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Peter M. Narins
that are capable of both providing an alternate pathway and supporting seismic
waves, such as underground tunnels, muddy soil, a dense mat of reeds, etc. It is
the relationship between habitat, signal structure and communication behavior in
seismically active animals that I wish to explore and understand.
2 Definition of Seismic Signaling
Terrestrial seismic communication is the exchange of information between
individuals using self-generated vibrational signals transmitted via a solid
substrate such as soil, a plant stem, or a blade of grass. Communication using
substrate-borne vibrations demands three physical prerequisites: (1) A sender must
have the structural apparatus to generate a seismic signal and couple it efficiently
to the substrate. This could take the form of an impulsive thump, delivered, for
example, to the ground using a limb, a vocal sac, or a specialized accessory
structure. (2) The existence of a channel for conducting the signal. Once produced,
the seismic disturbance travels outward from the source perhaps as a surface or
bending wave. Its propagation characteristics depend intimately on the physical
properties of the channel, for example, the substrate density, water content of the
soil, obstacles encountered, etc. (3) The seismic receiver must have the structural
and neural systems to detect the vibrational signal, extract it from the ambient
noise, and decode it for subsequent interpretation. In addition, the signal must be
capable of producing a reliable and quantifiable change in the recipient's behavior
for communication to have occurred.
This modality affords many advantages for terrestrial animals; seismic
communication signals propagate without light during day or night, are most
effective at close range, and have only short persistence. Thus, they are well suited
for information exchange between neighboring individuals - there is little danger
of their detection by distant predators (Narins 1990).
3 The Seismically Sensitive Vertebrates
Although anecdotes abound, evidence for the use of seismic signals for
intraspecific communication of biologically significant information has been
gathered in only three species of vertebrates to date: the white-lipped frog
(Leptodactylus) of Puerto Rico, the blind mole-rat (Spa/ax) oflsrael, and the Cape
mole-rat (Georychus) of South Africa. The western rattlesnake (Crotalus) of the
United States, the sandsfish lizard (Scincus) of the Sahara Desert, and the Namib
Desert golden mole (Eremitalpa) of Namibia are thought to use prey-generated
seismic cues for passive location, whereas spadefoot toads (Scaphiopus) in the
western United States respond to environmentally induced substrate vibrations.
Recently, it has been shown that the veiled chameleon (Chamaeleo) from Yemen
produces vibratory signals in response to both visual and tactile stimuli, whereas
Peter M. Narins
that are capable of both providing an alternate pathway and supporting seismic
waves, such as underground tunnels, muddy soil, a dense mat of reeds, etc. It is
the relationship between habitat, signal structure and communication behavior in
seismically active animals that I wish to explore and understand.
2 Definition of Seismic Signaling
Terrestrial seismic communication is the exchange of information between
individuals using self-generated vibrational signals transmitted via a solid
substrate such as soil, a plant stem, or a blade of grass. Communication using
substrate-borne vibrations demands three physical prerequisites: (1) A sender must
have the structural apparatus to generate a seismic signal and couple it efficiently
to the substrate. This could take the form of an impulsive thump, delivered, for
example, to the ground using a limb, a vocal sac, or a specialized accessory
structure. (2) The existence of a channel for conducting the signal. Once produced,
the seismic disturbance travels outward from the source perhaps as a surface or
bending wave. Its propagation characteristics depend intimately on the physical
properties of the channel, for example, the substrate density, water content of the
soil, obstacles encountered, etc. (3) The seismic receiver must have the structural
and neural systems to detect the vibrational signal, extract it from the ambient
noise, and decode it for subsequent interpretation. In addition, the signal must be
capable of producing a reliable and quantifiable change in the recipient's behavior
for communication to have occurred.
This modality affords many advantages for terrestrial animals; seismic
communication signals propagate without light during day or night, are most
effective at close range, and have only short persistence. Thus, they are well suited
for information exchange between neighboring individuals - there is little danger
of their detection by distant predators (Narins 1990).
3 The Seismically Sensitive Vertebrates
Although anecdotes abound, evidence for the use of seismic signals for
intraspecific communication of biologically significant information has been
gathered in only three species of vertebrates to date: the white-lipped frog
(Leptodactylus) of Puerto Rico, the blind mole-rat (Spa/ax) oflsrael, and the Cape
mole-rat (Georychus) of South Africa. The western rattlesnake (Crotalus) of the
United States, the sandsfish lizard (Scincus) of the Sahara Desert, and the Namib
Desert golden mole (Eremitalpa) of Namibia are thought to use prey-generated
seismic cues for passive location, whereas spadefoot toads (Scaphiopus) in the
western United States respond to environmentally induced substrate vibrations.
Recently, it has been shown that the veiled chameleon (Chamaeleo) from Yemen
produces vibratory signals in response to both visual and tactile stimuli, whereas