NB Naturalist Feature: Journey to the Milkweed Patch

July 7, 2021 — My name is Kenzie and I am one of the summer students with Nature NB, working alongside my co-worker Dani as a nature educator. One part of our job this summer is spending time monitoring natural milkweed fields for evidence of Monarch butterfly development and nesting. We wanted to share some of our findings from this project over the last five weeks to give some insight into the monitoring process, why this work is so important, and how to help protect this species at risk in future.

Our mission to spend our summer conserving milkweed fields stems from the fact that milkweed is the only plant that Monarch butterflies will nest and feed on, they even migrate 4,000 to 5,000 kilometers to New Brunswick every spring to nest on the Milkweed here. Unfortunately, the “Monarch population has declined by more than 80% over the past two decades” (1). Over the years, Nature NB has begun actively protecting the Monarchs by monitoring milkweed patches, advocating against mowing, and igniting support through educational events, programs, and social media.

We are spending the summer in the field weekly in the Saint John, Hampton, and Fredericton regions scouting out new fields, as well as continuously surveying the same fields in order to monitor the butterflies’ growth. We’ve spent our time collecting data on observations of the various Monarch life stages (eggs, chrysalis’, adults, and caterpillars).

The most significant discovery this year was the early arrival of the Monarchs this spring. We began our monitoring journey at the end of May and by the first week of June we were already seeing upwards of 108 eggs in one day in the Saint John region.

This discovery was remarkable, as compared with last year’s observations, Monarch eggs were not observed until the end of July. Nature NB and many Monarch supporters were shocked but delighted by the early presence of Monarchs and the great condition in which they presented themselves.

From the beginning, our observations were very promising; we found 174 eggs in total in our first three weeks of monitoring. Though over the next couple of weeks, we’ve noticed a steep decline in the amount of successfully developed eggs. From the initial 174 eggs, we have only found 65 caterpillars and even less as time goes on. This leads us to believe that there must be a factor at play which is working against the little larvae, whether it be predation from other species or their environment.

Many milkweed enthusiasts are aware that to successfully grow milkweed, there must be some shade in order to grow the plants to size. We were able to observe this shade deficiency in action at one of our consistent fields, as one of our more favorable patches in the beginning slowly became depleted of Monarch eggs and caterpillar larvae because of the hot weather and having no protection from the sun. Additionally, this patch contained a lot of diverse species that were observed on the milkweed plants, leading us to suggest there might have been some predation involved in the Monarch decline.

Overall, these past 6 weeks of monitoring milkweed patches in New Brunswick have been a fantastic learning experience. We have taken our findings and learned a great deal about the Monarch species as a whole, as well as the right conditions in which they need to live and maintain a healthy life cycle. Currently, we have only observed Monarch eggs and caterpillars and have yet to find any chrysalis but we will continue to observe the patches every week to watch as the butterflies develop. We even to a social media takeover every day we go out monitoring the patches, in order to share live observations with those who are interested. You can follow along on Nature NB’s Instagram.

One of the best ways to support the Monarchs is to educate yourself, plant milkweed plants in your garden, and advocate against the mowing of milkweed patches. For more information on getting involved with protecting the Monarch Butterfly population in New Brunswick, Nature NB has many resources and information available.