Trend of ‌Bird Population Changes and Diversity of the International Wetland of Rud-e-Shur, Rud-e-Shirin and Rud-e-Minab Deltas

Deltas of Rud-e-Shur, Rud-e-Shirin and Rud-e-Minab, consisting of mangroves and coastal mudflats, is one of the most important bird habitats on the shores of the Persian Gulf and are protected as an international wetland. In this study, a list of weland birds was prepared based on the data of the results of the semi-winter census of waterbirds, expert reports and field studies. Also, the trend of changes in the waterbird population in the period of 1988-2021 was calculated using the TRIM statistical package with the possibility of application in R ver3.6.3 software called RTRIM. The results showed that, a total of 156 species of 97 genera, 45 families and 18 orders including 98 species of waterbirds, 21 species of prey and 37 species of terrestrial species were identified. The population of waterbirds has a strong increase with a slope of 7.7% per year. In the last ten years, a moderate decline in population has been recorded with a slope of -4.1% per year. The average population of waterbirds in the wetland was 15,479 ± 2,669 and the average number of species was 41.6 ± 3.39. The largest population was in 2019 with 54,356 individuals and the highest number of species was in 2005 with 64 species. Although annual population fluctuations and diversity depended on census-related factors such as program support, bird-watching tools, number of sites, census coverage levels, and the experience of bird counters, the impact of habitat threats such as overfishing aquaculture and the increase in environmental pollution have also increased in recent years. A program to increase stakeholder awareness and strengthen participatory conservation can be effective in reducing wetland threats.