| Abstract: | Dramatic changes in the food habits and distribution of Chesapeake Bay canvasbacks (Aythya valisineria) generated a desire to better understand the energetics and behavior of this species on its wintering grounds. Captive canvasbacks were maintained ad libitum on 5 diets during the winters of 1978-80 to evaluate varying protein and energy levels in the diets. Food consumption, weight, blood, and behavior were variables measured to assess affect of diet. Food consumption was higher (P<0.05) for canvasbacks on the low energy (1543 kcal/kg) diets than birds on the high energy (3638 kcal/kg) diets, but body weights did not differ (P<0.05) between diets for males or females. Food consumption and body weights were greatest in November and April and least in January and February. Canvas backs lost weight and ate less during the most stressful periods in spite of adequate food supplies. Blood parameters and behavior of captive canvasbacks did not differ between diets, although differences (P<0.05) were detected for some blood parameters and behaviors between sexes, ages, and seasons. Canvasbacks were more inactive during the coldest months. Changes in behavior, weight, and food consumption appear to be a mechanism to conserve energy at a time when natural food supplies are less plentiful or less available. Aquatic vegetation has declined in quantity making canvasbacks more dependent on invertebrates. Availability of low energy food (e.g. clams) may be the limiting factor in regard to the winter survival of wild canvasbacks. |
| Genre: | Article |
| ProdID: | 5223156 |
| Citation Author: | Perry, M.C.; Kuenzel, W.J. |
| Citation Contributing Office: | Patuxent Wildlife Research Center |
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| Citation Issue: | 7 |
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| Citation Language: | English |
| Citation Larger Work Title: | Poultry Science |
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| Citation Publisher: | Poultry Science Association |
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| Citation Search Results Text: | Seasonal energetics and behavior of captive canvasbacks (Aythia valisineria); 1983; Article; Journal; Poultry Science; Perry, M.C.; Kuenzel, W.J. |
| Citation Start Page: | 1482 (abstract) |
| Citation Volume: | 62 |
| Citation Year: | 1983 |
| Type: | citation/reference |
| Text: | Seasonal energetics and behavior of captive canvasbacks (Aythia valisineria); 1983; Article; Journal; Poultry Science; Perry, M.C.; Kuenzel, W.J. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.3382/ps.0621370 |
| Date Other: | Wed, 16 Jun 2010 00:00 -0500 |
| Publisher: | Poultry Science Association |
