Aggressive tusk use by the narwhal (Monodon monoceros L.)

Silverman, H. B.; Dunbar, Moira

doi:10.1038/284057a0

Cited by 73 publications

(58 citation statements)

References 10 publications

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“…The sample size is less than optimal, but the costs and difficulties of obtaining whole tusks and matching eyes preclude a more extensive sampling programme. Furthermore, a high incidence of broken tusks in adult males (Silverman & Dunbar 1980) impedes sampling of old and complete tusks. The tusks in this study were not all complete (Table 1), which complicated the counting of GLGs, and there were some evident differences in the readability of the tusks that were impossible to quantify.…”

Section: Discussionmentioning

confidence: 99%

“…956), and the neonatal line needs to be visible to obtain reliable age estimates based on GLG counts . Another reason was that GLGs in teeth from old animals are more difficult to discern and count due to compact layering, wear of the teeth and often broken tips (Silverman & Dunbar 1980;Luque et al 2009). The two estimated 2k Asp values are, however, almost identical.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Aspartic acid racemization rate in narwhal (Monodon monoceros) eye lens nuclei estimated by counting of growth layers in tusks

et al. 2012

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Aspartic acid racemization rate in narwhal (Monodon monoceros) eye lens nuclei estimated by counting of growth layers in tusks

et al. 2012

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“…For example, males of the salmonid fish Salmo salar (Linnaeus) have an enlarged jaw and use it for contests over females and/or spawning sites (Garant et al 2003). Male narwhals, Monodon monoceros (Linnaeus), possess a spiralled tusk, and crossing tusks in contests for females can cause injury to their heads (Silverman & Dunbar 1980). In fiddler crabs, males have one greatly enlarged major claw that is used as a weapon during contests for breeding burrows (Backwell et al 2000), and the claw size is critically important to determine the process and outcomes of the contest (Morrell et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Rapid regeneration of the major cheliped in relation to its function in male-male contests in the hermit crab Pagurus middendorffii

Yasuda

Matsuo

Wada

2014

Plankton Benthos Res

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Abstract:Most crustaceans are known to regenerate their appendages after losing them, and the pattern of regeneration may be related to its function. The pattern of regeneration of the right major cheliped was examined after experimentally induced autotomy and its behavioral function during male-male contests for mates was investigated in the hermit crab Pagurus middendorffii. Males with an autotomized major cheliped regenerated it at the first molt after autotomy and showed smaller growth in body size than in control males. The shape of the regenerated cheliped was more slender than the original, implying that the regenerated major cheliped would be less robust and weaker than previously. The length of the major cheliped of an owner male (guarding a female at the start of a dyadic contest) and the body size of an intruder affected whether or not the contest escalated, but the major cheliped length of the intruder and the body size of the owner determined the outcome of the escalated contest. The intruder used the major cheliped as an offensive weapon to take the female away from the owner by force after the contest escalated. The owner often moved the major cheliped forward, similar to a fencing weapon, before escalation. Such movement of the owner seems to be effective to prevent the intruders from approaching, and the regenerated cheliped of the owner may not require much robustness and strength as a defensive weapon before escalation. Rapid regeneration of the major cheliped in P. middendorffii would therefore be beneficial to minimize the disadvantages incurred by loss of the major cheliped.

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“…It is unlikely that the healed scars on the head had anything to do with the cause of death as they are common in narwhal. They may have been traces of injuries sustained while swimming upside down close to the seabed (Dietz et al, 2007), through contact with ice during temporary ice entrapment (HeideJørgensen et al, 2002b; as reported in Huntington et al, 1999, for beluga whale), through failed predation attempts by killer whale (Orcinus orca) or polar bear (Ursus maritimus) (Hay & Mansfield, Fraser, 1974 1989; Reeves et al, 1994), or through intraspecific aggressive behaviour, although this is more typical in adult males (Silverman & Dunbar, 1980;Gerson & Hickie, 1985). Applying the Gompertz body mass growth model for West Greenland narwhal in Garde et al (2015), the mass of a 5-y-old narwhal would be 447 kg.…”

Section: Discussionmentioning

confidence: 99%

New Extralimital Record of a Narwhal (Monodon monoceros) in Europe

et al. 2018

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On 27 April 2016, a dead narwhal (Monodon monoceros) was found on the bank of the River Scheldt, Belgium. It was the first record of this high Arctic cetacean in Belgium, and one of the most southerly records ever in Europe. Due to the decomposition of the carcass, the results of the autopsy remained inconclusive, but it is likely that the animal had died due to a long process of starvation. In the stomach, a large number of litter items were found which were probably ingested during the process of dying. We further provide information on the sighting of the live animal prior to the stranding and present an overview of the very few known records of narwhal in northwestern Europe.

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Aggressive tusk use by the narwhal (Monodon monoceros L.)

Cited by 73 publications

References 10 publications

Aspartic acid racemization rate in narwhal (Monodon monoceros) eye lens nuclei estimated by counting of growth layers in tusks

Aspartic acid racemization rate in narwhal (Monodon monoceros) eye lens nuclei estimated by counting of growth layers in tusks

Rapid regeneration of the major cheliped in relation to its function in male-male contests in the hermit crab Pagurus middendorffii

New Extralimital Record of a Narwhal (Monodon monoceros) in Europe

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