Systematics of the Little Red Tree Frog, Litoria rubella (Anura: Pelodryadidae), with the description of two new species from eastern Australia and arid Western Australia

The Litoria rubella species complex (L. capitula and L. rubella) is distributed across much of continental Australia, southern New Guinea, and the Tanimbar Islands of Indonesia, in habitats ranging from deserts to tropical forests. We carried out an appraisal of molecular genetics, advertisement calls, and morphological variation in the species complex. Analyses of thousands of nuclear gene SNPs and nucleotide sequences from the mitochondrial ND4 gene identified four reciprocally monophyletic lineages in both marker types, two exclusively in Australia, one in Australia/New Guinea and one from the Tanimbar Islands. The advertisement calls of the three lineages on continental Australia have overlapping but significant differences in the number of pulses in the notes, dominant frequency, and call duration, particularly where the lineages come into contact. The Tanimbar Islands lineage is genetically and morphologically distinct and represents L. capitula. Molecular and advertisement call data together support the recognition of three species in Australia: a widespread central arid and northern tropics lineage, a western arid zone lineage, and an eastern mesic lineage. Litoria rubella sensu stricto is widespread across the tropical Kimberley and Top End regions, southern New Guinea, the central arid zone, and the Murray Darling Basin, making it an extreme climate-generalist. SNP data indicates that L. rubella has gene flow to the north of the Lake Eyre Basin but not the south, making it a possible ring species. The western arid zone lineage does not differ in appearance or advertisement call from L. rubella but is geographically disjunct and phylogenetically distinct. The eastern lineage is primarily distributed to the east of the Great Dividing Range and Cape York in Queensland. We redescribe L. rubella sensu stricto, describe the eastern lineage and western arid lineage as new species, L. pyrina sp. nov. and L. larisonans sp. nov. respectively. Although L. rubella and L. larisonans sp. nov. are morphologically similar, they do not overlap in distribution, making identification non-problematic. Litoria pyrina sp. nov. can be distinguished from L. rubella at contact zones by having advertisement calls with a higher dominant frequency. We investigated the history and morphology of the type for L. mystacina and designate it a nomen dubium. The three Australian species are likely to have a conservation status of Least Concern as they are widespread and abundant, with no significant threats. Little is known about L. capitula from the Tanimbar Islands outside of the few existing museum specimens.

Systematic evaluation of molecular genetic, morphological and acoustic variation reveals three species in the Litoria revelata complex (Anura: Pelodryadidae)

We used a combination of nuclear and mitochondrial genetic data, body measurements and colouration, and male advertisement calls to analyse the systematic implications of variation in the whirring treefrog Litoria revelata complex, which occurs in three allopatric populations-north-eastern New South Wales/south-eastern Queensland, mid-eastern Queensland, and northern Queensland. The three populations each form divergent lineages for both the nuclear (single nucleotide polymorphisms; SNP) and mitochondrial datasets and are diagnosable also on the basis of morphology and advertisement calls. In combination, we use these lines of data to recognise three species: L. revelata in north-eastern New South Wales/south-eastern Queensland, L. eungellensis sp. nov. in mid-eastern Queensland, and the resurrected L. corbeni in northern Queensland. We provide a preliminary conservation assessment for each species, with the latter two species being localised to very small upland areas and warranting conservation listing and attention.

Urbanization reduces diversity, simplifies community and filter bird species based on their functional traits in a tropical city

Understanding how organisms are coping with major changes imposed by urban intensification is a complex task. In fact, our understanding of the impacts of urbanization on biodiversity is scarce in the global south compared to the north. In this study, we evaluated how bird communities are affected by impact of urban intensification in a tropical city. Thus, we assessed whether increased urban intensification 1) jeopardizes bird diversity (taking into account taxonomic-TD, phylogenetic-PD, and functional-FD dimensions), 2) drives changes in bird community composition and enables the detection of indicator species of such impact, and 3) leads to changes in bird functional traits linked to reproduction, resource acquisition, and survival. We found that urban intensification has a direct impact on the bird community, reducing all three types of diversity. Communities in areas of greater urban intensity are represented by fewer species, and these species are PD and FD less distinct. In addition, we detected at least ten species of areas of lower urban intensity that proved to be more sensitive to urban intensification. With regard to bird traits, we found no significant responses from reproductive, habitat use and feeding variables. Body weight and tail length were the only variables with significant results, with higher urbanization intensity areas selecting for species with lower weights and longer tails. Given the global biodiversity loss we are observing, this information can guide urban managers and planners in designing urban landscapes to maintain biodiversity in cities.

Revision of Litoria rothii (Anura: Pelodryadidae) from northern Australia

Litoria rothii is a widespread pelodryadid frog with a charismatic laughing advertisement call, distributed across the Australian Monsoon Tropics and southern New Guinea. Given its large distribution spanning well-known biogeographic barriers, variation in male advertisement calls and the prevalence of unresolved species complexes in the Australian frog fauna, we examine the genetic, morphological and acoustic diversity in the species from across its range. Our analyses reveal the presence of a previously unrecognised species in western parts of the range of L. rothii sensu lato, which we describe herein as a new species. Litoria ridibunda sp. nov. is distinguished from L. rothii on the basis of paraphyly of nuclear gene trees with L. everetti from Indonesia, colour patterns on the posterior thigh and male advertisement calls. Compared to L. rothii, the new species has a less contrasting pattern on the posterior thigh and a male advertisement call with a greater number of notes per call and a greater call duration. In particular, the magnitude of call differences between the species is highest where the ranges of the two species are in proximity in north-western Queensland. Our study further emphasises the undiagnosed diversity that remains in Australian frogs, even in relatively large, charismatic, frequently encountered species that often share human dwellings.

The iNaturalist platform as a source of data to study amphibians in Brazil

Based on debilitating recent budget cuts for science, Brazilian researchers had to find alternative ways to continue scientific production. Here we provide a perspective for the use of citizen-science data deposited in the iNaturalist platform as an alternative source of data to support biodiversity research. Observations contributed by volunteers can be analyzed at large spatial and temporal scales and can respond to questions in behavioral and population ecology. We analyzed this potential through the example of Brazilian amphibians, a group that is less studied worldwide than birds. In fact, to our knowledge, only two studies have been published that are based on citizen-science data for Brazilian amphibians. At the time of writing, the iNaturalist platform has over 14,800 research grade observations from Brazil, representing 698 species, a number increasing daily. Compared to other species-rich countries, volunteer-collected datasets from Brazil cover a relatively high taxonomic diversity (61%), providing a plethora of valuable data. Despite this potential, there are large spatial gaps in sampling in Brazil. Here we encourage established and budding herpetologists not only to use the platform to retrieve data, but also to contribute to iNaturalist actively, with new observations, as well as by identifying species in existing records.

Anthropogenic habitat modification alters calling phenology of frogs

Anthropogenic habitat modification significantly challenges biodiversity. With its intensification, understanding species' capacity to adapt is critical for conservation planning. However, little is known about whether and how different species are responding, particularly among frogs. We used a continental-scale citizen science dataset of >226,000 audio recordings of 42 Australian frog species to investigate how calling-a proxy for breeding-phenology varied along an anthropogenic modification gradient. Calling started earlier and breeding seasons lengthened with increasing modification intensity. Breeding seasons averaged 22.9 ± 8.25 days (standard error) longer in the most modified compared to the least modified regions, suggesting that frog breeding activity was sensitive to habitat modification. We also examined whether calls varied along a modification gradient by analysing the temporal and spectral properties of advertisement calls from a subset of 441 audio recordings of three broadly distributed frog species. There was no appreciable effect of anthropogenic habitat modification on any of the measured call variables, although there was high variability. With continued habitat modification, species may shift towards earlier and longer breeding seasons, with largely unknown ecological consequences in terms of proximate and ultimate fitness.

Anuran accents: Continental-scale citizen science data reveal spatial and temporal patterns of call variability

Many animals rely on vocal communication for mating advertisement, territorial displays, and warning calls. Advertisement calls are species-specific, serve as a premating isolation mechanism, and reinforce species boundaries. Nevertheless, there is a great deal of interspecific variability of advertisement calls. Quantifying the variability of calls among individuals within a species and across species is critical to understand call evolution and species boundaries, and may build a foundation for further research in animal communication. However, collecting a large volume of advertisement call recordings across a large geographic area has traditionally posed a logistical barrier. We used data from the continental-scale citizen science project FrogID to investigate the spatial and temporal patterns of call characteristics in six Australian frog species. We found intraspecific call variability in both call duration and peak frequency across species. Using resampling methods, we show that variability in call duration and peak frequency was related to the number of individuals recorded, the geographic area encompassed by those individuals, and the intra-annual time difference between those recordings. We conclude that in order to accurately understand frog advertisement call variation, or "anuran accents," the number of individuals in a sample must be numerous (N ≥ 20), encompass a large geographic area relative to a species' range, and be collected throughout a species' calling season.