applications of a mixture of the sodium salt 

 of fenac with 2,4-D or other phenoxy 

 compounds also were effective. Floating 

 mat growth was not controlled by these 

 methods. 



Management implications of alligator- 

 weed control were investigated through 

 study of plant invaders of areas from which 

 alligatorweed had been removed. Weather- 

 wax ( Hydrochloa carolinensis ), which is a 

 common invader in many areas, proved to 

 be attractive to ducks and geese on areas 

 reflooded in early winter. 



Studies in management of waterfowl food 

 plants showed that the germination of wild 

 rice can be extended over a 2-year period 

 by planting mixed lots of seeds subjected 

 to different conditioning treatments. One 

 portion, held in water at normal refriger- 

 ator temperatures near 42° F., germinates 

 the year of planting. The other portion, 

 kept in water at normal roonn temperatures 

 of about 72°F., does not germinate until 

 the second year. At room temperatures, 

 water must be changed frequently during 

 the first 30 days to prevent undue putre- 

 faction. Other plant management studies 

 showed that attractive orchard grass and 

 clover meadows can be established on 

 droughiy and infertile sites by use of a 

 moderate layer of ripe seed mulch har- 

 vested in early July and spread in late 

 August. 



Mosquito control--wildlife relations. -- 

 Although drainage of marshes and certain 

 applications of chemical insecticides for 

 mosquito control nnay be harmful to water- 

 fowl and other forms of fish and wildlife, 

 the controlled flooding of marshes for the 

 same purpose may enhance these resources. 



managed water level fluctuations will be 

 compared on certain areas. Nine times as 

 many water and marsh birds were observed 

 in the impounded marshes as in the unim- 

 pounded ones. Coots, ducks, herons, and 

 shorebirds benefited most from the im- 

 poundments. 



Other Migratory Bird Studies 



In this budget subactivity of the Branch 

 of Wildlife Research are included studies 

 of doves, woodcock, and cranes, and bird- 

 banding services for all North Annerican 

 migratory birds, game and nongame. 



Doves. --Steps \vere taken to implement 

 the mourning dove management and re- 

 search program, developed jointly with the 

 International Association of Game, Fish, 

 and Conservation Commissioners last year, 

 by employing two additional dove biologists. 

 One is engaged in summarizing accumu- 

 lated banding data, and the other is study- 

 ing methods of improving population 

 inventory techniques. Several dove research 

 projects are being conducted by Cooperative 

 Units. 



Results of a study of penned mourning 

 doves at the Missouri Unit indicate that 

 mating is the major influence on cooing 

 frequency of a male dove. Tenfold increases 

 in frequency of coos resulted when penned 

 females were removed from their mates. 

 When the females were returned, cooing 

 dropped to the previous levels, if pair 

 bonds were restored. If these results can 

 be extended to the field, then any precise 

 interpretation of mourning dove call- count 

 data for inventory purposes requires in- 

 formation on the ratio of mated to unmated 

 birds. 



Studies of the effects of mosquito control 

 impoundments on wildlife were begun under 

 contract by the Florida State Board of 

 Health. Three study areas, each in a 

 different marsh type, were selected along 

 the eastern coast of Florida. Replicated 

 natural and impounded marshes have been 

 included in the experinnent. Natural and 



In Pennsylvania, the Cooperative Unit 

 initiated a study to determine the impor- 

 tance of conifer groves to mourning doves. 

 Preliminary data indicate that the conifer 

 groves are utilized heavily as roost sites 

 and for nesting. Gunning pressure also is 

 heavy at well-established dove roosts. 



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