Woltmann and Sherry • SURVIVAL AND TERRITORY DYNAMICS OF ANTBIRDS 
19 
TABLE 2. Number (sample size) of territory-years (T-Y), observed disappearances and switches, and adjusted 
disappearance rates for Chestnut-backed Antbirds in Costa Rica. D 0bs = observed disappearance rate; Am>r — false 
disappearance rate, calculated for 2005-2008, and Adjusted = Abs — Arror* which was used in place of A bs * n turnover 
calculations (Table 3). 
T-Y 
Obs. (#) disappeared 
Obs. (#) switched 
Dobs 
D en or 
^adjusted 
Male 
Adult 
100 
26 
4 
0.260 
0.014 
0.246 
Juvenile 
15 
6 
1 
0.400 
0.083 
0.317 
All 
115 
32 
5 
0.278 
0.024 
0.255 
Female 
Adult 
36 
16 
3 
0.444 
0.185 
0.259 
Juvenile 
9 
4 
1 
0.444 
0.125 
0.319 
All 
45 
20 
4 
0.444 
0.171 
0.273 
the course of our study, but four previously 
unoccupied territories became occupied (one gain 
resulted from a territory splitting). Between three 
and six once-occupied territories were empty in 
any given year, and density was relatively stable 
at 9.3-10.0 pairs/100 ha from 2006 to 2009. 
Territory locations and boundaries appeared 
stable regardless of the owner, suggesting territory 
locations are intrinsic to the environment, or 
become constrained by traditional boundaries. 
We identified seven males and one female (the 
female was not captured) on the 300-ha focal plot 
that appeared to be floaters. These were generally 
(6 of 8) unpaired individuals that responded 
TABLE 3. Annual turnover and territory switching of Chestnut-backed Antbirds compared to ecologically similar 
species. Numbers in columns represent males and females respectively, where available; a single value represents males 
and females combined. 
Turnover 
Switch rate 
Species 
Male 
Female 
Male 
Female 
Source 
Chestnut-backed Antbird 
Adult 
0.29 
0.34 
0.04 
0.08 
This study 
Juvenile 
0.39 
0.43 
0.07 
0.11 
All 
0.30 
0.36 
0.04 
0.09 
Spotted Antbird 
0.27 
0.32 
0.09 
0.12 
Willis 1974 
(Hylophylax 
naevioides) 
Bicolored Antbird 
0.39 
0.53 
0.12 
0.18 
Willis 1974 
(Gymnopithys 
leucaspis) 
Ocellated Antbird 
0.26 
0.49 
0.04 
0.12 
Willis 1974 
(Phaenostictus 
mcleannani) 
Checker-throated Antwren 
(Epinecrophylla 
fulviventris ) 
Dusky Antbird 
0.23 
0.25 
-0.33 
0.27 a 
Greenberg and 
Gradwohl 1997 
Morton et al. 2000 
(Cercomacra 
tyrannina) 
White-bellied Antbird 
0.36 
0.36 
0.25 
0.19 
Fedy and Stutchbury 
(Myrmeciza longipes) 
Buff-breasted Wren 
(Cantorchilus leucotis) 
0.07 
0.15 b 
2004 
Gill and Stutchbury 
2006 
d Estimated separately for a subset of contiguous territories (E. S. Morton, pers. comm.). 
Averaged over 3 years, derived from Gill and Stutchbury (2006: Table 1). 
