8 Memorandum : Vibration effects on amphibians (Leiopelmatid frogs) 64524 Vibration effects_memorandum (15 June 2022)_Final Rev 0 For Archey’s and Hochstetter’s frog, neither the absence of middle ear structures nor the lack of evidence for extratympanic pathways to transmit vibrations, nor the absence of studies investigating seismic sensing in Leiopelma species should preclude the possibility that vibration can be sensed. Rather, uncertainty remains surrounding vibration perception and sensitivity, and the potential importance of seismic stimuli in leiopelmatid frog ecology. 7.1 Potential impacts of mining specific vibration on Leiopelmatid frogs We have established that vibration perception and sensitivity in Leiopelmatid frogs remains unknown but is theoretically possible. In attempt to try and understand the potential effects of mine-generated vibrations on these frogs one can only draw from studies of other anurans and from information on the presence of frogs in areas subject to vibration effects (e.g., frog populations persisting adjacent to roads and historical mining operations). There are several possible responses by Leiopelmatid frogs to potential vibration (episodic) - caused by blasting associated with the construction and operation of the WUG: (a) No response, either because Leiopelmatid frogs do not sense vibration at all or do not perceive it as a stimulus that they need to respond to. (b) Physiological stress or flight response, resulting in increased heart rate and/ or startling in response to short duration/ high amplitude vibrations. May manifest as freezing or flight behaviour (e.g., jumping, moving away), the latter of which could potentially disrupt sensitive behaviours such as mating amplexus, or in the case of Archey’s frog, abandonment of eggs during male brooding if a male moves away from a female or eggs and does not return. (c) Dispersal response, causing movement away from an area influenced by an annoyance (episodic vibration caused by blasting), which may increase susceptibility to predators (d) Behavioural responses to anthropogenic vibration stimuli erroneously interpreted as environmental cues (e.g., emergence in response to vibrations misinterpreted as rainfall). Of these possible responses, (b)–(d) have the theoretical potential to cause heightened stress, avoidance behaviours, reduced/ failed reproductive output, and/ or changes in species distribution and species composition. In an attempt to understand possible responses to vibration in leiopelmatid frogs, three case studies, one of which is rather speculative, have been explored and scrutinised. These are described and discussed below. 1) Frog persistence over the duration of mining operations at Golden Cross Mine, Waitekauri Valley The Golden Cross gold mine, in the headwaters of the Waitekauri River at the southern end of the Coromandel Range was established in 1990 and operated by Coeur Gold New Zealand Limited (CGNZL)
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