The Population Ecology of Elephants By Kim Hodlin

Goals of Presentation

Introduce the basic ecology of elephants

Review several studies that examine the population ecology of elephants

Draw overarching conclusion from these studies

Introduction

There are three species of Elephants: Elephas maximas, Loxodonta africana, Loxodont

cyclotis.

Elephants are found in Asia and Africa.

They live in matrilineal

groups.

Elephants are generalist herbivores.

They have no primary

predators.

Asian elephants are endangered and the African

elephants are vulnerable. This is mainly a result of

anthropogenic effects.

Distributions of Populations Hema et al. 2011, Grant et al. 2008, and Chamaille-Jammes

et al. 2007 studied the distribution of elephant

populations.

All of these studies found that elephants preferred to live in areas with high abundances of water, high abundances of tree fall, and large distances

from human settlements.

In all three studies, these associations were stronger in the dry season than in the wet

season.

The Effect of Elephants on Prey Populations

Ssali et al. 2013 studied the effects of African savanna elephant populations on plant populations and looked into which species of plants elephants typically prefer to eat.

Elephants were found to prefer mid-successional plant species.

Elephants cause damage to their prey. They tend to break the branches of small plant species and

remove the bark on larger plant species.

Elephant damage was more prominent in open areas than those with heavy foliage.

This damage is increasing because the population density of these elephants is increasing. This could result in extinctions of elephant prey species.

Crop Raiding

Crop raiding is when elephants eat crops that humans grow.

Chiyo et al. 2005 studied the population dynamics of crop raiding in African elephant populations.

Crop raiding elephants tend to be males. They begin raiding as soon as they

disperse from their matrilineal groups.

The older the elephants, the more frequently they raided crops.

Male elephants tend to raid in groups.

They believe that this behavior could be influenced by intraspecific competition between males for finding mates.

Human Impacts on Elephant Populations

Elephant populations are declining due to their proximity to human settlements.

This decline is caused by increases in human populations, habitat fragmentation, and poaching.

Maisels et al. 2013 studied the decline of African forest elephant populations.

Reintroduction of Elephants

One approach to conserving elephants is to re-introduce them to the wild.

Evans et al. 2013 studied the release of captive male African savanna elephants into the wild. Overall, there were no significant behavioral differences

between the released and wild elephants. Both wild and released elephants stayed away from human

settlements and occupied similar habitats.

Released elephants tended to be less social.

Slotow et al. 2005 studied the translocation of African savanna elephant populations into reserves. They found these translocations to be successful.

Conclusions

Elephant populations are in decline.

Elephants prefer to live in habitats with a high abundance of water, dense foliage, and far distances from humans.

Elephant populations can negatively affect their prey populations.

Due to their increasing proximity with human populations, elephants are participating in crop raiding.

Elephant populations are heavily influenced by anthropogenic effects.

Reintroduction efforts to conserve elephant populations have been successful.

Works Cited CHAMAILLÉ-JAMMES, SIMON, MARION VALEIX, and HERVÉ FRITZ. "Managing Heterogeneity In Elephant Distribution: Interactions Between Elephant Population

Density And Surface-Water Availability." Journal Of Applied Ecology 44.3 (2007): 625-633. Academic Search Premier. Web. 21 Apr. 2013.

Chiyo, Patrick I., and Erica P. Cochrane. "Population Structure And Behaviour Of Crop-Raiding Elephants In Kibale National Park, Uganda." African Journal Of Ecology 43.3 (2005): 233-241. Academic Search Premier. Web. 21 Apr. 2013.

De Silva, Shermin, and George Wittemyer. “A Comparison of Social Organization in Asian Elephants and African Savannah Elephants.” International Journal of Primatology Online (2012): n. pag. Web. 31 Jan. 2012.

Evans K, Moore R, Harris S (2013) The Social and Ecological Integration of Captive-Raised Adolescent Male African Elephants (Loxodonta africana) into a Wild Population. PLoS ONE 8(2): e55933. doi:10.1371/journal.pone.0055933

Grant M. Harris, Gareth J. Russell, Rudi I. van Aarde and Stuart L. Pimm (2008). Rules of habitat use by elephants Loxodonta africana in southern Africa: insights for regional management. Oryx, 42, pp 66-75. doi:10.1017/S0030605308000483.

Hema, Emmanuel M., Richard F. W. Barnes, and Wendengoudi Guenda. "Distribution Of Savannah Elephants ( Loxodonta Africana Africana Blumenbach 1797) Within Nazinga Game Ranch, Southern Burkina Faso." African Journal Of Ecology 49.2 (2011): 141-149. Academic Search Premier. Web. 21 Apr. 2013.

Maisels F, Strindberg S, Blake S, Wittemyer G, Hart J, et al. (2013) Devastating Decline of Forest Elephants in Central Africa. PLoS ONE 8(3): e59469. doi:10.1371/journal.pone.0059469

Roever, C. L., van Aarde, R. J. and Leggett, K. (2012), Functional responses in the habitat selection of a generalist mega-herbivore, the African savannah elephant. Ecography, 35: 972–982. doi: 10.1111/j.1600-0587.2012.07359.

Slotow, Rob et al. “Population Dynamics of Elephants Re-introduced to Small Fenced Reserves in South Africa.” South African Journal of Wildlife Research 35.1 (2005): 23–32. Print.

Ssali, F., Sheil, D. and Nkurunungi, J. B. (2013), How selective are elephants as agents of forest tree damage in Bwindi Impenetrable National Park, Uganda?. African Journal of Ecology, 51: 55–65. doi: 10.1111/aje.12006

Surendra Varma, Nguyen Xuan Dang, Tran Van Thanh and R. Sukumar (2008). The Asian elephants Elephas maximus of Cat Tien National Park, Vietnam: status and conservation of a vanishing population. Oryx, 42, pp 92-99. doi:10.1017/S0030605308010090.

Wayne M. Getz, et al. "Usual Populations, Unusual Individuals: Insights Into The Behavior And Management Of Asian Elephants In Fragmented Landscapes." Plos ONE 7.8 (2012): 1-16. Academic Search Premier. Web. 21 Apr. 2013.

Wittemyer, George, David Daballen, and Iain Douglas-Hamilton. "Comparative Demography Of An At-Risk African Elephant Population." Plos ONE 8.1 (2013): 1-10. Academic Search Premier. Web. 21 Apr. 2013.

Questions?