Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain

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  Hidden diversity in plain sight: four new species of Nemesia (Araneae: Mygalomorphae) from the Córdoba Province of Spain Abstract A taxonomic revision of the species of Nemesia Audouin, 1826, distributed in the vicinity of Córdoba City, southern Spain, is presented. Four new species are described: Nemesia morana sp. nov. (female), N. kodama sp. nov. (male and female), N. rosae sp. nov. (male and female), and N. tamajoni sp. nov. (male and female). These species are distinguished by distinct morphological characters, including the shape of the spermathecae, palpal bulbs, and spinnerets, as well as by burrow architecture. Fieldwork was conducted across two of the three major habitat types in the region—the humid, forested mountains of Sierra Morena and the croplands and riparian forests of the Guadalquivir Valley—while the third, the “campiña”, which is mainly composed of agricultural landscapes, remains poorly explored. Sampling methods included pitfall trapping and the direct e...

If you are hidden, how will I know what you feel?: the role of tarantula burrows in buffering the external climatic conditions

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If you are hidden, how will I know what you feel?: the role of tarantula burrows in buffering the external climatic conditions

Abstract

Context

Thermal refuges, such as burrows, play a crucial role in the survival of ectothermic species by buffering environmental temperature fluctuations. The burrowing tarantula Grammostola vachoni inhabits rocky outcrops in central grassland of Argentina. Considering the importance of refuges for ectotherms, the significant differences between microhabitat and external environmental conditions, and the limited information available on tarantula habitats, understanding microclimate variations within burrows is crucial.

Aims

We investigated the temperature and humidity dynamics inside the burrows of G. vachoni in relation to the surrounding environment. We characterized microhabitat temperature and humidity in adjacent habitats, evaluated the stability of environmental conditions inside and outside the burrow, and analyzed these findings in relation to the known thermal limits of the species.

Methods

We conducted the study in the Ventania System (Argentina), measuring temperature and humidity throughout an entire year. Environmental parameters were recorded using a HOBO data logger, whereas burrow parameters were measured using iButton data loggers placed inside burrows occupied by adult females of G. vachoni. We also analyzed the stability of environmental and burrow conditions, the distribution of extreme temperatures, humidity variability, and the rates of cooling and heating.

Key results

We found that burrows exhibit greater thermal and hydric stability than the external environment, with temperatures inside remaining above 0°C during winter. Cooling and heating rates inside the burrows were slower, which allowed the spiders to avoid rapid and harmful temperature fluctuations. Humidity levels inside the burrows were consistently higher than outside, particularly during the warmer months.

Conclusions

Our results highlighted the importance of monitoring microhabitat conditions not only during the species’ activity periods, because burrows play a determinant role in other phases of the life cycle. Whereas burrows provide some level of thermal refuge, the increasing frequency and intensity of heatwaves could challenge the species’ thermal resilience. The fact that burrow temperatures can exceed both optimal temperature and critical thermal maximum, particularly in the warmer months, raises concerns about the suitability of these refuges in the face of climate change.

Implications

Understanding these microhabitat conditions is essential to grasp the fine-scale relationship between the organism and its environment.

Schwerdt Leonela, Ferretti Nelson, de Villalobos Ana Elena (2025) If you are hidden, how will I know what you feel?: the role of tarantula burrows in buffering the external climatic conditions. Wildlife Research 52, WR24202.

https://doi.org/10.1071/WR24202