I was recently emailed by a medical and environmentally focused writer. She posed a few questions to me that she will be addressing in her blog. I haven't requested permission to include her blog or her name, so I will guard her anonymity. However, the questions she posed are frequently sent my way via email or telephone calls, so I felt it would be good to list the questions she sent and my responses in this blog. I prefaced my responses to her questions by highlighting that I study anticoagulant exposure in wildlife, but am not an expert on rodent control practices.
Question 1 posed by writer: I read your answers to the July Ojai article in the summer. Do you have any more updated info or can I take the stats from that?
Response: New data from my project suggests that 95% of bobcats are exposed to anticoagulant rodenticides (ARs) across our study area. This includes data gathered from both urban areas and also from individuals in more "remote, pristine habitat" locations such as Point Mugu State Park. Bobcats found to inhabit agricultural, urban, and even State Park lands are exposed to ARs. This does NOT necessarily mean that bobcats in the parks are exposed to poisons placed on State Park land- merely that bobcat homeranges even for individuals that live in state park areas may abut urban or agricultural areas that the bobcats venture into. A fetal bobcat in our area was revealed to be exposed already to ARs and so this is an issue beginning for bobcats during prenatal development and likely persisting for the duration of an individual's lifetime.
Question 2 posed by writer: Is there any poison available in stores will not cause problems or will cause fewer? We ended up using a neurotoxin poison from Lowes and Home Depot, hoping it was better - is there any research on those. We ended up using that for our issue but now I wonder why wouldn't there be a food chain rxn with those?
Response: The bottom line about poisons available on the market in the US is that each and every one has risks for wildlife associated with their use, either through primary or secondary poisoning. Cholcalciforal, bromethelin, zinc phosphide, and strychnine pose both risks- primary and secondary poisoning. Further, I'd like to add that because anticoagulant rodenticides are the most commonly used method for rodent control worldwide, more research effort has been put in their direction. They are globally ubiquitous (perhaps with the exception of the UK, I feel like I read they are recently banned there). If people switched to other poisons, we may become more aware of the hazards they pose.
It sounds to me like you aim to be environmentally conscientious. In doing so, I encourage you to consider whether poisons are absolutely necessary. Must we replace one poison with another? This is the most frequent response of folks that I present my work to- if I can't use anticoagulants, then what poison shall I use? If we truly care about wildlife, we should aim to mitigate our poison use entirely. My stance is NOT that poisons, and even anticoagulants, are necessarily altogether banned. My stance IS that any poisons should be absolute last alternative, used only when human health or structural integrity of buildings is threatened by uncontrollable rodent populations, and in the case of ARs, for use against invasive rodent populations affecting endangered native wildlife. However, these are exceptional circumstances, and not the circumstances with which individual residents are typically faced.
I advocate the integrated pest management (IPM) approach, and according to San Francisco county guidelines for IPM - rarely, if ever, are residents truly faced with the need for poison use according to the "human health or structural integrity of buildings" concerns. I encourage you to look in that direction, and in fact, Camilla Fox and others in Nor.Cal. have successfully pushed towards the banning of anticoagulants in Marin County, and the adoption of IPM instead.
Question 3 posed by writer: What can the public do? for ex, the largest pest control co here in our area assured us their anticoag was safe, even after I shared research articles with them. What should a person do to combat this misinformation? And are there some pest control company rat control practices that are better - if so what?
Response: I encourage the public to be free-thinking educated consumers about the product they choose for pest control around their homes. For this reason exactly I present the information on my website in its present format. I understand what pest control companies tell people- I've heard it from folks who, like you, have presented them with information and they refuse to acknowledge the damage it does to native wildlife. The bottom line about pest control companies is that: 1) they have a product to sell. We must remember that they are a business and their products are poisons, 2) they are not scientists, chemists, biologists, wildlife naturalists out picking up the coyotes, owls, hawks, mountain lions etc. who have died of internal bleeding, or are chasing after the bobcats that die of notoedric mange. Should we expect them to truly know the true extent of the damage those products do to wildlife? I personally don't imagine them keeping up on the latest scientific research articles on the subject...particularly if it prevents them from effectively selling their product.
There are pest control agencies that practice IPM, and I encourage you to seek those out. Again, I'm not a pest control expert- I'm a grad student at UCLA trying to get my PhD, so this leaves me little time to explore alternatives and come up with great suggestions for people across CA. As a scientist, my first passion is research and wildlife...I hope that folks like you with an interest in trying to do well, will pick up where the research people like me do, and help find local "sustainable" pest control companies and spread the word. I personally lived for 3 years right next to Topanga State Park (ie., it was my backyard). I had various native rodents coming into my house when I first moved there, and I was able to successfully find the holes in the house where they entered each night and plug up the holes. It took all of half a day to remedy, and for three years, I never had another rodent enter my home. Poisons were not necessary. Another step I took was to NOT feed birds. I did when I first moved there, but then I quickly saw the ground squirrel flourish, and start chewing on the house and things outside when the food ran out. These are steps we should all take if we have rodent problems before we break out the poisons. And people may be surprised at how effective a strategy it is!