Appendix 6.3(11). Ecological characteristics of important waterfowl 



species in the Chenier Plain . 



Additional life history morphological aspects of selected species of 

 waterfowl are presented here. 



Size : Canada geese may weigh as much as 18 pounds, whereas green-wing 

 teal rarely exceed 1 pound. 



Clutch size : The number of eggs in a brood may vary from 3 to 4 for 

 most geese, to 20 for some duck species. One or two broods may be hatched 

 annually, depending upon length of breeding season. 



Sexual Maturity : Geese and some ducks are not sexually mature until 

 two or three years of age, whereas some duck species mature in less than a 

 year. 



Incubation period and mortality of young: Incubation usually requires 

 from 3 to 5 weeks; mortality of young birds ranges from 40% in some ducks 

 down to about 10% for geese. 



N esting : Materials used in the construction of nests, location of nests, 

 and the amount of territory required to defend nests vary greatly. 



Pair bond formation : Strongest in geese, which may mate for life. The 

 male takes a part in defending the nest. Pair bond formation is weak in the 

 redhead duck. Some ducks allow other species to raise their offspring. 



Family bonds : Geese have strong family bonds and juvenile geese will 

 remain with their parents until they reach breeding age. In many duck 

 species, family bonds end after the young reach their fledgling stage, about 

 40 to 50 days. 



Molt : Geese lack a prenuptial fall molt, whereas male ducks have a fall 

 molt. Postnuptial molt, at the time of fledging among the young, is common 

 to all species and sexes of waterfowl, and is a major reason for the lack of 

 post-fledgling parental bonds in ducks; parents simply cannot defend them- 

 selves and their offspring. 



Morphology : Waterfowl exhibit greater variation in such measures as 

 bill shape leg placement and wing size than other closely related groups of 

 birds. This variation influences the high degree of habitat exploitation 

 and the low interspecies competition for the same foods. Some differences 

 were mentioned in preceeding sections. One important area of morphology is 

 related to flying ability. In general, diving ducks have less bulky wings 

 than dabbling ducks; diving ducks can move more easily under water, but they 

 require longer distances for take off. 



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