THE AUTHOR 



RESEARCH SUMMARY 



DEAN E. MEDIN is a research wildlife biologist with 

 the Intermountain Research Station at the Forestry 

 Sciences Laboratory in Boise, ID. He earned a B.S. 

 degree in forest management from Iowa State 

 University in 1957, an M.S. degree in wildlife 

 management from Colorado State University in 1959. 

 and a Ph.D. in range ecosystems from Colorado State 

 University in 1976. His research assignments have 

 included studies in mule deer ecology, big-game range 

 improvement, big-game population modeling, and non- 

 game bird ecology and habitat management. 



ACKNOWLEDGMENTS 



I gratefully acknowledge the valuable field and 

 office assistance of James R. Groves. Robert Jordan, 

 Stan Baker, and Shiela Donovan. James F. Rathbun, 

 District Ranger, Boise National Forest, arranged for 

 part-time housing facilities near the study site. Walter 

 F. Megahan, James L. Clayton, Timothy L. Mosko. 

 Dale O. Hall, and Russell A. Ryker, Forestry Sciences 

 Laboratory, Boise. ID, provided support and 

 contributed in many other ways. 



Populations of breeding birds responded differently 

 to structural changes in a Douglas-fir forest caused by 

 diameter-cut logging. Little change occurred in total 

 bird density or standing crop biomass of birds either 

 between years or between logged and unlogged plots. 

 But there were pronounced changes in the composi- 

 tion of the breeding bird community. Logging the 

 forest resulted in increases in numbers for species 

 that require more open habitats and decreases in 

 populations for species that require more closed 

 habitats. Several species maintained relatively stable 

 densities on both logged and unlogged plots. 



The number of breeding bird species (species rich- 

 ness) was consistently higher on logged plots than on 

 unlogged plots and trended upward each year after 

 logging. Ten species were territorial only in the logged 

 forest. One species that was territorial in the unlogged 

 forest was absent from the logged forest. There were 

 no clear patterns in bird species diversity either 

 between years or between logged and unlogged plots. 

 The evenness (equitability) component of bird species 

 diversity declined each year after logging. 



Two categories (guilds) of birds— the foliage 

 foragers and the timber gleaners— were less numerous 

 on logged plots. The timber-gleaning guild, the most 

 severely affected, dropped to only one-third of prelog- 

 ging densities in the third year after logging. The 

 ground-foraging and flycatching guilds were more 

 numerous on logged plots. Of nine species 

 represented in the ground-foraging guild, each was 

 proportionately more abundant in the logged forest 

 than in the unlogged forest. The timber-drilling guild, 

 at least in total, was a relatively stable component of 

 the breeding bird population. 



Patterns observed in this study, and other studies 

 that were compared, suggest consistencies of 

 response among certain breeding bird species to 

 logging in western coniferous forests. 



