Hair (1979) found no significant difference between the sexes in the rate of 

 diving or in diving time. 



Lesser Scaup feed on a variety of foods but animal food predominates in 

 most areas. Studies summarized by Bellrose (1976) report animal food making 

 up as little as 1.0% of the diet (in North Carolina) to as much as 99.9% (off 

 coastal Louisiana). Plant foods of particular significance in one area or an- 

 other include pondweeds ( Ruppia , Najas , Zannichellia , Zostera , and especially 

 Potamogeton spp.), Scirpus sedges, wild celery ( Vallisneria spiralis ), sea let- 

 tuce ( Ulva lactuca ) , muskgrass ( Chara ) , coontail ( Ceratophyllum ) , and shoal- 

 grass ( Diplanthera ) (Bellrose 1976, Palmer 1976b). 



Animal foods are also varied. Molluscs are frequently the most consumed 

 food, according to studies cited by Palmer (1976b) and Bellrose (1976). Vari- 

 ous aquatic insects may also be important in the diet , and fish and Crustacea 

 are also eaten. Amphipods are apparently the principal food in breeding areas 

 and are also much eaten by migrants. Pelecypods, gastropods, or both may be 

 the principal foods eaten in other areas (Palmer 1976b). More specific lists 

 of foods eaten outside the southeast are found in Palmer (1976b) and Bellrose 

 (1976). We give below summaries of studies of food habits of Lesser Scaup in 

 the southeast. 



North Carolina Quay and Critcher (1965) reported the gizzard contents 

 of five wintering scaup collected on Currituck Sound, but they did not indicate 

 which species of scaup was involved. Bellrose (1976) assumed, or independently 

 learned, that these were Lesser Scaup, but the identification is still in doubt. 

 In any case, these Aythya had largely fed on the seeds and vegetative parts of 

 pondweeds ( Potamogeton sp. - 57.3% by volume) and widgeongrass ( Ruppia mari - 

 tima - 46.8%). Other plant foods identified included waxmyrtle ( Myrica - 10.0%) 

 and the vegetative parts of southern naiad ( Najas guadalupensis - 5.0%). 



South Carolina The crop and gizzard of a single wintering Lesser 

 Scaup collected near Georgetown in coastal South Carolina were nearly empty 

 (Conrad 1965). Conrad found only trace amounts of six plants: widgeongrass, 

 swamp and Pennsylvania smartweeds ( Polygonum hydropiperoides , P_. pensylvanicum ) , 

 aneileraa ( Aneilema keisak) , common spikerush ( Eleocharis palustris ) , panicgrass 

 (Panicum sp.), and a sedge ( Carex sp.). 



Kerwin and Webb (1972) reported the foods eaten by 15 scaup in coastal 

 South Carolina. Their sample was comprised of both Lesser and Greater Scaup, 

 so we do not summarize their information on food habits here. Bellrose (1976) 

 also attributed this report to Lesser Scaup, which makes the validity of the 

 report made in North Carolina (see above) more suspect. 



Landers et al. (1976) reported foods eaten by 21 Lesser Scaup at coastal 

 impoundments in South Carolina, but they listed only the plants eaten. Plant 

 material comprised 89.8% (by volume) of the diet and consisted almost solely 

 of two plants, widgeongrass (67.1%) and saltmarsh bulrush ( Scirpus robustus - 

 20.0%). 



Louisiana Chamberlain (1959) examined the gizzards of 9 scaup col- 

 lected on Rockefeller Refuge in Cameron Parish. He gave no detailed list of the 

 foods eaten, but indicated that plant seeds occurred in all gizzards, insects 



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