Bird Response to Clearings 93 



nesting species. Stauffer and Best (1980) reported this species tolerant of 

 habitat disturbance and Crawford et al. (1981) found titmice using a 

 wide range of habitats. 



Red-bellied woodpeckers used control and 45 kg/ ha plots more 

 frequently than clearcut or 23 kg/ ha plots (P<0.05) (Table 3). Control 

 and 45 kg/ ha plots were characterized by having higher basal area (x = 

 22.5 m^ha) than either clearcut (9.3 m^ha) or 23 kg/ ha plots (17.5 

 m^/ha). Red-bellied woodpeckers exhibited no association with aspect 

 or edge, but hairy woodpeckers used ridge-tops (9 individuals) more 

 (P<0.05) than north- or south-facing slopes (3 and 2 individuals, respec- 

 tively). Red-bellied woodpeckers used habitats with an open understory 

 (high crown cover) and high basal area. 



Sample sizes were insufficient to identify treatment, aspect, or habi- 

 tat preferences of 22 other species of breeding birds encountered during 

 the course of our study (Table 3). 



MANAGEMENT IMPLICATIONS 



Long-term effects of picloram herbicide application in field situa- 

 tions on soil invertebrates, invertebrates inhabiting herbicide-created 

 snags, plant succession, and reproductive physiology of terrestrial verte- 

 brates have not been thoroughly investigated. If future studies indicate 

 minimal effects of picloram herbicides on these ecological processes, 

 then pelletized picloram application may be a more desirable and less 

 expensive non-game bird management tool in remote or rugged terrain 

 than manually cutting trees. Four years after application of picloram 

 herbicide or clearcutting, increases in BSD through changes in species 

 composition and increased density of some species in the forest may be 

 expected, but no single treatment will accomplish this goal. Although 

 we found no differences in BSD among treatments, some species pre- 

 ferred or occurred exclusively on one or several treatments. 



Total bird density was higher on treated plots than control plots in 

 both winter and spring. This may have been due to the presence of edge 

 for some species (wintering hairy and red-bellied woodpeckers, red-eyed 

 vireos, and ovenbirds) and/ or to the changes in the biotic and abiotic 

 habitat characteristics produced by the treatment. For instance, changes 

 in habitat characteristics due to clearcutting produced predictable 

 occurrences of rufous-sided towhees and cardinals. Changes in habitat 

 structure brought about by herbicide application allowed predictable 

 occurences of some species (e.g., Kentucky warblers and ovenbirds) but 

 not others (black-throated green warblers and tufted titmice). 



We recommend that a range of pelletized picloram rates from 27 to 

 68 kg/ ha be used on small plots (0.5 - 1.0 ha) in conjunction with small 

 clearcuts to provide desirable habitat requirements for as many species 

 of birds as possible, and to increase the density of many of these species 



