Finding a place to live: conspecific attraction affects habitat selection in juvenile green and golden bell frogs

Abstract

Conspecific attraction plays an important role in habitat selection of several taxa and can affect and determine distribution patterns of populations. The behaviour is largely studied and widespread among birds, but in amphibians, its occurrence seems limited to breeding habitats of adults and gregarious tadpoles. The Australian green and golden bell frogs (Litoria aurea) have suffered considerable shrinking of their original distribution in south-eastern Australia since the 1970s. Currently, with only about 40 populations remaining, the species is considered nationally threatened. In natural conditions, these frogs are aggregated in the landscape and do not seem to occupy all suitable ponds within the occurrence area. To date, studies focusing on the frogs' habitat have failed in finding a general habitat feature that explains current or past occupancy. This led us to the hypothesis that social cues may play a key role in habitat selection in this species. Using two choice experiments, we tested the preference of juvenile green and golden bell frogs for habitats containing cues of conspecifics of similar size versus habitats without conspecific cues. Tested frogs did not show a preference for habitats containing only scent from conspecifics but did prefer habitats where conspecifics were present. Our results show that conspecific attraction is a determining factor in juvenile green and golden bell frog habitat selection. To our knowledge, this is the first time the behaviour is shown to occur in juvenile frogs in the habitat selection context. From a conservation management point of view, the behaviour may help to explain the failure of reintroductions to areas where the frogs have been extinct, and the non-occupation of suitable created habitats in areas where they still inhabit and develop appropriated management strategies.

Community level impacts of invasive mosquitofish may exacerbate the impact to a threatened amphibian

“…We found that post-metamorphic L. aurea abundance was higher at permanent ponds, and linked to vegetation in the riparian zone such as the amount of bushes and spikey rush (predominantly Juncus acutus) surrounding ponds, indicating that L. aurea require ponds with suitable surrounding vegetation for shelter (Pyke & White 1996). The distribution of L. aurea on Kooragang Island has previously been linked to the proximity of other nearby ponds and the presence of conspecifics (Hamer & Mahony 2010;Pizzatto et al 2015;Valdez et al 2015). Gambusia holbrooki abundance was also higher in permanent ponds, which is expected because ephemeral ponds are less able to support fish due to frequent drying.…”

Spatial patterns of the frog Oophaga pumilio in a plantation system are consistent with conspecific attraction

“…() found no evidence that Pelophylax perezi respond to chemical cues of conspecifics when selecting habitat; instead, they found individuals avoided chemical cues from predators. Similarly, experimental trials of juvenile Litoria aurea did not document an effect of chemical conspecific cues on habitat selection, but instead found a significant effect of conspecific presence on habitat selection (Pizzatto et al., ). These studies suggest that conspecific attraction in frogs may be driven, at least in part, by visually mediated conspecific cues, more than chemical cues.…”

“…If individuals metamorphose and enter the landscape within or near parental home ranges, then juvenile settlement might be influenced by parent recognition, either visually as a result of shared experiences during maternal provisioning or chemically through the MHC complex (Brown & Eklund, ; Pizzatto et al., ; Villinger & Waldman, ). If kin recognition occurs, then juveniles might exhibit preference toward settling into habitat near related individuals, which might partially confound patterns observed in this study.…”

“…Despite much interest in conspecific attraction by population and conservation biologists (e.g., Campomizzi et al, 2008;Fletcher, 2006;Lima & Zollner, 1996;Ward & Schlossberg, 2004), empirical studies of whether conspecific attraction influences selection are logistically challenging, because it can be difficult to control for habitat quality in natural heterogeneous landscapes (Stamps, 1988). However, support for conspecific attraction has been found for invertebrates (Crisp, 1976;Donahue, 2006;Meadows & Campbell, 1972;Muller, 1998), fish (Sweatman, 1985(Sweatman, , 1988, amphibians (Gautier, Olgun, Uzum, & Miaud, 2006;Pizzatto et al, 2015), reptiles (Clark, 2007;Stamps, 1987Stamps, , 1988, and birds (Muller et al, 1997;Danchin, Boulinier, & Massot, 1998;Etterson 2003;Ward & Schlossberg, 2004;Austin, Neil, & Warren, 2017). Together, these studies suggest conspecific attraction may be a pervasive mechanism among diverse animal groups.…”

“…Within amphibians, few studies have tested for evidence of conspecific attraction (Gautier et al, 2006;Gonzalo, Cabido, Galán, López, & Martín, 2006;Pizzatto et al, 2015), but there is good reason to suspect that conspecific attraction might be an important mechanism influencing the spatial ecology of frogs, particularly for poison frogs in the family Dendrobatidae. The single study supporting conspecific attraction in anurans suggested it may be mediated by visual cues (Pizzatto et al, 2015). Dendrobatids are diurnal frogs that both use visual and acoustic cues during mate choice (Narins, Hödl, & Grabul, 2003;Reynolds & Fitzpatrick, 2007;Summers, Symula, Clough, & Cronin, 1999) and parental care (Stynoski & Noble, 2012).…”