Original Article Quantifying Moonlight and Wind Effects on Flighted Waterfowl Capture Success During Night-Lighting TORE BUCHANAN, 1 Ontario Ministry of Natural Resources and Forestry, Wildlife Research and Monitoring Section, 2140 East Bank Dr, Peterborough, ON K9J 7B8, Canada RODNEY W. BROOK, Ontario Ministry of Natural Resources and Forestry, Wildlife Research and Monitoring Section, 2140 East Bank Dr, Peterborough, ON K9J 7B8, Canada MATTHEW P. PURVIS, Ontario Ministry of Natural Resources and Forestry, Wildlife Research and Monitoring Section, 2140 East Bank Dr, Peterborough, ON K9J 7B8, Canada J. CHRIS DAVIES, Ontario Ministry of Natural Resources and Forestry, Wildlife Research and Monitoring Section, 2140 East Bank Dr, Peterborough, ON K9J 7B8, Canada ABSTRACT Night-lighting is a common technique used to capture waterfowl, upland birds, and waterbirds. The method involves using bright artificial light and a steady loud noise to startle and confuse birds, allowing close approach and capture by hand or with a long-handled dip-net. Many researchers using this technique have noticed that moon phase (or relative brightness) and weather conditions can affect capture rates. Using 16 years (1996–2011) of night-lighting capture data collected during the Ontario Waterfowl Airboat Banding Program, Canada, the effects of moon phase and wind speed on capture rates for flighted waterfowl were quantified. Increasing moon brightness had a negative effect on capture rates for all species analyzed (mallard [Anas platyrhynchos], wood duck [Aix sponsa], blue-winged teal [Anas discors], green-winged teal [Anas crecca], ring-necked duck [Aythya collaris], hooded merganser [Lophodytes cucullatus], and American black duck [Anas rubripes]), with an increasing rate of decline in capture rates when the moon was >75% full (i.e., a bright night). Attempting waterfowl capture when the moon was >75% full led to 2-fold cost increase per bird captured over the average cost per bird captured. Increasing wind speed was positively correlated with capture rate for some species, but had no significant effect on capture rate for most species analyzed. Night- lighting capture of flighted waterfowl should be planned primarily during dark to moderately dark nights to maximize capture efficiency and reduce costs. Ó 2014 The Wildlife Society. KEY WORDS airboat, banding, capture, moon phase, night-lighting, waterfowl. Night-lighting as a method of capturing waterfowl, water- birds, and upland birds has been used by researchers and managers since the 1950 s (Lindmeier and Jessen 1961, Cummings and Hewitt 1964, Reeves 1966, Drewien et al. 1967). It was also used historically as a subsistence harvest method by indigenous North Americans on the Pacific coast, Northern Iranians on the Caspian Sea salt marshes, and by commercial waterfowl harvesters and poachers on the North American Atlantic coast (it was noted that they used the technique on the darkest nights; Reeves 1966). In general terms the technique involves the use of artificial light and loud constant noise to startle and confuse birds, making them easier to approach and capture. Researchers have noted the negative effect of moonlight on waterfowl approachability and capture rates (Cummings and Hewitt 1964, Reeves 1966; Snow et al. 1990; King et al. 1994). In a limited analysis with a relatively small sample size, Reeves reported capturing 5.5 birds/crew-hour during bright nights with full or nearly full moon as compared with 14.6 birds/crew-hour during low moon phase—more than a 2-fold difference. We used 16 years of data from the Ontario Waterfowl Airboat Banding Program to robustly quantify the effect of ambient light from the moon and wind speed on flighted waterfowl capture rate. The relative cost of capture and recommended levels of moon light to maximize efficiency were also compared. STUDY AREA The study area consisted of 35 marshes located in Ontario, Canada. The waterfowl roosting areas of these marshes ranged from 20 ha to 360 ha in size ( x ¼ 120 ha) and were characterized by shallow water depths (<2 m), organic substrate with emergent aquatic vegetation cover which varied by site but was most often dominated by wild rice (Zizania palustris), common cattail (Typha latifolia), picker- elweed (Pontederia cordata), and white water lily (Nymphaea odorata). Received: 16 December 2013; Accepted: 12 August 2014 1 E-mail: tore.buchanan@ontario.ca Wildlife Society Bulletin; DOI: 10.1002/wsb.514 Buchanan et al.  Moonlight and Wind Effects on Waterfowl Capture 1