WILD DUCKS OF THE BEAR RIVER MARSHES, UTAH. 19 



In a conservative enumeration made during May and June, 1916, 

 of the eleven species of breeding ducks, 3,650 pairs were counted, 

 and it is believed that this number represents between 60 and 100 

 per cent of the total number of breeding ducks occurring there that 

 season. Allowing 5 young reared to maturity as the average for 

 each pair, and considering 1916 as an average season, it may be 

 stated that between 25,000 and 30,000 wild ducks native to the marsh 

 are to be found there at the close of the breeding period. 



In addition, a large number of other ducks come in after the nest- 

 ing season in order to molt, and, after renewing their feathers, to 

 rest in the shelter of the marshes until fall. These nonbreeding 

 birds appear during the first part of June and are present in large 

 numbers by the first of July. They increase through July and 

 August, but during the first week in September a large proportion 

 migrate to other regions. Other ducks continue to come in from the 

 north, however, and by the opening of the hunting season on 

 October 1, a full complement again is present. 



Of the duck foods attractive to these birds, two plants, the sago 

 j)ondweed and the tule, or bayonet grass, both occurring in abun- 

 dance, furnish a large part of the vegetable portion ; in all, 49 plants 

 were found available as duck foods. In addition, the brine shrimp 

 and the immature stages of the alkali flies, both of which swarm in 

 the salt water below the marsh, are relished by certain ducks. 

 Though in other localities it has been possible in many instances to 

 add certain growths to the species already present, the food plants 

 occurring on the Bear River marshes seem to comprise the most 

 valuable of those capable of being propagated under the prevail- 

 ing alkaline conditions of soil and water. Wild celery might form 

 a useful addition, but its introduction would be in the nature of an 

 experiment. 



The practice of burning the marsh in fall .and winter destroys 

 the seeds held in the seed heads of the tules, a valuable supply of 

 food available to the ducks when they return to the marsh in spring. 

 Cutting wild hay along the banks of the river and the larger over- 

 flows before July 20 lays nests open to attack or may destroy them, 

 together with the brooding birds. This damage would be obviated 

 if haying were begun later, or if a strip at least 100 feet wide were 

 left uncut along the stream banks. These_ measures should be taken 

 where possible. Among other factors contributing to the destruc- 

 tion of ducks may be mentioned magpies, coyotes, and the domestic 

 cats which run wild on the marsh, and California and ring-billed 

 gulls. The gulls kill many ducks helpless from the duck sickness 

 that otherwise might recover, and in addition are more or less of a 

 nuisance in the shooting season, as they attack and mutilate many 

 ducks that have been killed by hunters. 



