The 'challenge hypothesis' posits that testosterone facilitates reproductive effort (investment in male-male competition and mate-seeking) at the expense of parenting effort (investment in offspring and mates). Multiple studies, primarily in North America, have shown that men in committed relationships, fathers, or both maintain lower levels of testosterone than unpaired men. Data from non-west...

The Fulani are semi-nomadic pastoralists of West Africa whose diet, culture, and economy are centred on cattle. Previous studies have shown that the Fulani of northern Nigeria derive 50% of their total calories from fat and 30% of their calories from milk, cheese, yogurt, and butter oil that contain significant amounts of trans fatty acids (TFAs), primarily vaccenic acid, which raise total seru...

Pastoralists are generally known for carefully selecting and maintaining their livestock. In this study, we examine the preferences of pastoralists goat traits. We employ discrete choice experiments all levels endpoints to investigate relative weights that in southern Ethiopia attach different traits does bucks. Based on data generated from 600 pastoral households, estimated willingness pay, tr...

In the western Algerian steppe, public authorities have carried out actions aimed at rural development (agricultural programs) and combating desertification (grazing reserves) to counter significant rapid loss of vegetation cover pastures by overgrazing, consequent impacts on local livelihoods. Rogassa area, these impacted land tenure ancestral collective way use access. These changes caused tr...