TY - JOUR
T1 - Postbreeding ecology of wood ducks in the Illinois River Valley
AU - Gilbert, Andrew D.
AU - Yetter, Aaron P.
AU - Hine, Christopher S.
AU - Lancaster, Joseph D.
AU - Osborn, Joshua M.
AU - Kross, Chelsea S.
AU - Fournier, Auriel M.V.
N1 - We thank The Nature Conservancy, the United States Fish and Wildlife Service (USFWS), and the Illinois Department of Natural Resources (IDNR) for allowing access to their properties for research. We thank C. Beach, S. Klimas, M. Williams, J. Trickey, A. Weigel, G. Mibbs, F. O'Hara, J. Lux, J. Spitzer, C. Cremer, W. Nixon, V. Drake, N. Pietrunti, B. Webber, and N. Hargett for help with data collection. We thank M. Lowers for project support. We acknowledge M. Cruce, Cruce Aviation LLC, for piloting aerial telemetry flights. Funding for this project was administered through the Federal Aid in Wildlife Restoration Act in cooperation with the USFWS, IDNR, and the Illinois Natural History Survey at the University of Illinois at Urbana\u2010Champaign.
PY - 2025/1
Y1 - 2025/1
N2 - The wood duck (Aix sponsa) consistently ranks within the top 5 harvested duck species for both Illinois and the Mississippi Flyway. While substantial research has been done on wood ducks, especially their breeding ecology, few studies have investigated the postbreeding ecology of the species. We captured and marked wood ducks with either a very high frequency (VHF) radio transmitter or a solar-charged global system of mobile communication (GSM) transmitter during the postbreeding period from August through September 2018–2020. Capture locations were within the La Grange Pool of the Illinois River extending from near Pekin, Illinois to the La Grange Lock and Dam near Meredosia, Illinois, USA. We used conventional radio-telemetry techniques to track wood ducks to determine cover type use, home range size, daily movement patterns, survival, and migration chronology. Home range size (95% minimum convex polygon) for wood ducks averaged 6,820 ± 572 ha (SE) and we did not find evidence for a difference by age, sex, or transmitter type. Daily movement distance in August (2,031 ± 51 m) was similar to daily movement distance in September (1,922 ± 44 m), but daily movement distances for August and September were less than daily movement distance for October (3,509 ± 53 m) and November (3,347 ± 106 m). Wood ducks primarily used wetlands with woody (45.0%) and emergent vegetation (40.4%), and the most commonly used wetland types by wood ducks were impounded wetlands (53.8%), lakes (17.6%), and ponds (10.7%). Model-derived survival during the postbreeding period was 0.79 (95% CI = 0.74–0.84). Daily survival was positively related to increased river level and had a mean increase of 4.06 ± 0.67% for every 0.3-m increase in the Illinois River level at low river levels (1.5–3.0 m) and a mean increase of 1.38 ± 0.32% for every 0.3-m increase in the Illinois River level at high river levels (4.0–5.5 m). Average departure date of wood ducks leaving the Illinois River Valley was 27 October (range =13 August–15 December), and adult male wood ducks left the study area 11–16 days earlier than the other age and sex cohorts (H2 = 11.6, P = 0.01). Providing additional waterfowl sanctuaries that contain wooded wetlands, especially in years of low river levels, may increase survival for wood ducks during the postbreeding period.
AB - The wood duck (Aix sponsa) consistently ranks within the top 5 harvested duck species for both Illinois and the Mississippi Flyway. While substantial research has been done on wood ducks, especially their breeding ecology, few studies have investigated the postbreeding ecology of the species. We captured and marked wood ducks with either a very high frequency (VHF) radio transmitter or a solar-charged global system of mobile communication (GSM) transmitter during the postbreeding period from August through September 2018–2020. Capture locations were within the La Grange Pool of the Illinois River extending from near Pekin, Illinois to the La Grange Lock and Dam near Meredosia, Illinois, USA. We used conventional radio-telemetry techniques to track wood ducks to determine cover type use, home range size, daily movement patterns, survival, and migration chronology. Home range size (95% minimum convex polygon) for wood ducks averaged 6,820 ± 572 ha (SE) and we did not find evidence for a difference by age, sex, or transmitter type. Daily movement distance in August (2,031 ± 51 m) was similar to daily movement distance in September (1,922 ± 44 m), but daily movement distances for August and September were less than daily movement distance for October (3,509 ± 53 m) and November (3,347 ± 106 m). Wood ducks primarily used wetlands with woody (45.0%) and emergent vegetation (40.4%), and the most commonly used wetland types by wood ducks were impounded wetlands (53.8%), lakes (17.6%), and ponds (10.7%). Model-derived survival during the postbreeding period was 0.79 (95% CI = 0.74–0.84). Daily survival was positively related to increased river level and had a mean increase of 4.06 ± 0.67% for every 0.3-m increase in the Illinois River level at low river levels (1.5–3.0 m) and a mean increase of 1.38 ± 0.32% for every 0.3-m increase in the Illinois River level at high river levels (4.0–5.5 m). Average departure date of wood ducks leaving the Illinois River Valley was 27 October (range =13 August–15 December), and adult male wood ducks left the study area 11–16 days earlier than the other age and sex cohorts (H2 = 11.6, P = 0.01). Providing additional waterfowl sanctuaries that contain wooded wetlands, especially in years of low river levels, may increase survival for wood ducks during the postbreeding period.
KW - Aix sponsa
KW - autumn
KW - departure date
KW - home range
KW - movement
KW - resource use
KW - survival
UR - https://www.scopus.com/pages/publications/85203439038
UR - https://www.scopus.com/pages/publications/85203439038#tab=citedBy
U2 - 10.1002/jwmg.22670
DO - 10.1002/jwmg.22670
M3 - Article
AN - SCOPUS:85203439038
SN - 0022-541X
VL - 89
JO - Journal of Wildlife Management
JF - Journal of Wildlife Management
IS - 1
M1 - e22670
ER -