Large herbivorous animals such as the hippopotamus have populations of insectivorous birds that feed off the many parasitic insects that grow on the hippo.
This fits with the popular image of small, nocturnal insectivorous mammals surviving in niches not accessible to the large, dominant contemporary dinosaurs.
Apart from possible habitat destruction, it appears that indiscriminate use of pesticides has a strong effect on this species due to its insectivorous habits.