... juvenile of the year or an adult bird . Proceed as follows : ( a ) If the tip of the tail - feather is normally ... Pintail and Wood Duck , all juveniles probably wear the juvenile tail until late in August ; all Mallards and Black ...
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... pintail . 212. Ducks , pintail , juvenile . 217. Ducks , ruddy . 202. Duck , wood . 202a . Duck , wood . 214. Ducks , Alameda County Infirmary Reservoir , winter of 1914 . 215. Ducks on pond at State Game Farm , Hayward , California ...
... Juvenile Mallard Adult 229 Mallard Juvenile 261 Black Duck Male Adult Black Duck Male Juvenile Black Duck Black Duck Juvenile Pintail Male Adult Pintail Male Juvenile Pintail Adult Pintail Juvenile 105 Baldpate Male Baldpate Male Baldpate ...
... pintail nests probably makes them unusually vulnerable to predators that locate nests visu- ally, such as crows ... Juvenile mortality. Because of the tendency for brood merging, counts of broods near the time of fledg- ing fail to ...
... juvenile mortality must take into considera- tion all factors that destroy eggs , nests , fe- males , or ducklings ... duck has survived the egg- laying and incubating periods , has hatched her eggs , and has led the ducklings ...
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... juvenile hens , 37 . of captive reared juveniles , 34-41 . definition of , 25 . of drakes , 40 . homing rate vs. calculated survival rate , 26 , 31 , 33 . of juvenile drakes , 36 , 40 . of mallards vs. pintail and teal , 36 . of pair to ...
... juvenile ring - billed gull . In other experiments it was demon- strated that juvenile ring - billed gulls are at ... pintail produced a typical , protracted , and fatal case of duck sickness . In another instance 0.2 g of toxic ...