This winter, Maine birders get a chance to help prevent bird mortality from cats, by helping get cats sterilized before spring’s unwanted pregnancies begin.  In a February “Beat the Heat” campaign at Freeport’s Community Spay-Neuter Clinic, and with help from a grant from PetSmart Charites, Dr. Elizabeth Stone, Director of Center for Wildlife Health Research, will be spaying an extra 250 female cats above and beyond the 9,600 cats (baseline of 250/month on average) that have been sterilized by Dr. Stone and her team since her spay-neuter program started 3 1/2 years ago.  Female cats will be sterilized for just $20 each. They need help getting the word out to cat owners that need to have this done.

Maine birders are likely well aware of the high numbers of birds killed by cats in the U.S. every year. In their 2013 Nature Communications paper titled, “The impact of free-ranging domestic cats on wildlife of the United States”, authors S.R. Loss, T. Will, and P.P. Marra concluded that an estimated  1.3–4.0 billion birds and 6.3–22.3 billion mammals are killed by cats annually. They go on to state, “Un-owned cats, as opposed to owned pets, cause the majority of this mortality. Our findings suggest that free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for US birds and mammals.”

Dr. Stone and her staff target unsterilized cats belonging to low-income households, where timely spay-neuter is unlikely to happen. Spay-neuter that targets low-income households can help to reduce the number of free-ranging cats that were identified by Loss et al. as causing the majority of bird mortality. In the 2009 paper, “Population Characteristics and neuter status of cats living in households in the United States” (JAVMA 234(8)) by K. Chu et al, only 51.4% of cats in households with annual incomes of $35,000 or less were neutered. U.S. Census data ( show that 36.8% of households in Maine fall in this income bracket.

Owned cats that are allowed outdoors are a source of free-ranging and feral cat populations. Preliminary data collected by Dr. Stone through client surveys show that 45% of cats brought to CSNC for sterilization are allowed outdoors. On average, 1 of 3 females have already had 1 litter (averaging 6 kittens per litter), and 23% of resulting kittens have been lost to the wild, potentially adding to the feral cat population. Approximately 71% of female cats presenting for sterilization were likely or highly likely, according to their owner, to become pregnant or pregnant again without affordable and convenient spay-neuter services such as we provide.

Loss et al. (2013) state that scientifically sound conservation and policy intervention is needed to reduce the impact on birds from cats. While we agree, at the same time, high-volume spay-neuter is a tool that can help towards the goal of reducing the population of unwanted cats. Affordable spay-neuter (not to include trap-neuter-release, or TNR) has the advantage of being immediately available in Maine, and having high acceptance among animal welfare, veterinary and wildlife professionals as an acceptable method for cat population control.

Dr. Stone’s team transports cats to the Freeport clinic from as far away as Waterville, Dover-Foxcroft and Rockland for day surgery for a subsidized fee ranging from $10-$60. Please help us get the word out about spaying and neutering cats. If you want to help, “Like” us (search Community Spay-Neuter Clinic) on FaceBook and consider posting fliers for the Beat the Heat campaign. Donations are also accepted. For more information, visit or write to Elizabeth Stone at  [email protected]