Why can drought and deep snow limit artiodactyl populations?

Drought and deep snow are critical environmental factors that can limit artiodactyl populations by restricting access to food and hindering movement.1

• Drought: This condition can lead to a severe shortage of forage. When food supplies are insufficient, animals may die of starvation, causing significant population declines that can persist for many years. Furthermore, undernourishment increases an animal's susceptibility to parasites and disease, which can indirectly contribute to mortality.1
• Deep Snow: For many Asian artiodactyls, the thickness of snow cover is a primary limiting factor. For instance, the saiga struggles to move in snow deeper than 40 cm, while the argali (Ovis ammon) is limited by snow deeper than 60 cm. Beyond physical obstruction, compacted snow or ice layers can prevent animals from reaching vegetation, while hoarfrost on plants can further reduce food availability. These conditions weaken animals, making them more vulnerable to predators or direct starvation.1

To survive these challenges, some species have evolved strategies such as long-distance migration or rapid maturation to recover population numbers after heavy losses.1