Body-condition dynamics in a northern ungulate gaining fat in winter

2009 ◽  
Vol 87 (5) ◽  
pp. 367-378 ◽  
Author(s):  
Serge Couturier ◽  
Steeve D. Côté ◽  
Jean Huot ◽  
Robert D. Otto
Keyword(s):  
Population Growth ◽  
Habitat Quality ◽  
Body Fat ◽  
Body Condition ◽  
Rangifer Tarandus ◽  
Herd Size ◽  
Summer Range ◽  
Long Term Trends ◽  
Individual Condition

Individual condition generally depends on density and is partly determined by habitat quality and climate. We studied long-term trends in the condition and productivity of female caribou ( Rangifer tarandus (L., 1758)) in two large migratory herds in the Quebec–Labrador peninsula (Canada), the George and the Feuilles herds. Females from the George herd were in better summer condition than those from the more abundant Feuilles herd in 2001–2002, while it was the opposite in 1988 when the Feuilles herd was less abundant than the George herd. Summer nutrition followed the same pattern between herds through time. Spring body condition of females in the George herd declined from 1976 to the mid-1980s during early population growth. Fall condition, however, did not change from 1983 to 2002 when caribou numbers first peaked and later declined. Pregnancy rates were inversely related to herd size in both herds. Vegetation quality (NDVI) in June was significantly related to body proteins in the fall. Albeit unusual for a northern ungulate, body fat increased from fall to spring in the George herd. We conclude that a relatively small and highly grazed summer range, as well as density-dependent effects, affected summer nutrition and the need to continue lipogenesis during winter.

Is mother condition related to offspring condition in migratory caribou (Rangifer tarandus) at calving and weaning?

2012 ◽  
Vol 90 (3) ◽  
pp. 393-402 ◽  
Author(s):  
J. Taillon ◽  
V. Brodeur ◽  
M. Festa-Bianchet ◽  
S.D. Côté
Keyword(s):  
Population Size ◽  
Body Condition ◽  
Rangifer Tarandus ◽  
Herd Size ◽  
Positive Influence ◽  
Maternal Characteristics ◽  
Calf Growth ◽  
Negative Effect ◽  
Summer Range ◽  
Positive Effect

Maternal characteristics can affect offspring traits, yet they are seldom included when considering density dependence of juvenile traits and population dynamics. We quantified the influence of population size and maternal traits on body condition of migratory caribou ( Rangifer tarandus (L., 1758)) calves at birth and weaning. We contrasted female–calf pairs of the Rivière-George (RG) herd, which has recently declined to low population size, with pairs of the much larger Rivière-aux-Feuilles (RAF) herd. Calves of the RAF herd were lighter, smaller, and leaner than calves of the RG herd at both birth and weaning. Differences between herds, however, were much greater at weaning than at calving, suggesting a combined effect of herd size and summer range conditions on calf growth. Maternal mass was positively related to calf body condition during both periods. The positive influence of maternal mass on calf body condition was greater for RAF than RG calves at birth, but it was similar for the two herds at weaning. Our results show that the negative effect of population size on calf body condition can be modulated by maternal mass at calving, and that the positive effect of maternal mass is greater at weaning.

scholarly journals Body size of female calves and natality rates of known-aged females in two adjacent Alaskan caribou herds, and implications for management

Rangifer ◽  
2003 ◽  
Vol 23 (5) ◽  
pp. 203 ◽  
Author(s):  
Patrick Valkenburg ◽  
Robert W. Tobey ◽  
Robert W. Tobey ◽  
Bruce W. Dale ◽  
Bruce W. Dale ◽  
...  
Keyword(s):  
Body Size ◽  
Population Growth ◽  
Body Mass ◽  
Real Option ◽  
Rangifer Tarandus ◽  
Herd Size ◽  
Adult Females ◽  
Potential Population ◽  
Newborn Calves ◽  
Natality Rate

We studied body mass of female calves and natality rate of adult females in two adjacent Interior Alaskan caribou (Rangifer tarandus granti) herds during 1991-2001. Mass of newborn calves was similar in both herds, but Delta calves gained significantly more mass over summer than Nelchina calves. In contrast, Nelchina calves consistently maintained their mass during winter while Delta calves lost mass. Metatarsus length was similar in both herds in 4-month-old and 10-month-old calves, and it increased over winter in both herds. Natality rates of females >3 years old were consistently higher in the Delta Herd than in the Nelchina Herd, primarily because natality in 3- to 5-year-old Nelchina females was low. Although body mass of Delta Herd calves consistently declined over winter, we concluded that nutrition was not significantly limiting herd growth. Managers are more likely to maximize harvest by maintaining the Delta Herd near its present size (i.e., 3500), or allowing it to increase only slightly. The only real option for increasing harvestable surpluses of caribou in the Delta Herd is reducing predation during calving and summer. In contrast, we conclude that summer nutrition significantly limits potential population growth and body mass in the Nelchina Herd, and managers are more likely to maximize harvest by maintaining herd size at or below 30 000 than by allowing the herd to grow to near historical highs (i.e., 60 000-70 000).

Growth and Trade: Some Hypotheses About Long-Term Trends

1964 ◽  
Vol 24 (4) ◽  
pp. 609-628 ◽  
Author(s):  
Richard N. Cooper
Keyword(s):  
Population Growth ◽  
Foreign Trade ◽  
The World ◽  
Long Term Trends ◽  
The Relationship

The relationship between long-term trends in foreign trade and long-term trends in income has long been a source of fascinating speculation for scholars. As early as 1821, Robert Torrens observed that “as the several nations of the world advance in wealth and population, the commercial intercourse between them must gradually become less important and beneficial.” He believed that trade was founded on the exchange of manufactures for foodstuffs and materials; as land became scarcer as a result of population growth, the basis for trade would disappear.

Morphological Prediction of Body Condition in Maned Ducks

1989 ◽  
Vol 16 (6) ◽  
pp. 605 ◽  
Author(s):  
SV Briggs
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Body Condition ◽  
Skinfold Thickness ◽  
Regression Equations ◽  
Fat Level ◽  
Bill Length ◽  
Best Fit ◽  
Paired T Test

Best-fit regression equations for estimating body-fat levels from morphological measurements of maned ducks (Chenonetta jubata) were developed. The cube of [body weight/(sternum x tarsus x bill length)] plus the square of skinfold thickness was the best predictor of body fat in females (r*2=0.81). The cube of (body weight x skinfold thickness) was the best predictor in males (r*2=0.75). These regression equations accurately estimated fat level in all seasons except females in winter, when estimated values were significantly higher (paired t test, P<0.02) by 18% than actual levels. Body weight alone predicted protein content well in males (r*2=0.81) and less well in females (r*2= 0.61). These equations enable long-term and relatively cheap monitoring of body condition in trapped maned ducks.

Factors influencing annual variation in breeding by common brushtail possums (Trichosurus vulpecula) in New Zealand

2002 ◽  
Vol 29 (1) ◽  
pp. 39 ◽  
Author(s):  
Dave Ramsey ◽  
Murray Efford ◽  
Phil Cowan ◽  
Jim Coleman
Keyword(s):  
New Zealand ◽  
Population Density ◽  
Body Condition ◽  
Annual Variation ◽  
Environmental Predictors ◽  
Major Exception ◽  
Individual Condition ◽  
Average Body ◽  
Long Term Studies

We assembled data on annual variation in breeding rates of brushtail possums from four long-term studies in the lower North Island of New Zealand, three of which spanned more than 20 years. In each study, more than 80% of adult females bred in most years. The major exception was in 1996, when breeding failed synchronously at sites separated by up to 122 km. The overall breeding rate in 1996 at these sites was 28% (n = 201). Other instances of low breeding rate (<70%) occurred asynchronously at particular sites. We analysed variation in breeding rates to determine the contributions to annual variation of individual condition (body weight), population density, food resources and other environmental predictors. The probability of breeding declined rapidly as body condition fell below average. An index of fruitfall of hinau (Elaeocarpus dentatus), a highly nutritious food used by possums, and population density in the previous year were the most important predictors of possum condition and breeding rate. High density in the previous year coupled with low hinau fruitfall in the current year predicted below-average body condition and reduced breeding rate. Although the magnitude of these effects were only significant in ‘extreme’ years, they are consistant with delayed density-dependent effects on fecundity in brushtail possums.

scholarly journals Sea ice predicts long‐term trends in Adélie penguin population growth, but not annual fluctuations: Results from a range‐wide multiscale analysis

2020 ◽  
Vol 26 (7) ◽  
pp. 3788-3798 ◽  
Author(s):  
David T. Iles ◽  
Heather Lynch ◽  
Rubao Ji ◽  
Christophe Barbraud ◽  
Karine Delord ◽  
...  
Keyword(s):  
Sea Ice ◽  
Population Growth ◽  
Multiscale Analysis ◽  
Adélie Penguin ◽  
Adelie Penguin ◽  
Long Term Trends

scholarly journals Carcass records of autumn-slaughtered reindeer as indicator of long-term changes in animal condition

Rangifer ◽  
2011 ◽  
Vol 31 (1) ◽  
pp. 7-20 ◽  
Author(s):  
Anna Olofsson ◽  
Öje Danell ◽  
Birgitta Åhman ◽  
Pär Forslund
Keyword(s):  
Population Density ◽  
Body Condition ◽  
Skeletal Development ◽  
Strongly Correlated ◽  
Range Use ◽  
Long Term Changes ◽  
Long Term Trends ◽  
Reindeer Population

This study investigates the possibility of using carcass records from the commercial slaughter of reindeer as indicator of long-term changes in animal condition and, thus, the condition and use of their snow-free pasture. The aim was to assess the suitability of this indicator for use within adaptive management programmes for reindeer husbandry grazing resources. Data comprising measurements of carcass weight, conformation and fatness taken from commercial reindeer slaughter between 1994 and 2007, were analysed in relation to year, slaughter date, herding district, population density, and three categories of animals selected for slaughter. The carcass measures were significantly affected by year, and the effects were strongly correlated among the three animal categories. There were generally positive trends over the 14-year period studied. We identified several factors that should be considered when using carcass data to indicate long-term changes in animal body condition: (i) slaughter date had different effects depending on animal category; (ii) reindeer population density negatively affected female and calf carcasses, but not male carcasses. The effects of herding district were similar for carcasses of calves and females, but differed between females and males. Some of the differences between animal categories may be due to differing timing of slaughter (point i above), by different slaughter selection among districts, or have ecological explanations, e.g. sex differences in range use. Uncertainties in the classification of animals when using skeletal development to discriminate between calf and yearling carcasses, may also add to differences among districts. That population density effects on body condition were detectable together with the similarities in the effects of year and general long-term trends between animal categories support the suggestion that carcass measures can be used to indicate general changes in reindeer body condition and range use.

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