Glassfrogs (Centrolenidae) are endemic in the Neotropics from southern Mexico to Bolivia. Their common name refers to the completely or partially transparent ventral surface of many species. Many glass frog species exhibit territoriality, including aggressive interactions among males. All members of this family are nocturnal and have a semi-arboreal reproductive mode where eggs are deposited out of the water on vegetation overhanging or rocks above streams. After hatching, the tadpoles drop into the water where they continue their development, and metamorphosis takes place.

Teratohyla spinosa (c) Anyelet Valencia-Aguilar


Although parental care in glassfrogs was previously considered to be rare and mostly conducted by males, maternal egg attendance has recently been described for several species of glassfrogs(Bravo-Valencia & Delia 2015, Delia et al. 2017). These studies show that although parental care occurs throughout the Centrolenid family, the caregiving sex changes across and within lineages, and that a brief period of maternal care is widespread and mostly occurs in species previously thought to lack care (Delia et al. 2017).

Hyalinobatrachium valerioi (c) 2012 Christoph Leeb


Several experimental studies have shown that parental care in male and female glassfrogs is flexibly adapted to changing environmental conditions and embryo requirements. For example, parental males actively take up and release water on clutches and remove capsule-less embryos (Delia et al. 2017b) and adjust the frequency of care to compensate for low humidity (Delia et al. 2013). Parents may also to actively defend clutches against predators (Drake & Ranvestel 2005, Lehtinen et al. 2014, Delia et al. 2010), or become more risk tolerant in a high-threat situation to protect their clutches (Ospina-L et al. 2019). Furthermore, since parental care is critical to offspring survival in some glassfrog species (Vockenhuber et al. 2009) embryos exhibit hatching plasticity in response to premature parental abandonment (Delia et al. 2014). The variation in parental behaviour within in this frog family offers excellent opportunities to investigate the relationship between space use, calling behaviour, mate choice, behavioural flexibility and parenting.