Are house cats scavengers? The answer is yes but domestic cats scavenge in a particular way by making informed choices while understandably avoiding foods that might make them very ill. When scavenging they try and ensure that their diet is varied to avoid a buildup of substances that might make them sick. House cats (fully domesticated cats living with humans) are normally less skilled at scavenging than stray and feral cats.
Cat behaviorist Dr Bradshaw carried out a test. He wanted to see whether cats deliberately made a choice to vary their diet as opposed to relying on one particular food which they had not killed. When domestic cats do not kill prey they do not know precisely what they are eating and therefore they vary their diet as an insurance policy.
In Dr Bradshaw’s test he put out two foods, one of which represented 90% of the total. The participating cats stopped grazing on the foods indiscriminately after a short period of time and started to find the rarer food. He puts this down to a desire to apply “nutritional wisdom”. The idea is that eating a variety of foods is more likely to produce a more balanced, safer and healthier diet rather than eating the easiest to find foods. In the test both types of food had the same nutritional value so, as mentioned, the cats were simply playing safe.
Dr Bradshaw also states that he believes that this nutritional wisdom has to be activated by the experience of having scavenged for a living and therefore this skill is likely to be seen in stray cats and less so in domestic cats.
In contrast, rats are omnivores with an extremely wide taste making them suited to a scavenging lifestyle. They nibble new foods to make sure that they are not poisonous. Once ingested the rat is able to analyse the food for ingredients such as protein and fat content. Cats are less sophisticated at scavenging than rats but still skilled in my opinion.
Comment: I believe that outdoor domestic cats have an instinctive desire to test food that they have not killed. I suspect that scavenging is quite commonplace for indoor/outdoor cats. For example, dead birds are probably often eaten or partially eaten. Domestic cats have an instinctive ability to reject non-nutritious and toxic foods. The test is carried out through smell first. My cat is always testing objects on the floor to see if they are nutritious.
Source: Dr Bradshaw’s book Cat Sense.