Habitat use and population dynamics of the Azure-Winged Magpie ...

Table 3.6 Life history of individuals that were born into this colony and banded as fledglings. No
data for breeding was recorded in 2006. Bred here is defined as individuals that
attempted breeding, but didn’t necessarily fledged chicks.
2007 2008 2009 2010
No. hatched 54 43 39 26
No. fledged 49 41 23 23
No. banded 23 34 16 18
No. sighted in autumn 40 31 17 22
No. bred as yearling - 0 2 0
No. bred - 0 2 1
No. helpers - 0 7 0
Table 3.7 shows the estimated number of adults and juveniles present in the colony between 2006
and 2010. This estimation is based on the re-sighting rate (p) obtained from MARK analysis of
adult and juvenile survival and recapture (re-sighting) rates (Fig. 3.15). The standard error for this
estimation is high, resulting in a wide confidence interval (CI), especially in 2009 for adults and
2008 for juveniles. The formula estimates are higher (Table 3.7) in 2008 and 2009 compared to
visual estimations (Table 3.5).Only in 2010 was the formula estimation comparable to the visual
estimation. Around 20 non-breeding birds left the colony in 2009 and were then not sighted again
that season (B Gantulga, pers. comm.), hence the lower number in September 2009 than in May
2009.
Table 3.7 Estimation of number of adults, and juveniles in the colony each year, from 2006 to
2010 using the methodology following Davidson & Armstrong (2002). There was no
breeding data for 2006, hence only total number of adults in colony was estimated.
2006 2007 2008 2009 2010
Estimated adults 19 31 35 63 10
95%CI (Lower, Upper) (12.89, 25.11) (21.01, 40.99) (23.90, 46.10) (43.02, 82.98) (6.67, 13.33)
Estimated juveniles - 35 52 24 27
95% CI (Lower, Upper) - (23.33, 46.67) (34.75, 69.26) (15.88, 32.12) (17.87, 36.14)
Estimated total colony
size
19
(12.89, 25.11)
66
(44.34, 87.66)
45
87
(58.65, 115.36)
87
(58.90, 115.1)
37
(24.54, 49.47)