Northern Prairie Wildlife Research Center
Mallard.óMallards attained highest densities in prairie and parkland of the southern prairie provinces and in the Copper River and Athabasca River deltas (Fig. 4A). Within the prairie and parkland area, densities decreased with distance from strata of highest densities.
Figure 4. (A) Average species density by stratum, 1955-81; (B) correlation between species density and local pond counts, 1955-81; and (C) correlation between species density and total pond counts, 1955-81.
Most mallards winter in the south-central United States. We estimate from information in Bellrose (1980) that about 70% of wintering mallards return in the spring through the southern entry, or portal (the Dakotas), versus about 30% from California and the Pacific Northwest through the western portal. Thus most mallards initially are exposed to wetland conditions in the southern portion of the surveyed area.
Mallard densities varied with local pond counts, the median correlation coefficient being 0.417 (Table 3). Highest correlations were in Alberta prairie and Saskatchewan parkland, but consistently high values were calculated for the southern portion of the prairie provinces, where mallards were very common, and in the Dakotas (except the 2 easternmost strata), where they were not as common (Fig.4b).
|Correlations with Pond Densities|
Female mallards, especially those that were successful in hatching a clutch the previous year, home at fairly high rates (Table 4). Males home at much lower rates presumably because pairing occurs during winter or spring migration, and the female leads the male to the breeding ground (McKinney 1965).
|42||24||Coulter and Miller (1968)|
|46||113||5+||140||Doty and Lee (1974)|
|58||19||14||14||Bishop et al. (1978)|
|60c||68||31||48||Lokemoen et al (unpubl. manuscript)d|
|26e||119||Lokemoen et al (unpubl. manuscript)d|
|66c||Lokemoen et al (unpubl. manuscript)d|
|40e||Lokemoen et al (unpubl. manuscript)d|
|41||54||9||236||7||28||2||42||Blohm (1978, 1979)|
|American Wigeon||38||21||9||11||33||3||0||6||R. A. Wishart (pers. commun.)|
|Green-winged teal||No information||No information|
|Blue-winged teal||14||58||0b||30||0b||19||Sowls (1955)|
|5||143||1+||226||Lokemoen et al (unpubl. manuscript)d|
|Northern Shoveler||42||19||8b||12||0b||12||Sowls (1955)|
|Northern Pintail||39||44||13b||115||2b||132||Sowls (1955)|
|Lesser scaup||20||330||3||34||12||626||0||557||Trauger (1971)|
|66||58||9||351||49||76||4||91||A. D. Afton (pers. commun.)|
aReported rates are minimal estimates of homing rates, as they
do not account for mortality between seasons or for birds that may have homed
but were not seen.
cSuccessfully nested previous year.
dJ. T. Lokemoen, H. F. Duebbert, and D. E. Sharp, Reproductive strategies of prairie mallards, gadwalls, and blue-winged teal, unpubl. manuscript, U.S. Fish and wildl. Serv., Jamestown, ND.
eDid not successfully nest previous year.