Burger 



Chapter 16 



Inland Habitat Associations in British Columbia 



Walbran in 1990. A larger data set (1 1 stations in 1991 and 13 

 in 1992) produced no significant correlations when occupied 

 detections (Pearson correlation, r = -0.081 and -0.271, 

 respectively) or total detections (r = -0.140 and -0.267, 

 respectively; P > 0.05 in all cases) were considered (fig. 4; 

 Burger 1994). The highest detection frequencies were found 

 at sites 8-17.5 km inland. All six nests found in Carmanah- 

 Walbran were more than 10 km from the ocean (Burger 1994). 



Precipitation Amount and Form 



Most of the old-growth forests in which high densities 

 of murrelets have been reported receive high rainfall (most 

 in winter) and relatively little snow. On Vancouver Island, 

 detection frequencies were significantly higher in the two 



moist ecosections (Western Island Mountains and Northern 

 Island Mountains; Demarchi and others 1990) than in the 

 drier Nahwitti Low land and Nanaimo Lowland ecosections 

 (Savard and Lemon, in press). Overall, detections were 

 significantly higher on the moister western side of Vancouver 

 Island than on the eastern side, but the latter area has also 

 been far more extensively logged and urbanized, which might 

 contribute to this difference. 



Rodway and others (1993a) reported no detections at 

 apparently suitable forest with large Sitka spruce at Gray 

 Bay, Queen Charlotte Islands. The spruce trees there had 

 virtually no moss development on their limbs, apparently as 

 a result of sea spray, which might have made them less 

 attractive to murrelets. 



1991 



FRD HEA STR SIS SW AC SH W90 RT BP HUM LCC UCC 



1992 



10 



FRD 

 Km from sea: 6.2 



Figure 4 Mean frequencies of occupied and other detections reported from 13 intensive survey stations 

 (arranged in increasing distance from the ocean) in the Carmanah-Walbran watersheds, Vancouver Island, in 

 the period 15 May through 16 July in 1991 and 1992 (from Burger 1994). Sample sizes (n) above columns are 

 numbers of surveys. The x-axis is labelled with the codes for each station. Codes for each station are: FRD = Ford, 

 HEA = Heaven Canp, STR = Stream Site, SIS = Three Sisters, SW = South Walbran Bridge, AC = August Creek, 

 SH = Sleepy Hollow, W90 = West Walbran 1990 Nest Site, RT = Research Tree, BP = Bearpaw Camp, HUM = 

 Hummingbird Camp, LCC = Lower Ctearcut, UCC = Upper Clearcut 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



155 



