# Mammalian Prey Digestibility by Bobcats > How much of a meal can you still read in a bobcat scat? In feeding trials with captive bobcats, the cats dissolved 99% of the bones and up to 93% of the hair of the squirrels and cottontails they ate, far more than coyotes do. The authors warn that diet studies built on bobcat scats need to be read with caution. Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/1982-johnson-aldred-mammalian-prey-digestibility-bobcats/ ## Citation and access - **Authors:** Mark K. Johnson and Don R. Aldred - **Year published:** 1982 - **Journal or source:** The Journal of Wildlife Management - **Full citation:** Johnson, M. K. and Aldred, D. R. 1982. Mammalian prey digestibility by bobcats. The Journal of Wildlife Management 46(2): 530. - **DOI:** 10.2307/3808674 - **Access status:** Publisher link only - **Where to find it:** https://doi.org/10.2307/3808674 ## Tags - **Species:** Mammals > Bobcat - **Tracking:** Bones; Hair; Scat; Tracking - **Methods and technology:** Descriptive statistics - **Data type:** Existing data; New field data - **Observer qualification:** Not needed - **Discipline:** Behaviour and ecology; Taphonomy - **Year published:** 1982 ## Detailed keywords - **Species:** Studied: bobcat (Felis rufus), 3 animals in feeding trials. Prey fed: gray squirrel (Sciurus carolinensis) and eastern cottontail (Sylvilagus floridanus), 30 of each. Comparison species: coyote (Canis latrans), using results from an earlier study by Meriwether and Johnson (1980). - **Location and habitat:** Not reported. The paper does not say where the feeding trials took place. The authors were based at Louisiana State University, Baton Rouge, Louisiana, and Wildlife Consulting Services, Inc., Helena, Alabama, United States. - **Topics:** scat analysis and diet estimation; digestibility of prey remains; dissolution of bone and hair during digestion; skeletal parts (bones, teeth and claws) and hair as the indigestible parts used to identify prey in scats; effect of prey body size; bobcat versus coyote digestion; bias in food habits studies from scats. Possible inconsistency or unclear point: the text calls the bobcat values “significantly higher” than the coyote values, but no statistical test is named or reported. - **Statistics or models:** Means with standard errors (SE) of the percentage of bone and hair dissolved. No statistical test is named. - **Data type:** New data from captive feeding trials (no dates given; received by the journal 10 February 1981), compared with existing coyote data from Meriwether and Johnson (1980). ## Synopsis ### 1. What they did Bones, teeth, claws and hair are usually thought of as the parts of prey that pass through a predator undigested, and they are what researchers use to work out a carnivore’s diet from their droppings. An earlier study by Meriwether and Johnson (1980) showed that coyotes dissolve a good part of these remains, and that small prey are digested more fully than large prey. The authors ran the same kind of feeding trials with bobcats to compare the two predators. - Measuring the prey. They dissected 10 gray squirrels and 10 eastern cottontails to find the average proportions of skeletal parts (bones, teeth and claws) and hair in each prey. - Feeding trials. After weighing, 10 of each prey were fed to each of 3 bobcats in separate trials, so 30 squirrels and 30 cottontails were used in all. - Recovering the remains. All droppings from one feeding trial were put together in a nylon bag and washed in an automatic clothes washer until the rinse water was fairly clear. The bags were tumbled dry in a clothes dryer, and the hair and skeletal remains were separated by hand and weighed. - Comparing. They compared the share of bone and hair dissolved by the bobcats with the coyote results from the earlier study, which used identical methods. ### 2. What they found Prey Bone dissolved, bobcat Bone dissolved, coyote Hair dissolved, bobcat Hair dissolved, coyote Gray squirrel 99% (± 1) 91% (± 4) 93% (± 1) 80% (± 9) Eastern cottontail 99% (± 1) 93% (± 2) 88% (± 5) 43% (± 12) Values are means with standard errors. Coyote data are from Meriwether and Johnson (1980). - Whatever the prey, bobcats dissolved 99% of the bones, teeth and claws they ate. - Bobcats dissolved 93% of the hair of gray squirrels and 88% of the hair of eastern cottontails. - The authors report these values as significantly higher than those for coyotes. ### 3. What they concluded - When a predator eats larger prey, the larger mass of food in the gut probably shields bones and hair from digestive acids for longer than with smaller prey. So remains of smaller prey might be missing from coyote droppings more often than remains of larger prey, and the authors say this problem is even greater for bobcat droppings. - They suggest caution when estimating the proportions of different foods in bobcat diets from scat analysis, because the importance of some food items is likely to be overestimated. ### 6. Other technologies, skills or innovations - Droppings were cleaned in nylon bags in an automatic clothes washer and dried in a clothes dryer, then hair and skeletal remains were separated by hand and weighed. ### 7. Implications for conservation (from the paper) - Diet estimates for bobcats based on scat analysis may be biased, because bobcats dissolve almost all the bone and much of the hair of the prey they eat. ### 8. Implications for tracking (Original Wisdom's observations) _These are Original Wisdom's observations, not the authors'._ - A bobcat scat may hold very little bone, even when the cat ate whole prey: in these trials about 1% of the bone was left. Identifying prey from a bobcat scat may depend mostly on hair, and the scat contents may not show everything the cat ate. ## Cite this summary Lawrence, K. 2026. Summary of: Mammalian Prey Digestibility by Bobcats (Johnson and Aldred, 1982). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/1982-johnson-aldred-mammalian-prey-digestibility-bobcats/