 The greater crested tern breeds in colonies , often in association with other seabirds . It is monogamous and the pair bond is maintained through the year and sometimes in consecutive breeding seasons . The colony size is related to the abundance of pelagic fish prey , and the largest documented colony , with 13 @,@ 000 to 15 @,@ 000 pairs , is in the Gulf of Carpentaria in northern Australia , a region which also supports major colonies of other seabirds . Since nesting in this area follows the summer monsoonal flooding , it is presumably a response to fish stocks rising , probably due to river run @-@ off providing extra nutrient to the Gulf . This tern does not show site fidelity , frequently changing its nest site from year to year , sometimes by more than 200 km ( 120 mi ) . 
