Giraffe

Above: a diagram explaining how tannin is used.

Selective Browsers

• A selective browser is an animal that mainly feeds on high-growing woody plants.

• Their diet is high in protein, water, and calcium content.

• Giraffes have been seen chewing on bones, presumably for minerals such as calcium and phosphorus.

Harvesting Equipment: Mouth & Tongue

• • In the mouth, the hardened upper palate helps protect against thorns.

  • The tongue has small, thickened papillae: this protects the tongue from getting cuts or scrapes from the thorns, too!

• Since males are taller than females, they browse at higher levels, reducing competition for food.

Specialized Digestive Tract: 

• Giraffes have adapted to digest acacia's toxins

  • They are able to digest the acacia's fatty acids

  • They cope with the toxic alkaloids in acacia

• Tannin is released as a defense mechanism by acacia trees, it warns nearby acacia trees of giraffes

  • Tannin inhibits digestion by interfering with protein and digestive enzymes

  • Binds to consumed plant proteins, making them harder to digest

  • Once tannin is released, giraffes move up to 100 meters to find acacia trees which were not affected by released tannin

(San Diego Zoo Wildlife Alliance Library staff, 2025)

Ruminant Animal 

• They have a rumen, reticulum, omasum, & abomasum.

• The structure of the gastrointestinal tract is different than that of grazers:

  • Smaller forestomachs compared to grazer-ruminants

  • Male giraffes have larger rumens compared to females due to size differences

• In comparison to grazer-ruminants, giraffes have shorter small and longer large intestines.

  • This compensates for the greater energy supply required by their large size!

• Large volumes of saliva are secreted from the salivary glands for regurgitation and remastication.

  • This thick saliva also coats any thorns that a giraffe might swallow.

(Mitchell, Roberts, van Sittert, 2015; Mitchell, 2021)