Avery el al. • MONK PARAKEETS IN SOUTH FLORIDA 
585 
FIG. 4. Body mass of nestlings in 35 Monk Parakeet nests removed from electnc utility substations m south Honda 
during April-May 2006 and 2007. Vertical bars denote maximum, minimum, and mean nestling body mass within eac 
brood. The solid and dashed horizontal lines across the graph denote the mean body mass ot adult (11-7 g) and tie g ing 
(102.7 g) parakeets, respectively, collected in south Florida in 2003-2004. 
r-statistic = 2.814) among 70 male-female pairs. 
The onset of primary molt in early to mid-April 
coincided with the first appearance of nestlings. 
Ninety-four percent (165 of 175) ol adults 
examined during June-August were replacing 
primary feathers. 
DISCUSSION 
The invasive Monk Parakeet population in 
south Florida has retained basic biological char¬ 
acteristics of the native population in South 
America during 40+ years. The timing has shitted 
-6 months (Table 3). but Monk Parakeets in 
Florida exhibit a fixed annual cycle presumably 
governed by photoperiod (Spreyer and Bucher 
1998). 
We conclude the parakeets in our study belong 
to the monachus subspecies (Spreyer and Bucher 
1998). Mean oilmen and tarsus lengths tor both 
male and female parakeets from south Florida 
exceed the upper end of the ranges given by 
Spreyer and Bucher {1998) for all subspecies 
except monachus. Measurements from south 
Florida parakeets overlap those given for mon¬ 
achus. The luchsi subspecies is closest in size to 
monachus. but luchsi occurs only in Bolivia and 
genetic evidence indicates south Florida Monk 
Parakeets originated from eastern Argentina and 
Uruguay (Russello el al. 2008). 
The body measurements also demonstrate that, 
despite considerable overlap, male parakeets 
average 1.5 to 3.5% larger than females. Slight 
sexual dimorphism occurs in other monogamous 
psiltacines. although detailed information is avail¬ 
able for only a few species (Collar 1997, Masello 
and Quillfeldt 2003). Monk Parakeets are monog¬ 
amous (Goncalves da Silva et al. 2010), a 
condition often associated with reduced male-male 
TABLE 3 Measurements of adult (Jan-Oct) and fledgling (Jun-Sep) Monk Parakeets from south Florida, 2003 and 
Tail leneth did no! dtlTer if > 0.251 between males and females in each age elass Male measurements exceeded 
female measurements for all other characters IP < UJ»5), except for fledgling wmg chonl If - 0.0631._ 
Adult 
Fledgliny 
Male Female 
Character 
n 
Mean 
± SE 
n 
Mean ± SE 
Body mass (g) 
255 
113.7 
± 0.5 
280 
1 1 1.6 ± 0.6 
Wing chord (mm) 
255 
150.2 
± 0.2 
280 
147.9 ± 0.2 
Wing flat (mm) 
255 
155.3 
± 0.2 
280 
153.0 ± 0.2 
Tail (mm) 
249 
138.3 
± 1.1 
273 
138.3 ± 0.8 
Tarsus (mm) 
64 
18.2 
± 0.1 
66 
17.8 ± 0.1 
Culmen (mm) 
253 
20.4 
± 0.1 
278 
19.7 ± 0.1 
Male 
n Mean - SE 
51 105.8 ±1.2 
51 149.3 ± 0.7 
51 152.6 ± 0.7 
51 145.0 ± 1.5 
39 18.2 ± 0.1 
51 19.6 ± 0.1 
Female 
ii Mean ± SE 
69 100.5 ±1.1 
69 147.5 ± 0.7 
69 150.1 ± 0.7 
69 142.3 ±1.9 
65 17.9 ±0.1 
69 19.2 ± 0.1 
