DO PHOTOPERIOD AND TEMPERATURE INFLUENCE THE MOLT CYCLE OF <i>PHOCA VITULINA</i> IN CAPTIVITY?

Mο, Giulia; Gili, Claudia; Ferrando, Paola

doi:10.1111/j.1748-7692.2000.tb00952.x

Cited by 14 publications

(23 citation statements)

References 14 publications

(14 reference statements)

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“…These factors could also be affecting the molt; however, photoperiod seems to be the most important variable as it defines the beginning of the molt (Mo et al . ) and the peak molting date (Cronin et al . ).…”

Section: Discussionmentioning

confidence: 99%

“…These photoperiods fall within the range reported by Mo et al . (), who found that in an aquarium in Italy, harbor seals require a photoperiod that lasts a minimum of 8 h 53 min and a maximum of 15 h 31 min to carry out the molt.…”

Section: Discussionmentioning

confidence: 99%

“…The beginning of the harbor seal's molt is strongly associated with photoperiod variation (Mo et al . ) and thus, the molting season varies latitudinally. Molting occurs first in southern areas and is delayed as the latitude increases (Daniel et al .…”

mentioning

confidence: 99%

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Molting phenology of the Pacific harbor seal (Phoca vitulina richardii) on two islands off the Baja California Peninsula, Mexico

Tapia-Harris

Heckel

Schramm

et al. 2017

Marine Mammal Science

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We document and compare the annual molt of the Pacific harbor seal (Phoca vitulina richardii) on two islands off the west coast of the Baja California Peninsula that are the northern and southern extremes of its distribution in Mexico. During 2014, observations were made from March to July on Todos Santos Island (northern extreme) and from January to June on San Roque Island (southern extreme). On Todos Santos, the premolt lasted 15 wk (March–June) and the molt 12 wk (April–July). On San Roque, the premolt lasted 22 wk (January–June) and the molt 17 wk (February–June). The proportion of seals undergoing molt peaked on 26 May on Todos Santos and on 7 June on San Roque. Shedding of old hair most commonly initiated on the torso and progressed to the head and flippers (reverse molting pattern). The period when the highest number of harbor seals haul out in Mexico is in late April on the more southerly islands and in early May on the more northerly islands, when a large proportion of seals are in premolt.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Molting phenology of the Pacific harbor seal (Phoca vitulina richardii) on two islands off the Baja California Peninsula, Mexico

Tapia-Harris

Heckel

Schramm

et al. 2017

Marine Mammal Science

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“…Photoperiod can serve as a trigger for the moulting cycle (Duby and Travis 1972;Mo et al 2000), but in many cases new fur growth, which is energetically costly, occurs sequentially with other energetically costly processes or conditions (but see King and Murphy 1985). For instance, the start of a moult cycle may be delayed in animals experiencing nutritional stress or in reproductively active females (e.g., Stewart and Macdonald 1997;Neuhaus 2000;Lu 2003).…”

Section: Moulting In Mammalsmentioning

confidence: 98%

Moulting matters: the importance of understanding moulting cycles in bats when using fur for endogenous marker analysis

2013

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Endogenous markers are a valuable indicator of individual animal ecology, but data interpretation requires a detailed understanding of the timing of tissue formation. Fur is commonly used in bat research using endogenous markers, but the moulting cycles of most bat species are not well documented. In this review, we (i) describe methods of investigating bat moulting; (ii) summarize the current literature on bat moulting cycles, highlighting broad trends; (iii) discuss knowledge gaps; and (iv) make recommendations for optimal fur sampling protocols. Three characteristics may indicate moulting in bats: changing skin pigmentation; visible fur growth and colour changes; and endogenous markers. Most studies reported new fur growth once annually during summer-fall, although there were exceptions. The timing of new fur growth varies among species, sexes, and age classes. Individuals commonly experience asynchronous new fur growth, with dorsal fur growth occurring before ventral. Specific moult progressions vary among species. Knowledge gaps include moulting cycles in tropical species and in subadult and yearling bats; migration during new fur growth; and the timing of fur growth compared with shedding. We recommend that fur samples taken dorsally from adult males are the most likely to be representative of the bat's site of summer residency.Résumé : Si les marqueurs endogènes constituent un indicateur utile de l'écologie individuelle des animaux, l'interprétation de ces données nécessite une compréhension détaillée du moment de la formation des tissus. Bien que le poil soit couramment utilisé dans la recherche sur les chauves-souris axée sur des marqueurs endogènes, les cycles de mue de la plupart des espèces de chauves-souris ne sont pas bien documentés. Dans le présent article, nous (i) décrivons des méthodes permettant d'étudier la mue des chauves-souris, (ii) présentons une synthèse des travaux existants sur les cycles de mue des chauves-souris pour en faire ressortir de grandes tendances, (iii) abordons les lacunes sur le plan des connaissances et (iv) formulons des recommandations relatives à des protocoles optimaux d'échantillonnage du poil. Trois caractéristiques pourraient indiquer qu'une chauve-souris est en mue, à savoir : un changement de la pigmentation de la peau, la croissance et des changements de couleur visibles des poils, ainsi que des marqueurs endogènes. Bien qu'il existe des exceptions, la plupart des études font état d'une croissance de nouveaux poils une fois l'an, à l'été-l'automne. Le moment de la croissance de nouveaux poils varie selon l'espèce, le sexe et la classe d'âge. Les individus présentent souvent une croissance non synchrone de nouveaux poils, la croissance des poils dorsaux étant plus hâtive que celle des poils ventraux. La progression de la mue varie également selon l'espèce. Les lacunes sur le plan des connaissances touchent notamment aux cycles de mue des espèces tropicales et des chauves-souris subadultes et d'un an, à la migration durant la croissance de nouveaux poils et au mo...

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“…Variation between individuals in the timing of molt can also be influenced by individual condition (influenced by prey capture success), sea temperature, and ambient air temperature also influencing molt duration (Bissonnette , Ling , Mo et al . , Yochem and Stewart , Paterson et al . ).…”

mentioning

confidence: 99%

Onset and duration of gray seal (Halichoerus grypus) molt in the Wadden Sea, and the role of environmental conditions

Schop

Aarts

Kirkwood

et al. 2017

Marine Mammal Science

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Surveys of gray seals (Halichoerus grypus) during the molt period, when they are abundant on land, can be used to monitor changes in population size, but accurate interpretation of results requires an understanding of the molt process and how it may vary between years. This study investigates variability in onset (start date) and duration of visible molt by gray seals in the Wadden Sea, and the influence of environmental conditions on the onset. Molt was monitored in nine captive seals and observed molt phases were applied to wild seals over seven annual molt periods between 2004 and 2010, monitored using aerial photography. The onset of visible molt varied significantly between years, for example it differed 28 d between 2008 and 2009. Model selection by AIC retained one environmental variable that correlated with molt onset; however, its effect was inconsistent within the molt season and did not explain some of the apparent observed annual variation. Hence, the main causes of interannual variability in the onset of molt remain unclear and warrant further study. Researchers should account for annual variability in the onset of molt when interpreting survey results based on molt counts.

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DO PHOTOPERIOD AND TEMPERATURE INFLUENCE THE MOLT CYCLE OF PHOCA VITULINA IN CAPTIVITY?

Cited by 14 publications

References 14 publications

Molting phenology of the Pacific harbor seal (Phoca vitulina richardii) on two islands off the Baja California Peninsula, Mexico

Molting phenology of the Pacific harbor seal (Phoca vitulina richardii) on two islands off the Baja California Peninsula, Mexico

Moulting matters: the importance of understanding moulting cycles in bats when using fur for endogenous marker analysis

Onset and duration of gray seal (Halichoerus grypus) molt in the Wadden Sea, and the role of environmental conditions

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