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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 3. September 2012 
at the mixed-deciduous-conifer site generally used 
all other cover types in accordance with avail¬ 
ability (A = 0.812. P = 0.353). We observed only 
one bird on 1 day (0.8% of observations) in a 
shrub-dominated clearcut at either site despite that 
cover type constituting 8-9% of the landscape at 
each site. All fledglings used areas of vegetation 
density similar to that of forested wetlands, 
sapling-dominated clearcuts, and mixed-conifer- 
deciduous forest understory, all of which were 
denser than the understory of the mature decid¬ 
uous forests we studied (Fig. 1). 
We observed evidence of predation of two 
(9%) fledgling Ovenbirds that had been indepen¬ 
dent from adult care for 2 and 10 days, respec¬ 
tively. We attributed both mortalities to Broad- 
winged Hawks (Buteo platypems) because we 
tracked and found one fledgling's transmitter in a 
Broad-winged Hawk nest, and we observed the 
other fledgling being carried by a Broad-winged 
Hawk the last day we received a transmitter signal 
(i.e., we chased the signal distances >500 m 
several times and each time the signal slopped 
moving we caught up with the perched hawk). We 
could not identify the locations of those fledglings 
when they were initially captured by hawks, but 
both were observed in mature forest with open 
understory the day before they were depredated. 
DISCUSSION 
Independent fledgling Ovenbirds we tracked 
used non-mature-forest stands as in previous 
studies (Pagen et al. 2000. Marshall et al. 2003, 
Vitz and Rodewald 2006). Fledgling Ovenbirds 
moved long distances 6.1 km) between areas 
used during the independent post-fledging period 
(after independence from adult care but before 
migration), likely explaining why nestlings banded 
in mature forest adjacent to clearcuts are rarely 
among the fledglings captured in those clearcuts 
(Streby et al. 2011b). Our results are consistent 
with those of Vitz (2008) who reported that 
independent fledgling Ovenbirds in Ohio did not 
use clearcuts more than expected based on 
availability, but rather used riparian areas, treefail 
gaps, and mature-forest with dense understory 
vegetation. Similarly, independent fledgling Black- 
poll Warblers (Setup/mga striata) and Yellow- 
rumped Warblers (S. coronata) moved through 
riparian areas ol river valleys in landscapes where 
legenerating clearcuts were available (Mitchell 
et al. 2010). Vitz (2008) suggested regenerating 
clearcuts may be more heavily used by fledgling 
Ovenbirds in areas with even-age open-understorv 
mature forest. Fledglings we tracked in deciduous 
forest with relatively open understory selected 
sapling-dominated clearcuts and forested wetlands 
substantially more than mature forest. Birds at our 
deciduous sites spent several days in and made 
considerable I-day movements (s 6.1 km) be¬ 
tween sapling-dominated clearcuts and/or forested 
wetlands, apparently moving through mature 
forest. Birds at the mixed-deciduous-conifer site, 
where mature-forest understory was relatively 
dense, made movements of similar distance to 
those at the deciduous site, but used cover types in 
accordance with their availability on the landscape 
with the exception of under using shrub-dominated 
clearcuts. This suggests resources available in 
forested wetlands and sapling-dominated clearcuts 
also are available in mature forests with a dense 
understory. We observed only one independent 
fledgling Ovenbird in a recently harvested, shrub- 
dominated clearcut. consistent with low mist-net 
capture rates in those stands, which may be related 
to low food availability despite very dense 
vegetation (Streby et al. 201 la). 
It is important to consider that selection of any 
cover type over another only suggests relative 
importance, and information about survival and 
food availability in those cover types is necessary 
to make conclusions about their relative value to 
birds that use them, Survival and food availability 
in our investigation of habitat use and survival of 
fledgling Ovenbirds still dependent on adult care 
were highest in sapling-dominated clearcuts and 
forested wetlands (Streby 2010). Survival of 
independent fledglings was too high to compare 
rales among cover types with our sample size, 
although the only tw'o mortalities we recorded 
apparently occurred in mature forest. Regenerating 
clearcuts can be important areas for fledgling 
Ovenbirds during the independent post-fledging 
period, but not until saplings establish, and not 
necessarily in landscapes in which dense mature- 
forest understory or forested wetlands are common. 
ACKNOWLEDGMENTS 
I hose data were collected during a project funded by the 
U.S. Fish and Wildlife Service and the U.S. Geological 
Survey through Research Work Order 73 at the Minnesota 
Cooperative Fish and Wildlife Research Unit with in-kind 
support trom the U.S. Forest Service. We handled, banded, 
and attached radio transmitters to Ovenbirds following 
Protocol #0806A3576I. approved by the University ol 
Minnesota Institutional Animal Care and Use Committee. 
We thank D, L). Dcssecker, A. C. Edmond. J. L. Hammers, 
