The Problem with Preble’s

By Mike Dubrasich

Once upon a time there was a taxonomy war waged between two armed camps: the Lumpers and the Splitters. That war is history now, long over. The Splitters won and the Lumpers lost, big time.

For the uninitiated, Lumpers were the taxonomists who believed most animals and plants should be classified as members of a few well-defined species. They lost. The victorious Splitters are those who believe every individual organism is a species unto itself.

At first glance, it’s difficult to see how mild mannered, obsequious and bespectacled academics puttering around labs and peering into dissection scopes could be accused of warfare. The assertion seems a trifle hyperbolic for mixed company. But it was a war, with territorial conquest, mass destruction, casualties of combatants and non-combatants alike, and plenty of collateral damage.

One of the bloodiest battles was over a common rodent. The Jumping Mouse (Zapus hudsonius) is a cute little furball distinguished by a long tapering tail, large hind feet, small front feet, and a propensity to hop erratically through the grass when disturbed. Sometimes called a kangaroo mouse, Z. hudsonius is native and common to Asia and North America, found from the Atlantic coast to the Great Plains, in the Southwest, in the Pacific Northwest, and northward to the arctic tree-line of Alaska and Canada, frequenting hayfields and wheat farms as well as native grasslands. Billions of the little critters live in perfect harmony with graziers and agriculturalists across two continents. They have the widest known distribution of mice in the subfamily Zapodinae.

That was before the Splitters weaponized the cowering wee beasties. Today there are dozens, possibly hundreds, of “recognized” species, sub-species, sub-subs, and Distinct Population Segments (DPS’s), including but not limited to:  Z. trinotatus orarius, Z. burti, Z. hudsonicus, Z. hudsonicus acadicus,· Z. hudsonius (Jumping Mouse), Z. hudsonius acadicus, Z. hudsonius alascensis (Alaska Jumping Mouse), Z. hudsonius alscensis, Z. hudsonius americanus, Z. hudsonius campestris, Z. hudsonius canadensis, Z. hudsonius hardyi, Z. hudsonius hodsonius, Z. hudsonius intermedius, Z. hudsonius ladas, Z. hudsonius luteus (Meadow Jumping Mouse), Z. hudsonius pallidus, Z. hudsonius preblei (Preble’s Meadow Jumping Mouse), Z. hudsonius tenellus, Z. insignis, Z. orarius, Z. princeps (Pacific Jumping Mouse), Z. princeps chrysogenys, Z. princeps cinereus, Z. princeps curtatus, Z. princeps idahoensis, Z. princeps kootenayensis, Z. princeps kootenayonsis, Z. princeps kootnayensis, Z. princeps luteus, Z. princeps major, Z. princeps minor, Z. princeps oreganus, Z. princeps oregonus (Big Jumping Mouse),  Z. princeps pacificus, Z. princeps palatinus, and  Z. princeps princeps (Western Jumping Mouse).

Is there any significant difference between these subspecies? Short answer: no. Dr. Matthew Cronin, PhD., Professor of Animal Genetics, Univ. Alaska Fairbanks, wrote in Cronin, M. A. 2007. The Preble’s meadow jumping mouse: subjective subspecies, advocacy and management. Correspondence, Animal Conservation 10 (2007) 159–161:

“… Briefly, the Preble’s mouse was designated a subspecies with limited descriptive morphological data. There are no diagnostic characters that unequivocally distinguish it from con-specifics. It does not have monophyletic mitochondrial DNA. It may be geographically isolated from, and have different allele frequencies than, con-specific populations. Sample sizes and locations studied are probably small relative to population numbers. The allele frequency differences are for DNA loci that are usually considered selectively neutral. There are no data documenting local adaptation…”

Limited descriptive morphology is akin to hog judging — not quite rigorous science. But no matter. Almost overnight, or so it seemed, one species became a plethora, and some of the obscure tribes were suggested to be, dum tata dum, in danger of going extinct! The Splitters got on the bandwagon and played mournful tunes across the land. Sue-happy enviros with monkeywrencher attorneys heard the dirge and danced a jig into court.

And so it came to pass that the Preble’s MJM (Zapus hudsonius preblei) was listed as a Threatened Species under the Endangered Species Act by bureaucratic functionaries of the US Fish and Wildlife Service.

When that happened, the proverbial stuff hit the fan because real people were really affected. Farmers, ranchers, and suburban home owners in the new Preble’s Zones stood to lose their homes, land, and livelihoods. The Preble’s MJM went off the ESA list and then back on, but only in certain states. The USFWS “experts” declared that the sub-species existed only up to a state line, which the mice never cross (for tax reasons, apparently). Congress got involved and fulminated. When the smoke finally cleared the battlefield, the deed was done and the war was lost. The Lumpers, what few of them were left, were defeated and cancelled. The spoils of war, mainly government grants and kickbacks, accrued to the victors.

That was 1995. Unsuccessful delisting litigations lasted until 2018. In the meantime, vast tracts of grassland were acquired and designated by various governments for Preble’s MJM habitat. Of course, ranching, farming, and dwellings were expressly forbidden on the preserves, because mice cannot co-exist with humans (or so it was claimed despite a zillion instances where they do). No Management was selected as the wisest course of action.

In due course the touchy-feelies in Boulder CO joined the victory parade. The Boulder County Comprehensive Plan designated Environmental Conservation Areas, Critical Wildlife Habitat and Migration Corridors, and Habitat Conservation Areas for the Preble’s Meadow Jumping Mouse. These were selected areas “of unique habitat which has a crucial role in sustaining populations of native wildlife and in perpetuating and encouraging a diversity of native species.”

And in due course last December one of the selected areas and adjacent subdivisions had a predictable wildfire, which destroyed 1084 residential structures and damaged another 149. Thankfully there were only two fatalities. Total countywide value of residential damage from the Marshall Fire is estimated to be $513,212,589 [here]. Naturally, global warming was blamed [here] instead of bogus taxonomists, grasping political functionaries, dimwit planners, and deluded enviro zealots.

The mice probably did okay. After all, Jumping Mice have been surviving grass fires for millions of years. The humans not so much. As is customary in war, many non-combatants were collaterally damaged by scorched earth. Unscathed in any way are the Splitters and their pals, who are all fat, happy, and busy planning more disasters.

If you know of any Lumper, please show some compassion and drop some coins in his cup. He and his taxon served valiantly and nobly, albeit not triumphantly. Dulce et decorum est pro patria mori.

About the author:  Mr. Dubrasich is a retired forester, forestry consultant, and forest biometrician. He was a founding partner of Pacific Analytics, LLC (statpros.com) and founder and former Executive Director of the Western Institute for Study of the Environment.