90 



The Canadian Field-Naturalist 



[Vol. XXXVI 



increase of land-birds but there was an invasion 

 of water birds as well. While the growth of rural 

 districts is favourable to the increase of various 

 species of land birds, the reclamation of marsh- 

 land usually connected with such development 

 entails the reduction of water-birds on a large 

 scale. In this case there was a reversal of the 

 usual process caused by the creation of an arti- 

 ficial lake to hold the Company's water supply. 



This reservoir, known as Lake Newell, lies in a 

 natural basin five miles south of Brooks; its area 

 is approximately twelve thousand acres and its 

 maximum depth twenty-seven feet. The water 

 is taken from the Bow River near Bassano and 

 reaches the reservoir through two main canals, 

 one entering at the north end and one at the south. 

 The surrounding land is non-irrigable and there 

 are no farms near the lake. Apart from the 

 spillways and the few concrete dams which link 

 up the ridges forming its shore line, Lake Newell 

 has not the appearance of an artificial lake. The 

 littoral is barren and sandy without brush or tree 

 growth and at the time of my visit (June 29th 

 and 30th, 1921) the sparse growth of short grass 

 was burnt crisp while the low Artemisia and the 

 several species of cacti indicated the prevailing 

 desert conditions. 



At first glance this arid waste surrounding the 

 lake seemed most unfavourable for the study of 

 bird life, but close inspection showed that various 

 modifications, not at first apparent, had taken 

 place during the seven years of the lake's existence. 

 Potamogeions and other water-weeds eaten by 

 Ducks have drifted in through the canals and in 

 the warm fresh water they have thrived and spread 

 to all parts of the lake. Masses of these weeds 

 that have been uprooted by storms frequently 

 cause trouble by drifting against the mechanism 

 of the headgates and interfering with their opera- 

 tion. Accompanying these water-plants have 

 come their attendant insects and mollusca. Fish 

 also have entered the lake through the same 

 channel and several species are now well estab- 

 lished. With this abundant focd supply there 

 naturally followed an invasion of water fowl. 

 The attraction of the fresh water and the insect 

 and plant food was so great that these water birds 

 remained to breed in greater numbers each year, 

 adapting themselves to the unfamiliar environ- 

 ment. I found that Ducks were nesting under an 

 artemisia, or a Russian thistle, or in any slight 

 cover available on the barren shores of the lake. 

 A Blue-wingtd Teal built her nest on one of the 

 trails by the lake where a shallow depression 

 between the waggon ruts ofi"ered an inducement. 

 The bird flushtd from almost under the bonnet 

 of the car as we jolted along the rough trail — 

 probably she was familiar with this form of 



disturbance. The seven eggs appeared hard set, 

 so let us hope her good luck held to the end. 



Scattered over the lake are a number of small 

 flat islands — hill summits before the lake was 

 made. The majority of these are less than an 

 acre in extent and have obtained full measure of 

 benefit from the life-giving water. This is mani- 

 fested by the luxuriant growth of thistles, mustard, 

 lambs' quarters, and other imported weeds — a 

 thick jungle of vegetation. Poplars and willows 

 are also springing up and their growth should be 

 phenomenal. On these islands, free from moles- 

 tation by predatory animals, the greater propor- 

 tion of water fowl have chosen to breed. I was 

 familiar with Pelican colonies, with Gull and Tern 

 colonies, but never before had I seen breeding 

 colonies of Ducks. For on several islands Ducks' 

 nests were so plentiful and so close together one 

 had to walk carefully to avoid treading on the 

 eggs. On one island of approximately one-third 

 of an acre I counted thirty nests of the following 

 species: White-winged Scoter, Scaup, Pintail, 

 Gadwall, Mallard and Baldpate. All these nests 

 contained the full complement of eggs and all 

 showed indications of being well advanced in 

 incubation. Several of the nests contained eggs 

 of two species, an indication of the crowding on 

 the island. A Gadwall's nest contained six 

 Gadwall eggs, two Mallard eggs, one downy 

 Gadwall and one downy Scaup. The Scaups 

 have an unpleasant habit of fouling their nests 

 when they are flushed and one wonders if this is 

 done as a protection for their eggs and against 

 what enemy. It was too late in the season to see 

 breeding Canada Geese, but one old nest was 

 found and I was informed that five or six pairs 

 bred on the lake. One pair nest on each island 

 in splendid isolation. I was told they will not 

 tolerate any Ducks in their vicinity. If this be so 

 it is fortunate that they are such early breeders. 

 Waders were represented on this island by two 

 pairs of Avocets, two pairs of Killdeer and one 

 pair of Spotted Sandpipers. 



Another of the islands visited contained a 

 breeding colony of Common (?) Terns, estimated 

 at two hundred pairs, three pairs of Avocets, and 

 as many breeding Ducks as were found on the 

 first island. From a distance the shore of this 

 island appeared snowy white with Gulls, which on 

 on closer inspection, proved to be Franklin's. As 

 the boat drew near the island they rose in three 

 sections, circled over the boat several times, and 

 then flew to an adjacent island where they settled 

 on the beach to rest as before. These birds were 

 about twenty miles from their breeding ground, 

 which is established in a marsh covering several 

 sections, southeast of Lake Newell. They were 

 all adults and their inactivity in the height of the 



