Michigan 2013 Grouse Forecast

Michigan 2013 Spring Breeding Surveys

Ruffed Grouse Drumming Survey

Ruffed grouse drumming counts were conducted statewide 
along 97 survey routes during April and May 2013. 
There was an average of 10.7 drums heard per routes 
statewide, a 13 % decline from 2012 (12.3) average

(Figure 8). 

Highest drumming counts were in Zone 1 
(Upper Peninsula; 14.4), following by Zone 2 
(Northern Lower Peninsula; 9.4) and Zone 3 
(Southern Lower Peninsula; 6.4) (Figure 7).

In 2012, 103 survey routes were conducted statewide and 
paired t - tests were performed to statistically compare 
data from 87 identical routes run in both 2012 and 2013. 

Statewide there was a 10.3 % decrease 
(n=87; t=1.15 , P=0.25) in the average number of 
drums heard per route between 2012 (11.8) and 2013 
(10.6). Analysis at the regional scale indicated there 
was no significant difference (n=26; t=0.82 , P=0.41) 
in the number of drums heard per route in Zone 1 
(Upper Peninsula) between 2012 (17.4) and 2013 (14.9). 
There was no significant change in the average number 
of drums heard per route in Zone 2 
(Northern Lower Peninsula)

between 2012 (9.9) and 2013 (9.1; n=53 ; t= 0.90 , P=0.38 ).

In zone 3, there were 8 routes conducted in both 2012 
and 2013. Due to the low sample size, statistical analysis 
at the Zone 3 regional scale is not appropriate.

See the Michigan DNR Report for the full study

Michigan Preliminary Grouse Drumming Results for 2011 - Counts Are Up

Ruffed grouse drumming counts were conducted statewide along 103 survey routes during April and May 2011 (Figure 1). There was an average of 14.7 drums heard per route statewide. Highest drumming counts were in the Zone 1 (Upper Peninsula; 20.9), followed by Zone 2 (northern Lower Peninsula; 11.3) and Zone 3 (southern Lower Peninsula; 5.7; Fig. 1). Zone boundaries are shown in Figure 2.

In 2010, 106 survey routes were conducted statewide and paired t-tests were performed to statistically compare data from 97 routes run in both 2010 and 2011. Statewide there was a 20% increase (n=97; t=2.3; P=0.02) in the average number of drums heard per route between 2010 (12.5) and 2011 (15.0). Analysis at the regional scale indicated there was no significant difference (n=47; t=0.6, P=0.55) in the number of drums heard per route in Zone 2 (northern Lower Peninsula) between 2010 (10.8) and 2011 (11.6). However, there was about a 37% increase in the average number of drums heard per route in Zone 1 (Upper Peninsula) between 2010 (15.3) and 2011 (20.9; n=41; t=3.0, P=0.004). In Zone 3, there were 9 routes conducted in both 2010 and 2011. Due to the low sample size, statistical analysis at the Zone 3 regional scale is not appropriate.

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