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THE WILSON JOURNAL OF ORNITHOLOGY • Vol 123, No. 4. December 2011 
Carpinus orientalis create an upper border of 
forests in northern Iran (Marvi Mohajer 2005) 
allowing appropriate habitat for nuthatches in an 
upland region. Beach forests have turbid air 
(because of moisture demand) that produces 
dew, one of the water resources for birds (Marvi 
Mohajer 2005). Water resources are among the 
important factors for bird species diversity 
(Rahbek 1995, Diaz et al. 2005) and can be 
effective for enhancing bird richness in the 1.500- 
1,800 m elevation range. The positive coefficient 
of the altitude variable in the third model indicates 
the probability of nuthatch presence increases at 
higher altitudes. 
The most important feeding guild in our study 
was of insectivorous bird species. Most species 
that belonged to this guild, such as the Red¬ 
breasted Flycatcher ( Ficedula parva ), Eurasian 
Nuthatch, Eurasian Golden Oriole ( Oriolus orio- 
lus), Common Cuckoo ( Cuculus canorus), and 
Common Chiffchaff {PhyHoscopus colly bit a), 
were seen in the entire forest. Associated species 
with nuthatches in the Kheyrud Forest were 
Common Chaffinch (F ring ilia coelebs), Coal Tit 
(Periparus ater). Eurasian Wren ( Troglodytes 
troglodytes ), Song Thrush (Tardus philomeios ), 
Common Blackbird (T. merula), European Green 
Woodpecker (Picas vihdis), Syrian Woodpecker 
(Dendrocopos syriaats). and Common Pheasant 
(Phasianus colchicus ). Most studies report that 
nuthatches nest in holes produced by woodpeckers 
and may overlap in habitats used. We cautiously 
conclude the Eurasian Nuthatch can potentially be 
considered as an indicator of old growth and intact 
Hyrcaman forests. Some species in Hyrcanian 
forests are of conservation concern; for example, 
the Common Pheasant is a protected species that 
live in northern forests. Pheasant habitat in the 
study area overlapped with habitats used by 
nuthatches. Thus, we can provide better habitat 
conditions for Common Pheasant survival in this 
area by maintaining nuthatch habitats in Hyrca¬ 
nian forests. 
Our model indicated habitat variables could 
predict the appropriate distribution of habitats. 
Habitat variables are good predictors of distribu¬ 
tion and our estimates were good approximations 
tor the actual distribution of nuthatches. The 
presence of an individual does not prove the 
jse. : r ,abh for breedin ” 1 
present , Pr T nCe ' abSenCC «“»• example. 
»eVe m e e „rCe'I™ Urred ^ 
an organized sampling 
method for bird species in the study area which is 
why we repeated the sampling and obtained 
similar results. The model we developed indicated 
high probability of species occurrence and 
validation indicated the model was effectively 
functional within the study area. 
ACKNOWLEDGMENTS 
Wc thank the many people who helped us with field 
work. In particular we thank Mansour Aliabadian and 
Vahid Etcmad for critical discussion and assistance in 
numerous other ways. The research was conducted with the 
Financial support of the Department of Fisheries and 
Environment. Faculty of Natural Resource, Tehran Univer¬ 
sity. Iran. 
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