Survey of reproductive phonology and breeding success of whiskered tern (Chlidonias hybrida) in Anzali Wetland (Western part of Wetland), Iran

This study was carried out to study the breeding success of Whiskered Tern (Chlidonias hybrida) from June to August in Anzali Wetland (Western part of Wetland). The factors affecting breeding success were studied. Reproductive phonology of whiskered tern started in June with nesting behavior and ended with the fledgling stage in late August. Breeding success was 45.15%. Clutch size varied from 1-4 eggs and cohort groups from 1-2 chicks per nest. There were no significant difference between clutch size and cohort group (P>0.05) but the difference in mortality rate between the different stages of reproduction (P<0.001) was significant. The inability of eggs to hatch and human factors were the major causes of mortality. There was no significant correlation between nest size (P=0.829) and breeding success. It was seen that daily survival rate was higher during the growth of chicks than the in the hatching period and increased until post-nestling stage.