Interannual variation in birth mass and postnatal growth rate of Juan Fernández fur seals

1998 ◽  
Vol 76 (5) ◽  
pp. 978-983 ◽  
Author(s):  
Hugo Ochoa-Acuña ◽  
John M Francis ◽  
Daryl J Boness
Keyword(s):  
Growth Rate ◽  
Body Mass ◽  
Growth Rates ◽  
Interannual Variation ◽  
Postnatal Growth ◽  
Male And Female ◽  
Fur Seals ◽  
Fur Seal ◽  
Attendance Pattern

The objectives of this study were to establish body mass at birth, postnatal growth rate, and the factors that influence these parameters for the Juan Fernández fur seal, Arctocephalus philippii. Females of this species have an unusual attendance pattern in which foraging trips and shore visits last, on average, 12.3 and 5.3 days, respectively. Pup mass was obtained from cohorts born during the reproductive seasons in 1988 through 1992. Birth masses of male and female pups were significantly different, averaging 6.1 and 5.5 kg, respectively (F = 13.2, P < 0.0003, n = 238). Birth masses also differed among cohorts, being lowest in 1992 and highest in 1990. During the first 2 months of life, male and female pups grew at the same rate (79 ± 61.5 g · day-1 (mean ± SD); F[1] = 0.03, P = 0.8562). Interannual differences in growth rate during the first month were significant (F[4] = 8.14, P < 0.0001), as was the interaction between month and year effects (F[2] = 6.81, P = 0.0012). Growth rates for the 1990 cohort were lower than those in all other years except 1992. Birth masses and postnatal growth rates of Juan Fernández fur seal pups are comparable to those of other otariid species.

Pup Growth and Maternal Care in New Zealand Fur Seals, Arctocephalus forsteri, at Maatsuyker Island, Tasmania

1997 ◽  
Vol 24 (3) ◽  
pp. 307 ◽  
Author(s):  
Mary-Anne Lea ◽  
Mark. A. Hindell
Keyword(s):  
New Zealand ◽  
Interannual Variability ◽  
Body Mass ◽  
Growth Rates ◽  
Maternal Care ◽  
Early Growth ◽  
Fur Seals ◽  
Fur Seal ◽  
New Zealand Fur Seal ◽  
Pup Growth

The growth, maternal attendance and sucking behaviour of 11 New Zealand fur seal pups, Arctocephalus forsteri, on Maatsuyker Island, Tasmania, were studied during the first six months of lactation. Early growth rates (0–50 days) ranged from 78 to 138 g day-1 and were amongst the highest recorded for any fur seal. Male pups from Maatsuyker Island in 1993 grew at double the rate reported from Kangaroo Island in 1989 and 1990. Growth of pups was influenced by the attendance behaviour of mothers. Mothers that spent relatively long periods at sea had pups that grew more slowly. The proportion of time spent sucking by pups decreased during the attendance period of mothers. Distinct interannual variability was also determined for body masses of pups weighed in March in five successive years, 1990–94, with mean body mass differing by up to 20% between years.

scholarly journals Ontogeny of body size and shape of Antarctic and subantarctic fur seals

2007 ◽  
Vol 85 (12) ◽  
pp. 1275-1285 ◽  
Author(s):  
Sebastián P. Luque ◽  
Edward H. Miller ◽  
John P.Y. Arnould ◽  
Magaly Chambellant ◽  
Christophe Guinet
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Morphological Traits ◽  
Body Shape ◽  
Size And Shape ◽  
Fur Seals ◽  
Fur Seal ◽  
Adult Body ◽  
Weaning Age ◽  
Lactation Duration

Pre- and post-weaning functional demands on body size and shape of mammals are often in conflict, especially in species where weaning involves a change of habitat. Compared with long lactations, brief lactations are expected to be associated with fast rates of development and attainment of adult traits. We describe allometry and growth for several morphological traits in two closely related fur seal species with large differences in lactation duration at a sympatric site. Longitudinal data were collected from Antarctic ( Arctocephalus gazella (Peters, 1875); 120 d lactation) and subantarctic ( Arctocephalus tropicalis (Gray, 1872); 300 d lactation) fur seals. Body mass was similar in neonates of both species, but A. gazella neonates were longer, less voluminous, and had larger foreflippers. The species were similar in rate of preweaning growth in body mass, but growth rates of linear variables were faster for A. gazella pups. Consequently, neonatal differences in body shape increased over lactation, and A. gazella pups approached adult body shape faster than did A. tropicalis pups. Our results indicate that preweaning growth is associated with significant changes in body shape, involving the acquisition of a longer, more slender body with larger foreflippers in A. gazella. These differences suggest that A. gazella pups are physically more mature at approximately 100 d of age (close to weaning age) than A. tropicalis pups of the same age.

The effect of level of environment on sex differences in pre-weaning growth rate in beef cattle

1977 ◽  
Vol 25 (1) ◽  
pp. 47-51 ◽  
Author(s):  
I. R. Hopkins
Keyword(s):  
Growth Rate ◽  
Sex Differences ◽  
Beef Cattle ◽  
Growth Rates ◽  
Additive Models ◽  
Regression Equations ◽  
Male And Female ◽  
Breed Differences ◽  
Per Se ◽  
Simple Regression

SUMMARYUsing pre-weaning records of 3822 calves from 11 Victorian herds, mean male and female growth rates and corresponding sex differences were calculated for each dam age and herd-year class. From these means simple regression equations relating sex differences and growth rates were calculated. There was a close similarity between equations based on dam age means and those based on herd-year means while correlations between sex differences and male growth rates were high.These results showed that sex differences and female growth rates could be predicted reliably from the level of environment as measured by male growth rate. Sex differences predicted by these regression relationships differed markedly from those predicted by the simple multiplicative and simple additive models generally used in adjusting for sex differences in selection.The results also suggested that other differences such as breed differences may be predictable in the same way and that such differences are determined primarily by the level of environment per se rather than differences in the nature of the components contributing to that level.

The Relative Growth of Parts in Palaemon Carcinus

1930 ◽  
Vol 7 (2) ◽  
pp. 165-174
Author(s):  
M. A. TAZELAAR
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Measurements ◽  
Relative Growth ◽  
Male And Female ◽  
Relative Growth Rates ◽  
Rate Of Growth ◽  
The Difference ◽  
Rates Of Growth

Linear measurements of certain appendages and the carapace of P. carcinus were made and plotted in various ways. The following conclusions were drawn: 1. The cheliped shows heterogonic growth in both male and female, but more markedly in the male, the values of k being: male 1.8 and female 1.48 2. The pereiopods in both male and female are slightly heterogonic. The relative growth rates are graded from p3 to p5, that of p3 being slightly greater than that of p5 3. Of the ordinary pereiopods the rate of growth of p1 is the smallest in the male, but the largest in the female. 4. The difference between the rates of growth of p1 and p3 in male and female is greatest where the rate of growth in the heterogonic organ, the cheliped, is most excessive in the male. 5. The growth of the 3rd maxilliped is slightly negatively heterogonic, the value of k in the male being 0.93 and in the female 0.95. Hence there seems to be a correlation between the marked heterogony in the cheliped on the growth rate of neighbouring appendages. In those immediately posterior to the cheliped the growth rate is increased and in those anterior decreased.

scholarly journals Postnatal growth and development of Natalus mexicanus (Chiroptera: Natalidae)

Therya ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 105-113
Author(s):  
Matías Martínez-Coronel ◽  
Anubis Molina-Gutiérrez ◽  
Yolanda Hortelano-Moncada
Keyword(s):  
Growth Rate ◽  
Body Mass ◽  
Growth Pattern ◽  
Growth Models ◽  
Postnatal Growth ◽  
Linear Growth Rate ◽  
Southern Mexico ◽  
Insectivorous Bats ◽  
Eye Opening ◽  
Forearm Length

Natalus mexicanus is a bat species distributed from northern México to Central America.  It inhabits various types of tropical vegetation, roosting mainly in caves with high relative humidity and temperature, and feeding mostly on arachnids.  This study investigated postnatal growth and flight development of populations under natural conditions inhabiting “Los Laguitos” cave, Chiapas, southern México.  Forty-four females and 50 males were monitored from birth to 55 days of age; at five-day intervals, we measured body mass, forearm length, cartilaginous epiphyseal gap of the fourth metacarpal-phalangeal joint, and development of four characters.  We used statistical analyses and growth models to quantify the changes in morphometric parameters.  Neonates are altricial; the ears began to unfold since day one, while the eyes opened at day 25.  Greyish hair appeared between 25 to 35 days.  Forearm length and body mass increased linearly over 35 days, then the growth rate decreased.  The cartilaginous epiphyseal gap increased in size until day 25 and then started to close.  The logistic equation yielded the best fit for forearm length (K = 0.07) and body mass (K = 0.10).  Sustained flight was first achieved at 35 days of age.  N. mexicanus neonates are altricial and relatively small compared with other bats.  Eye-opening and fur development took place at a slower rate than in most species of insectivorous bats.  In the Chiapas population, eye-opening, fur development, and volancy occurred more slowly relative to the population inhabiting Álamos, Sonora.  These differences are probably consequences of local variations.  The morphometric postnatal growth pattern of N. mexicanus was like that of other insectivorous bats, i. e., linear growth rate before the onset of flight and slowing down thereafter.  As in other studies, the logistic model best fitted the growth pattern of body mass and forearm length, but growth coefficients were lower versus other tropical bats.  The cartilaginous epiphyseal gap of the fourth digit closes at an intermediate age relative to other insectivorous bats.  Sustained flight was attained when the relative body mass and forearm length of individuals approached adult body dimensions, as in other bat species.

Placental restriction of fetal growth reduces size at birth and alters postnatal growth, feeding activity, and adiposity in the young lamb

2007 ◽  
Vol 292 (2) ◽  
pp. R875-R886 ◽  
Author(s):  
Miles J. De Blasio ◽  
Kathryn L. Gatford ◽  
Jeffrey S. Robinson ◽  
Julie A. Owens
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Feeding Activity ◽  
Later Life ◽  
Postnatal Growth ◽  
Postnatal Life ◽  
Absolute Growth ◽  
Accelerated Growth ◽  
Early Postnatal Life ◽  
Size At Birth

Intrauterine growth restriction (IUGR) is associated with accelerated growth after birth. Together, IUGR and accelerated growth after birth predict reduced lean tissue mass and increased obesity in later life. Although placental insufficiency is a major cause of IUGR, whether it alters growth and adiposity in early postnatal life is not known. We hypothesized that placental restriction (PR) in the sheep would reduce size at birth and increase postnatal growth rate, fat mass, and feeding activity in the young lamb. PR reduced survival rate and size at birth, with soft tissues reduced to a greater extent than skeletal tissues and relative sparing of head width ( P < 0.05 for all). PR did not alter absolute growth rates (i.e., the slope of the line of best fit for age vs. parameter size from birth to 45 days of age) but increased neonatal fractional growth rates (absolute growth rate relative to size at birth) for body weight (+24%), tibia (+15%) and metatarsal (+18%) lengths, hindlimb (+23%) and abdominal (+19%) circumferences, and fractional growth rates for current weight ( P < 0.05) weekly throughout the first 45 days of life. PR and small size at birth reduced individual skeletal muscle weights and increased visceral adiposity in absolute and relative terms. PR also altered feeding activity, which increased with decreasing size at birth and was predictive of increased postnatal growth and adiposity. In conclusion, PR reduced size at birth and induced catch-up growth postnatally, normalizing weight and length but increasing adiposity in early postnatal life. Increased feeding activity may contribute to these alterations in growth and body composition following prenatal restraint and, if they persist, may lead to adverse metabolic and cardiovascular outcomes in later life.

scholarly journals Relationship between the female attendance pattern and pup growth rate in the South American sea lion (Carnivora)

2021 ◽  
Vol 85 (2) ◽  
pp. 81-90
Author(s):  
Massimiliano Drago ◽  
Luis Cardona ◽  
Valentina Franco-Trecu ◽  
Federico G. Riet-Sapriza ◽  
Enrique A. Crespo ◽  
...  
Keyword(s):  
Growth Rate ◽  
Energy Density ◽  
Body Mass ◽  
Female Body ◽  
Minor Role ◽  
Significant Variable ◽  
South American ◽  
Attendance Pattern ◽  
Female Body Mass ◽  
Pup Growth

Changes in the duration and frequency of foraging trips by female otariids may result in changes in the duration and frequency of lactation bouts and hence influence pup growth rate, unless females modify milk energy density and/or the total amount of milk delivered depending on the trip duration. To test this hypothesis on South American sea lions, we measured two attendance pattern components (foraging trip and haul-out duration) and three diving behaviour components of nursing females (dive time, bottom time and number of dives per h) at two different rookeries in Uruguay and Argentina, the composition and energy density of their milk, and the growth rate of their pups. Female foraging trip and haul-out durations depended on pup sex and weight, whereas milk energy density depended on female body mass and foraging trip durations. By contrast, the three dive variables were independent of female body mass or pup sex. Pup growth was also independent of the foraging trip and haul-out duration, with pup sex as the only significant variable. This suggests that individual differences in female foraging behaviour play a minor role in determining pup growth rates during the first three weeks after birth.

Population structure, growth rates and spatial distribution of two dioecious tree species in a wet forest in Puerto Rico

2010 ◽  
Vol 26 (4) ◽  
pp. 433-443 ◽  
Author(s):  
Jimena Forero-Montaña ◽  
Jess K. Zimmerman ◽  
Jill Thompson
Keyword(s):  
Growth Rate ◽  
Puerto Rico ◽  
Life History ◽  
Growth Rates ◽  
Cost Of Reproduction ◽  
Sexual Differences ◽  
Reproductive Costs ◽  
Dioecious Species ◽  
Male And Female ◽  
Males And Females

Abstract:Dioecious plants often exhibit male-biased sex ratios and sexual differences in life history traits such as plant size, growth rate and frequency of flowering, which arise from the different costs of reproduction for male and female plants. In tropical dioecious species sexual differences in reproductive costs have been demonstrated for several subcanopy species, but few canopy dioecious trees have been studied. We recorded the sexual expression of c. 2600 trees of Cecropia schreberiana and Dacryodes excelsa, two canopy dioecious species, during several censuses over 2 y in a 16-ha plot located in ‘subtropical wet forest’ in the Luquillo Mountains, Puerto Rico. There were similar numbers of male and female trees of C. schreberiana but D. excelsa had a female-biased population. Cecropia schreberiana showed no differences in male and female diameter distributions or growth rates, suggesting that reproductive maturation and longevity are similar for both sexes. This lack of differences in size and growth rate in C. schreberiana may result from mechanisms to compensate for the higher cost of reproduction in females, no resource limitation related to its pioneer life-history, or similar male and female reproductive costs. In contrast, D. excelsa males were larger than females, probably because males grow slightly faster than females. This sexual difference in D. excelsa may reflect a higher cost of reproduction in females than in males. Spatial segregation of males and females into different habitats is not common in tropical forest and neither C. schreberiana nor D. excelsa males and females exhibited significant spatial segregation. The contrasting results for these two canopy species reflect their different life history strategies in this hurricane-affected forest.

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