Abstract
Although most male frogs call to attract females, vocalizations alone can be ineffective long-range signals in certain environments. To increase conspicuousness and counter the background ...noise generated by rushing water, a few frog species around the world have evolved visual communication modalities in addition to advertisement calls. These species belong to different families on different continents: a clear example of behavioural convergent evolution. Until now, long-distance visual signalling has not been recorded for any species in the glassfrog family (Centrolenidae). Sachatamia orejuela, an exceptionally camouflaged glassfrog species found within the spray zone of waterfalls, has remained poorly studied. Here, we document its advertisement call for the first time — the frequency of which is higher than perhaps any other glassfrog species, likely an evolutionary response to its disruptive acoustic space — as well as a sequence of non-antagonistic visual signals (foot-flagging, hand-waving, and head-bobbing) that we observed at night.
The Tropical Andes is the world's most biodiverse hotspot. This region contains >1,000 amphibian species, more than half of which are endemic. Herein we describe two new glassfrog species ...(Centrolenidae:
) that we discovered within relatively unexplored and isolated localities of the Ecuadorian Andes.
We employed morphological, acoustic, and molecular methods to test the hypothesis that
sp. nov and
sp. nov. are species new to science. Following standard methods, we generated mitochondrial sequences (16S) of 37 individuals in the genus
. We inferred the phylogenetic relationships of the two new species in comparison to all other glassfrogs using Maximum Likelihood. In addition to describing the call of
sp. nov., we performed a discriminant analysis of principal components (DAPC) with the advertisement call characteristics of several congeners.
Based on an integrative taxonomy approach, we describe two new species. Morphological traits and the inferred phylogeny unambiguously place the new taxa in the genus
. Both species are distinguished from other glassfrogs mainly by their dorsal coloration (
., dorsum lime green with small light yellow spots, head usually with interorbital bar) and transparent pericardium (
., the heart is visible through the ventral skin). The new species exhibit a high morphological similarity (
., cryptic) and occur within relatively close geographical proximity (closest aerial distance = 18.9 km); however, their uncorrected
distance for the mitochondrial gene 16S is 4.6-4.7%, a value that greatly exceeds the genetic distance between closely related species of centrolenid frogs. The DAPC revealed that the advertisement call of
sp. nov. is acoustically distinct.
Our findings are congruent with several previous studies that report a high degree of endemism in the Toisán mountain range, which appears to be isolated from the main Andean cordillera for some amphibian groups. We recommend that both
sp. nov. and
sp. nov. be listed as Endangered, following IUCN criteria. These new species provide another example of cryptic diversity in the Andes-further evidence that the region fosters much more biodiversity than we have the resources to catalog. Threatened by mining and other exploitative industries, these glassfrogs and many other yet-to-be-discovered Andean species highlight the dire need for effective conservation measures-especially in northwestern Ecuador.
Although the COVID‐19 lockdowns in 2020 had some environmental benefits, the pandemic's impact on the global economy has also had conservation repercussions, especially in biodiverse nations. ...Ecuador, which is heavily reliant on petroleum, agricultural exports, and ecotourism, experienced a rise in poverty in response to pandemic shutdowns. In this study, we sought to quantify levels of illegal timber extraction and poaching before and after the start of COVID‐19 lockdowns throughout two protected areas (Reserva Jama Coaque JCR and Bosque Seco Lalo Loor BSLL) in the endangered Pacific Forest of Ecuador. We analyzed chainsaw and gunshot acoustic data recorded from devices installed in the forest canopy from December 2019 to March 2020 and October 2020 to March 2021. Results from generalized linear mixed effects models indicated less chainsaw activity before lockdowns (βpost.lockdown = 0.568 ± 0.266 SE, p‐value = .030), although increased average rainfall also seemed to negatively affect chainsaw activity (βavg.rainfall = −0.002 ± 0.0006 SE, p‐value = .003). Gunshots were too infrequent to conduct statistical models; however, 87% of gunshots were detected during the ‘lockdown’ period. Observational data collected by rangers from these protected areas also noted an increase in poaching activities beginning mid to late 2020 and persisting into 2021. These results add to the steadily growing literature indicating an increase in environmental crime, particularly in biodiverse nations, catalyzed by COVID‐19‐related economic hardships. Identifying areas where environmental crime increased during pandemic lockdowns is vital to address both socioeconomic drivers and enforcement deficiencies to prevent further biodiversity loss and disease outbreaks and to promote ecosystem resilience. Our study also demonstrates the utility of passive acoustic monitoring to detect illegal resource extraction patterns, which can inform strategies such as game theory modeling for ranger patrol circuits and placement of real‐time acoustic detection technologies to monitor and mitigate environmental crimes.
Although COVID‐19 lockdowns have had some environmental benefits, the impact on the global economy has also led to conservation repercussions. In our study, we analyzed bioacoustic data from the canopy of the Pacific Forest of Ecuador to compare chainsaw activity before and after the start of COVID‐19 lockdowns. Our results indicate that COVID‐19 lockdowns were associated with an increase in chainsaw activity.
With automated telemetry, Barve et al. tracked cooperatively breeding acorn woodpeckers during ‘power struggles’—complex conflicts wherein ‘warrior’ birds fight for breeding positions as ‘spectator’ ...birds watched. Telemetry was used to quantify effort expended by warriors gaining territories and spectators receiving social information.
Species may circumvent the impacts of climate warming if the habitats they use reduce ambient temperature. In this study, we identified which frog species from a tropical montane rain forest in the ...Philippines may be vulnerable to climate warming. To do so, we selected five anuran species that utilize four breeding habitats and identified the sensitivity and exposure of tadpoles and direct-developer eggs to heat by measuring their critical thermal maximums (CT max ) and the habitat-specific temperatures they experience. Our study species included two direct-developer frogs—one species that lays its eggs on exposed leaves, and another that lays its eggs in ferns—and three species that produce aquatic free-swimming tadpoles—two stream breeders, and one phytotelm (tree hole) breeder. We compared thermal tolerances derived from microclimates of breeding habitats with tolerances derived from macroclimate (i.e., non-buffered air temperature taken from the rain forest canopy). We also examined whether differences in CT max existed across life-history stages (egg, metamorph/young-of-year, and adult) for the two direct-developer frog species. Habitats buffered ambient temperature and expanded thermal tolerances of all frog species. We found that direct-developers, however, are more vulnerable to increased temperatures than aquatic breeders—indicated by their high sensitivity to temperature, and exposure to high temperatures. Direct-developer eggs were more sensitive to warming than both metamorph and adult life-history stages. Thermally buffered microhabitats may represent the only protection against current and impending climate warming. Our data highlight the importance of considering sensitivity and exposure in unison when deciphering warming vulnerability of frogs.
Student attrition is a persistent challenge in the life sciences, particularly among underrepresented minorities, first-generation students, and women. Experiential learning through short-term study ...abroad opportunities diversify curricula by immersing students into non-traditional academic environments. However, most experiential learning and study abroad opportunities are primarily available to upper-division undergraduates. Here, we present a qualitative analysis of an experiential learning opportunity offered exclusively to first-year U.S. undergraduate students from underrepresented demographics. We performed ethnographic observations of a 10-day field component in the Galápagos Islands, and analyzed self-reported survey results and field journals. Students consistently reported strong cognitive gains in their understanding of basic evolutionary concepts. Most students also benefited socially, although we observed higher variation in self-reported social gains. Our findings suggest that immersive field courses may increase scientific literacy and retention of underrepresented students by engaging them in experience-driven learning.
Abstract Peripheral arterial disease (PAD) is an atherosclerotic disease. Evidence suggests that atherosclerosis is an inflammatory condition and long chain n −3 fatty acids, found in oily fish and ...fish oils, have been shown to reduce inflammation. Genetic and lifestyle factors such as body mass index (BMI) also influence inflammation. In this study we have examined the effect of fish oil in patients with claudication secondary to PAD. Fish oil supplementation, providing 1 g EPA and 0.7 g DHA per day for 12 weeks, increased walking distance on a treadmill set at 3.2 km/h with a 7% incline. Walking distance to first pain increased from 76.2±8.5 m before fish oil to 140.6±25.5 m after fish oil (mean±SEM, p = 0.004 ) and total distance walked increased from 160.0±21.5 m before fish oil to 242.1±34.5 m after fish oil ( p = 0.002 ). Fish oil supplementation also improved ankle brachial pressure index (ABPI) from 0.599±0.017 before fish oil to 0.776±0.030 after fish oil ( p < 0.001 ). The increase in walking distance was dependent on both BMI and genotype for single nucleotide polymorphisms in the genes encoding the pro-inflammatory cytokines tumour necrosis factor- α and interleukin (IL)-1 β and the anti-inflammatory cytokine IL-10 (detected using amplification refractory mutation system polymerase chain reaction). Neither BMI nor any of the genotypes examined affected the ability of fish oil to increase ABPI. The mechanisms by which fish oil affects walking distance and ABPI do not appear to be the same.
In postinfarction left ventricular aneurysm, abnormal geometry and desynchronized wall motion may cause a highly inefficient pump function. The traditional endoventricular patch plasty according to ...the Dor technique might result in a truncated and restrictive left ventricular cavity in small adults. We report a modified technique of left ventricular anteroapical aneurysm repair by using a semispherical reshaping patch to restore the left ventricular geometry.
Abstract Objectives The Women's Health Initiative (WHI) randomized trial of calcium/vitamin D supplementation found reduced bone loss with active treatment compared to placebo. Now we examine whether ...the treatment affected self-reported physical functioning and objective measures of physical functioning. Design A randomized, double-blind, placebo-controlled trial of 1,000 mg calcium carbonate plus 400 IU vitamin D3 per day or matching placebo pills. Subjects/setting The study included 33,067 women (50 to 79 years old) at 40 US study centers. Main outcome measures Physical functioning was assessed by questionnaire at enrollment in WHI, 1 year prior to calcium/vitamin D trial randomization and at study close-out (average follow-up 7.1 years). Objective physical performance and self-reported exercise measures were collected at WHI baseline (1 year prior to calcium/vitamin D enrollment) and 2 years and 4 years after calcium/vitamin D trial enrollment in a subsample (n=3,137). Statistical analyses performed Calcium/vitamin D effects were tested in unadjusted and interaction linear models for each of the physical function measures. Covariates were baseline total calcium intake, fracture risk score, treatment arm in the hormone therapy and dietary modification trials (ie, active drug or placebo, low-fat diet intervention or usual diet, respectively) and age. Results Neither intention to treat nor high adherence analyses produced substantial effects of calcium/vitamin D compared to placebo on physical functioning or performance. The interaction analyses also did not result in differences because of calcium/vitamin D. Conclusions As the first long-term randomized trial to examine the effectiveness of calcium and vitamin D in protecting against decline of physical functioning in older women, the results did not support benefit.
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