238 



S. IdLm Nelson Testdmany on H.R. 2866 5 



impacts such as Isolation of sxibpopulatlons , habitat 

 fragmentation, and edge effects. A compari son of historic2Ll 

 information available on murxelet populations with current data 

 suggests a decline in numbers, especied-ly in portions of its 

 range wher« logging has been ejctensive (Carter and Erickson 1992, 

 Nelson et al. 1992) . The number of older-aged forests available 

 to murrelets is declining in number and is extremely limited in 

 certain are£is of the species range (Carter and Erickson 1992, 

 Nelson et al. 1992) . 



Predation of ciur:relet nests has been occurring at «^iat seem 

 to be alarming rates (Nelson, unpubl. data) . Seventy- three 

 percent of nnirxelet nests have failed and 54% failed because of 

 predation. Predators of murrelet nests include the Steller's Jay 

 (Cj'aiiocitta stellerl) , Common Eaven {Cotvus cotsx) , and Great- 

 Homed Owl (Bubo q-fTYjrfT77aTTTTg) (Nelson ISSi, 1992, Naslund et al. 

 in press) . Predation by these species (imd Great -Homed Owls) is 

 known to increase witii the fragmentation of older-aged forests 

 (Yahner and Scott 1988) , and bird nesting success is lower in 

 small forest fragments than larger intact forests because of 

 predation and decreEised fecundity C&mbuel and Temple 1983, Andren 

 et al. 1985, Wilcove 1985, Tensile and Cary 1988). Stellar's 

 Jays, Common Ravens, and Great -Horned Owls are edge species that 

 become increasingly concentrated as edge is increased with the 

 fragmentation of habitat (Yahner and Scott 1988} . In addition, 

 Corvids (jays, ravens and crows) are extremely intelligent 

 predators that have refined search, images for loc«iting prey 

 (Kilham 1989, Goodwin 1976, Zach 1979) . 



Habitat - MaTra gement 



Retention of older-aged forests throughout the historic 

 range of the murrelet will be in^jerative for the short-term 

 viability of the species (Report of the Scientifc Analysis Team 

 1993} . No matter how small »r\A isolated, habitat on all Itmds 

 will be iggortBTit for recovery of the species within its historic 

 range. Regrowing suitable habitat in areas where it no longer 

 exists ^^^ growing buffers around existing small stands will also 

 be key to the long-term viability of the species (Report of the 

 Scientific Analysis Team 1S93) . Exact sizes of buffers and 

 \ stands required fay murrelets is unknown at this time. However, 

 ^ predation rates on bird nests were higher in edge habitat (within 



lS-100 m of the forest edge) compared to interior forest (Gates 

 and Gysel 1978, Small and Hunter 1988) , and were extreme in 

 managed stands in basins that were more than 25% fragmented 

 (Tahner and Scott 1988) . Large, ijatact habitat blocks in 

 unfragmented basins will provide optimal habitat for Marbled 

 Murrelets. 



There is evidence that alcids are poor colonizers. A 

 breeding colony of the Atlantic Puffins {Pra.Ze:rcala. arctica) wais 

 extirpated from Eastern Egg- Rock, Maine, in 1887. Puffins from 

 neighboring islands (within 20 mi) faiiled to re-establish the 



