We appeal to the concept of a broad spectrum of solidarities, including those typically dismissed as merely rhetorical and parasitical. The concept of a solidarity spectrum captures both the phenomena of nonhuman solidarities among wild so-called co-predators, working together, and human solidarity with co-predators. We first consider the present normative literature on solidarity to establish the case for understanding solidarity as a spectrum of relations, practices, and actions, with different and morally ambiguous consequences for in- and out-group members. We then apply this concept of a spectrum of solidarities to the zoological and ethological research concerning co-predation alliances among members of different species reducing their own vulnerabilities in the wild, but only at the expense of other species. We also consider interspecies solidarity through practices like alloparenting. Finally, we argue human solidarity with wild co-predatory killers represents yet another gradation along the broad spectrum of solidarities. Our analysis contributes an approach to understanding diverse forms of solidarity across different species lines otherwise lacking in the recent solidarity literature concerning nonhuman and human animals.