GROWTH IN YOUNG GRAY WHALES <i>(ESCHRICHTIUS ROBUSTUS)</i>

Sumich, James L.

doi:10.1111/j.1748-7692.1986.tb00035.x

Cited by 41 publications

(38 citation statements)

References 5 publications

(17 reference statements)

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“…v www.esajournals.org variance (R 2 ¼ 0.997; Sumich et al 2013). The girth-to-length ratio for newborn calves was assumed to be 0.5 6 0.02L (Norris andGentry 1974, Sumich 1986).…”

Section: Gray Whale Female Energetic Demandsmentioning

confidence: 99%

“…Parameter L for newborn calves was based on late term fetuses and neonates measurements (Rice and Wolman 1971, Rice 1983, Sumich 1986. L for older calves was estimated using the Gompertz equation from Sumich et al (2013), L ¼ 8:85e Àe ðÀ0:47À0:068tÞ , R 2 ¼ 0.911, where t is age in weeks. Although we did not estimate uncertainty for this relationship, we assumed length at age varied the same as when calves are born (SD ¼ 0.5; Appendix D).…”

Section: Gray Whale Female Energetic Demandsmentioning

confidence: 99%

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A bioenergetics model to evaluate demographic consequences of disturbance in marine mammals applied to gray whales

et al. 2015

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While sophisticated tools are used to monitor behavioral changes of large marine vertebrates, determining whether these changes are meaningful for management and conservation is challenging. The Population Consequences of Disturbance model proposed a bioenergetics model to detect biologically meaningful population responses, where disturbance costs are linked to lost energy. The model assumes that changes in behavior, caused by disturbance, compromise maternal condition, reducing energy delivery to offspring, leading to reduced reproduction, increased offspring mortality, and eventually increased adult mortality. Given its coastal habits and past whaling history, gray whales' (Eschrichtius robustus) life history and ecology are better known than for many other baleen whales. However, their preference for coastal habitat increases their exposure to human disturbance. We created a female gray whale bioenergetics model to determine energy requirements for a two‐year reproductive cycle and determined the consequences of lost energy under three possible disturbance scenarios. An annual energetic loss of 4% during the year in which she is pregnant, would prevent a female from successfully producing/weaning a calf. For this reason, gray whale reproduction is particularly sensitive to disturbance during pregnancy. During the year in which she is lactating, she would wean her calf at a lower mass with a 37% energetic loss. A female would lack the energy to become pregnant during a year with a 30–35% energetic loss, and female mortality would likely occur at 40–42% annual energetic loss. Our model can be used for assessing disturbance costs or other effects associated with climate change and/or anthropogenic activities and can be applied to other species with similar life histories.

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“…v www.esajournals.org variance (R 2 ¼ 0.997; Sumich et al 2013). The girth-to-length ratio for newborn calves was assumed to be 0.5 6 0.02L (Norris andGentry 1974, Sumich 1986).…”

Section: Gray Whale Female Energetic Demandsmentioning

confidence: 99%

Section: Gray Whale Female Energetic Demandsmentioning

confidence: 99%

A bioenergetics model to evaluate demographic consequences of disturbance in marine mammals applied to gray whales

et al. 2015

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“…A recent dissection (February 2008) of a young male gray whale (LACM 95548, stranded 7 February 2008 at Huntington Beach, Orange County, California) measuring 517 cm in total body length provided the opportunity to examine some poorly known or undescribed anatomical features relevant to understanding the evolution and specialized feeding strategy of E. robustus . Based on total length data in Sumich (1986) this gray whale was approximately 2 mo old at the time of death and therefore represents a neonate.…”

mentioning

confidence: 99%

Observations on the musculoskeletal anatomy of the head of a neonate gray whale (Eschrichtius robustus)

Johnston¹,

Deméré

Berta

et al. 2009

Marine Mammal Science

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“…More commonly, alternating light and dark zones in the large waxy ear plugs of mysticetes have been used (Figure 14.14). Several studies have established that one GLG, consisting of one light and one adjacent dark band, represents an annual increment (Laws and Purves, 1956;Roe, 1967;Rice and Wolman, 1971;Sumich, 1986b), although only slightly more than one half of the ear plugs collected in each of two studies of gray whales by Rice and Wolman (1971) and Blokhin and Tiupeleyev (1987) were considered readable. Additionally, in older animals, there often is some loss of ear plug laminae deposited in an animal's early years, and this technique is usually not considered a reliable estimator of age much beyond the onset of sexual maturity.…”

Section: Age Determination and Longevitymentioning

confidence: 99%