Climate drives anuran breeding phenology in a continental perspective as revealed by citizen‐collected data

Abstract

AimAs anuran reproduction is generally linked to the availability of water, frogs and toads are particularly sensitive to climate. We tested the effect of climate on anuran reproductive phenology and daily activity by analysing temporal patterns of reproductive behaviour based on citizen‐collected observations.LocationBrazil.MethodsWe obtained vocalizations and photographs of frogs with inflated air sacs, as well as images of amplectant couples, nests, eggs or tadpoles in initial stages of development from iNaturalist. We analysed hourly patterns, seasonality and duration of the reproductive period using circular statistics in different climate types and tested phylogenetic signals. We analysed data for Bufonidae, Hylidae, Leptodactylidae and Phyllomedusidae in detail. We also reviewed relevant literature.ResultsAmong the 8478 (acoustic and photographic) records, 738 (8.7%) had evidence of reproduction with 284 acoustic records and 454 photographs, representing 184 taxa identified at the species level belonging to 16 families. Climate affected the period and duration of the reproductive season, as well as daily patterns of vocalization. These results were considered phylogenetically independent, as the reconstructions of ancestral character states did not suggest strong phylogenetic signals for temporal patterns of vocalization or reproduction. In Brazil, most frogs reproduce between October and January. Patterns were similar to the results of the literature review, however in the literature data, Bufonidae start reproduction 2 months earlier, and many Hylidae species reproduce until February. In general, frogs from warmer and drier climate regions had shorter and aggregated reproductive seasons, while in tropical monsoon climate they had a uniform temporal pattern.Main conclusionsAt the continental scale, reproductive phenology of anurans and their daily activity is affected by climatic conditions regardless of phylogeny. We found that community science can provide valuable information in Brazil that can be harnessed to monitor effects of climate change on amphibian reproduction.

Melanesia holds the world’s most diverse and intact insular amphibian fauna

“…Mobile phones are widely used throughout Melanesia, so app-and online-based identification resources may become increasingly accessible. Smartphone-friendly citizen science platforms like iNaturalist 56 or even Facebook groups 57 also provide potentially powerful resources through which locally collected data can be captured, vetted and disseminated, although their use is currently limited in Melanesia due to patchy internet coverage in many areas. Working with and supporting people from Melanesia to explore and increase the use of these resources could help to ensure longer-term preservation and accessibility of species records and associated data.…”

Phenological patterns in ecology: Problems using circular statistics and solutions based on simulations

“…those collected by iNaturalist [https://www.inaturalist.org/]) do not represent standardized effort among time intervals or unbiased observations of targeted biological activities such as reproductive status (Bird et al., 2014). For example, a study on diurnal activity and reproductive phenology of anurans in Brazil based on data from iNaturalist was characterized by a number of data issues that result in inappropriate use of circular statistics (Forti, Hepp, et al., 2022). For analyses of diurnal activity, it is more likely that citizen scientists are making observations early in the night or just before sunrise, rather than during the middle of the night.…”

iNaturalist is an open science resource for ecological genomics by enabling rapid and tractable records of initial observations of sequenced biological samples

“…When accessed in bulk through the Global Biodiversity Information Facility (GBIF), sets of iNaturalist observations can be given digital object identifiers (DOIs) that enable replication studies [ 15 , 16 ], and, within the iNaturalist platform, observations can be collected into projects. Since it is now common to find genomics studies that include hundreds or thousands of samples collected from multiple species across broad geographical or long temporal scales [ 17 , 18 ], the collation of collection records into tractable projects/datasets will enable researchers to keep track of the samples used in a study that they may be planning, carrying out, or have already published.…”