Reducing vulnerability to hazards is a major challenge for pastoral settlements in the dry lands of sub-Saharan Africa. Accumulation of a stock of living animals is a major means of livelihood security that pastoralists use to cope with their constraints, amongst which is high environmental variability. Diversification and long-distance mobility are other means of livelihood security, implying specific family organization. We analysed the combination of these means in ensuring the livelihood security of 508 familial settlements in the rural community of Ferlo, Tessekre (Senegal). At least 40% of the settlements surveyed were small pastoral families, composed of one or two households with small herds (less than 50 cows and 50 sheep). Herds were the major means of livelihood security, but due to lack of a sufficient labour and other assets, the situation of these impoverished families was very precarious. In 28% of the settlements, families combined livestock, crops and non-farming activities as livelihood means. The remaining 32% of the settlements were pastoral settlements supported by large cattle herds and, in many cases, the production of Aïd el Kebir rams (for the major Muslim religious event). Non-farming activities were also present in these settlements with large herds, especially activities in the livestock trade. Diversification can reinforce the function of herds as savings accounts and might also enable the pastoralists to invest in livestock activities. There were three groups of settlements based on the characterization of livelihood security strategies used by pastoral herders. Over time, pastoralists have to utilize several means of security to cope with climatic shocks such as droughts, and familial events such as the death of the familial chief. Family organization (dispersal or grouping), diversification and mobility are important means used to recover after major losses of animals.