To update the avian checklist and note their conservation status in Marivan County, western Iran, we report the addition of 28 species belonging to six orders and 13 families recorded during our field observations in 2015–2017 outside the range of Zarivar Wildlife Refuge. With 255 species reported in previous surveys from the Zarivar Wildlife Refuge and Marivan County as well as 28 additions here, the avian checklist of Marivan County reaches 283 species from 19 orders and 57 families, which is equivalent to about 51.2% of total bird species recorded from Iran. Appendix I of the Convention on International Trade in Endangered Species applies to five species and the Appendix II applies to 34 species. The Red List considers six species as Vulnerable, three species as Endangered and 11 species as Near Threatened. In addition, 15 species are endangered and another 43 species are protected species based on the rules and regularities/laws of the Iranian Department of the Environment.
