Artificial incubation of trumpeter swan eggs: Selected factors affecting hatchability
Publication Type: |
Journal Article |
Year of Publication: |
1999 |
Authors: |
E. C. Hamilton, D. B. Hunter, Dale A. Smith, P. Michel |
Publication/Journal: |
Zoo Biology |
Publisher: |
Inc., John Wiley & Sons |
Keywords: |
artificial incubation, cygnus buccinator, egg collection, egg weight loss, hatchability, trumpeter swan |
ISBN: |
1098-2361 |
Abstract:
Abstract 10.1002/(SICI)1098-2361(1999)18:5<403::AID-ZOO5>3.3.CO;2-# Eggs collected from captive trumpeter swans (Cygnus buccinator) in 1993 (n = 33) and 1994 (n = 42) were artificially incubated with careful monitoring to identify factors contributing to the low hatch success reported by the Ontario Trumpeter Swan Restoration Program. Fertility was > 80% in both years, whereas hatch success of fertile eggs was 14.3% (n = 4) of 28 eggs in 1993 and 37.1% (n = 13) of 35 eggs in 1994. Necropsy of non-viable eggs indicated a high incidence of embryonic mortality during early and late incubation. Early embryonic mortality was associated with egg storage times exceeding 7 days (P < 0.05) and bacterial contamination of eggs (P < 0.01). Late mortality was associated with (P < 0.001) increased weight loss during incubation period and may have resulted from incubator temperature and humidity fluctuations. We established patterns of weight loss for eggs and determined that hatched eggs lost 11–15% of initial mass and that weight loss >15% resulted in embryo mortality. Results from this study indicate that collection and handling of eggs before incubation and precise control of the incubator environment are critical to hatchability of eggs. Zoo Biol 18:403–414, 1999. © 1999 Wiley-Liss, Inc.