SHORT COMMUNICATIONS 
615 
TABLE 1. Nests of White-collared Swifts in Mallfn, Cdrdoba, Argentina, October 2001-March 2002. 
Location 
# of nests 
Nest code 
Date found 
Distance from water (m) 
Waterfall Creek 
Garganta del Diablo' 
3 
SI 
30 Sep 2001 
1 
5 
S2 
30 Sep 2001 
4 
5 
S5 
27 Dec 2001 
10 
4 
Cabeza del Indio’ 
1 
S6 
06 Jan 2002 
3 
4 
'Cueva de los Pajaritos’ 
2 
S3 
30 Sep 2001 
15 
4, 5 
S4 
13 Oct 2001 
17 
3 
'Lluvia del Amor' 
0 
Pajaritos’ where they also included some leaves of 
angiosperms. 
Breeding Chronology .—The reproductive peri¬ 
od of S. zonaris coincided with the rainy season. 
Egg-laying started with arrival of the first 
moderate rains (Oct and Nov). More intense rain 
occurred in January when fledglings were leaving 
nesting areas. Peak precipitation was recorded 
when the breeding season had ended in mid 
January. 
Four active nests with 1-2 adults were found 
between late September and mid-October. Two 
other nests were found between December and 
January, each with two nestlings (Table 1). Nest 
S4 was not successful. The reproductive period of 
S. zonaris lasted 81 days from early November 
until mid to late January (Fig. 1). 
Egg Laying .—The duration of this phase was 
estimated based on active nests (n = 5), although 
only two eggs were observed. These eggs were 
white in color and sub-elliptical in shape, and 
were deposited in the center of the nest. Egg 
laying occurred over 21 days from 1 to 21 
November (Fig. 1); clutch size was one (n = 2) 
to two (/t = 3) eggs. 
Incubation .—Incubating adults were found 
during 41 days from early November to mid- 
Dccember (Fig. 1). Eggs were incubated for an 
average of 22 days (range = 20—25 days) and 
were exposed on few occasions. 
Hatching .—Hatching date was ascertained for 
nests SI and S2, and estimated for nest S3. The 
remaining two nests were found in the nestling 
stage. Eggs in nest S1 hatched on the afternoon of 
Fledging 
Nestling 
Hatching 
Incubation 
Egg Laying 
Month 
FIG. 1. Breeding chronology of the White-collared Swift in Cordoba, Argentina, 2001-2002. 
