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Biological and environmental influences on parturition date and birth mass of a seasonal breeder.

Wolcott DM, Reitz RL, Weckerly FW - PLoS ONE (2015)

Bottom Line: Random effects revealed considerable variation among mothers and years.This study demonstrates that, in long-lived polytocous species, environmental factors may have a greater influence on natal features than previously supposed and the influence from biological factors is also complex.The documented responses to environmental influences provide unique insights into how mammalian seasonal reproductive dynamics may respond to current changes in climate.

View Article: PubMed Central - PubMed

Affiliation: Texas State University, Department of Biology, San Marcos, Texas, United States of America.

ABSTRACT
Natal features (e.g. Julian birth date and birth mass) often have fitness consequences and can be influenced by endogenous responses by the mother to seasonal fluctuations in nutritional quality and photoperiodic cues. We sought to further understand the biological and environmental factors that influence the natal features of a polytocous species in an environment with constant nutritional resources and limited seasonal variation. During a 36-year study we assessed the influence of biological factors (maternal age and litter type [i.e., litter size and sexual composition]) and environmental factors (total precipitation and mean maximum temperature during months encompassing conception, the last trimester of gestation, and the entire length of gestation) on Julian birth date and birth mass using linear-mixed effects models. Linear and quadratic functions of maternal age influenced both natal features with earliest Julian birth dates and heaviest birth masses occurring at prime-age and older individuals, which ranged from 5-9 years of age. Litter type influenced Julian birth date and birth mass. Interestingly, environmental factors affected Julian birth date and birth mass even though mothers were continuously allowed access to a high-quality diet. Random effects revealed considerable variation among mothers and years. This study demonstrates that, in long-lived polytocous species, environmental factors may have a greater influence on natal features than previously supposed and the influence from biological factors is also complex. The documented responses to environmental influences provide unique insights into how mammalian seasonal reproductive dynamics may respond to current changes in climate.

No MeSH data available.


Related in: MedlinePlus

Percent frequency of Julian birth dates for litters (n = 1,403) of captive white-tailed deer at Kerr Wildlife Management Area, Kerr County, Texas, USA from 1977–2012.The vertical, solid line represents the mean Julian birth date (164, 13 June) and the vertical, dashed lines represent the standard deviation (144 and 185, 24 May and 4 July, respectively).
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pone.0124431.g002: Percent frequency of Julian birth dates for litters (n = 1,403) of captive white-tailed deer at Kerr Wildlife Management Area, Kerr County, Texas, USA from 1977–2012.The vertical, solid line represents the mean Julian birth date (164, 13 June) and the vertical, dashed lines represent the standard deviation (144 and 185, 24 May and 4 July, respectively).

Mentions: During the 36-year study of white-tailed deer, 2,290 neonates were born to 510 individual mothers for a total of 520 singletons (222 females and 298 males) and 885 twin litters (193 female twin litters, 243 male twin litters, and 449 mixed twin litters). Number of births per individual female varied during the study, with an average of 4.5 young born during the lifetime of an individual mother (min = 1, max = 17, SE = 0.2). Average maternal age was 4 years (SE = 0.05), with a range of 2–13 years. The mean date of parturition during our study was 13 June (Julian date = 164, SE = 0.5), with the earliest birth occurring on 13 April (Julian date = 103) and the latest on 10 September (Julian date = 253). A Kolmogorov-Smirnov 1-sample test revealed that dates of Julian birth were normally distributed during this study (D = 0.527, P = 0.944, Fig 2). Average neonate body mass was 2.6 kg (min = 0.7, max = 6.1, and SE = 0.01).


Biological and environmental influences on parturition date and birth mass of a seasonal breeder.

Wolcott DM, Reitz RL, Weckerly FW - PLoS ONE (2015)

Percent frequency of Julian birth dates for litters (n = 1,403) of captive white-tailed deer at Kerr Wildlife Management Area, Kerr County, Texas, USA from 1977–2012.The vertical, solid line represents the mean Julian birth date (164, 13 June) and the vertical, dashed lines represent the standard deviation (144 and 185, 24 May and 4 July, respectively).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401666&req=5

pone.0124431.g002: Percent frequency of Julian birth dates for litters (n = 1,403) of captive white-tailed deer at Kerr Wildlife Management Area, Kerr County, Texas, USA from 1977–2012.The vertical, solid line represents the mean Julian birth date (164, 13 June) and the vertical, dashed lines represent the standard deviation (144 and 185, 24 May and 4 July, respectively).
Mentions: During the 36-year study of white-tailed deer, 2,290 neonates were born to 510 individual mothers for a total of 520 singletons (222 females and 298 males) and 885 twin litters (193 female twin litters, 243 male twin litters, and 449 mixed twin litters). Number of births per individual female varied during the study, with an average of 4.5 young born during the lifetime of an individual mother (min = 1, max = 17, SE = 0.2). Average maternal age was 4 years (SE = 0.05), with a range of 2–13 years. The mean date of parturition during our study was 13 June (Julian date = 164, SE = 0.5), with the earliest birth occurring on 13 April (Julian date = 103) and the latest on 10 September (Julian date = 253). A Kolmogorov-Smirnov 1-sample test revealed that dates of Julian birth were normally distributed during this study (D = 0.527, P = 0.944, Fig 2). Average neonate body mass was 2.6 kg (min = 0.7, max = 6.1, and SE = 0.01).

Bottom Line: Random effects revealed considerable variation among mothers and years.This study demonstrates that, in long-lived polytocous species, environmental factors may have a greater influence on natal features than previously supposed and the influence from biological factors is also complex.The documented responses to environmental influences provide unique insights into how mammalian seasonal reproductive dynamics may respond to current changes in climate.

View Article: PubMed Central - PubMed

Affiliation: Texas State University, Department of Biology, San Marcos, Texas, United States of America.

ABSTRACT
Natal features (e.g. Julian birth date and birth mass) often have fitness consequences and can be influenced by endogenous responses by the mother to seasonal fluctuations in nutritional quality and photoperiodic cues. We sought to further understand the biological and environmental factors that influence the natal features of a polytocous species in an environment with constant nutritional resources and limited seasonal variation. During a 36-year study we assessed the influence of biological factors (maternal age and litter type [i.e., litter size and sexual composition]) and environmental factors (total precipitation and mean maximum temperature during months encompassing conception, the last trimester of gestation, and the entire length of gestation) on Julian birth date and birth mass using linear-mixed effects models. Linear and quadratic functions of maternal age influenced both natal features with earliest Julian birth dates and heaviest birth masses occurring at prime-age and older individuals, which ranged from 5-9 years of age. Litter type influenced Julian birth date and birth mass. Interestingly, environmental factors affected Julian birth date and birth mass even though mothers were continuously allowed access to a high-quality diet. Random effects revealed considerable variation among mothers and years. This study demonstrates that, in long-lived polytocous species, environmental factors may have a greater influence on natal features than previously supposed and the influence from biological factors is also complex. The documented responses to environmental influences provide unique insights into how mammalian seasonal reproductive dynamics may respond to current changes in climate.

No MeSH data available.


Related in: MedlinePlus