The structure of the calls made by the echolocating fruit bat Rousettus aegyptiacus while flying within a flight tunnel were investigated. Calls are impulsive clicks lasting around 250 μs, with most energy occurring during the first 100 μs. Such a call duration is much shorter than that previously reported for this species. The ability of R. aegyptiacus to detect and avoid obstacles was tested in both the light and total darkness. Bats were able to detect and avoid 6 mm diameter wires significantly more often than 1.3 mm diameter wires when tested in the light. In the dark, the same relationship held, with no decrease in the ability to detect and avoid the obstacles. Bats used echolocation in both the light and the dark conditions. The simple impulsive clicks used in echolocation by this species are thus able to detect wires of at least 6 mm in diameter and probably smaller. The detection problems associated with very short duration signals is discussed. The possession of both a good visual system, and a good echolocation system in this species has implications for the evolution of echolocation in bats.
LITERATURE CITED
H. T. Arita
, and
M. B. Fenton
.
1997. Flight and echolocation in the ecology and evolution of bats. Trends in Ecology and Evolution, 12: 53–58. Google Scholar
W. W. L. Au
1980. Echolocation signals of the Atlantic bottlenose dolphin (Tursiops truncatus) in open waters. Pp. 251–282,
in
Animal sonar systems (
R. G. Busnel
and
J. F. Fish
, eds.).
Plenum, New York, 1082 pp. Google Scholar
R. J. Baker
,
M. J. Novacek
, and
N. B. Simmons
.
1991. On the monophyly of bats. Systematic Zoology, 40: 216–231. Google Scholar
G. P. Bell
, and
M. B. Fenton
.
1986. Visual acuity, sensitivity and binocularity in a gleaning insectivorous bat, Macrotus californicus (Chiroptera: Phyllostomidae). Animal Behaviour, 34: 409–114. Google Scholar
R. B. Coles
,
M. Konishi
, and
J. D. Pettigrew
.
1987. Hearing and echolocation in the Australian grey swiftlet, Collocalia spodiopygia. Journal of Experimental Biology, 129: 365–371. Google Scholar
R. Dooling
1980. Behaviour and psychophysics of hearing in birds. Pp. 261–288,
in
Comparative studies of hearing in vertebrates (
A. Popper
and
R. Fay
, eds.).
Springer-Verlag, Berlin, 457 pp. Google Scholar
J. Eklöf
,
T. Tranefors
, and
L. B. Vazquez
.
2002. Precedence cues in the emballonurid bat Balantiopteryx plicata. Mammalian Biology: 67, 42–16. Google Scholar
J. H. Fullard
,
R. M. R. Barclay
, and
D. W. Thomas
.
1993. Echolocation in free-flying Atiu swiftlets (Aerodramus sawtelli). Biotropica, 25: 334–339. Google Scholar
D. Griffin
1953. Acoustic orientation in the oilbird, Steatornis. Proceedings of the National Academy of Sciences, 39: 884–893. Google Scholar
D. R. Griffin
,
A. Novick
, and
M. Kornfield
.
1958. The sensitivity of echolocation in the fruit bat Rousettus. Biological Bulletin, 155: 107–113. Google Scholar
R. S. Heffner
,
G. Koay
, and
H. E. Heffner
.
1999. Sound localisation in an Old-world fruit bat (Rousettus aegyptiacus): acuity, use of binaural cues, and relationship to vision. Journal of Comparative Psychology, 113: 297–306. Google Scholar
O. W. Henson
, and
H.-U. Schnitzler
.
1980. Performance of airborne biosonar systems: II. Vertebrates other than Microchiroptera. Pp. 138–195,
in
Animal sonar systems (
R. G. Busnel
and
J. F. Fish
, eds.).
Plenum, New York, 1082 pp. Google Scholar
H. Herbert
1985. Echoortungsverhalten des Flughundes Rousettus aegyptiacus (Megachiroptera). Zeitschrift für Säugetierkunde, 50: 141–152. Google Scholar
P. Holler
, and
U. Schmidt
.
1996. The orientation behaviour of the lesser spearnosed bat, Phyllostomus discolor (Chiroptera) in a model roost — concurrence of visual, echoacoustical and endogenous spatial information. Journal of Comparative Physiology A, 179: 245–254. Google Scholar
G. Koay
,
R. S. Heffner
, and
H. E. Heffner
.
1998. Hearing in a Megachiropteran fruit bat (Rousettus aegyptiacus). Journal of Comparative Psychology, 112: 371–382. Google Scholar
E. Kulzer
1956. Flughunde erzeugen Orientierungslaute durch Zungenschlag. Naturwissenschaften, 43: 117–118. Google Scholar
F. P. Möhres
, and
E. Kulzer
.
1956. Über die Orientierung der Flughund (Chiroptera-Pteropodidae). Zeitschrift für Vergleichende Physiologie, 38: 1–29. Google Scholar
G. Neuweiler
1962. Bau und Leistung des Flughundes (Pteropus giganteus). Zeitschrift für Vergleichende Physiologie, 46: 13–56. Google Scholar
G. Neuweiler
1983. Echolocation and adaptivity to ecological constraints. Pp. 280–302,
in
Neuroethology and behavioural physiology (
F. Huber
and
H. Markle
, eds.).
Springer-Verlag, Berlin, 412 pp. Google Scholar
K. S. Norris
, and
G. W. Harvey
1974. Sound transmission in the porpoise head. Journal of the Acoustical Society of America, 56: 659–664. Google Scholar
J. D. Pettigrew
1991a. A fruitful, wrong hypothesis? Response to Baker, Novacek, and Simmons. Systematic Zoology, 40: 231–239. Google Scholar
J. D. Pettigrew
1991b. Wings or brain? Convergent evolution in the origins of bats. Systematic Zoology, 40: 199–216. Google Scholar
J. D. Pettigrew
,
B. Dreher
,
C. S. Hopkins
,
M. J. McCall
, and
M. Brown
.
1988. Peak density and distribution of ganglion cells in the retinae of microchiropteran bats: Implications for visual acuity. Brain Behavior and Evolution, 32: 39–56. Google Scholar
J. D. Pye
, and
A. Pye
.
1988. Echolocation sounds and hearing in the fruit bat Rousettus. Pp. 1–12,
in
Advances in audiology 5: Measurement in hearing and balance (
S. D. G. Stephens
and
S. Prasansuk
, eds.).
Karger, Basel, 278 pp. Google Scholar
L. H. Roberts
1975. Confirmation of the pulse production mechanism of Rousettus. Journal of Mammalogy, 56: 218–220. Google Scholar
S. Schmidt
, and
J. Thaller
.
1994. Temporal summation in the echolocating bat Tadarida brasiliensis. Hearing Research, 77: 125–134. Google Scholar
H-U. Schnitzler
,
C. F. Moss
, and
A. Denzinger
.
2003. From spatial orientation to food acquisition in echolocating bats. Trends in Ecology and Evolution, 18: 386–394. Google Scholar
J. A Simmons
,
M. J. Ferragamo
,
P. A. Saillant
,
T. Haresign
,
J. M. Wotton
,
S. P. Dear
, and
D. N. Lee
.
1995. Auditory dimensions of acoustic images in echolocation. Pp. 146–190,
in
Hearing by bats (
A. N. Popper
and
R. R. Fay
, eds.).
Springer-Verlag, New York, 515 pp. Google Scholar
N. B. Simmons
, and
J. H. Geisler
.
1998. Phylogenetic relationships of Icaronycteris, Archaeonycteris, Hassianycteris, and Palaeochiropteryx to extant bat lineages, with comments on the evolution of echolocation and foraging strategies in Microchiroptera. Bulletin of the American Museum of Natural History, 235: 4–182. Google Scholar
J. R. Speakman
1993. The evolution of echolocation for predation. Symposia of the Zoological Society of London, 65: 39–63. Google Scholar
M. S. Springer
,
E. C. Teeling
,
O. Madsen
,
M. J. Syanhope
, and
W. W. De Jong
.
2001. Integrated fossil and molecular data reconstruct bat echolocation. Proceedings of the National Academy of Science, 98: 6241–6246. Google Scholar
R. A. Suthers
, and
D. H. Hector
.
1982. Mechanism for the production of echolocating clicks by the grey swiftlet, Collocalia spodiopygia. Journal of Comparative Physiology, 148: 457–170. Google Scholar
R. A. Suthers
, and
D. H. Hector
.
1985. The physiology of vocalisation by the echolocating oilbird, Steatornis caripensis. Journal of Comparative Physiology A, 156: 243–266. Google Scholar
R. A. Suthers
, and
C. A. Summers
.
1980. Behavioral audiogram and masked thresholds of the megachiropteran echolocating bat, Rousettus. Journal of Comparative Physiology, 136: 227–233. Google Scholar
E. C. Teeling
,
O. Madsen
,
R. A. Van Den Bussche
,
W. W. De Jong
, and
M. J. Stanhope
.
2002. Microbat paraphyly and the convergent evolution of a key innovation in Old World rhinolophoid microbats. Proceedings of the National Academy of Science, 99: 1431–1436. Google Scholar
D. A. Waters
, and
G. Jones
.
1995. Echolocation call structure and intensity in five species of insectivorous bats. Journal of Experimental Biology, 198: 475–189. Google Scholar
D. A. Waters
,
J. Rydell
and
G. Jones
.
1995. Echolocation call design and limits on prey size: a case study using the aerial-hawking bat Nyctalus leisleri. Behavioral Ecology and Sociobiology, 37: 321–328. Google Scholar
L. Wiegrebe
, and
S. Schmidt
.
1996. Temporal integration in the echolocating bat, Megaderma lyra. Hearing Research, 102: 35–12. Google Scholar
