...Unfortunately, no one has read the band on the new female at Red Deer so far. The small clutch (3) suggests she may be breeding for her first time. We may get a chance to read her band in the coming weeks - most likely she is from Alberta but may be from as far away as Winnipeg!...
I didn't know that a clutch of 3 was considered to be a small clutch. I thought that 3 would be considered an average clutch, with 4-5 a larger clutch. Does the size of the clutch depend both on the age and experience of the birds, TPC, as well as on the genetic make-up of the birds?
Okay, in the north and Mexico, mean clutch size is 3.0 to 3.3 eggs (so 3 eggs is the norm). Southern Canada and continental USA (where anatum subspecies lives) it is 3.72 eggs, so 3-4 is the norm. Aleutian Islands of Alaska mean is 3.8, so 4 is the norm more times than not. Clutches of 5+ eggs is considered occasional about 1% of all nests.
That is a general statement. For some pairs 5 is the norm, and anything under that is small for them. For others 3 is the norm, so 4 eggs would be considered large for them. Larger is always the issue/concern, feeding 1+ more mouth is obviously harder (requires exponentially more labour, time and resources) than feeding 1+ fewer mouths.