Pj. Bergmann et al., INFLUENCE OF BROOD REARING ON FEMALE MALLARD SURVIVAL AND EFFECTS OF HARNESS-TYPE TRANSMITTERS, Journal of field ornithology, 65(2), 1994, pp. 151-159
A total of 62 Mallard (Anas platyrhynchos) females were captured at th
eir nests in eastern South Dakota during 1990 and 1991. Females were c
aptured on an island, a peninsula cut off from the mainland by excavat
ion, and a peninsula protected by an electric fence that deters mammal
s. Loop harnesses were used to attach radio transmitters to females to
evaluate possible effects of marking females on survival of their duc
klings and to determine the influence of brood rearing on female survi
val. No difference was found in duckling (P = 0.999) or brood (P = 0.4
58) (e.g., one or more ducklings alive in brood) survival to 7 d for f
emales marked from 1 d prior to hatch to immediately post hatch (still
in nest) compared with those marked at 3-9 d before hatch (P = 0.081)
. There also were no differences in survival by age class between mark
ed broods that did not suffer total mortality and unmarked broods (P >
0.05). If survival of broods was influenced by harness attachments on
females, it likely occurred in females suffering total brood loss ear
ly in brood rearing. Marked females with broods had poorer survival to
21 d than marked females that had lost or abandoned their clutches or
broods (73.5% vs. 100%, P < 0.001).