Weather Conditions

As in other parts of northwestern Canada, spring 1998 in the southern Yukon was one of the warmest and driest on record. The below average snowpack melted very early, and many breeding areas were completely snow and ice free by the end of April. This warm, dry trend continued through the summer. Water levels in most wetlands were lower than normal, but none of the survey wetlands were drastically low.

Surveys

A total of 189 wetlands were surveyed at least once between May 5 and June 6 in 1997, and a total of 177 wetlands were surveyed at least once between May 5 and June 6 in 1998 (Tables 1,2). A total of 139 wetlands was surveyed 5 times each in the same 5-week period each year (i.e. 5 May - 6 June 1997, 5 May - 6 June 1998).

Overall Populations

A mean of 1446 waterfowl were counted on each of the 5 surveys in 1998, up 57% from 920 in 1997. Indicated pairs were 575, up 31% from 1997 (Table 3, Table 4). Totals and indicated pairs of dabbling ducks were up 108% and 53% respectively, from 1997 values. Diving duck totals and indicated pairs were up 23% and 11% respectively, from 1997. These follow on decreases of 25% and 22% respectively in pairs of dabblers and divers from 1996 to 1997. The net result is that pairs of dabblers and divers are at 135% and 75% of 1991 levels, respectively (Figure 3). Most of the common species of ducks showed increases in breeding pairs from 1997 to 1998(Figure 2). This increase was significant for Mallard (51%), American Green-winged Teal (53%), Blue-winged Teal (717%), Northern Shoveler (208%), Scaup species (13%) and White-winged Scoter (180%). Mallard (49%), Blue-winged Teal (778%), Northern Shoveler (393%) and Common Loon (350%) showed significant increases in total birds. Overall, 13 of 72 comparisons were statistically significant (all increases), whereas about four would be significant by chance alone at the 5% probability level.

 Populations by Stratum

There were statistically significant increases as follows (Table 5): In stratum 1, total Ring-necked Duck and total Divers. In stratum 2, indicated pairs of Mallard, Dabblers and All Species and total American Green-winged Teal, Northern Shoveler, Dabblers and All Species. In stratum 3, pairs and total Northern Shoveler. In stratum 4, total and indicated pairs of Northern Shoveler. In stratum 5, pairs of Northern Shoveler, Northern Pintail, Scaup sp, Divers, All Species, and total Northern Shoveler and Bufflehead. There were statistically significant declines in total and pairs of Northern Pintail in stratum 3 and pairs of Barrow's Goldeneye in stratum 3. Overall, 23 of 120 comparisons were statistically significant (20 increases and 3 decreases), whereas six of these comparisons would be significant by chance alone at the 5% probability level.