SHORT COMMUNICATIONS 
379 
over M (hereafter HM). She had a vascularized 
brood patch and weighed 176 g, conditions 
indicative of an incubating female. We viewed 
the burrow entrance every 3-5 days over the next 
month. On 11 and 14 May we observed a pair: the 
female had a black Acraft band, but we were 
unable to read the alphanumeric code. On 18 May, 
we recorded one adult at the nest entrance and, on 
21 May. using an infrared video probe, we 
detected one juvenile in the nest burrow. The 
juvenile was estimated to be 13 days of age. based 
on comparison to a Burrowing Owl photographic 
age guide modified from Priest (1997); this 
implies it hatched on ~8 May suggesting that 
HM hegan incubating between 10 and 16 April 
using a 22-day incubation period (Conway et al. 
in review). 
We observed only the male at the nest entrance 
on 25 May and. on 29 May. the same male was 
still present. A new female was in attendance and 
subsequently trapped, at which time we observed 
three eggs. This new female had been banded on 
22 April (black Acraft band with 9 vertical bar 7; 
hereafter 97) at a nest burrow where she had five 
eggs, and she was last seen there on 27 April. 
Female 97’s first nest was 900 m from HM’s nest 
and that nest failed between 27 and 30 April; one 
egg was found outside the burrow on 30 April and 
female 97 was not seen then or subsequently al 
her first nest burrow. This new' pair (female 97 
and HM's male) was still present at HM’s nest 
burrow on 31 May, but on 13 June we found four 
abandoned eggs and no owls present. We found 
no owls on four subsequent nest visits in June. 
Female HM was seen next on 12 July 2003 in 
the Nashlyn Prairie Farm Rehabilitation Act 
pasture (49.1 N. 109.5 W) in southern Saskatch¬ 
ewan. Canada, when we were conducting brood 
counts in the area. Wc captured HM with an 
unhanded male and 7 young on 18 July 2003. Her 
brood patch was starting to grow in with pin 
feathers and she weighed 137 g. We confirmed 
both bands while she was in hand. This pasture is 
1.860 km north of the nest at which she was 
banded in Arizona. 
We estimated the oldest young to be 24-26 days 
of age on 18 July, while one young was much 
younger, based on the length of primary 9 and tail 
measurements (T. 1. Wellicome. unpubl. data). 
We estimated HM's first egg was laid on 27 May 
based on a 22-day incubation period which started 
mid-way through the laying period, a 1.5-day 
laying interval between eggs, and a seven-egg 
clutch (Haug 1985, Wellicome 2005, Conway et 
al. in review). 
DISCUSSION 
The identification of this owl is certain because 
we trapped her in both locations and the U.S. 
Geological Survey and Acraft bands were con¬ 
tinued in hand. This female Burrowing Owl laid 
and incubated a clutch (and hatched at least 1 
nestling) in Tucson, Arizona and then moved 
1.860 km north and successfully nested in 
Saskatchewan. We do not know which of the 
two females were present on 11 and 14 May so the 
departure date when HM left Tucson is unknown 
(we believe she likely departed just after her 
clutch hatched on 8 May). Female 97 could not 
have hatched the nestling (hatch date ~ 8 May) 
since she was involved in her own first nesting 
attempt until at least 27 April. Two other 
examples of females abandoning young nestlings 
and moving to initiate second nests with a new 
male have been observed at the Tucson study site 
(CJC. unpubl. obs.). This is the first time a second 
brood has been documented following long¬ 
distance dispersal by a Burrowing Owl. 
Burrowing Owls have been documented with 
renests and second broods in California (Gervais 
and Rosenberg 1999, Catliti 2004. Rosier et al. 
2006), in Florida (Millsap and Bear 1990), and in 
Arizona (Conway et al. in review). The intervals 
between fledging or failure of the first attempt and 
initiation of the subsequent attempt ranged from 
16 to 150 days. Rosier et al. (2006) documented 
eight owls to disperse up to 54.1 km (mean = 
14.9 km) but not all owls bred at the dispersal site 
that season. A. M. Fueutes Romero and M. 
Marquez Olivas (unpubl. data) documented a 
banded pair of Burrowing Owls in Texcoco, 
Distrito Federal. Mexico (19.5 N, 98.9 W) 
successfully producing two broods of three young 
each that hatched in March and December 2008. 
Catlin (2004) documented two pairs that produced 
three and four clutches after eggs were experi¬ 
mentally removed in Calilornia. These examples 
were from non-migratory populations and the 
females remained in the same nest burrow or only 
moved short distances (max = 54.1 km: Rosier et 
al. 2006) between nest attempts. 
Encounters of Burrowing Owls banded in 
Canada indicate two migration patterns, one for 
Bunowing Owls east of the Rocky Mountains 
through the Great Plains, and the second for 
British Columbia along the west coast of North 
