18 BULLETIN 672, U. S. DEPARTMENT OP AGRICULTURE. 



storm that covered the mountains with snow. After the 3torm the 

 sun oame out warm and bright, and a number of the swallows gath- 

 ered about the shallow pools on the barren flats. Apparently in play, 

 they were forming mud pellets such as they use in building their 

 nests. The strong alkalis concentrated in this surface mud affected 

 many of these birds severely, so that during the next few days I picked 

 up several swallows about the laboratory unable to fly, and there is no 

 means of telling how many escaped unnoticed in the salt grass The 

 affection in the cases examined was similar to that found in the ducks. 

 Though mortality among ducks and other birds ceases when the 

 fall water fills the rivers, yet many birds are still more or less seriously 

 affected. During the hunting seasons in the years 1914 to 1916, 

 inclusive, the writer examined many hundreds of ducks as they were 

 cleaned and prepared for the market in the duck houses at the gun 

 clubs on Bear River. In birds examined during the first week or 10 

 days there was severe irritation in the intestinal tract in almost every 

 case. After October 10, there was a great influx of migrants from 

 the north. These birds were shot in many cases before they had 

 been long on the marshes, but still many of those examined had the 

 intestine much irritated. In cases of severe affection that do not 

 terminate fatally individual ducks use up their stores of fatty tissues 

 while recovering from the duck sickness and become thin and poor 

 in flesh. When shot in this condition they are culled by the duck 

 pickers as unfit to eat. I was told by men familiar with conditions 

 that many more ducks are thrown out now than previous to 1910. 

 Certain observations made by the writer seem to prove this. In 

 1916 sick ducks were last found in numbers in the eastern end of 

 North Bay. After the hunting season opened a larger percentage of 

 culls was noticed among the birds killed in this area than elsewhere. 



REMEDIAL MEASURES. 



Fresh water is the onty agency that has been found of value in 

 combating the duck sickness. Birds slightly affected, and even 

 many entirely helpless, recover in almost all cases when given 

 plenty of moderately fresh water to drink. With an abundance 

 of good water in the marshes sick ducks are infrequent, as when the 

 bays are well filled and well drained many birds that become affected 

 recover in a few days. For remedial agencies, therefore, measures 

 must be adopted that tend to supply fresh water or to drive ducks 

 out from areas where they are liable to obtain alkalis in harmful 

 quantity. Three methods of treatment that promise success in 

 dealing with this trouble are concerned with (1) increasing summer 

 water in streams, (2) draining affected areas, and (3) collecting sick 

 birds for treatment. These methods as outlined in the following 

 pages will prove applicable also in areas outside of Utah where birds 

 are subject to the duck sickness. 



