Pigeons have always presented many problems for Vancouver’s TransLink SkyTrain system. From interrupted train operations to messy droppings, pigeons are considered pests to both customers and TransLink’s maintenance support team.
Since pigeons can easily migrate and repopulate, controlling the pigeon population requires a bit of effort. As an alternative to extermination — which some view as inhumane and only acting as a short-term solution to a long-term problem — Nadia Xenakis of UBC’s animal welfare program is working with BC SPCA and TransLink to dispense birth control to help control Vancouver’s pigeon population. The program, first announced in 2019, has just reached its halfway point for data collection.
Xenakis feeds the pigeons OvoControl, a non-toxic bird contraceptive, at various stations using bird feeders that accommodate pigeons’ different body sizes and beak shapes. She records the birds daily and monitors their activity. Although contraceptives aren’t an instant fix, TransLink saves money in the long run by reducing expensive and continuous extermination costs.
“[This project is] something that’s different and it’s such a large industry. And if we could shift people’s mindset into a more co-existing mindset, I think that’d be really cool,” said Xenakis. “What attracted me to this project is shifting what pest control can be.”
OvoControl includes the compound nicarbazin which hinders bird fertility in a non-toxic and non-lethal way. The product is fed daily to birds during the reproductive season and interferes with the pigeon’s ability to hatch eggs.
Although nicarbazin now works as a bird contraceptive, its initial use was aimed at curing broiler chickens from a parasitic disease called coccidiosis. In the 1950s, many farmers realized that the medicated ingredient also resulted in non-viable egg embryos for however long the birds were being fed the ingredient.
Since the effects of OvoControl are fully reversible once the birds stop consuming it, the contraceptive is ideal for areas with dense pigeon populations where a reduction of the population, but not an elimination, is needed.
If left uncontrolled, pigeons can reproduce quickly. According to OvoControl, one pigeon can birth 12 new babies each year, and in six months’ time those new pigeons can begin breeding themselves. Since SkyTrain stations have many attractive qualities to pigeons such as high aerial space and a lot of people feeding them, many of them gather and live in those areas.
“Pigeons pose a public health and safety risk when in large numbers, [and] they can trigger the alarms on SkyTrain tracks leading to stoppages,” said Erin Ryan, communications specialist at the BC SPCA. “In one particular instance, a stoppage related to a pigeon nest on the track caused a sudden stop that resulted in a young boy breaking his arm.”
While the one-year data collection period for this project is only halfway through, Xenakis says she's been able to observe a period of stability within the pigeon population.
“I have seen some patterns in the pigeons showing up reliably at the feeders when they are set to dispense as well as populations slowly growing while birds become baited to the feeders,” said Xenakis.
“I’m excited to see how this shifts with time.”