112 



THE GAME BREEDER 



and new grounds can be created. This 

 means much in the effort to preserve our 

 valuable wild ducks. In the present cir- 

 cular it is proposed to give a brief state- 

 ment of the value of the three plants 

 as duck food, to show by means of de- 

 scription and illustration how each may 

 be recognized, and to explain where and 

 how each may be propagated. 



Pondweeds. 



Referring to the tabulation of duck 

 food (above), it will be seen that pond- 

 weeds (Potamogeton) compose a greater 

 percentage of the food of the 16 species 

 there mentioned than wild rice and wild 



Thus it constitutes a slightly greater pro- 

 portion of the subsistence of the bird 

 than wild celery. The importance of this 

 plant was pointed out several years ago 

 by Mr. H. L. Skavlem, of Janesville, 

 Wis., who found that at Lake Kosh- 

 konong its tubers formed from 60 to 80 

 per cent, of the canvasback's food. 



Besides the tubers on the roots, some 

 pondweeds have winter buds among the 

 leaves, and these, as well as the seeds, 

 rootstocks, and indeed the whole plant, 

 are eaten by ducks. As many as 350 

 - tubers and no fewer than 560 seeds 

 have been found in single stomachs. 

 Pondweeds are really staple food for 



Percentages of the food of sixteen species of wild ducks provided by wild rice, zvild celery, and 



pondweeds. 



Common na)ne. 



Mallard 



Black duck 



Gadwall 



Baldpate.. 



Green-winged teal 



Blue-winged teal 



Shoveler 



PiDtail 



Wood duck 



Redhead 



Canvas back 



Scaup, or bluebill 



Lesser scaup, or bluebill.. 



Goldeneve 



Bufflehe'ad.... 



Ruddy duck 



Average. 



Scientific name. 



A nas platyrfiynehos 



Anas rubripes 



Chaulclasmus streperus . 



Mareca americana 



Nation carolinense 



Querquedula discors 



Spatula clypeata 



Dafila acuta 



Aixsponsa 



Mania americana 



Marila I'allisneria 



Marilamarila 



Marila affinis 



Clangulac. americana ... 



Charitonetta albeola 



Erismatura jamaicensis . 



Number 

 of stom- 

 achs ex- 

 amined. 



209 

 51 

 37 

 30 



120 

 86 

 49 

 67 

 75 

 60 

 60 

 67 



126 

 23 

 36 

 41 



Per cent of total contents composed of- 



Wild 

 rice. 



17. 13 

 12.05 



7.16 

 4.56 

 3.46 



4.95 

 11.62 

 4.41 

 .33 

 1.26 

 7.49 



2.22 



Wild 

 celery. 



2.48 

 2.37 



10.00 

 .69 

 .20 



1.80 



3.17 



11.71 



23.71 



14.46 



17.53 



2.95 



5. 66 



9.54 



4.78 



6.65 



Pond- 

 weeds. 



12. 07 

 S.35 



17.64 



13. 71 

 10.32 



9.83 



7.83 



13. 39 



0.72 



24.38 



42.35 



23.20 



8.18 



6. 50 



4.40 



12.50 



13.88 



Total of 

 the three. 



32.28 

 22.77 

 17.04 

 30.87 

 15.57 

 13.49 



7.83 

 20.14 

 21.51 

 40.50 

 60. 39 

 38.92 

 33.20 



9.51 

 12. ,34 

 22.10 



25. 31 



celery together. This is owing to the 

 wider distribution of pondweeds, allow- 

 ing ducks to feed on them in winter as 

 well as during migration and in the breed- 

 ing season. There are no fewer than 38 

 species of pondweeds in the United 

 States, of which at least 9 (figs. 9-17) 

 are of practically universal distribution. 

 One of the latter number, the fennel- 

 leaved or sago pondweed (P. pectinatus, 

 fig. 17), produces numerous tubers (fig. 

 18) upon the rootstocks, which are 

 eagerly sought by certain ducks. 



This one species makes up five-eighths 

 of the whole amount of pondweeds eaten 

 by the canvasback and more than a 

 fourth of the entire food of the bird. 



ducks, and nothing is more common in 

 the stomachs than the seeds of these 

 plants. 



As mentioned above, there are many 

 species of pondweeds, and they present 

 quite a diversity of forms. Illustrations 

 (figs. 9-17) of the 9 species of general 

 distribution serve to show the general 

 appearance of some of these plants. All 

 Potamogetons are eaten by clucks, and 

 any one of them would be a valuable 

 acquisition for a ducking ground. 



The pondweed illustrated by figure 14- 

 (Potamogeton perfoliatus) is known as 

 redhead or duck grass, and is an impor- 

 tant duck food, said to be especially at- 

 tractive to redheads. We have found 



