Four New Zealand students who competed at the International Biology Olympiad in Armenia have all returned home with medals after excelling on the world stage.

Sarah Ellis from St Peter's School in Cambridge and Jacob Miller from Mount Albert Grammar School both won bronze medals, while Janet Guo from Hillcrest High school and Richard Li from Rangitoto College won silver medals.

The team was led by Dr Angela Sharples from Murupara Area School and Michelle Isbister from Hauraki Plains Area School.

The NZ team competed against the top four students from 68 different countries at the Olympiad which started on July 10.

The competition included two extremely challenging theory exams and a range of practical tasks, from determining the activity of alcohol dehydrogenase, to assessing plant vulnerability to climate change, bioinformatics, and the biosystematics of Armenian freshwater fishes.

'This is a huge achievement for our team and a tribute to their dedicated study for over 18 months and the support of their teachers, whānau, the NZIBO committee and our university partners,” says Dr Sharples.

'It is also a testament to all those who supported us when government support was not available, donating through Givealittle, purchasing raffle tickets, and attending fundraisers. Without this support the team could not have competed. We can't thank our supporters, large and small, enough.”

In addition to competing on the world stage, the successful team has explored Rome, Vatican City, and Yerevan - one of the ancient cities of the world in Europe, and learnt Armenian dancing.

Dr Sharples is incredibly proud of the students' achievements.

'They represented New Zealand at the highest level of academic endeavour for secondary school students in the world and rose to the occasion to bring home the medals. It reflects their hard work, perseverance, and sheer biological brilliance,” says Dr Sharples.

The NZ team travelled home via Dubai arriving back on Wednesday July 20.

Students keen to take part in the NZ International Biology Olympiad programme and potentially attend the 34^th IBO in the United Arab Emirates should enrol at www.nzibo.org