Fausto Nomura

Increased tolerance to humans among disturbed wildlife

Human disturbance drives the decline of many species, both directly and indirectly. Nonetheless, some species do particularly well around humans. One mechanism that may explain coexistence is the degree to which a species tolerates human disturbance. Here we provide a comprehensive meta-analysis of birds, mammals and lizards to investigate species tolerance of human disturbance and explore the drivers of this tolerance in birds. We find that, overall, disturbed populations of the three major taxa are more tolerant of human disturbance than less disturbed populations. The best predictors of the direction and magnitude of bird tolerance of human disturbance are the type of disturbed area (urbanized birds are more tolerant than rural or suburban populations) and body mass (large birds are more tolerant than small birds). By identifying specific features associated with tolerance, these results guide evidence-based conservation strategies to predict and manage the impacts of increasing human disturbance on birds.

Do animals generally flush early and avoid the rush? A meta-analysis

Optimal escape theory predicts that animals should balance the costs and benefits of flight. One cost of not fleeing is the ongoing cost of monitoring an approaching predator. We used a phylogenetic meta-analysis to test the general hypothesis that animals should initiate flight soon after they detect a predator—the ‘flush early and avoid the rush’ hypothesis. We found a large, significant overall relationship between the distance at which animals were approached or first detected a threat and the distance at which they fled. While these results are the first general test of the flush early and avoid the rush hypothesis, future work will be required to determine whether animals flush early to reduce ongoing attentional costs, or if they flush early as a form of risk reduction.

Nitrogen fluxes from treefrogs to tank epiphytic bromeliads: an isotopic and physiological approach

Diverse invertebrate and vertebrate species live in association with plants of the large Neotropical family Bromeliaceae. Although previous studies have assumed that debris of associated organisms improves plant nutrition, so far little evidence supports this assumption. In this study we used isotopic (15N) and physiological methods to investigate if the treefrog Scinax hayii, which uses the tank epiphytic bromeliad Vriesea bituminosa as a diurnal shelter, contributes to host plant nutrition. In the field, bromeliads with frogs had higher stable N isotopic composition (δ15N) values than those without frogs. Similar results were obtained from a controlled greenhouse experiment. Linear mixing models showed that frog feces and dead termites used to simulate insects that eventually fall inside the bromeliad tank contributed, respectively, 27.7% (±0.07 SE) and 49.6% (±0.50 SE) of the total N of V. bituminosa. Net photosynthetic rate was higher in plants that received feces and termites than in controls; however, this effect was only detected in the rainy, but not in the dry season. These results demonstrate for the first time that vertebrates contribute to bromeliad nutrition, and that this benefit is seasonally restricted. Since amphibian–bromeliad associations occur in diverse habitats in South and Central America, this mechanism for deriving nutrients may be important in bromeliad systems throughout the Neotropics.

Comparative feeding kinematics of tropical hylid tadpoles

SUMMARY Anuran larvae, which are otherwise simple in shape, typically have complex keratinized mouthparts (i.e. labial teeth and jaw sheaths) that allow them to graze upon surfaces. The diversity in these structures among species presumably reflects specializations that allow for maximal feeding efficiency on different types of food. However, we lack a general understanding of how these oral structures function during feeding. We used high-speed digital imaging (500 Hz) to observe tadpoles of six species from the anuran family Hylidae grazing on a standardized food-covered substrate. Tadpoles of these species vary in the number of labial tooth rows, belong to two different feeding guilds (benthic and nektonic), and inhabit ponds and streams. We confirmed that the labial teeth in these species serve two functions: anchoring the mouth to the substrate and raking material off of the substrate. In general, tadpoles with a larger maximum gape or those with fewer labial tooth rows opened and closed their mouths slower than tadpoles with smaller gape or more tooth rows. Nektonic feeding tadpoles released each of their tooth rows proportionally earlier in the gape cycle compared with benthic feeding tadpoles. Lastly, we found some support for the idea that deformation of the jaw sheaths during a feeding cycle is predictable based on tadpole feeding guild. Collectively, our data show that anatomical (e.g. number of labial teeth) and ecological features (e.g. feeding guild) of tadpoles significantly influence how tadpoles open and close their mouths during feeding.

Evaluating genotoxic risks in Brazilian public health agents occupationally exposed to pesticides: a multi-biomarker approach

This is the first study demonstrating genotoxic effects and whole transcriptome analysis on community health agents (CHAs) occupationally exposed to pesticides in Central Brazil. For the transcriptome analysis, we found some genes related to Alzheimer’s disease (LRP1), an insulin-like growth factor receptor (IGF2R), immunity genes (IGL family and IGJ), two genes related to inflammatory reaction (CXCL5 and CCL3), one gene related to maintenance of cellular morphology (NHS), one gene considered to be a strong apoptosis inductor (LGALS14), and several transcripts of the neuroblastoma breakpoint family (NBPF). Related to comet assay, we demonstrated a significant increase in DNA damage, measured by the olive tail moment (OTM), in the exposed group compared to the control group. Moreover, we also observed a statistically significant difference in OTM values depending on GSTM1 genotypes. Therefore, Brazilian epidemiological surveillance, an organization responsible for the assessment and management of health risks associated to pesticide exposure to CHA, needs to be more proactive and considers the implications of pesticide exposure for CHA procedures and processes.

Detecting genomic damages in the frog Dendropsophus minutus: preserved versus perturbed areas.

The aim of the study was to use the comet assay (single-cell gel electrophoresis) and micronucleus test to assess the extent of genomic damage in the whole blood of Dendropsophus minutus from agroecosystems with great use of agrochemicals and to compare the results to those obtained from animals living in unpolluted areas. Our results indicated that specimens of D. minutus collected in perturbed areas exhibited higher amounts of DNA damage in blood cells in comparison to animals from areas free of agricultural activities. The average and standard deviation of all comet assay parameters (tail length, percentage of DNA in the tail, and olive tail moment) and micronuclei frequency were significantly higher in specimens collected in perturbed areas than in the animals from preserved areas. Our study showed that animals from perturbed areas, such as agroecosystems, tend to have higher amounts of DNA damage than animals from reference areas. Moreover, we can conclude that D. minutus tadpoles could be included as a model organism in biomonitoring studies.

Diversidade de Anuros (Amphibia) na reserva extrativista Lago do Cedro e seu entorno, Aruanã, Goiás

The Cerrado is a tropical savannah with a diversified anuran assemblage, with 209 to 271 known species, of which approximately 51% are endemic. In this study, we report results of an anuran survey performed in the Extractivist Reserve of the Lago do Cedro, located in the northwestern region of the state of Goias, Brazil. In this area, we recorded 36 anuran species, distributed in five families, from which five species are Cerrado endemics. This high species richness found in the Extractivist Reserve of the Lago do Cedro could be explain by the different vegetational types within the reserve boundaries that promote a high local heterogeneity. Species richness and representativeness per family are similar to other assemblages reported for different areas in the Cerrado domain, being the local anuran assemblage composed by generalist and widely distributed species. The families Hylidae and Leptodactylidae are the most diversified in the studied area, a common pattern found in neotropical assemblages. The Extractivist Reserve Lago do Cedro is an important area for Cerrado conservation because of the anuran diversity and geographic location, which allows the connection among other protected areas within the Araguaia basin.

Visual signals or displacement activities? The function of visual displays in agonistic interactions in nocturnal tree frogs

The efficiency of intraspecific communication directly affects male reproductive success. Acoustic signaling is the primary form of communication in nocturnal anurans. However, visual signaling can also be important in social interactions. We tested the hypothesis that open environments favor visual signals in a territorial defense context, in a nocturnal tree frog. We established three treatments each with eight males of Hypsiboas albomarginatus: (1) Clear Vision, with a mirror without visual obstacles; (2) Obstructed Vision, with half the mirror covered, and (3) Control, with mirror completely covered. We classified behavioral responses into orientation/locomotion, visual display, or acoustic signal. We calculated the mean emission rate per minute per behavior in each treatment and compared them among treatments using one-way ANOVA. Orientation and locomotion, visual display, and the advertisement call did not differ among treatments. However, the emission of aggressive calls in the Obstructed Vision treatment was significantly higher than in the Clear Vision treatment. The lowest rate of aggressive calls occurred in the Control. Thus, visual recognition of an intruder male was enough for resident males to adjust their rate of emission of acoustic aggressive signals, but not visual displays. Therefore, the recognition of the intruder male is not the only feature required for the evolution of visual signals in nocturnal tree frogs during agonistic interactions. This suggests that some visual displays may not be directly used for communication but rather constitute displacement activity.

The Tadpole of Phyllomedusa itacolomi (Anura, Hylidae), with a Description of the Internal Oral Morphology

ABSTRACT. We describe the external morphology and the internal oral features of the tadpole of Phyllomedusa itacolomi (Anura, Hylidae) from Serra de Ouro Branco, Municipality of Ouro Branco, State of Minas Gerais, Brazil. Tadpoles were found at mid water in a temporary pool, in an open montane meadow. Phyllomedusa itacolomi (Gosners stage 37) is characterized by a tooth row formula 2(2)/3(1), labial tooth row P3 smaller than P1 and P2, marginal papillae of oral disc with wide dorsal and narrow ventral gaps. External morphological features were compared with other tadpoles of the Phyllomedusa hypochondrialis species group. Additionally, we provide information on egg clutches of P. itacolomi and P. megacephala.

The tadpole of Adelphobates galactonotus (Steindachner, 1864) (Amphibia, Anura, Dendrobatidae)

The systematics of the dart-poison frogs, family Dendrobatidae, experienced several taxonomic rearrangements over time (e.g., Grant et al. 2006, 2017; Brown et al. 2011). Currently, this family comprises 194 described species organized in three sub-families and 15 genera (Frost 2018). Among them, the genus Adelphobates Grant, Frost, Caldwell, Gagliardo, Haddad, Kok, Means, Noonan, Schargel, Wheeler, 2006, comprises three species, all distributed in Central and lower Amazon drainage of Peru and Brazil, and possibly in northeast of Bolivia (Grant et al. 2006; Frost 2018). Adelphobates galactonotus (Steindachner 1864) is an endemic Brazilian frog, and can be found throughout Pará, Maranhão, Mato Grosso and Tocantins states (Hoogmoed Avila-Pires 2012), related to Amazon forest formations and also in transitional areas between the Cerrado and the Amazon forest (Valdujo et al. 2012). Despite this species is classified as Least Concern (Rodrigues et al. 2010), several threats are known. First, its geographic distribution coincides with the so-called Amazonian Deforestation Arc, which comprehends the southeastern portion of the Amazonian Forest that has been rapidly converted into pasture and crop areas or being flooded due to the construction of hydroelectric power plants (Hoogmoed Avila-Pires 2012). Also, this species is present in Appendix II of CITES as a target for illegal trade, and their commercial exploitation should be controlled to avoid that this species become seriously endangered in the near future (see a case study in Paula et al. 2012). These threats are of deeper concern because despite A. galactonotus has been described since more than 150 years (Steindachner 1864), its tadpole remains unknown. Without a better understanding of the natural history of A. galactonotus, attempts of conservation strategies and population management are inefficient. In an effort to fill the knowledge gaps about this species natural history, we present a detailed description of the external morphology of the A. galactonotus tadpole.