What’s Going On With These Scruffy Deer?

May 21, 2020

Question: I photographed these two scruffy looking deer near my home in Mariposa. Are the disheveled, ratty hides caused by ticks and irritation? (Ralph)

Answer: We showed your photos to California Department of Fish and Wildlife (CDFW) biologist Nathan Graveline, who has worked with deer populations for over a decade. He says there are several possible explanations for the way the deer look. Their scruffiness could simply be due to the time of year. In late spring, deer are shedding their winter coats, which are several months old and can start to look tattered. Other possibilities include old age, a copper deficiency or parasitic lice (or an overabundance of other external parasites).

But Graveline says his best guess is that the deer are being fed by locals. The deer in the front looks thin and drawn-in around the belly, which we often see in suburban deer that are being fed by residents. The deer digestive system can’t handle consumption of large amounts of grain. When a deer eats too much grain, its rumen (a chamber in its stomach) produces excessive amounts of acid, which can lead to ruminal acidosis, a disease that leads to declining health or even death. This is just one reason why feeding big game mammals is a bad idea – it’s also against the law, as per California Code of Regulations (CCR) Title 14, section 251.3.