Evidence for echolocation by cetaceans

Schevill, William E.; McBride, Arthur F.

doi:10.1016/0146-6313(56)90096-x

Cited by 53 publications

(22 citation statements)

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“…In the case of homoplasy, the trait may arise as a consequence of adaptation to the demands of a particular environment. The presence of echolocation in unrelated groups of mammals is a very good example of homoplasy; echolocation has evolved independently in bats (Griffin, ), whales (Schevill & McBride, ), and shrews (Tomasi, ). We suggest that the presence of an expanded distal CA1 in ungulates and carnivores represents an ancestral trait belonging to the clade Fereuungulata.…”

Section: Discussionmentioning

confidence: 99%

“…There is empirical evidence to suggest that large herbivores rely on accurate spatial memory to improve foraging efficiency (Bailey et al, 1996), and this is consistent with a view that ungulate migratory behaviors would benefit from an enhanced ability to integrate topographical features into spatial navigation. It is important to note that the method of navigation employed by ungulates is very different to the navigation methods used by birds (Wiltschko & Wiltschko, 2005;Zapka et al, 2009), bats (Griffin, 1958), shrews (Tomasi, 1979), and cetaceans (Schevill & McBride, 1956). Rather than relying on a memory of topographical features, these animals instead utilize gradients in the earth's magnetic field, the position of the sun, or echolocation for navigation.…”

Section: Spatial Memory and Navigation In Ungulatesmentioning

confidence: 99%

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Elongation of the CA1 field of the septal hippocampus in ungulates

Watson

Binks

2018

J of Comparative Neurology

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It is widely assumed that the hippocampal formation seen in laboratory rodents and in primates is typical of that seen in other mammals. We have tested this assumption by examining sections of brains of 56 mammals from 20 mammalian orders from images on the http://brainmuseum.org website. We found wide variation in the form of the hippocampal formation, the most extreme examples of which are seen in ungulates, which possess an unusual elongation of the distal CA1 of the septal hippocampus. This phenomenon has not previously been reported. In individual coronal sections of the brains of seven artiodactyl ungulates, the pyramidal layer of CA1 is four times as long as CA2 + CA3. In a perissodactyl ungulate (Burchell's zebra) the distal end of CA1 is so large that it forms a number of folds. A similar but less pronounced CA1 elongation was seen in the brains of 14 carnivores. A modest elongation of CA1 is also present in some other placental mammals, notably the elephant shrew, hyrax, capybara, beaver, and rabbit. The elongation was not present in brains of primates, marsupials, or monotremes. The distal part of CA1 has been shown to play a role in object integration into the spatial map. We hypothesize that the distal CA1 enlargement could serve to enhance the ability to integrate objects into spatial navigation, which would be an advantage for migrating herds of ungulates. We suggest that the remarkable elongation of Q5 CA1 represents a major evolutionary specialization in the ungulates.

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Section: Discussionmentioning

confidence: 99%

Section: Spatial Memory and Navigation In Ungulatesmentioning

confidence: 99%

Elongation of the CA1 field of the septal hippocampus in ungulates

Watson

Binks

2018

J of Comparative Neurology

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“…Bats and toothed whales have independently evolved a sophisticated biosonar system [1], [2], allowing both clades to diversify and occupy many different niches [3], [4]. Toothed whales constitute a morphologically and ecologically diverse group of predators, inhabiting every ocean and several large, freshwater river systems [5].…”

Section: Introductionmentioning

confidence: 99%

Clicking in Shallow Rivers: Short-Range Echolocation of Irrawaddy and Ganges River Dolphins in a Shallow, Acoustically Complex Habitat

Jensen

Rocco²,

Mansur³

et al. 2013

PLoS ONE

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Toothed whales (Cetacea, odontoceti) use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica) and Irrawaddy dolphins (Orcaella brevirostris) within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB) re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191) re 1 µPapp. These source levels are 1–2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.

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“…He 12 commented that the highly developed odontocete cerebral cortex may have been driven by very 13 acute hearing and need for acoustic processing, analogous to the rapid growth and differentiation 14 of the primate cortex as a response to its complex optic structures and binocular stereoscopic 15 vision. Indeed, researchers began suspecting that odontocetes might echolocate and "see " 16 through their hearing in 1947 (Schevill and McBride, 1956). 17 The first underwater recordings of cetacean vocalizations were made in the 1940's, which 18 greatly advanced our understanding of the sounds used by cetaceans (Schevill and Lawrence, 19 1949).…”

Section: Early Investigations 23mentioning

confidence: 99%

Hearing in Cetaceans: From Natural History to Experimental Biology

Mooney

Yamato

Branstetter

2012

Advances in Marine Biology

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1Sound is the primary sensory cue for most marine mammals, and this is especially true for 2 cetaceans. To passively and actively acquire information about their environment, cetaceans 3 have perhaps the most derived ears of all mammals, capable of sophisticated, sensitive hearing 4 and auditory processing. These capabilities have developed for survival in an underwater world 5 where sound travels five times faster than in air, and where light is quickly attenuated and often 6 limited at depth, at night, and in murky waters. Cetacean auditory evolution has capitalized on 7 the ubiquity of sound cues and the efficiency of underwater acoustic communication. The sense 8 of hearing is central to cetacean sensory ecology, enabling vital behaviors such as locating prey, 9 detecting predators, identifying conspecifics, and navigating. Increasing levels of anthropogenic 10 ocean noise appears to influence many of these activities. 11Here we describe the historical progress of investigations on cetacean hearing, with a 12 particular focus on odontocetes and recent advancements. While this broad topic has been 13 studied for several centuries, new technologies in the last two decades have been leveraged to 14 improve our understanding of a wide range of taxa, including some of the most elusive species. 15 This paper addresses topics including how sounds are received, what sounds are detected, 16 hearing mechanisms for complex acoustic scenes, recent anatomy and physiology studies, the 17 potential impacts of noise, and mysticete hearing. We conclude by identifying emerging 18 research topics and areas which require greater focus. 19 20 3

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Evidence for echolocation by cetaceans

Cited by 53 publications

References 0 publications

Elongation of the CA1 field of the septal hippocampus in ungulates

Elongation of the CA1 field of the septal hippocampus in ungulates

Clicking in Shallow Rivers: Short-Range Echolocation of Irrawaddy and Ganges River Dolphins in a Shallow, Acoustically Complex Habitat

Hearing in Cetaceans: From Natural History to Experimental Biology

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