Use of Olfactory Cues by Newly Metamorphosed Wood Frogs (Lithobates sylvaticus) during Emigration

Abstract

Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs (Lithobates sylvaticus) to investigate: (1) the existence of innate (i.e., inherited) directionality, and (2) the use of olfactory cues, specifically forested wetland and natal pond cues during emigration. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction (suggested by previous studies) when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. Animals reared in semi-natural conditions (1500 l cattle tanks) showed a strong avoidance of forested wetland cues in two different experimental settings, although they had not been previously exposed to such cues. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond (cattle tank) water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

Movement in the matrix: substrates and distance‐to‐forest edge affect postmetamorphic movements of a forest amphibian

“…Amphibians have been shown to rely on a diversity of orientation mechanisms including, but not limited, to olfaction (Popescu et al. ), visual cues, or light polarization (Dall'Antonia and Sinsch , Phillips et al. ), acoustic cues (Bee ), and magnetic reception (Landler and Gollmann ), although we were unable to test these mechanisms.…”

“…Frogs in lawns tend-ed to exhibit forest directionality at greater distances compared to hayfields (i.e., up to 44-56 m and nearly significant at distances extending to 80 m; Appendix C, panel A). Amphibians have been shown to rely on a diversity of orientation mechanisms including, but not limited, to olfaction (Popescu et al 2012), visual cues, or light polarization (Dall'Antonia and Sinsch 2001, Phillips et al 2010, acoustic cues (Bee 2013), and magnetic reception (Landler and Gollmann 2011), although we were unable to test these mechanisms.…”

Usage rates of an under-road tunnel by three Australian frog species: implications for road mitigation

“…If individuals were homing towards their site of origin, it is expected there would have been greater numbers of juveniles entering and travelling through the tunnel from the north and heading south. Nonetheless, these individuals must have been responding to some environmental cue despite the fact that our study was conducted in an artificial setting where the frogs were not exposed to all of the environmental cues that anurans otherwise use to orient across the landscape (Patrick, Calhoun & Hunter, ; Popescu et al ., ). For example, we found that the proportion of tunnel usage among Lim.…”

The integrative effects of behavior and morphology on amphibian movement

“…Juvenile dispersal is a movement phase that is often a major life history transition, requiring individuals to navigate new and unfamiliar habitats (Clobert, Massot, & Le Galliard, ; Popescu, Brodie, Hunter, & Zydlewski, ). For example, amphibian and macroinvertebrate metamorphosis, with subsequent transition from aquatic to terrestrial habitats, represents a distinct shift in habitat in which movement ability is dependent on newly acquired morphological traits, such as legs and wings (Bilton, Freeland, & Okamura, ; Rowe & Ludwig, ; Smith & Green, ).…”

“…For example, a highly mobile hummingbird (green hermit, Phaethornis guy) will increase movement distance and path sinuosity to remain in their preferred forested habitats while homing through a complex composition landscape (Hadley & Betts, 2009). Organisms experiencing unfamiliar habitats, such as newly metamorphosed amphibians experiencing terrestrial habitats for the first time, must rely heavily on innate behaviors to guide their movements (Popescu et al, 2012;Rothermel, 2004). Thus, the integration of morphological and behavioral trait response may be the guiding principle in shaping juvenile orientation and dispersal (Patrick, Harper, Hunter, & Calhoun, 2008).…”