FOOD AND FEEDING BEHAVIOR 



Here again, the amount of information given varies depending on the rela- 

 tive importance of the species in the southeastern marine avifauna and on the 

 amount of information available. In all cases we gave at least a brief general 

 statement on the types of foods eaten and the primary feeding methods. In some 

 instances we included more detailed information on food habits, briefly abstract- 

 ing recent studies and indicating proportions of different varieties of foods 

 eaten. For a few species for which much recent information is available, we 

 summarized food habits by geographic area. For species whose food habits have 

 been well documented, we pointed out differences in food habits of adults and 

 young, and commented on seasonal variation of food habits as well as difference 

 in foods eaten in different habitats. We gave little specific data on food 

 habits in southeastern waters because little or nothing is known of the diet in 

 this area. 



IMPORTANT BIOLOGICAL PARAMETERS 



This section presents basic information to allow biologists to infer the 

 effects of developing oil resources on populations and to help choose alternate 

 courses of action in the planning of such developments. We include this infor- 

 mation for only thirteen of the species discussed in this report because these 

 species are those most likely to be affected by oil in southeastern waters. 

 Much of the information is derived from studies conducted outside the southeast 

 because only a few species of waterfowl breed in the southeast. 



The data in this section consist of brief summaries of the egg-laying peri- 

 od, mean clutch size, incubation period, hatching success, fledging success, age 

 at first breeding and at fledging, mortality of eggs and young (including infor- 

 mation on renesting) , maximum natural longevity, and weight. Data on egg laying, 

 incubation period, and age at fledging allow one to estimate when birds breeding 

 within the study area are most vulnerable to disturbance. Information on mortal- 

 ity and renesting describes factors that lower reproductive success and suggest 

 the potential for recovery following a nesting failure. Data on clutch size and 

 hatching and fledging success allow an estimate of productivity. Detailed life 

 table data are unavailable for most of the species covered in these reports. 

 Consequently, we have provided figures for known maximum natural longevity that 

 will in some instances allow a crude comparison between species of the total re- 

 productive potential. The maximum natural longevity is given in terms of "esti- 

 mated minimum age" in years and months following Kennard (1975), and may list 

 information based on banding in the United States and Canada and In the Old 

 World. Finally, we include information on weights, since this and population 

 data given elsewhere in the report will allow planners to compare species in 

 terms of biomass affected as the result of any given oil-related activity. 



The quality and quantity of this information vary from species to species 

 and from topic to topic. Many of the waterfowl treated in the second volume of 

 this report are among the best-studied wild birds. For such species we make no 

 attempt to give all the information available, but confine ourselves to brief 

 summaries. For other species, particularly some of the seaducks , information 

 is sparse or nonexistent. We have indicated this in each account. 



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