Endangered Species Monday: Bombus occidentalis
“1/3 bites of food we eat comes from a plant that was pollinated by a bee”
What are we humans doing to Planet Earth?, We are destroying so many pollinating animals, that soon they’ll be none left. When or if that day occurs, when there are no more pollinators, we ourselves will be fighting to stay alive, can you imagine that? Human extinction is slowly in the making… …No matter how many vegans or vegetarians there are, we all require plants. No plants = No life!
That’s a Scientific Fact of Life!
Dr Jose Depre
This Monday’s Endangered Species Post (E.S.P) I document on the Western Bumble Bee. Scientifically identified as Bombus occidentalis this particular species of bee is listed as (vulnerable), and is now nearing complete extinction within the wild, despite conservation efforts aimed at reducing dangers, things certainly are not looking good for the bee, or crops the species pollinates either. Image credits: Rich Hatfield
The species was identified back in 1858 by Dr Edward Lee Greene, Ph.D, (August 10, 1843 – November 10, 1915) was an American botanist known for his numerous publications including the two-part Landmarks of Botanical History and the naming or redescribing of over 4,400 species of plants in the American West.
Endemic to: Canada (Alberta, British Columbia, Northwest Territories, Saskatchewan, Yukon); United States (Alaska, Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Utah, Washington, and Wyoming). To date we still don’t know what the “exact current rate of decline is”, or even if the Western Bumble Bee is going to be with us within the next decade. Its ‘likely that based on current surveys the species will be extinct within the next 10 years (max)”.
Since 2008-2014 there has been quite a significant rate of decline st 11%-12%, sparking concerns that the Western Bumble Bee ‘may eventually be listed as critically endangered’ within the United States and Canada. Scientists confirmed that in one area which is [unknown], possibly the United States via field surveys the species was not found during the years of 2003-2007 (which is of course quite concerning), especially when the species is a major pollinator, and has been seen only in very low numbers at (one to seven per year) each year from 2008 to 2014.
A study conducted focusing on ‘range decline’ relating to some eight separate species native to the United States, showed that the Western Bumble Bee species alone had decreased in population size within its (range), by some 28% (EST) between the years of 2007-2008. A further study conducted by conservation scientists concluded that by 2007-2009 surveys detected the species only throughout the Intermountain West and Rocky Mountains; it was largely absent from the western portion of its range.
Further declines have been reported within the [US] states’ of Oregon and Washington, however populations seem to be somewhat stable within (northeastern Oregon). Populations are also to a degree stable within Alaska and the Yukon. Average decline for this species was calculated by averaging the change in abundance, persistence, and EOO.
- Current range size is estimated to be at some 77.96%
- Persistence in current range relative to historic occupancy: 72.56%
- Current relative abundance relative to historic values: 28.51%
- Average decline: 40.32%
From viewing all data records I can confirm that the (exact rate of decline) within the species range, and its persistence total some 20%, with a 70% rate of decline in ‘abundance’. Surveys have also proven the this decades rate of decline is bar far lower than the last decades, which again raises some rather large concerns about a near future extinction occurring.
Image: Western Bumble Bees’ extant zones.
In the past, B. occidentalis was commercially reared for pollination of greenhouse tomatoes and other crops in North America. Commercial rearing of this species began in 1992, with two origins. Some colonies were produced in rearing facilities in California by a company which imported the technology for rearing bumble bees and applied it to rearing B. occidentalis locally in California.
This same year, a distributor for a competitor which did not have rearing facilities in North America at the time was granted permits by the US Department of Agriculture – Animal and Plant Health Inspection Service (USDA-APHIS) for a three year window of time (1992-1994) to export queens of B. occidentalis and B. impatiens to European rearing facilities for colony production.
Following rearing, these colonies were then shipped back to the U.S. for commercial pollination. In 1997, commercial producers began experiencing problems with disease (Nosema) in the production of B. occidentalis. Eventually, the availability of B. occidentalis became critically low, and western crop producers who had become dependent on pollination provided by this species began requesting that APHIS allow the shipment and use of B. impatiens in western states.
In 1998, the USDA-APHIS issued permits to allow B. impatiens to be used in the western U.S. However, within a few years, the USDA-APHIS stopped regulating the interstate movement of bumble bees altogether, citing their lack of regulatory authority. Bombus occidentalis is no longer bred and sold commercially and B. impatiens is used widely in the western U.S. One has to wonder though that since the the US Government stopped granting permits for Bombus occidentalis mostly due to species decline, primarily due to human ignorance, will the same rate of decline now be seen with the species B. impatiens?
Currently to date the only ‘known conservation actions that are under way is that of management, research and surveys’, meanwhile its likely that come the next decade we’ll have lost the species due to a lack of improving/increasing populations, and habitat while failing to decrease disease and virus.
Populations of this declining species have been associated with higher levels of the microsporidian Nosema bombi and reduced genetic diversity relative to populations of co-occurring stable species. The major decline of the subgenus Bombus was first documented in B. occidentalis, as Nosema nearly wiped out commercial hives, leading to the cessation of commercial production of this species. Wild populations crashed simultaneously and the closely related B. franklini has been pushed to the brink of extinction.
However, Koch and Strange (2012) found high levels of infestation by Nosema in interior Alaska where this bumble bee was still quite common. In addition to disease, this species is faced with numerous other stressors including habitat loss and alteration due to agricultural intensification, urban development, conifer encroachment (resulting from fire suppression), grazing, logging and climate change.
Modifications to bumble bee habitat from over grazing by livestock can be particularly harmful to bumble bees by removing floral resources, especially during the mid-summer period when flowers may already be scarce. In addition, livestock may trample nesting and overwintering sites, or disrupt rodent populations, which can indirectly harm bumble bees. Indirect effects of logging (such as increased siltation in runoff) and recreation (such as off-road vehicle use) also have the potential to alter meadow ecosystems and disrupt B. occidentalis habitat.
Additional habitat alterations, such as conifer encroachment resulting from fire suppression, fire, agricultural intensification, urban development, and climate change may also threaten B. occidentalis. Insecticides, which are designed to kill insects directly, and herbicides, which can remove floral resources, both pose serious threats to bumble bees. Of particular concern are neonicotinoids, a class of systemic insecticides whose toxins are extraordinarily persistent, are expressed in the nectar and pollen of plants (and therefore are actively collected by bumble bees), and exert both lethal and sublethal effects on bumble bees.
Since B. occidentalis has recently undergone a dramatic decline in range and relative abundance, reduced genetic diversity and other genetic factors make this species especially vulnerable to extinction, and may lead to increased pathogen susceptibility. Recent research indicates that populations of B. occidentalis have lower genetic diversity compared to populations of co-occurring stable species.
It is therefore regrettable, that despite research, management and surveys - extinction is imminent, when though, we simply don’t know, however when it does happen, it means that yet another pollinator that we humans and animals depend on will be gone for good.
Image: Female B. occidentalis
Humans will never learn or understand just how critically important our wildlife is, until its gone. They’ll then be fighting over themselves, fighting to stay alive. By that time, human extinction will already be in the process.
Dr Jose C. Depre
Chief Environmental & Botanical Officer.
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