Bumblebees are fascinating creatures. They collect nectar, pollinate flowers and look fuzzy and cute, for an insect. But for Robin Owen, a biology professor at Mount Royal University, it was the evolutionary genetics of bumblebees that grabbed his attention and led to a lifelong obsession with the species.
Owen has always had a particular interest in biology, but during his time at the University of Toronto, a study on the mimicry of bumblebees captured his attention. Ever since then, he has been studying various aspects of bumblebees along with other social insects that belong to the order of Hymenoptera, a type of species that ants and wasps fall under.
Before coming to Calgary, Owen pursued an undergraduate degree and a PhD in zoology at the University of Toronto. During his PhD he did some work on the genetics of bumblebee colour polymorphism — a genetic variation affecting colour patterns within a species.
Owen later spent two years in Melbourne, Australia where he did a postdoctoral fellowship at La Trobe University.
In 1984 he started a five-year research fellowship at the University of Calgary and then finally made his way to Mount Royal in 1989 when it was still a college.
Owen has always participated in research during his time at MRU. Currently, he is teaching courses on introductory biology, evolutionary biology, genetics and invertebrate zoology.
“In science you don’t take anything for granted, especially whatever anybody has said. You’re always questioning things and even published data can be reanalyzed and different conclusions can be made from it. That’s how science advances.” -Robin Owen
One area of study that has always interested him is theoretical population genetics, or the genetic differences surrounding populations. He also studies haplodiploidy, which is a reproductive trait that determines the sex of the offspring in bumblebee colonies.
“It’s a remarkable adaptation and it means they can control the sex ratio of the offspring,” said Owen.
With this system, the queen can determine whether to lay a fertilized or unfertilized egg, which will then become a female or male respectively. Earlier in the season, the queen will lay female eggs to be the workers, while later in the year she will lay male eggs to be the reproducers.
In addition to haplodiploid systems, other areas of study for Owen surround bumblebee mimicry, the relationship of Bombus moderatus to other European species, and the expansion of the species in Alberta.
Mimicry not only ensures the survival of different bumblebee species, but also aids the survival of some species of flies. These examples are of two different types of mimicry and Owen has collected samples from both.
Batesian mimicry is a concept where animals defend themselves from predators by resembling another noxious animal.
“A palatable, tasty insect, like these flies, can get protection by looking like the bumblebees,” said Owen.
Owen has taken many samples of flies from Barrier Lake in the Kananaskis area that resemble bumblebees.
“They’ve got the fur, they’ve got the same colour patterns, and what’s really more remarkable is that they behave the same way. These [flies] are found early in the spring when the bumble bee queens just come out of hibernation,” said Owen.
“Since the pussy willow is the only thing in bloom, you’ll find the bees around it and these flies circle around in exactly the same way that the bees do. They even buzz a little bit. This is remarkable mimicry.”
Owen points out the difference between bumblebees [top left] and the flies that mimic bumblebees [bottom left] in his office at Mount Royal University on Dec. 7, 2017. Photo by Brittany Willsie.
In 1980, Owen published a paper quantifying Mullerian mimicry, where different bumblebees share similar colour patterns.
“If a number of noxious species all look alike then it’s easier for predators to learn what to avoid each year and as a result, the numbers of each individual in each species of bumblebee will gain,” said Owen.
Another paper was published where researchers refuted the idea that mimicry is important in bumblebees. Owen said he was very sceptical of this study as mimicry is crucial to bumblebee survival.
“New birds coming out of the nest need to learn what to avoid and if they only have to learn one or two colour patterns then the overall mortality of the insects is lower,” said Owen.
After he peer-reviewed the article, the study was re-examined and published again.
“In science you don’t take anything for granted, especially whatever anybody has said. Also, you don’t expect anyone is going to take what you say as the gospel truth. You’re always questioning things and even published data can be reanalyzed and different conclusions can be made from it. That’s how science advances,” said Owen.
Owen said that defending your ideas and keeping an eye on what other people are doing is just as much a part of research as actually doing it.
Most recently, Owen has been looking at the spread of a bumblebee species throughout southern Alberta. In the 80’s he got to know the local species in the area. At first, Bombus moderatus was never found around Calgary, but around 1986 they started to appear in the Kananaskis area.
For a long time the moderatus was lumped together with a European species called Bombus lucorum. Owen worked with Adolf Scholl, a professor from Switzerland, to find out if there was a difference between the two. “We did some biochemical genetic work and it showed that it really was different than the European species,” said Owen.
The Bombus moderatus has now spread into Calgary and is the most abundant type of bumblebee in the area. It has a distinctive yellow stripe right in the middle of its abdomen while the body is mostly black except for a white tail.
Many bumblebee species have been declining, so the increase in the Bombus moderatus is something to note. If researchers can determine why the moderatus is doing well, it could reveal a solution to help some of the other decreasing species, like the Bombus occidentalis.
“I’ve always considered my research to be mainly fundamental. Now with species of bumblebees in decline, it is more applied because it relates to real life situations.” -Robin Owen
While the moderatus was increasing and moving east into Calgary, the occidentalis was decreasing in numbers and fading from the Calgary area.
“We don’t quite understand why this is happening, but that’s the most recent thing I’ve been looking at,” said Owen.“Species that are declining are probably under some kind of stress while the others that are expanding are doing well.”
Potential causes of stress in bumblebees include habitat loss, agrochemicals, pathogens, parasitic mites and climate change. One area of study that deals with the effects of stress in insects is fluctuating asymmetry.
“Stress in the larval stage creates asymmetry and it can be measured statistically,” said Owen. “Often the dimensions of the wings will be asymmetrical.”
Determining whether asymmetry applies to species that are declining can be done by comparing it to species that are expanding, like the moderatus, or remaining the same.
“Results are not too clear yet,” said Owen. “I would like to follow up on that.”
Ideally, Owen would like to have students working on this study in the next few years as it can be done locally.
“The nice thing with bumblebees is they’re easy to collect and they’re pretty abundant around here. Also, it’s fun going out for the day collecting.”
The sample size for bumblebee studies is largely dependent on the type of study. Often Owen will collect as many samples as he can. However, for fluctuating asymmetry, Owen said that ideally you would want to have around 100 of each species. “The more you have, the better,” he said.
It is an assumption that populations in decline are under stress. There is a possibility that it could be due to other unknown reasons and, “it may not have a definite answer.”
“I’ve always considered my research to be mainly fundamental,” said Owen. “Now with species of bumblebees in decline, it is more applied because it relates to real life situations.”
Ethically, Owen’s only concern is collecting a species that is in decline. However, he said that despite the decline of Bombus occidentalis around Calgary, the species thrives in B.C: “There is a vast number of bumblebees out there and only a few are collected every season. I don’t think it could possibly make a dent really in the populations.”
In the past, Owen has had funding from the National Sciences Engineering Research Council. He’s also had a few internal MRU grants, which he mostly used to pay students to do research in the summer. He doesn’t have a grant right now, but suspects he will apply again soon.
“Some of the more theoretical work only takes a pencil, some paper and a computer so you don’t need to spend a lot of money – I’ve been very fortunate,” said Owen.
Owen has made various efforts towards the success of his work, including publishing papers and attending conferences. “Research really isn’t finished until you let other people know about it,” he said.
Looking back, Owen wished he would have done more in many areas surrounding his research, including DNA work. “There’s still a lot of things I would like to follow up on, but there isn’t time,” he said.
Overall, his interest in the bumblebee population is the heart of his research.
To find out more about Robin Owen’s work you can visit his website here
- By Brittany Willsie