Nest parasitism in dabbling ducks is uncommon. Northern Shovelers (Anas clypeata) are considered infrequent parasites and Blue-winged Teal (A. discors) are rarely hosts to nest parasitism. We documented parasitism of a Blue-winged Teal nest by a Northern Shoveler. We reviewed 3,003 records from nests located in 1994 to 1997 in North Dakota and documented only one duck nest parasitized by a Northern Shoveler. Only nine of 1,494 Blue-winged Teal nests were parasitized. We found no evidence of Northern Shovelers parasitizing Blue-winged Teal nests in our nest records and only one account in the literature. Received 12 January 2010. Accepted 24 March 2010.

We conducted 262 call-broadcast point-count surveys (1-6 replicate surveys on each of 62 points) using standardized North American Marsh Bird Monitoring Protocols between 31 May and 7 July 2006 on St. Vincent National Wildlife Refuge, an island off the northwest coast of Florida. We conducted doubleblind multiple-observer Surveys, paired morning and evening Surveys, and paired morning and night surveys to examine the influence of call-broadcast and time of day on detection probability. Observer detection probability for all species pooled was 75% and was similar between passive (69%) and call-broadcast (65%) periods. Detection probability was higher on morning than evening (t = 3.0, P = 0.030) or night (t = 3.4, P = 0.042) surveys when we pooled all species. Detection probability was higher (but riot significant for all species) on morning compared to evening or night Surveys for all five focal species detected on surveys: Least Bittern (Ixobrychus exilis). Clapper Rail (Rallus longirostris), Purple Gallinule (Porphyrula martinica), Common Moorhen (Gallinula chloropus), and American Cool (Fulica americana). We detected more Least Bitterns (t = 2.4, P = 0.064) and Common Moorhens (t = 2.8, P = 0.026) on morning than evening surveys, and more Clapper Rails (t = 5.1, P = 0.014) on morning than night surveys.

The rapid biofouling of fish-cage netting in Tasmania, Australia, necessitates the frequent changing of nets for on-shore cleaning. To reduce the cost associated with this capital- and labour-intensive process, a prototype underwater net cleaner was designed and constructed for the Tasmanian Atlantic salmon industry. This study describes trials aimed to determine the efficacy of this prototype, and to identify areas for improvement. The reduction in open area of netting mesh due to fouling growth, together with subsequent increases in open area after cleaning, were monitored by image analysis of underwater photographs. The preferential removal of larger fouling species and the occurrence of resistant species were documented. The design of the cleaning head and displacement of netting away from the cleaner reduced the severity of scrubbing, limiting fouling removal. However, with increased contact between the brushes and netting the cleaner prevented significant fouling development over a 10-week period, Scanning electron microscopy was used to identify the extent of residual fouling after cleaning, and the difficulty of removing fouling from crevices in the netting surface and from the sides of netting bars. The system can be highly effective, but the current design for presentation of the brushes greatly limits cleaning efficacy, The research has identified areas for design improvement, the problems associated with residual fouling and regrowth and the requirements for effective in situ net cleaning. (C) 1997 Elsevier Science B.V.