NE San Antonio Swainson's Hawks, 2006,
2007, 2008
Nesting Season Summary
Page
Highlights
Images of the male: in cottonwood, in hackberry
Images of the female: on Gauranty bank Building favorite morning perch
videos of adults bringing food: jerky early
July, later smoother mid July
better videos: favorite perch
and surroundings
landing on favorite
perch
circling favorite
perch
soaring around the
territory
descending to
2007 nest
map of the established nesting territory
for 2006, 2007, 2008, and nest location for 2006
Many more photos and videos on the
main page.
Abbreviated
calander of events, based on 3.5 seasons observations
The male returns between 2/21st
and
3/28th
The female returns about a week later. Both adults glide
together, establishing, a
nesting territory in late March through April
Gliding is commonly done in close synchronization with both
birds
wheeling at the same moment, male usually slightly higher in altitude.
The male does not like its reflection in upper story windows and
attempts to grab it during April of each season.(4/18/07, 4/10/08,
4/11/08)
Mating occurs continuously. Male lands directly on
females back and after copulation, lifts off back into the
air. Male never climbs up onto the female.
Building or choosing a nest; late April through May 10th.
The 2006, 2007, and 2008 nests have all been within 100 yards of each
other. The 2008 nest was a fixer-upper, used probably last in
2004 or 2005.
Incubation; starts between May
2nd and May 15th(May 2nd 2008) Male shares incubation, especially
the earlier two weeks, starting off with half the incubation, tapering
off to much less later on.
More gliding together during
incubation; afternoons between about 3PM and 5PM, short
periods only.
Food delivery to the female during
incubation and young chicks; observed on 6/24, 7/1, 7/5 of 2006,
and 6/7 and 6/27 of 2007; and on 6/5 amd 6/9 of 2008.
Female's first long stay away from the
nest after weeks of incubation; 7/5/2006, 7/6/2007, 6/27/08
Hatching? around July 5th in 2006 and 2007?, Prior to June 17th
in 2008.
Food delivery to the nest on days both adults hunted; observed
on 7/5, 7/9, 7/10, 7/12, 7/14, 7/18, 7/24, 7/26 of 2006 and
8/1/2008.
Both adults enjoy dropping prey from hundreds of feet, to swoop down
and retrieve it before it hits the ground.
Copulation; observed
in April, May, and Julyof the three seasons observed so far. Male
always approaches female from the air, not by climbing up.
Fledglings leave the nest;
7/28/06(single), 7/27/07(single), 7/22/08(three), balancing in the tops
of trees around the nest.
Fledgling's first long sustained flight;
8/7/06, 8/7/07
Later fledgling flights;
observed on 8/11, 8/14, 8/15, 8/16, 8/24 of 2006 & 8/22, 8/24, 8/29
& 8/30 of 2007
Fledgeling develops good soaring
skill; 8/22-8/24/07
Breeding season ends
Fledgling last seen in the area; 8/24/06, 9/10/07
Hunting territory expands beyond
nesting territory, 8/24-9/10
Female last seen in the area;
8/28/06, 10/4/07
Male last seen in the area;
9/30/06, 9/17/07
Other information
The adults commonly eat prey while in the air. This was observed
on 7/14 and 7/24/06 and in 4/2008.
Adults sometimes drop prey just for fun or to get a different grip,
observed twice, once on 7/14/06
Adults sometimes bring several prey to the nest, one in each talon,
observed on 7/14/06
Near the end of flegeling's feeding, adults would drop prey from
hundreds of feet altitude for the fledgling to snatch from the air
before it got to the ground, observed 8/24/07
These adults started nearly each day with a perch facing south from the
Gauranty Bank Building, looking over the landscape, prior to
hunting. The male preferred to perch to the female's right.
Prey could sometimes be obtained in as little as 15 minutes, observed
6/26/06.
Copulation continues all summer long, peaking first in late April, then
again in mid-July, after eggs hatch.
Detailed observation logs and more
information, photos, and videos
main Swainson's Hawk page
2006 Observation log
2007
Observation log
2008
Observation log