نتایج جستجو برای: rare species
تعداد نتایج: 777083 فیلتر نتایج به سال:
A field survey was conducted in Wukari, Taraba State to assess the diversity and abundance of insect species in selected habitats (residential, open field made up of grassland and an agroecosystem). Sampling were done biweekly using light, pitfall and yellow pan traps set in 3 replicates, 30 m apart. Insects recovered were wet preserved in 70% ethanol except butterflies and moths. Representativ...
during 2010-2011 a faunistic survey was carried out for collection and identification of edaphic mesostigmatic mites (acari: mesostigmata) in jiroft and suburb. mites were extracted from soil samples by berlese funnel. the mites were cleared in nesbit fluid and were mounted in hoyer medium on microscopic slides. in this study 43 spices from 26 genera and 16 families were collected and identifie...
—Wildlife monitoring surveys are prone to nondetection errors and false positives. To determine factors that affect the incidence of these errors, we built an Internet-based survey that simulated avian point counts, and measured error rates among volunteer observers. Using similar-sounding vocalizations from paired rare and common bird species, we measured the effects of species rarity and obse...
Multi-species indices (MSI) are widely used as ecological indicators and instruments to inform environmental policies. Many of these combine species-specific estimates relative population sizes using the geometric mean. Because mean is not defined when values zero occur, usually only commoner species included in MSIs replaced by a small non-zero value. The latter can exhibit an arbitrary influe...
PREMISE OF THE STUDY Differences in rarity among species can be caused by adaptation to local conditions along with correlated evolution in characters that limit geographic range size. For this kind of divergence, the resulting species differ in their ability to thrive in varying environments. Because rare species are more prone to extinction than widespread species, trade-offs in life history ...
this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...
This study focuses on Anguilliformes specimens revising which collected during 2006-08 in some Iranian museums. For this study, all museum samples from Iranian coastal waters of the Persian Gulf and Oman Sea were investigated. The results indicated that species diversity in the Iranian waters can be classified into six families of Anguiliformes (Eels and Morays fishes). A total of 11 species...
abstract information on reduviidae species are sporadic and very rare in iran due to the few survey conducted on this bugs. a study was done to determine the diversity of this family during 2008 - 2009. several species were collected among them holotrichius mesoleucus (kiritshenko, 1914) was found to be the species recorded for the first time in iran. this species was collected from avena fatua...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید