We investigated whether persons’ sense of connectedness with nature could substitute a loss of belongingness through increased interest and concern for animals. We manipulated participants’ perceived sense of connectedness to other humans by providing them false results from a questionnaire on their future social belongingness. Participants who were primed to feel less socially connected were predicted to feel lonely and report weaker belongingness with others. Furthermore, loneliness-primed people with a higher relatedness to nature were expected to show the strongest interest and concern for animals, extending their affiliative tendencies towards animals. Results showed that participants who were led to believe they would be less socially connected in the future, and reported higher nature relatedness scores, were found to have the highest average animal caring tendency. Our results demonstrate how people who relate strongly with their natural surroundings have a stronger potential to refocus their affiliative tendencies towards animals when they are made to feel less socially connected. The results direct attention on the relationship between our perceived relatedness to nature and on the current need for social belongingness. The two may interact to influence human-animal relationships, including keeping pets, engaging in animal welfare activities, or taking action for wildlife conservation.