The coyote diet in Southern California includes 68% fewer cats than 20 years ago. The ubiquitous coyote, a successful opportunistic predator, is preying far less often on outdoor domestic, stray and feral cats. The big question is why it is happening.
If we argue that the number of outdoor/indoor cats in southern California is approximately the same as it was 20 years ago then the reason will not be because there are more indoor cats. The indications are by the way that cat owners’ attitudes in the area towards letting their cats roam freely have not changed over the past 20 years.
We can assume that the coyote has not changed its preferences with respect to prey. Therefore, there are either less feral and wandering domestic cats in southern California and/or cats in general are successfully avoiding coyotes (a learned behavior).
TNR programs
Alley Cat Rescue conducted a national survey on feral cat colony caretakers in 2017. They found that TNR programs appeared to have reduced the feral cat birth rate by 72% since 1992. It’s interesting that the figure of 72% almost mirrors the figure of 68% which is the reduction in predation of coyotes on cats in southern California. However, I an not sure that it is as simple as that. Although it is highly encouraging and it does strongly point to the success of TNR programs.
San Diego
The general downward trend of coyote predation on cats is not reflected in an area near San Diego where it appears that there has been a 20% increase of coyote predation on cats over the past 15 years. But this may be an isolated statistic on the basis that TNR programs are run by volunteers and perhaps in this area they are less active.
8% of coyote diet
The Los Angeles Times reports on a statement by graduate researcher, Danielle Martinez, of the California State University at Fullerton who said that cats appear to make up about 8% of the local coyote diet.
Stomach contents
The stomach contents of dead coyotes were examined in order to assess their diet. A study has documented the contents of 104 coyote stomachs. The study is ongoing and the intention is to examine 300 by the end of 2018. The coyotes died across Los Angeles and Orange counties under a variety of circumstances.
Increase in TNR neutering and spaying
The 2017 Alley Cat Rescue survey mentioned above also found that more than half of all cats sterilized by TNR programs occurred over the period 2012-2017. In other words, more cats have been sterilized in TNR programs over the past five years than in the previous 20. This is very encouraging.
Success of TNR despite ornithologists
The back story to the success of TNR programs in Southern California and elsewhere is set against a quiet war between TNR advocates and ornithologists and their societies. Ironically it may have been a court case in 2009 at the Los Angeles Superior Court that promoted TNR programs. Judge Thomas McKnew ruled that the California municipal governments cannot assist and promote TNR programs without first completing an environmental impact report. This appears to have been an application by a group of ornithological societies to try and stop TNR programs. It appears to have had the opposite effect.
We know that ornithologists disagree strongly with TNR because they argue that it leaves feral cats on the ground to attack birds whereas eradicating feral cats would protect birds. Although it has been found that this argument is flawed because of the well-known vacuum effect.
More research
More research is no doubt needed because the findings are somewhat uncertain. However, there are clear indications that TNR is working well. Citizens of southern California should be proud of their TNR advocates and volunteers who work tirelessly to treat feral cats humanely while using their own funds to do so. They have my admiration.