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Are Native Bees Dying?

Native bees are apparently in trouble. They are dying by the millions. We all need to plant more flowers to try and save the bees. Turns out that much of this is based on false information. We don’t actually know the status of most native bees.

In this post I will look at how this myth got started and discuss some real facts about native bees.

Are native bees dying? Bumblebee on flower

Are native bees dying? Bumblebee on flower

Pseudoscience Speaks – the Media Follows

In early 2017, the Center for Biological Diversity (CBD), delivered its monumental study entitled “Pollinators in Peril: A systematic status review of North American and Hawaiian native bees“. It appeared to show clear evidence that native bees were in trouble.

The media quickly picked up the story. Reuters reported “Hundreds of North American bee species face extinction”. TIME magazine produced a video and titled their piece “More than 700 North American Bee Species Are Headed Toward Extinction”. Numerous other media outlets followed suit and social media went wild with the story.

Did nobody notice that the TIME video introduction for their story shows honey bees – not native bees? Do their staff not know the difference? More evidence to support my post Honey Bees vs Native Bees.

Who is the Center for Biological Diversity?

This certainly sounds like a legitimate organization who would know something about the subject matter. The Center for Biological Diversity is a nonprofit conservation organization with more than 1.2 million members and online activists. In 2014 it generated more than $14 million in support and revenue. It is virulently opposed to genetically engineered crops and promotes a number of positions out of alignment with the consensus of science. Its staff consists of more lawyers than scientists, and its executive director is a former member of the radical environmentalist group Earth First”.

The Center for Biological Diversity is neither a research organization, nor an unbiased group. It has no expertise in bee research.

The referenced report is an internal report which has not been published in a peer review journal.

What Does the Study Say?

Here are some of the highlights of the study (ref 3).

Systematic Review

The CBD “conducted a systematic review of the status of all 4,337 North American and Hawaiian native bees.”

In the U.S. and Canada, there are only about 3,600 valid bee species. The status of most of these is not know so it is hard to understand how the CBD reviewed their status or how they can report on 700 bee species that do not exist?

More Than 50% are Declining

“Among native bee species with sufficient data to assess (1,437), more than half (749) are declining.” No data is presented to support this conclusion.

Insufficient Data

“For many of the bee species lacking sufficient population data [67 percent, 2,900 out of 4,337 ], it’s likely they are also declining or at risk of extinction.” If there is not enough data how can you make such a conclusion? This is clearly just a wild guess which happens to align itself with the groups mission.

Reason For Declines

“A primary driver of these declines is agricultural intensification, which includes habitat destruction and pesticide use”. The study makes no attempt to look at information about the root causes of decline. This is pure speculation but is presented as one of the findings in the so-called systematic review. Habitat destruction is probably a factor, but studies do not indicate that declines are due to pesticide use. In the case of Colony Collapse Disorder in honey bees the root cause is not pesticides.

Problems With the Study

When Sam Droege, a top native bee expert, was asked about the study he said ” it wasn’t peer reviewed; statistical, taxonomic, and natural history problems regarding the species’ records were not addressed” (ref 1).

In layman’s terms the report contains no data to support its conclusions and even a cursory review by media authors would revel this problem. In fact there is almost no data in the report.

The report’s main author, Kelsey Kopec, is NOT an expert on the subject and “it was not written by a team of bee specialists or by independent entomologists. It excluded any input or even a review from wild bee experts” (ref 1).

In short, none of the conclusion reached by the study are valid or supported by science.

Status of Native Bees

What do we know about native bees? To be honest, not very much. With 20,000 native bees in the world and very little research money, progress is slow. Most native bees are solitary bees and are extremely difficult to study.

For most species there is not enough scientific data to accurately asses their status.

Ken Droege is developing native bee survey techniques and monitoring programs and has this to say about the information we know, “I know all of the data—in fact, we generated a lot of that—and there’s statistically almost nothing you can do with the information that’s out there to talk about the status,” (ref 1).

Are Some Native Bees in Trouble?

Definitely. The number of bees on endangered lists is much smaller than suggested by either the above mentioned report or the media.

The first bees to be added to the endangered list in the US occurred in 2016 when “All seven species belonging to the Hylaeus genus of bees, commonly known as “yellow-faced” or “masked” bees were declared endangered. These species are responsible for pollinating some of Hawaii’s indigenous plant species, many of which are threatened themselves.” (ref 4).

In early 2017, “The U.S. Fish and Wildlife Service designated the rusty patched bumblebee an endangered species — the first such designation for any bee species in the continental U.S. (ref 5).

The European Red List of Bees concluded that “9.2% of bees (total of 1,965 species) are considered threatened in all of Europe. However, for 1,101 species (56.7%) in Europe there was not enough scientific information to evaluate their risk of extinction and thus, they were classified as Data Deficient ” (ref 6).

Reasons for Decline

It is very hard to explain why some native bees are on decline, mostly because we don’t know enough about them.

Habitat Loss

Habitat loss is almost certainly a main factor. Many native bees are specialists that require specific habitats to survive. Some rely on a single type of flower. It is no surprise that such bees will have trouble as habitats are lost.

Pesticides

Are pesticides a main factor? For the honey bee the more modern pesticides, like the neonics, do not seem to be a main cause of death. However, we do not know how native bees react to the pesticides.

It would be incorrect to say pesticides have no effect, but the research does not support the commonly held belief that this is a major reason for decline.

In Honey Bees vs Native Bees, I reported on the fact that chemicals can affect native bees quite differently than honey bees – sometimes the chemical is more toxic and sometimes less. Yet almost all our information about pesticides is for honey bees.

Are Honey Bees Killing Native Bees?

The varroa mite and numerous viruses are causing significant deaths in honey bees. Recent research suggests that honey bees can transmit this pest and some of the viruses to native bee populations, resulting in the death of native bees (ref 7, ref 8).

It is still early days in this type of research, but if this turns out to be true, your efforts to attract honey bees to your garden may contribute to the death of your native bees.

There is still much to learn, but it is important the we separate fact from fiction.

References:

  1. Scientists Challenge Center for Biological Diversity Report Claiming Wild Bees Near Extinction; https://www.geneticliteracyproject.org/2017/04/04/scientists-challenge-center-biological-diversity-report-claiming-wild-bees-near-extinction/?source=science20.com
  2. Treatment-free Beekeepers; https://thoughtscapism.com/2017/04/10/treatment-free-beekeepers-give-varroa-mite-free-rein/
  3. Pollinators In Peril; https://www.biologicaldiversity.org/campaigns/native_pollinators/pdfs/Pollinators_in_Peril.pdf
  4. Bees Added to the US Endangered Species List; https://www.washingtonpost.com/news/speaking-of-science/wp/2016/10/03/u-s-bees-were-just-added-to-the-endangered-species-list-for-the-first-time/?utm_term=.e2a78bc16494
  5. U.S. Puts Bumblebee On The Endangered Species List For 1st Time; http://www.npr.org/sections/thetwo-way/2017/01/11/509337678/u-s-puts-first-bumblebee-on-the-endangered-species-list
  6. European Red List of Bees; http://ec.europa.eu/environment/nature/conservation/species/redlist/downloads/European_bees.pdf
  7. Do managed bees drive parasite spread and emergence in wild bees?; http://www.sciencedirect.com/science/article/pii/S2213224415300158
  8. Commercial Bees Threaten Wild Bees; http://www.bbc.com/news/science-environment-30831257
  9. Photo Source; Christian Bauer

 

Robert Pavlis
Editor of GardenMyths.com
I live in southern Ontario, Canada, zone 5 and have been gardening a long time. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

I hope you find Garden Myths an educational site that helps you understand your garden better.

2 Responses to 'Are Native Bees Dying?'

  1. Thanks again Paul . . .

  2. Mike Ricci says:

    Excellent write up! Mites are a big deal here with our honeybees. We use pesticides including neonics, but have never seen any bee mortality or impact on our hives. In most cases, the bees do not forage in neonic treated crops like potatoes and we have not witnessed them foraging in sweet corn either. By the time our squash are blossoming, we are only spraying fungicides and we do that late in the day after blossom closure. But the mites weaken the bees and can hamper their efforts to overwinter. The mites are also quite capable of moving from foraging bee to foraging bee. If these mites are attacking native bees, than they will certainly be impacted. And by the way, we’ve had the Rusty Patched Bumblebee nest behind an ornamental 1/2 barrel hanging on the side our house a couple of years running now! Thank you for an unbiased discussion on this issue.