorithms on spectral bands called Vegetation Indices (VI) to identify infestations, providing a new opportunity to assess habitat quality for woodpeckers. In this paper, we tested the ability of 102 VI to estimate tree attributes explaining habitat quality for Magellanic woodpeckers for its usage as a reliable foraging habitat quality estimator. We hypothesized that space use of Magellanic woodpeckers is positively associated with the spatial distribution of decayed trees in the landscape. We developed a methodological framework based on high-resolution, multispectral imagery with three basic steps. First, we mapped individual Nothofagus trees based on estimates of species composition from a supervised classification procedure, VI estimates and image segmentation. Second, we selected the best VI predicting the tree quality for Magellanic woodpeckers. Third, we tested these habitat quality predictors, the species composition and tree age, by using two Synoptic Models of Space Use (SMSU) of Magellanic woodpeckers based on very high-frequency (VHF) radio-telemetry and global positioning system (GPS) telemetry data. Generalized Linear Mixed Models (GLMM) showed that the VI that best predicted habitat quality at the tree-scale was the Plant Senescence Reflectance Index (PSRI, computed as [Red-Blue]/Red-edge), included in almost all the most parsimonious models. The most parsimonious SMSU included only PSRI as an independent covariate, with a strong positive relation. Although coefficient differences were found between telemetry data (VHF vs. GPS data) both showed a positive overall response. Consequently, Red-edge based PSRI can be considered a reliable estima-tor of tree-scale foraging habitat quality at landscape extents for future research and management activities including Magellanic woodpeckers living on heterogeneous Nothofagus forests.

Agonistic behavior in woodpeckers has been described for a wide range of species, although previous studies have not reported aggressive encounters resulting in the death of adults. In this study, we provide the first evidence of lethal agonistic behavior between two male Magellanic Woodpeckers  (Campephilus magellanicus) inhabiting Patagonia. This species is commonly regarded as the largest extant Campephilus woodpecker. The agonistic encounter was video recorded within the core territory of the dead individual and his mate, a previously banded and monitored pair, as part of a monitoring research on this species carried out during the last 2 years. A week after the fight, we recorded a non-banded young male
Magellanic Woodpecker accompanying the dead individual’s
mate. This young male Magellanic Woodpecker is potentially the offspring of the former pair or perhaps a new mate replacing the dead individual. From this observation, we deduced that the previously occupied territory of the dead individual, as well as its breeding role, was subjected to reallocation by competing adjacent woodpecker families. This mortality event offers novel insight into the behavior of Magellanic Woodpeckers and suggests that lethal agonistic behavior likely could contribute to territory plasticity and family structure in this species.

Understanding how species respond to habitat structure in landscapes transformed by human activities is crucial to design management strategies that promote the conservation of wildlife in human-created lands. The aim of this study was to test the ecological hypothesis that fine-grain habitat structure may be an important determinant of habitat use of medium-size predators across transformed landscapes when comparing with coarse habitat classification. We assess habitat use of species by using occupancy modeling framework accounting for imperfect detection, and obtained three LiDAR-derived vegetation metrics at different scale to describe the fine-grain habitat structure in a landscape comprised by native forest and exotic tree plantations in central-south Chile. Four species were detected: Lycalopex culpaeus, L. griseus, L. fulvipes and Leopardus guigna, L. culpaeus and L. griseus largely occurred throughout the study area (w = 0.54 ± 0.08 and 0.18 ± 0.04). Coefficients of the better-ranked models based on AIC indicated a positive relation between understory cover at 250 m scale and the habitat use of L. fulvipes, L. guigna and L. griseus, while a negative relation with the habitat use of L. culpaeus. On the other hand, habitat use of L. fulvipes and L. guigna increased as structural diversity of forest increased while the habitat use of L. culpaeus and L. griseus decreased. Low support was found for the habitat use of L. guigna and L. culpeus being affected by habitat type (plantation or native forest). Our results showed that habitat use of these mesocarnivores responded to fine-grain habitat structure attributes as derived from LiDAR, but only some of them responded weakly to habitat type. Both results indicate that understory structure, and not a coarse classification of habitat type, may be better determinants for explaining the habitat use of native carnivores in this landscape comprised by native habitat and forest plantations. Our results can be extended to sustainable management of forest plantations for carnivore conservation by enhancing the vegetation structure of native shrub species within these production-oriented lands.

The ability of animals to collect and use environmental information in fragmented landscapes may considerably  decrease as the spatial scale at which they search for feeding resources increases. Here, we used anindividual-based model to assess the scale-dependent movement patterns of woodpeckers when searching for their main foraging resources (wood-boring larvae). Two movement strategies for woodpeckers were compared in simulated landscapes where resources were spatially clustered at two hierarchical levels (trees and forest patches): (1) “top-down” foragers, whose movement decisions respond primarily to memorized information on forest patches; and (2) “bottom-up” foragers with random, purely exploratory movements that result from tree-scale foraging experiences. Top-down foragers were able to find more resources than bottom-up foragers, except in landscapes with very few and poor quality patches. Thus,the combined use of spatial memory and random exploration should considerably benefit woodpeckers that forage in landscapes with low fragmentation levels. Contrary to our expectations, bottom-up foragers had larger connectivity values by visiting more patches across the landscape. Thus, model results support the idea that as the landscape becomes fragmented the home-range size of woodpeckers increases. We conclude that landscape planning must aim at maintaining habitat quality and quantity above critical thresholds below which woodpeckers both lack enough resources and the ability to make efficient use of memory-based decisions.

It is a long-standing question how tsunamis can influence wild populations of animals and plants. Here, we assessed short-term changes in the population of the critically endangered Juan Ferna´ndez Firecrown (Sephanoides fernandensis) by using abundance data recorded 1 year before and 1 year after the 2010 Chilean tsunami. We tested that the abundance of Firecrowns declined in the areas where the tsunami caused the massive loss of Cabbage Trees, an important seasonal nectar source for Firecrowns. The abundance of Juan Ferna´ndez Firecrowns decreased after the tsunami, but also was affected by the habitat type, altitude, and the abundance of Cabbage Trees.