when do red tailed hawks lay their eggs
Red-tailed hawk In most of the interior contiguous United States the first egg is laid between mid-March and early April, ranging from 3 to 5 weeks after the nest is constructed, with the clutch completed 2 to 5 days after the initial egg is laid.[9][302] The average date of the laying the first egg can be variable: peaking mid-January in Puerto Rico, averaging March 9th in Arizona, March 26 in the Front Range Urban Corridor and May 1st in Alberta.[9][52][141][241] The mean initiation of clutches may bump weeks later if 10 cm (3.9 in) or more of snow is still on the ground in Wisconsin during March.[101] A clutch of one to three eggs is laid in March or April, depending upon latitude, with four eggs being uncommon and five and perhaps even six increasingly rare.[77] Clutch size depends almost exclusively on the availability of prey for the adults. At the species level, body size also determines clutch size. For example, while the total clutch weighs up to 18% of the females weight and the clutch size averages 2 to 3, a larger raptor like the golden eagle lays a smaller clutch, usually not more than two, that weighs less than 10% in total of the female’s body mass, whereas a smaller raptor like the kestrel lays a larger clutch averaging five that weighs 50% of the females weight.[4] Average clutch size vary from 1.96 in Alaska when prey populations were low up to 2.96 in Washington.[94][303] Eggs are laid approximately every other day. Average egg sizes in height and width (each with a sample size of 20) are in the following subspecies- B. j. borealis: 59.53 mm × 47.49 mm (2.344 in × 1.870 in); B. j. calurus: 60.04 mm × 47.1 mm (2.364 in × 1.854 in); B. j. fuertesi: 59.42 mm × 46.99 mm (2.339 in × 1.850 in).[304] The eggs of red-tailed hawks are mostly white, sometimes with a faint buffy wash; at times the eggs manifest a sparsely or heavily marked with blotches of buff, pale reddish-brown, dark brown, or purple. The markings often appear indistinctly and may combine to form a fine speckling.[305] They are incubated primarily by female, with the male substituting when the female leaves to hunt or merely stretch her wings. Rarely do the males incubate more than four hours of daylight. The male brings most food to the female while she incubates.[9][77][257][284]
American robin The American robin begins to breed shortly after returning to its summer range. It is one of the first North American bird species to lay eggs, and normally has two to three broods per breeding season, which lasts from April to July.[12]