An Experimental Demonstration of Echolocation Behavior in the Porpoise, Tursiops Truncatus (Montagu)

Norris, Kenneth S.; Prescott, John; Asa-Dorian, Paul V.; Perkins, Paul J.

doi:10.2307/1539374

Cited by 155 publications

(100 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The author concluded that dolphins are able to distinguish various sizes of stimuli, and navigate the surrounding environment by using echolocation. Norris et al (1961) also studied bottlenose dolphins to investigate echolocation and the ability to discriminate stimuli. Though the dolphins were blindfolded with latex cups, the animals were still able to locate targets suspended randomly below the water surface.…”

Section: Echolocationmentioning

confidence: 99%

Somatosensation, Echolocation, and Underwater Sniffing: Adaptations Allow Mammals Without Traditional Olfactory Capabilities to Forage for Food Underwater

et al. 2013

View full text Add to dashboard Cite

Section: Echolocationmentioning

confidence: 99%

Somatosensation, Echolocation, and Underwater Sniffing: Adaptations Allow Mammals Without Traditional Olfactory Capabilities to Forage for Food Underwater

et al. 2013

View full text Add to dashboard Cite

“…Echolocation type signals have been reported in over 70 studies in a variety of odontocete species, indicating that the entire clade utilizes echolocation (e.g., review in Au, 1993;Miller et al, 1995;Johnson et al, 2004;Li et al, 2005;Madsen et al, 2005a,b). Evidence for echolocation in dolphins was described early, but not until a study by Norris et al (1961) was the discrimination ability of dolphins using echolocation demonstrated. This was the first study to blindfold a toothed whale (bottlenose dolphin, Tursiops truncatus) and conduct experiments testing the animal's ability to discriminate between inanimate objects and fish.…”

Section: Echolocation and Sound Sourcesmentioning

confidence: 99%

“…This was the first study to blindfold a toothed whale (bottlenose dolphin, Tursiops truncatus) and conduct experiments testing the animal's ability to discriminate between inanimate objects and fish. In addition, it was noted that the echolocation beam appeared to be directional (Norris et al, 1961).…”

Section: Echolocation and Sound Sourcesmentioning

confidence: 99%

“…Cranford et al (1996) The biosonar apparatus produces a sound that leaves the head of an odontocete in a particular trajectory. The directionality of echolocation signals was suggested by Norris et al (1961), but experiments by Au et al (1995) provided evidence for this hypothesis.…”

Section: Echolocation and Sound Sourcesmentioning

confidence: 99%

“…Norris, 1961;review in Au, 1993;Miller et al, 1995;Johnson et al, 2004;Li et al, 2005;Madsen et al, 2005a,b), suggesting that the entire lineage utilizes echolocation. During echolocation, the animal produces a sound and then listens for a returning echo from the target.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Shape analysis of odontocete mandibles: Functional and evolutionary implications

Barroso¹,

Cranford²,

Berta³

2012

Journal of Morphology

View full text Add to dashboard Cite

Odontocete mandibles serve multiple functions, including feeding and hearing. One hypothesis is that sound enters the hearing apparatus via the pan bone of the posterior mandibles (Norris, 1968). Another viewpoint, based on computer models, suggests that sound enters primarily through the gular apparatus and the opening created by the absent medial wall of the posterior mandibles. The posterior region of each mandibular ramus has a large, hollow cavity called the mandibular foramen that contains a bulging mandibular fat body (MFB), which terminates on the bony tympanoperiotic complex. The acoustic properties of these fat bodies suggest that they refract sound. This unambiguous link between form and function has catalyzed this current study of mandibular shape. Previous studies have described odontocete mandibles using linear morphometrics and focused on multiple populations within single genera. Geometric Morphometrics (GM) is used to avoid some limitations of linear morphometric studies, using relative 3-D landmark positions instead of lengths. This technique measures shape only, excluding any scaling, rotational, and positional effects.The primary objective of this study is to use GM to quantify mandibular shape across all major lineages of Odontoceti. Eighty-five mandibles, comprised of 40 species, representing all major lineages were included in the shape analysis. Twelve landmarks found on each mandible represent regions of the symphysis and mandibular foramen. The majority of shape variation was found in Jaw Flare and Symphysis Elongation (85.5%). Shape differences in the mandibular foramen also accounts for a portion the total variation (10.9%). The mandibles are an integral component of the sound reception apparatus in toothed whales and the geometry of the mandibular foramen likely plays a role in hearing.The second objective of this study is to assess correlates of hearing and mandibular foramen geometry derived from the GM shape analysis, as well as from linear morphometrics. Echolocation peak frequency (EPF) was used as a measure of sound reception. Odontocete anatomy may emphasize frequencies they need to hear and suppress others in a returning echo during echolocation. Frequencies can be characterized by corresponding wavelengths. Surface area between the four landmarks that represent the mandibular foramen was calculated to assess the relationship between EPF and dimensions of a receiving structure (i.e. mandibular foramen and corresponding MFB). A significant relationship between size of the foramen and EPF was found, suggesting that size of the foramen may limit lower frequencies (longer wavelengths) from propagating through the mandibular fat body.

show abstract

Functional morphology and homology in the odontocete nasal complex: Implications for sound generation

1996

Self Cite

View full text Add to dashboard Cite

An Experimental Demonstration of Echolocation Behavior in the Porpoise, Tursiops Truncatus (Montagu)

Cited by 155 publications

References 7 publications

Somatosensation, Echolocation, and Underwater Sniffing: Adaptations Allow Mammals Without Traditional Olfactory Capabilities to Forage for Food Underwater

Somatosensation, Echolocation, and Underwater Sniffing: Adaptations Allow Mammals Without Traditional Olfactory Capabilities to Forage for Food Underwater

Shape analysis of odontocete mandibles: Functional and evolutionary implications

Functional morphology and homology in the odontocete nasal complex: Implications for sound generation

Contact Info

Product

Resources

About