Why the Indian subcontinent holds the key to global tiger recovery.
With only approximately 3,000 wild individuals surviving restricted to just 7% of their historical range, tigers are now a globally threatened species. Therefore, conservation efforts must prioritize regions that harbor more tigers, as well try to capture most of the remaining genetic variation and habitat diversity. Only such prioritization based on demographic, genetic, and ecological considerations can ensure species recovery and retention of evolutionary flexibility in the face of ongoing global changes. Although scientific understanding of ecological and demographic aspects of extant wild tiger populations has improved recently, little is known about their genetic composition and variability. We sampled 73 individual tigers from 28 reserves spread across a diversity of habitats in the Indian subcontinent to obtain 1,263 bp of mitochondrial DNA and 10 microsatellite loci. Our analyses reveals that Indian tigers retain more than half of the extant genetic diversity in the species. Coalescent simulations attribute this high genetic diversity to a historically large population size of about 58,200 tigers for peninsular India south of the Gangetic plains. Furthermore, our analyses indicate a precipitous, possibly human-induced population crash approximately 200 years ago in India, which is in concordance with historical records. Our results suggest that only 1.7% (with an upper limit of 13% and a lower limit of 0.2%) of tiger numbers in historical times remain now. In the global conservation context our results suggest that, based on genetic, demographic, and ecological considerations, the Indian subcontinent holds the key to global survival and recovery of wild tigers.
Mondol
Samrat
S
National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
Karanth
K Ullas
KU
Ramakrishnan
Uma
U
D000818:Animals; D003247:Conservation of Natural Resources; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation; D007194:India; D018895:Microsatellite Repeats; D046010:Tigers / Q000235:genetics*
D004272:DNA, Mitochondrial
Mol Ecol. 2005 Jul;14(8):2611-20
15969739
PLoS Biol. 2004 Dec;2(12):e442
15583716
Evol Bioinform Online. 2007 Feb 23;1:47-50
19325852
Mol Ecol. 2001 Feb;10(2):305-18
11298947
Genetics. 1996 Dec;144(4):2001-14
8978083
Genetics. 1996 Nov;144(3):1225-35
8913763
Science. 2001 Nov 30;294(5548):1923-6
11729317
PLoS Biol. 2006 Feb;4(2):e25
16417405
Evolution. 2002 Apr;56(4):817-29
12038539
Proc Natl Acad Sci U S A. 2004 Apr 6;101(14):4854-8
15041746
Bioinformatics. 2006 Mar 15;22(6):768-70
16410317
Mol Biol Evol. 2003 Jan;20(1):76-86
12519909
Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):4334-9
12655042
Genetics. 1999 Dec;153(4):2013-29
10581303
Bioinformatics. 2003 Dec 12;19(18):2496-7
14668244
Science. 2007 Sep 7;317(5843):1312-4
17823325
Ecology. 2006 Nov;87(11):2925-37
17168036
J Hered. 2001 Nov-Dec;92(6):497-502
11948217
Evolution. 2002 Jan;56(1):154-66
11913661
Genomics. 1999 Apr 1;57(1):9-23
10191079
Mol Ecol. 2005 Jan;14(1):9-17
15643947
Mol Ecol. 2003 Apr;12(4):869-80
12753208
Proc Natl Acad Sci U S A. 2005 Nov 1;102(44):15942-7
16243969
Genetics. 2000 Jun;155(2):945-59
10835412