Using Population Ecology in the Conservation of the Black Rhinoceros James Booth
Goals
Provide background info on Rhino biology and life history
Highlight threats facing Rhino populations and their effects
Discuss studies that have been conducted on rhino populations that directly affect their conservation
Focus on possible solutions to issues facing these populations
Background
800-1,400 kg
Dark yellow brown, dark brown, gray coloration
Two horns
Prehensile upper lip (differentiates from White)
Native to grasslands-forest transition areas, range to desert/mountain forests
Eastern, Central, Western, Southern Africa
Feed on Acacia, woody plants, legumes, shrubs, mineral licks
Social Structure & Life History
Most adults solitary, but maternal groups are formed
Battles during courtship
Lifespan: 40-50 years
Age of First Repro: Males (10-12), Females (6-7)
Gestation: ~1.3 years, 2.5-3.5 years between calves
K-Selected
IUCN Summary
Critically Endangered
Seen 97% decrease in original population between 1960-2010 (100,000 to 2,400)
Massive conservation efforts have gotten the numbers back to ~5,000
Mostly limited to reserves and protected areas, extinct in certain countries
Threats
Overhunting/Poaching
- Began with European Settlers in the 1600’s (easy targets)
- Demand from Asian medicine market
- Organized poaching gangs (military grade tech)/instability of governments
Habitat Loss
Genetics in Conservation
Most remaining rhinos split into groups of <100
Use microsatellite arrays taken from fecal samples to observe genetic relatedness in small populations of rhinos
Leads to very accurate paternity testing, evidence of polygyny with varying success
Information useful in PVAs, reasoning for translocations, subspecies identification
Browsing Competition
Elephants and Giraffes in Rhino reserves deplete vegetation at 2% per year, 5% if growth rates continue
Leads to unsustainable habitat, negatively affects rhino breeding
Some proposed solutions are translocating elephants or expanding reserve area and vegetation as a result
Protection and Lingering Issues
Studies show that protecting key areas of rhino habitat with armed park guards and strong management techniques decreasing effects of poaching and resulting population decline
However, some population decline was still noted, possibly due to increased dispersal and reclusiveness of rhinos.
Cross-border-monitoring and translocation necessary
Summary
Poaching is the primary cause of rhino population decline, but it is furthered by habitat destruction, lack of genetic diversity (polygyny, genetic isolation), slow population turnover, and increased dispersal.
Can be counteracted by increasing reserve area, increasing security, close monitoring of genetic composition of populations, and possible translocation of rhinos in order to increase genetic diversity in a given population.
Sources
HARLEY, E. H., BAUMGARTEN, I., CUNNINGHAM, J. and O'RYAN, C. (2005), Genetic variation and population structure in remnant populations of black rhinoceros, Diceros bicornis, in Africa. Molecular Ecology, 14: 2981–2990. doi: 10.1111/j.1365-294X.2005.02660.x
Birkett, A. (2002), The impact of giraffe, rhino and elephant on the habitat of a black rhino sanctuary in Kenya. African Journal of Ecology, 40: 276–282. doi: 10.1046/j.1365-2028.2002.00373.x
Garnier, J. N., Bruford, M. W. and Goossens, B. (2001), Mating system and reproductive skew in the black rhinoceros. Molecular Ecology, 10: 2031–2041. doi: 10.1046/j.0962-1083.2001.01338.x
iucn.redlist.org/blackrhinoceros
wwf.panda.org/blackrhinoceros
Questions?