Model thresholds are more important than presence location type: Understanding the distribution of lowland tapir (Tapirus terrestris) in a continuous Atlantic forest of southeast Brazil

Modeling the distribution of rare and endangered species is challenging, and there is substantial debate regarding what species distribution models (SDMs) actually represent. Here I investigated whether locations of different lowland tapir signs (feces, trails and tracks) generated different distributions of suitable habitat using a presence-only species distribution modeling technique. Comparison of the equivalence and overlap of the predicted distributions showed no significant differences between the different signs. The contribution of the 11 variables used to build the distribution models was also similar between signs. Although predictions from different signs were similar, the use of different threshold selection methods generated substantially different suitable areas and omission errors. These results highlight the importance of a fundamental understanding of species natural history to determine not only appropriate model parameters, but also the biological relevance of SDMs. My findings also support the need for healthy skepticism regarding what is represented by presence-only species distributions. To help address this skepticism I conclude by providing guidelines for generating reliable local-scale distribution models. © Darren Norris

The Spectroscopic Age of 47 Tuc

High signal-to-noise integrated spectra of the metal-rich globular cluster 47 Tuc, spanning the H-gamma(HR) and Fe4668 line indices, have been obtained. The combination of these indices has been suggested (Jones & Worthey 1995, ApJ, 446, L31) as the best available mechanism for cleanly separating the age-metallicity degeneracy which hampers the dating of distant, unresolved, elliptical galaxies. For the first time, we apply this technique to a nearby spheroidal system, 47 Tuc, for which independent ages, based upon more established methods, exist. Such an independent test of the technique's suitability has not been attempted before, but is an essential one before its application to more distant, unresolved, stellar populations can be considered valid. Because of its weak series of Balmer lines, relative to model spectra, our results imply a spectroscopic ``age'' for 47 Tuc well in excess of 20 Gyr, at odds with the colour-magnitude diagram age of 14+/-1 Gyr. The derived metal abundance, however, is consistent with the known value. Emission ``fill-in'' of the H-gamma line as the source of the discrepancy cannot be entirely excluded by existing data, although the observational constraints are restrictive.Comment: 17 pages, 4 figures, LaTeX, accepted for publication in The Astronomical Journal, also available at http://casa.colorado.edu/~bgibson/publications.htm

Anthropogenic influences on the distribution of a threatened apex-predator around sustainable-use reserves following hydropower dam installation

Although previous studies demonstrate declines in many large bodied species following hydropower dam installation, others suggest that some species, including the giant otter (Pteronura brasiliensis) may return to newly created reservoir habitats. Yet, there is a lack of evidence to support such theories. Here, we analyzed the effects of a hydropower dam on giant otters using a before-after control-impact study design in the eastern Brazilian Amazon. We collected data 3 years before (2011–2012 and 2015) and after (2017–2019) dam construction, totaling 6,459 km of surveys along rivers with 43 direct sightings of giant otters. Contrary to expectations, our results revealed that giant otters did not remain nor did they return to the dam reservoir. Beyond the zone directly impacted by the dam giant otter occurrence and relative abundance declined next to sustainable-use reserves where the river was more intensely used by people. Our study showed that in the absence of active management sustainable-use reserves and low human density were not sufficient to maintain this apex-predator. Our findings suggest a need to proactively create and maintain areas with low levels of anthropogenic disturbance to enable sustainable coexistence between energy demands and biodiversity across Amazonia

Feature coding dataset for trained and untrained working memory tasks in randomized controlled trials of working memory training.

The data presented in this article are produced as part of the original research article entitled "Working memory training involves learning new skills" (Gathercole, Dunning, Holmes & Norris, in press). This article presents a dataset of coded features for pairs of trained and untrained working memory (WM) tasks from randomized controlled trials of WM training with active control groups. Feature coding is provided for 113 untrained WM tasks each paired with the most similar task in the training program, taken from 23 training studies. A spreadsheet provides summary information for each task pair, its transfer effect size, and coding of the following features for each task: stimulus category, stimulus domain, stimulus modality, response modality, and recall paradigm

Short term patterns of germination in response to litter clearing and exclosure of large terrestrial vertebrates along an Amazon forest regrowth gradient

Efforts to restore tropical forest ecosystem services depend on understanding the barriers to germination of species of economic and cultural interest. Here we use two important non-timber forest product species (NTFP: Inga capitata. Desv. – Fabaceae and Euterpe oleracea Mart. – Arecaeae) to compare germination across a forest regrowth gradient in the northeast Brazilian Amazon. Experimental treatments were used to examine the effects of mid to large-bodied vertebrates and litter cover on seed fate (germination, removal and invertebrate infestation) in 15 lowland sites within small-holder properties. Regrowth stage was classified into three groups, with five sites each of: late second-regrowth forest, early second-regrowth forest and abandoned pasture. We conducted a paired split-plot experiment using experimental plots composed of a vertebrate exclosure versus an open treatment and subplots with and without litter. We used Generalized Linear Mixed-Effects Models (GLMMs) to compare additive and interaction effects of treatments across regrowth stages compared with 15 paired control sites. We found that the effects of regrowth stage and exclosure were species specific and these effects differed between responses (germination, removal and invertebrate infestation). Clearing litter generated a significant effect only for invertebrate infestation, which increased in the cleared plots. Our findings show that seed removal limits germination success for both species across forest regrowth stages, with invertebrate infestation also having important but secondary effects. Increased removal and unfavorable abiotic conditions make direct seeding unviable in pasture sites. We suggest that direct seeding is a viable alternative for the establishment of these widely available NTFP species in late and early regrowth forests. © 2017 The Author

Riqueza e composição de vertebrados em latrinas ativas e inativas de Pteronura brasiliensis (Carnivora, Mustelidae) na Amazônia Oriental, Brasil

This study aimed to evaluate the richness and composition of the medium and large sized vertebrates in active and inactive latrines of Giant otters [Pteronura brasiliensis (Gmelin, 1788)] in a Sustainable Use conservation unit in the Eastern Brazilian Amazon. The study was performed in 45 latrines along 230 km of the Falsino and Araguari rivers (0°55'N, 51°35'W) and from this total, 24 presented fresh feces of Giant otters while 21 presented only old feces. From July to November 2012 each latrine was continuously monitored with a camera trap set to operate for 24 hours. The effort resulted in 458.8 camera trap/days, with 247.5 camera trap/days in latrines with fresh feces and 211.3 camera trap/ days with old feces. From this effort we obtained photos from a total of 22 vertebrate species. Most species photographed at latrines were mammals (n = 13), followed by birds (n = 6) and reptiles (n = 3). The most frequently photographed species were paca [Cuniculus paca (Linnaeus, 1766), n = 21], ocelot [Leopardus pardalis (Linnaeus, 1758), n = 11], white-tipped dove (Leptotila verreauxi Bonaparte, 1855, n = 8), giant otter [Pteronura brasiliensis (Gmelin, 1788), n = 7], and tapir [Tapirus terrestris (Linnaeus, 1758), n = 6], that accounted for 55.8% of all records. Most records (69.5%) were obtained in latrines with fresh feces and the number of vertebrate species was greater (n = 19) than in latrines with old feces (n = 15). However, the dissimilarity between the vertebrate communities of latrines with fresh and old feces did not differ statistically. However, the mean visitation of vertebrates to latrines with fresh feces was slightly higher than with old feces, although this difference was only marginally significant. There was an increase in records of felids [Leopardus pardalis, Leopardus wiedii (Schinz, 1821), and Panthera onca (Linnaeus, 1758)] in latrines with old feces, but it was only marginally significant. Thus, the presence of fresh feces of giant otters seems to increase the records of vertebrates, being especially important for groups with similar trophic guild

Working memory training involves learning new skills

We present a new framework characterizing training-induced changes in WM as the acquisition of novel cognitive routines akin to learning a new skill. Predictions were tested in three studies analyzing the transfer between WM tasks following WM training. Study 1 reports a meta-analysis establishing substantial transfer when trained and untrained tasks shared either a serial recall, complex span or backward span paradigm. Transfer was weaker for serial recall of verbal than visuo-spatial material, suggesting that this paradigm is served by an existing verbal STM system and does not require a new routine. Re-analysis of published WM training data in Study 2 showed that transfer was restricted to tasks sharing properties proposed to require new routines. In a re-analysis of data from four studies, Study 3 demonstrated that transfer was greatest for children with higher fluid cognitive abilities. These findings suggest that development of new routines depends on general cognitive resources and that they can only be applied to other similarly-structured tasks

Carbon nutrition of \u3cem\u3eEscherichia coli\u3c/em\u3e in the mouse intestine

Whole-genome expression profiling revealed Escherichia coli MG1655 genes induced by growth on mucus, conditions designed to mimic nutrient availability in the mammalian intestine. Most were nutritional genes corresponding to catabolic pathways for nutrients found in mucus. We knocked out several pathways and tested the relative fitness of the mutants for colonization of the mouse intestine in competition with their wild-type parent. We found that only mutations in sugar pathways affected colonization, not phospholipid and amino acid catabolism, not gluconeogenesis, not the tricarboxylic acid cycle, and not the pentose phosphate pathway. Gluconate appeared to be a major carbon source used by E. coli MG1655 to colonize, having an impact on both the initiation and maintenance stages. N-acetylglucosamine and N-acetylneuraminic acid appeared to be involved in initiation, but not maintenance. Glucuronate, mannose, fucose, and ribose appeared to be involved in maintenance, but not initiation. The in vitro order of preference for these seven sugars paralleled the relative impact of the corresponding metabolic lesions on colonization: gluconate \u3e N-acetylglucosamine \u3e N-acetylneuraminic acid = glucuronate \u3e mannose \u3e fucose \u3e ribose. The results of this systematic analysis of nutrients used by E. coli MG1655 to colonize the mouse intestine are intriguing in light of the nutrient-niche hypothesis, which states that the ecological niches within the intestine are defined by nutrient availability. Because humans are presumably colonized with different commensal strains, differences in nutrient availability may provide an open niche for infecting E. coli pathogens in some individuals and a barrier to infection in others