Ralph and others 



Chapter 1 



Overview of Ecology and Conservation 



critical habitat and managed to reduce harm to murrelets. 

 Threats to murrelets at sea include entanglement in fishing 

 nets (particularly nearshore gill nets), oil spills, the presence 

 of other pollutants (especially those that might affect the 

 availability of prey organisms), and other factors causing 

 loss of forage fish. However, we see the greatest challenges 

 in the marine habitat to be the reduction of human-caused 

 mortality of adult murrelets, rather than the enhancement of 

 prey availability. Managing at-sea conditions will require 

 overcoming jurisdictional problems involving overlapping 

 responsibilities of multiple agencies (NOAA, U.S. Navy, 

 U.S. Coast Guard, National Marine Fisheries Service, 

 Environmental Protection Agency, U.S. Fish and Wildlife 

 Service, USDA Forest Service, marine sanctuaries, tribal 

 agencies and groups, and various state agencies, among others). 

 Any solution will require close coordination and cooperation 

 among all relevant agencies, and will be most effective if 

 coordination is started at the highest political level (e.g., 

 between Secretaries of relevant departments, and with 

 coordination amoung appropriate state agencies and tribes). 

 There is also a need for international cooperation between 

 the United States and Canada in marine management. Already 

 in place is the British Columbia/Washington Environmental 

 Cooperation Council with a Marine Science Panel, as well 

 as the British Columbia-Alaska-Washington-Oregon- 

 California Oil Spill Task Force. 



Research Needs 



We suggest a series of high-priority research needs for 

 the species, as follows. We list these approximately in the 

 order of what we consider their importance, although, in dif- 

 ferent regions, different priorities would apply. 



Inland Range of the Species 



The protection of nesting habitat requires defining the 

 inland extent of murrelet habitat use. This has been based on 

 observations of birds at inland sites. At some distance from 

 the coast, the abundance of birds drops dramatically. Agencies 

 have required that surveys be conducted at and beyond the 

 farthest inland records of the species. We suggest that surveys 

 to determine habitat use be concentrated at distances from 

 the coast where the great majority of the population lives. We 

 see little virtue in surveys conducted where murrelets only 

 rarely explore. It is our opinion that these extremely peripheral 

 areas can contribute very little to the species' survival. We 

 also suggest that surveys be conducted at a distance from the 

 coast in which more than 99.9 percent of the individuals in a 

 region have been detected. The U.S. Recovery Plan (U.S. 

 Fish and Wildlife Service, in press), defines "critical habitat" 

 as being within 40 miles of salt water in Washington, 35 

 miles in Oregon and California north of Trinidad Head, and 

 25 miles for the remainder of California. With limited resources 

 available for surveys, it seems prudent, from the standpoint 

 of the conservation of the bird, to concentrate the majority of 

 murrelet survey effort to these zones. 



Inland Habitat Association Surveys 



Habitat association patterns have received much 

 attention, but a greater information-gathering effort needs 

 to be made in most areas. Especially needed are surveys in 

 forests of Alaska and British Columbia. Also needed are 

 systematic surveys throughout actual and potential habitats 

 to determine relative abundances (as estimated by activity 

 level) according to the variables described in the various 

 chapters, as well as along coastal-inland transects. Among 

 the most important variables are the size of stands, their 

 structure, and landscape configuration. While we have a 

 good idea of the correlation of some variables with abundance 

 of murrelets, knowledge is lacking of the actual way that 

 these variables are important to the reproductive success of 

 the species. We do not suggest, however, that large-scale 

 manipulative experiments be launched with the idea of using 

 this worthy method, especially from Washington south, 

 where the potential negative effects of experimentation on 

 already tenuous populations would be great. Rather, humans 

 and nature have provided a range of natural conditions that 

 can give a retrospective view of the habitat suitability. 

 These effects include partial harvesting of timber, as well as 

 thinning due to disease, fire, and windthrow. 



Related to the above is the minimum stand size for 

 occupancy. Part of the research involving stand size should 

 include the gathering of data on the number of birds occupying 

 a stand and the number of nests present. Using the number of 

 detections in a stand (currently the only metric available), 

 one could then estimate, at least in part, if bigger stands 

 support more or fewer birds per unit area than smaller stands. 



Evaluate Importance of Human Causes of 

 Mortality at Sea 



It is essential to obtain robust data on the take of murrelets 

 in inshore gill nets and to relate that take to densities of 

 murrelets in the area being fished, as well as the modes of 

 fishing. Modifications of fishing techniques, such as limiting 

 fishing to daylight hours or appropriate changes in mesh size, 

 should be sought in areas where murrelets are killed, so as to 

 reduce the bycatch. Gill-net fishing in inshore waters where 

 murrelets are abundant should be prohibited at an early date, 

 if less drastic measures are not successful. The concerns 

 about loss to gill nets are particularly great in Washington and 

 British Columbia, but apply throughout the species' range. 

 Similar concerns apply to loss from oil spills and detailed 

 knowledge of the distribution of murrelets could alert managers 

 to potential areas of extreme risk to certain populations. 



Risk of Nest Predation Versus Forest Structures 



It is essential to determine the role of predation in 

 populations by studying nesting success. We must also deter- 

 mine the influence of forest stand structure, and in particular 

 the importance of the ratio of forest edge to interior area, on 

 the number of predators present and how these factors affect 

 the probability that a nest will be lost to predation. Surveys 

 of the populations of potential predators in forest stands of 



20 



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



