On the basis of table 15-7, duck broods from 1956 to 1965 were most abundant 

 in fresh meadows (1.91 in Wildlife Managment Unit 8, and an average of 0.85 in 

 the three Wildlife Management Units combined). Duck broods were most abundant 

 in deep fresh marshes from 1966 to 1976 (3.34 in unit 6, 2.24 in unit 7, 0.81 

 in unit 8, and 2.63 for the three units combined), but no breed counts were 

 made in fresh meadows during that period. Abundance declined slightly from 

 0.46 to 0.43 for the three regions in the two time periods, and Statewide 

 averages declined from 0.21 to 0.13. Causes for these differences are 

 unknown. An average of 5 ducklings fledged per brood was estimated for 

 waterfowl. This estimate is considered to be conservative, generally constant 

 from year to year, and somewhat higher than for the eider. 



The waterfowl breeding habitat by wetland type for the coastal units, and the 

 Statewide acreage and number of areas are summarized in table 15-8. Table 15- 

 9 compares the National Wetlands Inventory Classification scheme with the 

 wetland types identified by the MDIFW. Brood abundance from 1966 to 1976 is 

 used to calculate estimated annual brood production (table 15-7) . The data 

 indicate that 64% of the annual brood production of Maine (exclusive of 

 eiders) is in the coastal units. The coastal Wildlife Management Units 

 produced an average of 67,500 ducklings (exclusive of eiders) annually from 

 1966 to 1976. No known major changes have occurred since. Further 

 extrapolation of these data would probably be subject to considerable error. 



The fledging survival for eiders is difficult to determine due to their 

 creching behavior (broods combine and are reared by a female) and because 

 brood rearing takes place in open coastal waters, usually adjacent to islands. 

 The smaller clutch size of the eider (4 to 6 eggs) plus the exposure of newly 

 hatched ducklings to gull predation and other hazards of the coastal 

 environment suggest fewer than 4 ducklings per brood live to the flight stage. 

 Assuming 3 fledglings for the 11,500 broods, an estimate of 34,500 young 

 eiders survived. 



Migration and Staging Areas 



Migratory waterfowl tend to concentrate at certain locations and exhibit 

 relatively strong habitat preferences. Most of the southerly migration takes 

 place in August through November. Some stay a few days, others remain for a 

 month or two. It is characteristic of the dabblers (black ducks, mallards, 

 wood ducks, green-winged teals, and blue-winged teals) to concentrate in 

 relatively protected areas near an abundance of food. These are called 

 staging areas. Migratory waterfowl in the fall are frequently composed of a 

 high percentage of young birds (only a few months old) . 



Merrymeeting Bay in region 2 is one of the largest staging areas in the 

 northeast Atlantic. Each autumn and spring this bay supports up to 40,000 

 waterfowl at one time. Concentrations begin to build in mid-August and last 

 until the hunters or weather sends them southward. Black ducks and green- 

 winged and blue-winged teal are most common but a number of other waterfowl 

 species have been recorded, including the fulvous whistling duck. The 

 attractiveness of Merrymeeting Bay to waterfowl is due to the remarkable 

 abundance of high quality aquatic vegetation. Among the latter, wild rice 

 ( Zizania aquatica ) is of prime importance. 



15-28 



