Female mammals kill the offspring of their competitors when resources are scarce

Dieter Lukas and Elise Huchard have now looked into infanticide by female mammals. In previous studies, males have been found to kill when females will not mate with them if they are still caring for an offspring sired by their previous partner. "Across mammals, females are more likely to commit infanticide when conditions are harsh and when having offspring is particularly costly to females," says Huchard. "The potential triggers and likely benefits of infanticide however appear to differ according to the specific circumstances."

source https://www.lifetechnology.com/blogs/life-technology-news-blog/female-mammals-kill-the-offspring-of-their-competitors-when-resources-are-scarce