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?