Vol. XXXVIll 



L920 



Wetmore, Birds of Lake Burford, N. Mex. 2i2iO 



General Conditions 



The water of Lake Burford, while not bad, was at the same time 

 distinctly alkaline as has been previously stated, so that the aquatic 

 and semiaquatic vegetation was limited to those forms of plant life 

 characterized by a marked tolerance for alkali. The round-stem- 

 med bulrush or tule (Scirpus occidentalis) was the most prominent 

 of these. Considerable areas along the south, west and north 

 shores were entirely bare and open but elsewhere this plant formed 

 a growth in the water, extending from the shoreline out for a dis- 

 tance of from one to fifty feet. In general it grew as a fringing 

 band from six to ten feet broad (Plate VII, fig. 2). The dead 

 stems of this tule formed dense masses, matted firmly by the 

 winter's snow and ice, to be penetrated and traversed only with 

 much trouble, a safe cover for many nests as the ducks were able 

 to creep in underneath the interlaced stems and here conceal their 

 eggs. On May 24 the new growth was just starting and much of 

 it had been frost-bitten so that the tips showed as brown dead 

 spikes. Two weeks later the new growth was extensive and form- 

 ed an efficient cover (Plate VIII, fig, 1). New clumps were ap- 

 pearing in shallow open water also where all last year's growth had 

 been destroyed by ice so that by the first of July the area covered 

 by this plant must have been extensive. 



Bayonet grass or three-square (Scirpus paludosus) was com- 

 mon and salt grass (Distichlis spicata) was abundant in suitable 

 places along the shore where it grew with foxtail (Hordeum juba- 

 tum). Sage brush {Artemisia tridcntata) covered all of the knolls 

 and rolling slopes, in most places coming down to the beach. A 

 linear leaved pondweed (Potamogeton pectinatus) was the most 

 abundant of the truly aquatic plants and with it, clogging and en- 

 veloping its leaves, were great masses of a green alga. On May 23, 

 when work was begun at the lake, the pondweed was appearing as 

 scattered filaments on the floors of sheltered bays. As the water 

 became warmer this growth increased and by June 18, it had be- 

 gun to appear in large areas at the surface. By July 1, it must 

 have covered practically the entire lake. Ditch-grass (Ruppia 

 occidentalis) was found in the Laguna de la Puerta and a musk- 

 grass (Chara sp.) was common in the spring holes from which we 



