Some alarming statistics have recently been reported concerning the number of birds killed by cats in both Canada and the United States. According to a study by Avian Conservation Ecology (2013) between 100 million and 350 million birds are killed each year by cats in Canada. In a report by the Migratory Bird Center of the Smithsonian Conservation Biology Institute published in January of 2013 between 1.4 and 3.7 billion birds are killed each year by cats in the United States.
Both of these studies looked at the overall mortality of avian mortality resulting from mowing and other mechanical operations, industrial forestry, domestic cats, collisions with windows, wind turbines, power lines and vehicles, by catch in commercial fisheries and both offshore and terrestrial oil and gas exploration and production.
“A major reason for the current nonscientific approach to management of free-ranging cats is that the total mortality from cat predation is often argued to be negligible compared with other (human-caused) threats such as collisions with manmade structures and habitat destruction,” researchers concluded. Clearly the mortality from cat predation is not negligible and should be a wakeup call about the severe decline in bird populations.
Pet cats are not deemed to be the major offender rather it is strays and feral cats that are responsible for the majority of the death toll. Frankly, I do not make a distinction between domestic and feral cats, if they are free ranging then both are likely to predate on birds. On my street there are only 12 houses, with 6 pet cats. Many days I chase up to 5 different cats from my yard, most are neighbourhood cats, and some are feral cats. Of those that I chase away from my feeders I find both domestic and feral stalking and waiting to ambush birds.
In my experience, most domestic cat owners are irresponsible, that is they do not: (1) use a collar and bell, (2) use an outdoor cat enclosure, (3) wear a cat harness and (4) keep the cat indoors.
As a responsible dog owner for my entire life, I have many times asked the question “If my municipality requires that I purchase a licence for my dog, why don’t they have the same requirement in place for cats?” Why would we allow a double standard for our cherished domestic pets? The group “Alley Cat Allies” has stated that “Mandatory cat licensing ordinances are a license to kill. They operate on the principle that any unlicensed cat should be brought to a pound or shelter, where over 70% of all cats are killed”.
For feral cats a program called Trap-Neuter-Return has been introduced:
Trap-Neuter-Return (TNR) is a humane, simple three-step method to manage the number of feral cats immediately and reduce their numbers naturally in the long term.
Step 1 – Trap: Feral cats are trapped using humane cage traps.
Step 2 – Neuter: Cats are spayed/neutered, vaccinated, and ear-tipped.
Step 3 – Return: Fixed cats are then released to the site of capture.
Over the long-term, TNR is much more effective and humane than traditional trap-and-kill. Trap-and-kill often results in the “vacuum effect” — new cats move into the emptied area and breed. Sterilized feral cats that are returned to their site of capture do not breed and keep fertile outsiders away. The population in a managed colony is reduced over time as kittens are removed to adoptive homes, seriously ill or injured cats are euthanized, and others die due to natural causes. Any new cats that arrive in a managed colony are identified and sterilized before they breed.
To maintain the integrity of our ecosystems, we have to conserve the animals that play integral roles in those ecosystems. “Every time we lose another bird species or suppress their population numbers, we’re altering the very ecosystems that we depend on as humans. This issue clearly needs immediate conservation attention.”
The value of ecosystems services is not small and should not be underestimated, for example insectivorous birds exert top-down control on populations of invertebrates in many ecosystems, and crop yields are known to be higher in areas where bird populations control populations of herbivorous insects.
So, what is the answer to this very serious problem some would argue “The big message is responsible pet ownership”. For myself I have been dealing with neighbour’s cats that not only predate on birds, but also use my gardens and lawn as a litter box, destroy flowers, and scratch the paint on my vehicles. My approach to cats in the future will be more proactive in protecting my property and our avian friends.
