Blue Ear Tag on a Doe?

Tagged doe
Tagged Deer in Mendocino National Forest. Photo courtesy of Rosanna Ocegueda.

Question: I was hunting up in the Mendocino National Forest and saw a doe with a blue ear tag on her left ear. I have never seen this before and was curious as to whether or not you may know what the tag means. I have attached a picture that I took of the deer. I hope you satisfy my curiosity! (Rosanna)

Answer:  Thank you for the photo! We shared it with our Deer Program biologists, who were tickled to see that one of their study deer – aka 7303 with the blue left ear tag 804 – was alive and well in the Mendocino National Forest – almost eight years after she was captured and tagged there by our biologists. She is estimated to be 14 years old today.

Deer 7303 is a survivor for sure. She was part of a five-year population assessment — from 2009 to 2013 — of Columbian black-tailed deer in the Mendocino National Forest conducted by the California Department of Fish and Wildlife (CDFW) and researchers from UC Davis. The 2014 Final Project Report is still available online.

Deer 7303 was one of 57 adult female deer captured as part of the study, along with 137 fawns and seven mountain lions. Deer 7303 was captured by tranquilizer dart on June 6, 2012, and determined to be 7 years old at the time. She also had a fawn with her. In addition to the blue ear tag, deer 7303 was outfitted with a GPS tracking collar, which she wore for 453 days before the collar dropped off. All collars were fitted with automatic releases to drop off after a certain amount of time.

Deer 7303 has fared much better than many of the other study deer. The study found that while Columbian black-tailed deer in the Mendocino National Forest were abundant with average pregnancy and birth rates, their population was on the decline primarily as a result of low adult female survival. Researchers investigated deer mortalities and confirmed predation accounted for approximately 57 percent of the 21 deaths investigated by staff. Most of the predation was from mountain lions, one was killed by a black bear, poachers took two of the does, and seven died from unknown causes. Black bears, however, were the main predators of fawns, particularly within 30 days of birth. The researchers also found that habitat quality – or lack thereof – played a role in low fawn and doe survival.

The assessment of deer in the Mendocino National Forest is just one of many studies conducted by CDFW deer biologists to better understand the mechanisms that drive deer populations throughout California.

Illegal to feed feral cats?

Question: I’ve seen a couple of feral cat feeding stations located around urban areas. I thought that feeding feral cats was illegal under the California Code of Regulations Title 14, section 251.1, “Harassment of Animals.” I know you folks have a lot more important things to do, but is this something we should notify our local game warden about? (Mark G.)

Answer: Section 251.1 states that “no person shall harass, herd or drive any game or nongame bird or mammal or furbearing mammal. For the purposes of this section, harass is defined as an intentional act which disrupts an animal’s normal behavior patterns, which includes, but is not limited to breeding, feeding or sheltering.” But feral cats do not meet the definition of “game or nongame mammal” or “furbearing mammal” – and as they are still technically domesticated, they are not considered to be wildlife.

Even though the code does not apply to domestic animals, there may be local (city) ordinances that prohibit feeding feral cats. Large cat colonies can attract larger predators, including coyotes and mountain lions, which is never a good idea in an urban area. Your local animal control office will be able to answer questions about feral cat management in your area.

Keeping an eye out for quagga

Question: Do you have a map of California waters that are infested with quagga mussels? (Walter)

Answer: CDFW’s Fishing Guide is updated in real time. Just select the filter for “Quagga Infested Areas” on the left.

You can also find a printable map of infested waters on our website. It is current, including the most recent quagga discovery in the Upper San Gabriel River in October 2017. However, it does not indicate all of the waters without mussels, nor does it depict stretches of flowing waters that are infested (e.g., the lower Colorado River).

CDFW works to monitor for new infestations of quagga and zebra mussels and other invasive species, but it is possible an infestation may be present but not yet detected. In order to prevent spreading mussels and other aquatic invasive species, watercraft and equipment that comes into contact with the waterbody should be cleaned, drained and dried after every outing.

Visit CDFW’s website to learn more about quagga and zebra mussel management in California, and the precautions you can take to help prevent the spread of these invasive species. If you have specific questions, you are welcome to contact CDFW’s Invasive Species Program at (866) 440-9530 or