A black male swan was found by officials in the University lake last weekend.
He was aged ‘at least 17 years old’ and had been at the campus ‘since 2001’, officials said.
Pottle and Duguid have said they will replace the bird if elected.
Speaking in the Green Room at the University Radio York’s Candidate Night, they added that they wanted to set-up “green campus colleges” to improve campus efficiency.
Charles and Oliver will find out if they have got the part-time role on Friday 28 February once voters have gone to the polls.
Ballot casting opens on Monday in the YUSU Elections for 2014.
You can view the candidates and the positions by clicking here.