Are Hummingbirds The Next Victim Of Neonicotinoid Exposure?

Hummingbirds Steady Decline

Over the last decade, the North American hummingbird population has been declining. Are they suffering from the same pesticides which are impacting our honey bees? In this segment of The Organic View Radio Show, hosted by June Stoyer, Dr. Christine Bishop from Environment and Climate Change Canada is going go talk about her latest research focused on North American hummingbirds. To listen to the segment, click the video below.

JS: When was the decline first observed?

CB: For the Rufous Hummingbird, they are declining about 2% a year. That adds up to almost 60% since the Brainbridge survey was initiated. What’s interesting about that is that there was an initial decline in the late 70’s and it’s been a steady decline since then. It hasn’t been extremely drastic any particular year but it’s been steady decline and hasn’t shown any increases for the Rufous Hummingbird during that time.

Rufous Hummingbird Migration Map

According to the Audubon Society, the Rufous Hummingbird moves northwest in early spring, mostly through Pacific lowlands, and moves southeast beginning in late June, mostly through the Rocky Mountain region. Adult males migrate slightly earlier than females or young. Strays occur widely in the east, and many now winter regularly in the Gulf Coast states. Below is a map of their migration.

Pesticide Exposure Evident

This is a hummingbird in a wrap so it can be banded. Sometimes, while they are in this position, they produce fluid (aka pee) that can be sampled non- invasively with a pipette. This is analyzed for pesticides.

JS: Can you talk about the actual study? Can you talk about the crops that were studied in that region?

Rufous hummingbird sipping nectar from Elliott’s blueberry. Photo by Janeen Langley.

CB: The work that we are doing is near Vancouver but what we call The Fraser Valley. A huge proportion of this valley is agriculture. One of the important cash crops in that area is berry production and specifically in our research, we are looking at potential exposure for the birds besides blueberry crops. So what we did was we had study sites that were right beside a blueberry field. From where we were dropping the birds we could walk over to the blueberry field. So, within 250 meters from the blueberry field, we also had reference sites that were further away, about a kilometer away. Then we had some references sites that were in watersheds where there were no blueberry fields. What we found was that the birds that were living next to the blueberry fields were definitely picking up the pesticides and passing them out into their urine. We also found that the ones who were a kilometer away but still in the Fraser Valley, some of them had detectable pesticides but the ones who were living in the watershed, where there is no berry fields, we had no detectable levels of neonicotinoid pesticides.

A banded Rufous Hummingbird.  Photo credit: Tristan Coatta.

JS: How long will the study continue?

CB: We started in 2015 at the set up of our study sites from agriculture. The first couple of years have been pilots. So, what we want to do is look at these sites now that we’ve established them for about another 5 years. The questions we want to ask are whether or not are the birds that live around agricultural areas are they returning from their migration at the same rate? What is their survivorship from one year to the next compared to sites with better quality habitat and potentially cleaner, in terms of pesticide exposure. We’ll be able to do that once we have more information about what the birds are doing agriculturally.

What we did find when we started working with the hummingbird banders is that when people do banding they often are choosing better quality habitat, because they want to catch birds and track the populations in the best case scenario. When we set up this study, this is the first of its kind, where we’re actually looking at birds in agricultural areas. So that means we have to look at survey, a reasonable sample size to understand how many birds are in the area and how they are returning from one year to the next in these agricultural areas.