Let’s Measure Overlap for Grevy’s Zebra and Cape Buffalo

In this case the calculation is:

Sorenson's index formula $\frac{2 \times number of shared plant species = 2 \times 5 = 10}{2 \times no. of shared species + no. species for zebra (animal 1) only + no. species for buffalo (animal 2) only = 10 + 7 + 7 = 24}$

Sorenson's index answer $10 / 24 = 0.42$

Sorenson’s index values range from 0 to 1. High values indicate high overlap, while low levels indicate little overlap.

To express overlap as a percentage multiply the index values by 100. The diets of the zebra and buffalo overlap by 42%.

Plant species found in dung samples from **Grevy's Zebra** and **Cape Buffalo**. (Table scrolls horizontally) Show Venn diagram
Animal	Plant Species
Grevy's Zebra Only	Aristida congesta, grass	Crassulaceae (family), browse	Lintonia nutans, grass	Eragrostis sp., grass	Digitaria velutina, grass	Chloris virgata, grass	Eragrostis racemosa, grass
Cape Buffalo Only	Garnotia (genus), grass	Echinochloa pyramidalis, grass	Leersia hexandra, grass	Pennisetum sp., grass	Acacia drepanolobium, browse	Malva parviflora, browse	Abutilon mauritianum, browse
Grevy's Zebra and Cape Buffalo	Themeda triandra, grass	Aristida kenyensis, grass	Eragrostis superba, grass	Panicum maximum, grass	Setaria sphacelata, grass