scholarly journals Growth Rate and Energetics of Arabian Babbler (Turdoides squamiceps) Nestlings

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 519-524 ◽  
Author(s):  
Avner Anava ◽  
Michael Kam ◽  
Amiram Shkolnik ◽  
A. Allan Degen

Abstract Arabian Babblers (Turdoides squamiceps) are territorial, cooperative breeding passerines that inhabit extreme deserts and live in groups all year round. All members of the group feed nestlings in a single nest, and all group members provision at similar rates. Nestlings are altricial and fledge at about 12 to 14 days, which is short for a passerine of its body mass. Because parents and helpers feed nestlings, we hypothesized that the growth rate of nestlings is fast and that they fledge at a body mass similar to other passerine fledglings. Using a logistic growth curve, the growth rate constant (k) of nestlings was 0.450, which was 18% higher than that predicted for a passerine of its body mass. Asymptotic body mass of fledglings was 46 g, which was only 63% of adult body mass, a low percentage compared to other passerines. Energy intake retained as energy accumulated in tissue decreased with age in babbler nestlings and amounted to 0.29 of the total metabolizable energy intake over the nestling period. However, energy content per gram of body mass increased with age and averaged 4.48 kJ/g body mass. We concluded that our hypothesis was partially confirmed. Growth rate of babbler nestlings was relatively fast compared to other passerine species, but fledgling mass was relatively low.

1996 ◽  
Vol 74 (3) ◽  
pp. 442-450 ◽  
Author(s):  
Katherine L. Parker ◽  
Michael P. Gillingham ◽  
Thomas A. Hanley ◽  
Charles T. Robbins

Foraging efficiency (metabolizable energy intake/energy expenditure when foraging) was determined over a 2-year period in nine free-ranging Sitka black-tailed deer (Odocoileus hemionus sitkensis) in Alaska, and related to foraging-bout duration, distances travelled, and average speeds of travel. We calculated the energy-intake component from seasonal dry matter and energy content, dry matter digestibility, and a metabolizable energy coefficient for each plant species ingested. We estimated energy expenditures when foraging as the sum of energy costs of standing, horizontal and vertical locomotion, sinking depths in snow, and supplementary expenditures associated with temperatures outside thermoneutrality. Energy intake per minute averaged 4.0 times more in summer than winter; energy expenditure was 1.2 times greater in summer. Animals obtained higher amounts of metabolizable energy with higher amounts of energy invested. Energy intake during foraging bouts in summer was 2.5 times the energy invested; in contrast, energy intake during winter was only 0.7 times the energy expended. Changes in body mass of deer throughout the year increased asymptotically with foraging efficiency, driven primarily by the rate of metabolizable energy intake. Within a season, summer intake rates and winter rates of energy expediture had the greatest effects on the relation between foraging efficiency and mass status. Seasonal changes in foraging efficiency result in seasonal cycles in body mass and condition in black-tailed deer. Body reserves accumulated during summer, however, are essential for over-winter survival of north-temperate ungulates because energy demands cannot be met by foraging alone.


2002 ◽  
Vol 138 (2) ◽  
pp. 221-226 ◽  
Author(s):  
A. ALLAN DEGEN ◽  
B. A. YOUNG

Body mass was measured and body composition and energy requirements were estimated in sheep at four air temperatures (0 °C to 30 °C) and at four levels of energy offered (4715 to 11785 kJ/day) at a time when the sheep reached a constant body mass. Final body mass was affected mainly by metabolizable energy intake and, to a lesser extent, by air temperature, whereas maintenance requirements were affected mainly by air temperature. Mean energy requirements were similar and lowest at 20 °C and 30 °C (407·5 and 410·5 kJ/kg0·75, respectively) and increased with a decrease in air temperature (528·8 kJ/kg0·75 at 10 °C and 713·3 kJ/kg0·75 at 0 °C). Absolute total body water volume was related positively to metabolizable energy intake and to air temperature. Absolute fat, protein and ash contents were all affected positively by metabolizable energy intake and tended to be related positively to air temperature. In proportion to body mass, total body water volume decreased with an increase in metabolizable energy intake and with an increase in air temperature. Proportionate fat content increased with an increase in metabolizable energy intake and tended to increase with an increase in air temperature. In contrast, proportionate protein content decreased with an increase in metabolizable energy intake and tended to decrease with an increase in air temperature. In all cases, the multiple linear regression using both air temperature and metabolizable energy intake improved the fit over the simple linear regressions of either air temperature or metabolizable energy intake and lowered the standard error of the estimate. The fit was further improved and the standard error of the estimate was further lowered using a polynomial model with both independent variables to fit the data, since there was little change in the measurements between 20 °C and 30 °C, as both air temperatures were most likely within the thermal neutral zone of the sheep. It was concluded that total body energy content, total body water volume, fat and protein content of sheep of the same body mass differed or tended to differ when kept at different air temperatures.


The Auk ◽  
2007 ◽  
Vol 124 (4) ◽  
pp. 1158-1167
Author(s):  
François Fournier ◽  
William H. Karasov ◽  
Kevin P. Kenow ◽  
Michael W. Meyer

AbstractWe measured the energy requirements during postnatal development of six hand-reared Common Loon (Gavia immer) chicks using continuous feeding trials and doubly labeled water. At fledging, the mean (± SE) body mass of chicks was 3,246 ± 51 g. They reached asymptotic body mass in ≈66 days and had a mean growth rate constant of 0.089 ± 0.002 day−1, which was greater than growth rate constants of other, similar-sized precocial birds. Between hatch and day 66, chicks allocated 16.5% of their metabolizable energy to new tissue, lower than the average for other bird species (20%), which might be expected considering their precocial mode of development. There was a developmental change in the assimilation efficiency of food (metabolizable energy coefficient), with a mean of 0.64 ± 0.03 in chicks aged 21 days, rising to 0.83 ± 0.07 in chicks aged 35 days.Les besoins en énergie durant la croissance chez des jeunes Gavia immer élevés en captivité


1991 ◽  
Vol 69 (8) ◽  
pp. 2128-2132 ◽  
Author(s):  
Scott R. Decker ◽  
Peter J. Pekins ◽  
William W. Mautz

Red oak acorns (Quercus rubra), fruits of multiflora rose (Rosa multiflora), common juniper (Juniper communis), winterberry holly (Ilex verticillata), and barberry (Berberis spp.), fertile fronds of sensitive fern (Onoclea sensibilis), corn, and apples were fed as mixed rations to eight eastern wild turkeys (Meleagris gallopavo silvestris). Crude protein content of the foods ranged from 2 (apples) to 19% (sensitive fern). Red oak acorns and juniper berries were 14% fat; other foods were 1–7% fat. Apples were lowest in gross energy content (3.9 kcal/g dry matter (1 cal = 4.1868 J)), and sensitive fern was highest (5.5 kcal/g). Little variation existed in nutrient composition and energy content of the mixed diets. Metabolizable energy values of the diets ranged from 65 to 84% of gross energy intake and from 3.1 to 4.0 kcal/g. Solution of simultaneous equations based on the mixed-diet data yielded metabolizable energy values of individual foods; juniper had the highest metabolizable energy (4.6 kcal/g) and sensitive fern the lowest (2.1 kcal/g); other foods ranged from 3.3 to 4.1 kcal/g. Acorns, corn, and shrubs with persistent fruits (juniper, winterberry, barberry, and multiflora rose) were the most nutritious foods. Metabolizable energy intake of the mixed diets, excluding the juniper-dominated diet, approximated or exceeded the predicted daily energy expenditure of wild turkeys.


2015 ◽  
Vol 99 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
M. Thes ◽  
N. Koeber ◽  
J. Fritz ◽  
F. Wendel ◽  
B. Dobenecker ◽  
...  

The Condor ◽  
2001 ◽  
Vol 103 (1) ◽  
pp. 108-117
Author(s):  
James A. Robinson ◽  
Keith C. Hamer ◽  
Lorraine S. Chivers

Abstract Arctic Terns (Sterna paradisaea) and Common Terns (S. hirundo) are similar in many aspects of their breeding ecology, but Common Terns generally lay three eggs per clutch whereas Arctic Terns lay two. In our study, Common Terns had a higher rate of food delivery and energy supply to the nest and higher nest attendance, indicating that they made trips of shorter average duration. This suggests that the number of chicks raised by these two species was primarily limited by the rate at which parents could supply food. However, estimated daily metabolizable energy intake of chicks was about 30% higher in Common Terns than in Arctic Terns. Common Tern chicks apparently spent a higher proportion of daily energy intake on maintenance of body temperature. It remains unknown whether this difference was because Common Tern parents could not brood three chicks as effectively as Arctic Terns brooded two or because the energy requirements for heat production in the third-hatched Common Tern chick were particularly high. If brooding did play a less important role in the energy budgets of Common Terns, the number of chicks that Arctic Terns could raise may have been limited not only by the rate at which parents could supply food to the nest but also by the requirements of chicks for brooding. We suggest that more detailed studies on the role of brooding constraints in limiting brood size in these species are required to clarify this matter.


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