|
 |
|
GADWALL
 BIOLOGICAL DESCRIPTION OF THE GADWALL
TAXONOMY
KINGDOM: ANIMALIA
PHYLUM: CHORDATA
SUBPHYLUM: VERTEBRATA
CLASS: BIRDS
ORDER: ANSERIFORMES
FAMILY: ANATIDAE
GENUS: Anas
SPECIES: strepera
IT MEASURES FROM 46 TO 56 cm. MALES WEIGH 953 g. AND FEMALES 835 g. IT IS MEDIUM SIZE GRAYISH COLOR WITH WHITE PATCHES IN THE BACK BORDER OF THE WING AND A BLACK BEHIND, WITH A SAND COLOR HEAD. THE PEAK IS BLACK. FEMALES BROWNISH WITH THE BACK BORDER OF THE WINGS WHITE. THE PEAK IS BLACK WITH ORANGE BORDERS (ROBBINS, BRUUN, ZIM, 1966)
THESE ARE THE DUCKS THAT ARRIVE THE LATEST FROM MIGRATION LEAVING IN MARCH OR APRIL AND THEIR REPRODUCTION STARTS ON MAY.
THEY LAY FROM 7 TO 13 CREME COLOR EGGS PER NEST AND THE INCUBATION DURATION IS FROM 24 TO 27 DAYS. THEY ONLY REPRODUCE ONCE A YEAR. THE NEST IS BUILT 300m FROM THE WATER IN PLACES WITH DENSE VEGETATION AND NEAR TO THE PLACES WHERE THEY BUILT THEIR LAST NEST. (EHRLICH, DOBKIN, WHEYE, 1988) (RINGELMAN, 1990)
THEY ARE COMPLETELY FEATHERED AT THEIR 48 TO 56 DAYS OLD.
THEY MAKE A SOUND SIMILAR TO THOSE OF WHISTLES
THEY LIVE IN OPEN SPACES AND IT IS ONE OF THE DUCKS WITH THE GREATEST DISTRIBUTION IN NORTH AMERICA. IN THE WINTER IN THE LOUISIANA COASTS AND TEXAS, MEXICO COASTS, TO YUCATAN AND THE WEST COAST OF MEXICO.
THEY ARE BASICALLY HERBIVOROUS BUT DURING SPRING THEY EAT SOME AQUATIC INVERTEBRATES.
THE MAJORITY OF THESE DUCKS START MIGRATING IN SEPTEMBER BUT SINCE THEIR REPRODUCTION IS DELAYED, SOME FEMALES STAY THERE UNTIL OCTOBER.
|
COMMON NAME: GADWALL
SCIENTIFIC NAME: Anas strepera
TYPE OF GAIN: Cinegetico
TYPE OF MARKING: HUNTING LICENSE
|
CHRONOLOGY OF THE GADWALL
MONTHS
|
ACTIVITY
|
J
|
F
|
M
|
A
|
M
|
J
|
J
|
A
|
S
|
O
|
N
|
D
|
|
COURTSHIP
|
X
|
X
|
X
|
|
|
|
|
|
|
|
|
X
|
|
SPRING MIGRATION
|
|
|
X
|
X
|
|
|
|
|
|
|
|
|
|
NESTING
|
|
|
|
X
|
X
|
X
|
|
|
|
|
|
|
|
WINTER MIGRATION
|
|
|
|
|
|
|
|
X
|
X
|
X
|
X
|
X
|
|
|
|
|
|
|
|
|
|
