title: Distinguishing between determinate and indeterminate growth in a long-lived mammal.
abstract: BACKGROUND
  The growth strategy of a species influences many key aspects of its life-history. Animals can either grow indeterminately (throughout life), or grow determinately, ceasing at maturity. In mammals, continued weight gain after maturity is clearly distinguishable from continued skeletal growth (indeterminate growth). Elephants represent an interesting candidate for studying growth because of their large size, long life and sexual dimorphism. Objective measures of their weight, height and age, however, are rare.
  
  
  RESULTS
  We investigate evidence for indeterminate growth in the Asian elephant Elephas maximus using a longitudinal dataset from a semi-captive population. We fit growth curves to weight and height measurements, assess sex differences in growth, and test for indeterminate growth by comparing the asymptotes for height and weight curves. Our results show no evidence for indeterminate growth in the Asian elephant; neither sex increases in height throughout life, with the majority of height growth completed by the age of 15 years in females and 21 years in males. Females show a similar pattern with weight, whereas males continue to gain weight until over age 50. Neither sex shows any declines in weight with age.
  
  
  CONCLUSIONS
  These results have implications for understanding mammalian life-history, which could include sex-specific differences in trade-offs between size and reproductive investment.
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK. hs.mumby@gmail.com.
authors.forename: Hannah S
authors.initials: HS
authors.lastname: Mumby
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK. snchapman93@gmail.com.
authors.forename: Simon N
authors.initials: SN
authors.lastname: Chapman
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK. jahcrawley1@gmail.com.
authors.forename: Jennie A H
authors.initials: JA
authors.lastname: Crawley
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK. k.mar@sheffield.ac.uk.
authors.forename: Khyne U
authors.initials: KU
authors.lastname: Mar
authors.affiliation: Ministry of Environmental Conservation and Forestry, Myanma Timber Enterprise, Yangon, Myanmar. winhtut641@gmail.com.
authors.forename: Win
authors.initials: W
authors.lastname: Htut
authors.affiliation: Ministry of Environmental Conservation and Forestry, Myanma Timber Enterprise, Yangon, Myanmar. thurasoemteelephant@gmail.com.
authors.forename: Aung
authors.initials: A
authors.lastname: Thura Soe
authors.affiliation: Ministry of Environmental Conservation and Forestry, Myanma Timber Enterprise, Yangon, Myanmar. KoHtooAung723@gmail.com.
authors.forename: Htoo Htoo
authors.initials: HH
authors.lastname: Aung
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK. v.lummaa@sheffield.ac.uk.
authors.forename: Virpi
authors.initials: V
authors.lastname: Lummaa
mesh_terms: D000818:Animals; D001835:Body Weight; D003247:Conservation of Natural Resources; D004606:Elephants / Q000254:growth & development* / Q000502:physiology; D005260:Female; D008297:Male; D012098:Reproduction; D012727:Sex Characteristics