Nutritional quality and digestibility of foods eaten by whooping cranes on their Texas wintering ground /
Food items eaten by whooping cranes (Grus americana) were
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1995.
|
| Subjects: |
| Summary: | Food items eaten by whooping cranes (Grus americana) were collected in the fall and winter of 1993-1994 from Aransas National Wildlife Refuge (ANWR) and Matagorda Island, Texas. Blue crab (Callinectes sapidus) , stout razor clam (Tagelus plebeius , common Rangia clam (Rangia cuneta) wolfberry fruit (Lycium carolinanum), and live oak acorn (Quercus were collected from foraging areas of whooping cranes and were analyzed for proximate composition. Among different foods, gross energy was 3-5 times higher for acorn than for wolfbeny, blue crab, and stout razor clam. Crude protein was 2-4 times higher for blue crab and stout razor clain than for acorn and wolfberry. Rangia cuneata was high in ash and low in gross energy and protein. Blue crab, Rangia cuneata, wolfbeny fruit, and live oak acorn were dried, ground, mixed with commercial crane breeder feed, and formed into pellets which were fed to captive whooping cranes at Patuxent Environmental Science Center (PESC), Laurel, Maryland. Gross energy, dry matter, crude protein, and total lipid digestibilities as well as metabolizable energy were determined for crane breeder feed and test ingredients. Apparent metabolizable energy coefficients for crab, clarn, wolfbeny, and acorn were 0.355, 0.746, 0.438, and 0.434. Digestion coefficients for protein were lower for plant foods (from 0.483 to 0.52 1) than for anirnal foods (from 0.702 to 0.753). Digestion coefficients differed for total lipid among foods: highest lipid digestibility was for live oak acorn (0. 865), and lowest lipid digestibility was for wolfbeny ftwt (0. 5 98). Daily energy expenditure (DEE) was measured for five captive whooping cranes at PESC. DEE for 4 cranes averaged 421.3 + 28.7 kcal/day (avg. ︢95% CI). A tixne- energy budget (TEB) model was developed based on observed time-activity budgets for captive whooping cranes and energy expenditures for activities of avian species. Range of prediction error by the TEB equation was +6.04 to -9.23% for 4 captive whooping cranes. The TEB model was applied to free-living whooping cranes using energy expenditure coefficients for flight, rest, active, and foraging behaviors and time-activity budgets. By this model, energy cost of free existence for a 5-kg whooping crane on the wintering ground was estimated to be 465 kcal/day. |
|---|---|
| Item Description: | Vita. "Major subject: Wildlife and Fisheries Sciences". |
| Physical Description: | xii, 95 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references. |