Common Nighthawk

5557 5732 24778 27108 33275 34036 67315 89306

Records

45. Burke Museum nest record cards=20; egg sets=25.

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Counties

Adams=1; Benton=2; Douglas=1; Grant=1; Grays Harbor=1; King=4; Kittitas=1; Lewis=1; Lincoln=1; Pierce=16; Skagit=1; Spokane=14; Yakima=1.

First-egg dates

Earliest 30 April (Julian day 120); latest 30 July (Julian day 211).

First-egg dates tend to be earlier for western than eastern Washington. For western Washington the median first-egg date is 24 June (Julian day 175); for eastern Washington it is 4 July (Julian day 185); this difference just misses statistical significance (Mann-Whitney test, P = 0.066).

First-egg dates are also earlier for regions below 2000′ (Median 24 June; Julian day 175), than for higher elevations (Median 6 July; Julian day 187); this difference is significant (Mann-Whitney test, P = 0.03).

Clutch size

28 usable records. Mean 1.9 eggs. Distribution: 1 egg (N=3), 2 eggs (N=25).

Season and clutch size

No significant change with extrapolated first-egg date was observed, but most clutches had 2 eggs.

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