A swan died and another was shot with an arrow in a “cruel and mindless” attack in Kirkcaldy.
A female swan needed surgery after the arrow narrowly missed her vital organs and spine.
Enquiries are on-going to ascertain how the male swan died, although two arrows were found close to its body, one in the water and one on the bank.
The SSPCA was alerted when the birds were discovered on Wemyss Estate off the Standing Stane Road on Saturday.
Officers said they were a pair and had been returning to the estate for several years.
Police Scotland and the SSPCA are investigating the incident, thought to have happened some time on Friday.
The estate’s owner is assisting in the inquiry.
SSPCA inspector Sarah Gregory said: “A female swan had been shot through the wing in a cruel and mindless attack believed to have occurred on Friday evening.
“The swan underwent surgery at a vet’s and is now in the care of our National Wildlife Rescue Centre in Fishcross.
“She is doing well and we are hopeful she will make a full recovery.”
Ms Gregory added that a post mortem had been carried out on the male swan and until the results were received, she could not say for certain if he was also shot.
“These swans are a pair who have been returning to the estate for several years and why anyone would want to injure or kill these defenceless birds is beyond all reasoning,” she said.
PC Lindsay Kerr, Fife Division Wildlife and Environmental Crime Officer, appealed for anyone for information about the “atrocious” act to come forward.
“At this early stage of inquiry we cannot say for certain that the death of the male swan was deliberate however we are keeping an open mind to the possibility that both animals were targeted in a single incident,” he said.
“This sort of animal cruelty is completely unacceptable and we’re carrying out various lines of inquiry in an effort to trace and arrest whoever is responsible.
“Wildlife and environmental crime is a key priority for Police Scotland and we work closely with several organisations, including the Scottish SPCA, in order to tackle such offences.”
Anyone with information is being urged to contact the Scottish SPCA Animal Helpline on 03000 999 999 or Police Scotland on 101.