Salamander using its prehensile tail - Bolitoglossa cf. nympha (Plethodontidae; sub-genus Nanotriton), Honduras

Abstract

Keywords: Salamander, Prehensile tail, Caudal prehensility, defence, behaviour, adaptation, hanging, dropping, hook-like, Cusuco National Park, Honduras,

Full text

36 Herpetological Bullen 152 (2020)
Bolitoglossa nympha Campbell, Smith, Streicher, Acevedo,
& Brodie 2010 is a diminuve salamander; snout-vent-
length <43 mm, tail-length/SVL rao 0.70–0.95 (Kohler,
2011). It occurs at low-to-mid elevaons (275 to 1165 m
asl) from Huehuetenango and Baja Verapaz provinces in
Guatemala, through to Copán, Cortés, and Yoro in Honduras
(Frost, 2020). The species belongs to a complex of four
closely related bolitoglossine salamanders in the Bolitoglossa
rufescens group (subgenus Nanotriton; Parra-Olea et al.,
2004). In north-western Honduras, in-situ idencaon of
Bolitoglossa (Nanotriton) is tentave given the occurrence
of at least two crypc taxa (B. nympha & B. rufescens) in
microsympatry; both these species being morphologically
indisnguishable in the eld (Hess et al., 2017). Species of
Bolitoglossa (Nanotriton) primarily inhabit lowland tropical
rainforest habitats, but are also associated with agricultural
habitats such as banana plantaons (Rovito et al., 2012 a&b).
They are primarily nocturnal and semi-arboreal, frequently
climbing moist vegetaon to use leaf-axil refugia and
bromeliads (Rovito et al., 2012b). Unlike other Bolitoglossa,
species of the subgenus Nanotriton are unique in having
small robust bodies, with a tail length usually shorter than
their SVL, and underdeveloped feet with extensive webbing
(Parra-Olea et al., 2004; Kohler, 2011).
Previously, the tail of Bolitoglossa (Nanotriton) spp. has
been linked to defensive strategies such as raising, posturing
and autotomy (Arrivillaga & Brown, 2018). However, the
following note details B. cf. nympha using its tail to grasp and
assist climbing following a ip and fall defensive manoeuvre.
On 14 July 2016, c. 19.40 h, I encountered an adult
Bolitoglossa (Nanotriton sp. - assumed to be B. nympha)
acve on streamside vegetaon bordering agricultural land,
in the lowland buer region of Parque Nacional El Cusuco
(PNC), Santo Tomas, Cortés, Honduras. The individual was
climbing c. 2m above ground, but when approached, ipped
and dropped from its perch, then caught itself using the
tail like a hook to grasp a stem c. 1 m below (Fig 1A). Aer
dangling moonless for c. 1 minute, the tail was used to
lever the body upwards and prevent the salamander from
falling (Fig 1B). Such a mechanism might not only protect
the salamander from an injurious fall, but could also fool a
predator as to its whereabouts, assuming it to have fallen
completely to the ground.
Long prehensile tails are a widespread adaptaon among
arboreal plethodond salamanders (Duellman & Trueb,
1986), but evidence of their use in assisted climbing, escape
and/or defence remains rare. Phillips & Nicholson (2013)
coined the term ‘caudal prehensility’ to dene this behaviour
in salamanders, reporng an observaon of Bolitoglossa
lignicolor using its tail in a hook-like fashion to catch itself
following a ipping escape. Unl now, B. lignicolor remained
the only Bolitoglossa species in which this behaviour was
reported denively. The present observaon demonstrates
prehensility in B. cf. nympha, suggesng that even short
tails like those of sub-genus Nanotriton are praccal for
locomoon and defence in an arboreal seng. Our collecve
studies call for more eld observaons in order to determine
whether prehensility is widespread in bolitoglossine species.
ACKNOWLEDGEMENTS
A special thanks to the management, sta and local eld
guides of Operaon Wallacea (UK) for facilitang biological
research expedions in PNC, Honduras, as well as to Dr.
Tom Marn and Dr. Sean M. Rovito who provided helpful
reviews of this note. This observaon was made under
permit number ICF-DVS-104-2016; ICF-193-2016, issued to
Operaon Wallacea by the Instuto Nacional de Conservación
y Desarrollo Forestal, Áreas Protegidas y Vida Silvestre (ICF),
Tegucicalpa, Honduras.
REFERENCES
Arrivillaga, C. & Brown, T.W. (2018). Primary descripons of
defence mechanisms employed by neotropical
salamanders (Bolitoglossa, Oedipina, Nototriton, and
Cryptotriton sp.: Plethodondae) in Cusuco Naonal
The Herpetological Bulletin 152, 2020: 36-37
Salamander using its prehensile tail - Bolitoglossa cf. nympha
(Plethodondae; sub-genus Nanotriton), Honduras
TOM W. BROWN1,2
1Operaon Wallacea, Hope House, Old Bolingbroke, Lincolnshire PE23 4EX, UK
2Kanahau Ula Research & Conservaon Facility, Isla de Ula, IB 34201, Honduras
*Author e-mail: tom@kanahau.org
hps://doi.org/10.33256/hb152.3637
NATURAL HISTORY NOTE
Figure 1. Nanotriton (B. cf. nympha) exhibing caudal prehensility
following a ip and fall escape, A. The salamander hanging
momentarily aer having caught itself using the tail to grasp a stem,
B. The salamander levering itself back up onto the stem

Herpetological Bullen 152 (2020) 37
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Salamander using its prehensile tail - Bolitoglossa cf. nympha
Accepted: 21 March 2020