<div dir="ltr">So, friends... in newspaper accounts, in almost everyone single one, we see the statement that <i>B. affinis</i> populations have declined by 87%.<div><br></div><div>But have they? I think this is an inaccurate presentation of the situation and a misinterpretation of the FWS assessment of population status:</div><div><br></div><div>See: <a href="https://www.fws.gov/midwest/endangered/insects/rpbb/pdf/SSAReportRPBB.pdf">https://www.fws.gov/midwest/endangered/insects/rpbb/pdf/SSAReportRPBB.pdf</a></div><div><br></div><div>In fact, I think this values greatly under-represents declines in this species.</div><div><br></div><div>First in the FWS report they talk about an 89% decline in the number of U.S. counties occupied, it does not mention 87% anywhere, so am not sure where that figure came from.</div><div><br></div><div>That 87/89% figure does not seem to account for any Canadian counties (or whatever the comparable jurisdiction might be).</div><div><br></div><div>These figures also define occupancy data for a county as a specimen of <i>B. affinis </i>collected after 2000 as "occupied" but is that the best value? From Ohio East there have been thousands and thousands of bumble bees collected and photographed and only a handful of specimens of <i>B. affinis </i>have been collected. In most of these "occupied" counties only single individuals were collected. </div><div><br></div><div>Bees collected in the early 2000's and not seen since are almost certainly the tail end residue of formerly healthy populations, not representatives of hidden <i>B. affinis </i>populations, or people would have found more afterwards ...like they have in the Upper Midwest.</div><div><br></div><div>An occupied county should have locations where <i>B. affinis </i>can be found every year, again this is what we see in some places in the Upper Midwest but do not see outside that area.</div><div><br></div><div>Note too that the number of counties occupied is a very different thing from population size. </div><div><br></div><div>1 single bumble bee or 100,000 bumble bees in an individual county both yield a value of "occupied" for that county but the actual population size would be orders of magnitude different.</div><div><br></div><div>Currently I know of no active colonies of <i>B. affinis </i>from Ohio East</div><div><br></div><div>If we use the more conservative designation (and I think more accurate) of an occupied county as a county having regularly occurring <i>B. affinis </i>in the last 5 years then we have to presume that <i>B. affinis</i> lack viable populations from Ohio East.</div><div><br></div><div>In the Upper Midwest and perhaps Southern Ontario, there are extant colonies of <i>B. affinis</i> But are the number of bees in those counties at their historic highs? Likely not. We don't even have accurate information about the trends or status in these residual sites, but all arrows point towards these as small not large populations.</div><div><font color="#ff0000"><br></font></div><div><font color="#ff0000">I think we need to better clarify the values going out to the public regarding populations status and put the proper perspective on this matter. </font></div><div><br></div><div>Biologically, population size has almost certainly declined far more than 99.9%. And if you defined occupancy at a smaller geographic scale than a county then occupancy decline is also probably near 99.9%.</div><div><br></div><div>I think we have to stop using the value of 87%...particularly when it gets transmitted or interpreted as population decline rather than a perhapsa too rosy estimation of occupancy.</div><div><br></div><div>sam</div><div><br></div><div><div>Sam Droege <a href="mailto:sdroege@usgs.gov">sdroege@usgs.gov</a> </div><div>w 301-497-5840 h 301-390-7759 fax 301-497-5624</div><div>USGS Patuxent Wildlife Research Center</div><div>BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD 20705</div><div><a href="Http://www.pwrc.usgs.gov">Http://www.pwrc.usgs.gov</a></div><div><br></div><div>"Statistics should be like a drunk leaning on a lamppost; for</div><div>support rather than illumination."</div><div> -author unknown</div></div><div><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div style="text-align:center"><i><b>Bees are Not Optional</b></i></div><div style="text-align:center"><i><b><font size="1">Apes sunt et non liberum</font><br></b></i></div></div></div>
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