Drivers of Hirola Antelope Diet Selection in Natural and Managed Habitat in Eastern Kenya

TL;DR

This study examines the diet and forage preferences of the critically endangered hirola antelope in Kenya to guide habitat restoration and reintroduction efforts.

Contribution

The study identifies specific forage species and nutrient differences between natural and managed habitats for hirola antelope.

Findings

Hirola antelope prefer Chloris virgata grass and Commelina benghalensis and C. diffusa forbs.

Natural habitats have higher phosphorus, magnesium, and digestibility, while managed habitats have more sodium, potassium, and crude protein.

Seasonal variations in calcium and magnesium levels were observed, affecting forage quality.

Abstract

Diet selection, referring to the food that is ingested by an animal along with its nutritional composition, is essential for animal fitness, survival and behavior. The hirola (
Beatragus hunteri
), with ~500 individuals remaining, is classified as Critically Endangered by IUCN and with range degradation from tree encroachment implicated in their decline. For effective hirola recovery, there has to be a clear understanding of habitat‐specific forage quality, prior to planned re‐introduction efforts from managed into natural habitats. We studied populations in natural and managed breeding habitat in eastern Kenya to assess the dietary selection of hirola. Hirola consumed a total of 17 species with
Chloris virgata
being the most preferred grass, while
Commelina benghalensis
and
Commelina diffusa
were the most preferred forbs. Cyperus kilimandscharicus was the only moderately preferred sedge. We then analyzed nutrient content for 14 variables, including crude protein (CP), fiber fractions, in vitro dry matter digestibility (IVDMD), and key minerals. Forage in natural habitats was more closely associated with higher levels of phosphorus (P), magnesium (Mg), and IVDMD, while managed habitats were characterized by elevated sodium (Na), potassium (K), and CP levels. Seasonal differences were also detected, particularly in calcium (Ca) and Mg concentrations. Our results reveal substantial variation in plant chemical composition, forage quality and diversity between habitats, necessitating adaptive foraging strategies. Future habitat restoration programs should focus on monitoring and reseeding preferred forage species and the provisioning of supplementary diets with appropriate chemicals to support newly released herds or in the breeding facility.

Hirola (
Beatragus hunteri
) populations in eastern Kenya consumed 17 forage species, favoring the grass
Chloris virgata
and the forbs
Commelina benghalensis
and
C. diffusa
. Nutrient analyses showed that natural habitats offered higher phosphorus, magnesium, and digestibility, whereas managed sites provided more sodium, potassium, and crude protein, with notable seasonal shifts in calcium and magnesium. These patterns highlight the need for habitat‐specific reseeding of preferred plants and targeted mineral supplementation during future restoration and reintroduction efforts.

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