Monarch butterflies are making their way through Saskatchewan in August as part of their annual migration and throughout the month, Nature Saskatchewan is asking for help to spot them.

Ashley Vass, who is a habitat stewardship coordinator for the organization, said the monarch population has declined as much as 90 per cent in North America in the last 20 years.

But what are the contributing factors in the decline of the species?

"A lot of them are human caused," Vass said. "Mainly habitat loss."

Protecting an at-risk species

Vass blames urban development and agriculture mainly, but said weather also kills off the insects.

Monarch caterpillar

Monarch reproduction is dependent on a certain species of plant, called milkweed, which is often killed by herbicide. The monarch is seen here as a caterpillar. (Nature Saskatchewan)

She explained that monarch reproduction is dependent on a certain species of plant, called milkweed. A lot of herbicides currently used by food producers are eliminating milkweed altogether.

So planting it in your own yard can do a lot of good for the butterfly species.

Another way to help the monarchs is to plant wildflowers, which Vass said they feed on throughout their lives.

"The more people you can tell about monarchs, hopefully the more awareness and the more consideration for them we'll have," Vass said.

Vass said the species is at-risk and Nature Saskatchewan is trying to monitor population. The research institute is asking people to call in with any monarch sightings in the province so it can determine the locations to direct habitat conservation efforts.

Spotting a monarch

While looking for monarch butterflies, it is common to confuse them for other species including queen butterflies, painted lady butterflies and viceroys.

First of all, Vass said monarchs are very large, commonly growing to about 8-12 cm. Their bodies have white spots, with stripes above. They are orange with black veining throughout their wings and have two rows of white spots around the edges of their wings.

Vass said it's easiest to provide a photo for verification.

Monarch butterflies move north throughout the summer, laying eggs along the way. Vass said it often takes place over four generations. Eventually, the butterflies are triggered by weather to head back south.

"The monarch migration is really one of the most spectacular migrations. It's the longest and largest of insect migrations in North America," she said.

If you see a Monarch butterfly, and want to pass along the details, you can call Nature Saskatchewan at 1-800-667-4668.

With files from CBC Radio's Sask Weekend