In a rejoinder to Gill et alia (2021), Martin (2022) accuses us of perpetuating misconceptions about human nutrition and erroneously describing geophytes as a dietary staple. We provide authoritative definitions for the terms “essential” and “dietary staple” to show that it is Martin who mischaracterizes and misunderstands the foundational role of geophytes and other plant foods to human diets and subsistence economies in Native North America outside of the Arctic. Recent data demonstrate that carbohydrate-rich geophytes were abundant, regularly utilized, and essential resources on the Northern Channel Islands, a dietary staple that was a rich source of calories and complemented the protein-rich shellfish and finfish that were also staple foods for the Island Chumash.

In response to Steve L. Martin's critique of our recent paper we provide further evidence in support of our central contention: that geophytes were a nutritionally important part of the precontact diet, and that they functioned as dietary, cultural, and economic staple foods for many peoples of the Pacific Northwest.

In a recent issue of American Antiquity, two articles (Gill et al. 2021; Lyons et al. 2021) perpetuate the common misconception that dietary carbohydrates are an essential component of the human diet and that plants—the main source of dietary carbohydrates—must be consumed to promote health. In fact, carbohydrate is a nonessential macronutrient with adequate amounts of energy—the sole function of carbohydrates in the human diet—being produced via gluconeogenesis and ketogenesis in the absence of dietary carbohydrate. Additionally, both articles erroneously employ the term “dietary staple” in reference to geophyte consumption.

The foraging behaviour of captive colonies of the highveld mole-rat Cryptomys hottentotus pretoriae was investigated in an artificial soil-filled burrow system provided with four trays (patches) that varied in geophyte density and mass. An initial trial involving empty trays (only soil) revealed that there was no preference for any specific tray. There were no statistically significant preferences for excavating in any of the patches of different geophyte density. No preferences were evident for excavation in patches containing geophytes of different mass classes. Empty patches seemed to be preferred over patches containing geophytes when combinations of geophyte density/mass were investigated. The duration of handling and the rate of consumption of geophytes were recorded for 23 individuals of two mass classes. Handling time of geophytes was not related to mole-rat sex, but was strongly linked to mole-rat mass class. Handling time of geophytes was related to geophyte mass class. Small geophytes were less profitable to consume. These findings are considered in light of optimal foraging theory and the situation in the field. It was concluded that the mole-rats generally followed the qualitative predictions of optimal foraging theory, although falling short of being energy maximizers.