Ruffed Grouse 157 



The happy medium is the fundamental principle of game ecology, and the basic 

 rule of game management. The skilled manager is one who knows what the 

 happy medium is for each species, and how to get it. 



Winter Losses. A severe sleet is said by Kinzinger to have killed most 

 of the grouse in Oconto, Calumet, and Oconomowoc Counties, Wisconsin, in 

 1917. 1917 was of course a year of cyclic mortality, which leaves an unanswered 

 question whether the loss was caused by the sleet or by disease. The alleged winter 

 loss in Door County in 1902, described by Nelson, mentions dead birds being 

 found on top of the snow. This is some indication of disease, it being the com- 

 mon opinion that grouse dive into the snow -to roost in very severe weather, unless 

 prevented by crust. 



Sutherland reports that near Janesville in Rock County, Wisconsin, "the 

 winter of 1863 killed all the quail and many of the partridges (ruffed grouse). 

 Partridges have stayed scarce ever since." As a matter of curiosity it may be 

 noted that a nine-year cycle, projected backward from the earliest known mor- 

 tality in 1881, would fall in 1872 and 1863. This conjecture of course proves 

 nothing. 



These observations collectively, however, suggest that some of the alleged 

 winter killings may represent cyclic mortality. The ruffed grouse being an habitual 

 budder and roosting under snow, makes it improbable that it is ever devoid of 

 food and roosting shelter, except when heavy sleets crust the snow and also cover 

 all the buds. Whether buds alone are sufficiently nourishing to sustain the bird 

 over long periods remains an open question. 



Predators. Superintendent Hopkins, of the Moon Lake Refuge, Fond du 

 Lac County, Wis., removed 150 horned owls from the refuge during the past 

 three years without perceptibly increasing the resident population of about 20 

 pairs of ruffed grouse. 



Stoddard found the remains of many ruffed grouse killed by goshawks in 

 Sauk County, Wisconsin, during the invasion of 190506 (or 190607). Taxi- 

 dermist Ochsener, of Sauk County, mounted three goshawks in 1927-28. The 

 largest flight he can remember yielded seven, but he cannot date this. 



Harold Wilson, an experienced ornithologist, has seen but one goshawk in 

 Door County, Wisconsin. This was in 1927. 



Taxidermist Slusser remembers only one big flight in Oneida County, Wis- 

 consin. This was 4 or 5 years ago (about 1925). 



H. C. Sturdevant, an experienced ornithologist, has never seen a goshawk in 

 La Crosse County, Wisconsin. 



All known invasions of goshawks in Wisconsin are shown on Chart 8. 



Since ornithologists and taxidermists are the persons most likely to know of 

 goshawk invasions, it would appear from the scarcity of records that invasions are 

 much too local and infrequent to account for the periodic Statewide decimation in 

 ruffed grouse, although goshawks doubtless accentuate the shortages where and 



