What's in a name: taxonomy Serving Conservation

 

Human persecution of lions has resulted in geographic range collapse and declining populations where they remain.

To understand the consequences of range and population collapse, we surveyed the genetics of more than 500 lions from throughout their remaining range, both in Africa and in Asia.   Most of the sequencing and all the microsatellite analyses were done in Dr. Dubach’s laboratory at Loyola University.

 

There are two major branches of lions: (1) East and South Africa, and (2) Asia and West and Central Africa.

 



Gene substitution networks also show that Asian lions are much closer to those in West and Central Africa than this group is to other African lions.

This map shows Lion Conservation Units (in blue) and haplotypes (coded letters) of the cytochrome-b gene for our 120 samples.  The dotted line separates the two principal genetic lineages of living lions, with Asian lions belonging to the West and Central African clade.

This Structure diagram classifies individual lions by their microsatellites and shows relatively homorgenous populations (like Etosha and Kunene) and highly heterogeneous ones (like the Caprivi Strip and Kwando in Botswana).

In late 2012, the US Fish & Wildlife Service reviewed a petition for uplisting of lions to Endangered Species status.  This move would effectively eliminate sport hunting of lions, as no US sportsmen would be permitted to import trophies.  Vast areas of the African savanna are managed as hunting concessions, remaining in native vegetation because revenue from trophy fees offsets the costs of maintaining them.  Although uplisting lions would surely reduce mortality from hunting, it could bankrupt many concessions and trigger wholesale land conversions to agriculture.

Authorities currently organize international law around Panthera leo leo (African lions) and Panthera leo persica (Asian lions).  However, our analyses show that this does not represent an accurate picture of genetic diversity in living lions. Much larger differences exist among African lions than those between African and Asian lions.  So at least three subspecies are needed to encompass the diversity of lions today: (1) persica, for the Asian lions, (2) leo for the extinct Barbary lion and closely related forms from West and Central Africa, and (3) melanochaita for a large, heterogeneous assemblages of lions in Eastern and Southern Africa.  The last-named group is far more diverse than the prior two, but lions are highly variable and delimiting regional variants within this last form is difficult.  Coordinated studies of genetic, cranial and pelage variation will be needed to arrive at a truly satisfying taxonomy. However, it is important to note that even three names would allow resource managers to better conserve lions.  Only 300 individuals of persica and 500 of leo remain, so these populations clearly warrant the highest levels of federal and international protection.  However, more than 32,000 lions live within the range of what is here treated as melanochaita; accordingly, limited offtake to sport hunting may be managable for this form if (a) it is very carefully regulated and (b) it raises the revenue needed to prevent further fragmentation and loss of the savanna habitats on which both lions and their prey depend. To learn more about this work, see our recent paper: Dubach, J.M., M.B. Briggs, P.A. White, B.A. Ament & B.D. Patterson*. 2013. Genetic perspectives on “Lion Conservation Units” in Eastern and Southern Africa. Conservation Genetics DOI: 10.1007/s10592-013-0453-3.

To see other research from our laboratory, visit these pages:

http://sites.google.com/a/fieldmuseum.org/bruce-pattersons-lab/