Why are there so many geese in Metro Vancouver?

You can't miss them as they strut aroundMetro Vancouver: hefty birds sportingbrown andblack featherswith white chin straps as they congregatein noisy gaggles.

Yes, they're Canadageese but why are they crowdingparks, beaches,the seawall and even crossing busy streets?

Urban biodiversity planner Jennifer Rae Pierce told The Early Edition host Stephen Quinn the geese were re-introduced to the area in the 1970sto boost the population for hunting and consumption purposes.

But, unlike their native cousins,Pierce said these geese don'tmigrate.

"Their impact on local ecosystems isquite different," said Pierce in aphone interview. Thenative goosepopulationchanges from season to season as they migrateand are affected by predators and hunters whilelocals stick around the whole year.

What about all that poop?

Just like the bird itself,theirpoop seems to cover Metro Vancouver'ssidewalks and grassy areas.

That's because geese don't have a very efficient system for processing foodcompared to other animals, according to Pierce.

"They actually produce more poop volume for their size and for the amount of food that they eat than most other species," she said.

Some people worry that the hugeamount of droppings willcontaminate water sources and spread diseases, but Pierece says that's rare andwater is more likely to be contaminated with human-derived feces.

She said there are diseases found in goose feces that have thepotential toinfecthumans, but it's so uncommon there isn't enough data to study the issue.

"The feces are primarily an estheticconcern," said Pierce.

It canbe a concern, however, onsmaller ponds or grass patches where children might come into contact with the poop, she added.

Controlling the population

In order to control the population, the City of Vancouver uses a technique called egg addling. It's a process of sterilizing eggs soon after they are laid. Eggs can be shaken, frozen or covered in oil, said Pierce in a 2016 reportfor the City of Vancouver.Once the eggs are sterilized, they're placed back in nests to reduce the chances of the goose laying more.

Pierce said in the study the practice is commonand approved by organizations like the animal rights groupPETA.

Buturban geesehave adapted to this process and try to hide their nests from humans.

"They'll attempt to nest outside of park areas and more on private land to avoid managementtechniques," she said.

Click the link below to listen to the full interview: