As scores of sea lions get comfortable on beaches, backyards and parks around Dunedin this breeding season, they leave evidence of their presence in a variety of ways.
University of Otago post-graduate researcher Hanna Ravn said examining scat and vomit was the best, most non-invasive way to understand a sea lion's diet.
"We're looking at hard bits, so basically bones and squid beaks and stuff like that, whatever we can find," Ms Ravn said.
During breeding season, she was able to collect samples from female sea lions around Dunedin.
As they isolated themselves from males then, she was able to collect samples and be certain of which animal they came from.
When waste was collected from tagged animals, any changes or variations in diet could be tracked, Ms Ravn said.
"She had a nice poo right next to her," Ms Ravn said.
"It looked very, very fresh. Definitely hers, you know, right at her bum.
"[We] take a photo of the poo itself with a little measuring tape so that we have a catalogue of what they look like in the field.
"While we were getting that sample, she made another sample for us right in front of us, I've also had a few sea lions throw up right in front of me."
Once a sample was collected, it was processed at Portobello Marine Lab, ready to be studied.
Ms Ravn worked closely with the Department of Conservation and local community groups to identify common sea lion haunts.
"It's relying a lot on the community information."
She hoped the public would continue to be a part of her research, an upcoming survey would help her identify areas of conflict and similarity between the humans and sea lions.
"The kaimoana [seafood] that we live off ... is that similar to the sea lions'? What do we share? What don't we share? It's really highlighting what makes encounters stand out, in terms of creating positive emotions and communities that care.
"If you do see a congregation of [tagged] sea lions and poo around them ... [I] would love to hear about it."
Researchers were not the only people taking an interest in sea lion byproducts.
Fulton Hogan worker Audrey Harbrow said she encountered sea lions while on maintenance patrols at this time of year, putting up warning signs and dealing with sea lion waste was "just part of the job".
"It's probably only the last ... three years that they've been coming around and we've had to run round after them.
"They just do their own thing," she said.
Anyone with reports of waste from tagged sea lions can contact Ms Ravn on hanna.ravn@otago.ac.nz
