As indicated in the previous report, drought in the eastern parts 

 of these two Mexican States, has greatly reduced the number of fresh- 

 water lakes and ponds available for wintering waterfowl. The present in- 

 vestigation showed the situation to be much worse, more than 90 percent 

 of the inland lakes and ponds being completely dry by midwinter, many of 

 them in this oondition early in the season. Because of the low stage of 

 the Rio Grande, many adjacent oxbow lakes, or "bancos, n were dry or nearly 

 so* These were not replenished until March 27, when an early rise of the 

 river level sent water into old channels and other undiked lowlands. The 

 salt-water lagoons west of the barrier ridge contained seepage water from 

 the Gulf of Mexico but were much reduced in area as compared with 1938-39* 



The Lag-ana Madre itself had a level below that of the previous year 

 because of a series of northers, which blew much water out through the 

 four passes into the Gulf* All but one of these passes are narrow and 

 shallow, so that the volume of water entering the lagoon, even at high 

 tide, was not sufficient to maintain a satisfactory level* As a result, 

 broad bays and other shallow areas near the north and south ends were 

 entirely dry* This condition, however, did not affect the ducks as much 

 as did the lack of fresh-water ponds and lakes on the mainland to the 

 west and on the peninsula and islands to the east* Nevertheless, even 

 in this the worst drought in a score of years, there were some ponds on 

 the mainland near La Carbonera, on the Barreda ranch farther south, and 

 also near Loreto and San Jose* On the peninsula a few ponds and a small 

 marshy area of a few acres remained, but fresh water on the barrier is- 

 lands was apparently limited to a few wells dug for cattle* 



Serious drought extended south at least to northern Vera Cruz* The 

 most recent floods causing water to spill over into the adjacent lagoons 

 and marshes from the Tamesi and Panuco Rivers had been in the fall of 

 1936* Thus, the T uapico lagunas were about as low as at any period old- 

 timers could recall, and large lagunas, as the Champayan, had receded 

 so much that scores of square miles of mud flats, covered with dry aquatio 

 vegetation, surrounded the shrunken water area* 



Despite all these obviously unsatisfactory conditions, the waterfowl 

 that wintered in the region apparently had no difficulty in finding suit- 

 able habitats* So far as oould be determined, there was no limiting fac- 

 tor present that reduoed the carrying capacity below the number of ducks 

 that desired to winter in or temporarily occupy the areas* The potential 

 oarrying capacity for both diving and shoal-water species, was far in ex- 

 cess of the number that actually used it. There was an abundance of 

 ohoioe food plants, including wigeongrass, wildcelery, and pondweeds* 



From a consideration of all the studies made, it was concluded that 

 the total number of ducks wintering in eastern Mexico showed a slight 

 increase over that of 1938-39, despite the fact that certain species, as 

 the gadwall and baldpate, showed from a little to a pronounced decrease. 



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