PHOTO COURTESY OF GARRY KESSLER
Red-tailed hawks and other wild predators are far better than rat poison at controlling rats and mice, according to wildlife veterinarian Dr. Mark Pokras.
February 20, 2015, Page A5, A6
By Annie Reid
Westborough Community Land Trust
Good tips from a wildlife veterinarian
Never mind the mountains of snow – spring is right around the corner.
We’ll soon be out and about, and so will our local wildlife. Here are some tips and tidbits about how we can do well by our local wildlife. They come from veterinarian Dr. Mark Pokras of the Wildlife Clinic at Tufts University Cummings School of Veterinary Medicine in Grafton. A Westborough resident and member of the Westborough Community Land Trust, he has spent many years tending and mending the wild creatures that share our natural environment.
What should you do if you find a baby bird on the ground? Dr. Pokras reassures us that most of the baby birds and other young animals that people find and believe to be orphaned are not actually in trouble. He notes that young birds typically leave the nest a week or two before they can fly well. During this time their parents continue to feed and care for them. It’s best for people to leave these birds where they find them, but if a baby bird is out of the nest and in harm’s way, it’s okay to move it to a safer, more protected location nearby.
“It’s not true that the mother won’t accept a baby bird if a human touches it,” Dr. Pokras says, correcting a common misconception.
Is something wrong with birds that look bald when they come to a bird feeder? Dr. Pokras points out that for the majority of the birds, this appearance is not an illness, especially in August-September.
“It’s the seasonal molt – they’re growing a new set of feathers and losing the old ones,” he says.
What should you do if animals nest in your chimney?
“Don’t light a fire – call animal control,” Dr. Pokras advises.
Raccoons, hooded mergansers, screech owls, and wood ducks all normally nest in hollow trees, but they sometimes mistakenly nest in chimneys or wood stove pipes.
Also, in the summer, our area gets chimney swifts, which are birds that normally nest in uncapped chimneys. Dr. Pokras reports that chimney swifts are in trouble as a species, due to pollutants, capped chimneys that prevent them from nesting, and their long migration flights to and from Brazil.
What kinds of injuries to wild animals are commonly seen at the Wildlife Clinic? During his years of practicing medicine on injured animals, Dr. Pokras has observed that most traumatic injuries to wildlife are inadvertently caused by people. Harm comes to wild animals from our system of roadways, our windows, and many plastic items that can be hazardous to animals.
The Tufts Wildlife Clinic typically sees a lot of turtles that have been hit by cars, Dr. Pokras says, especially on rainy spring nights when the ground is soft and female turtles are out looking to dig holes where they lay can their eggs. He explains that the shell is part of a turtle’s skeletal system, so the Wildlife Clinic repairs the injured turtles’ shells whenever possible. If the mother can’t be saved, the Wildlife Clinic incubates the eggs that were inside her body and makes sure that the young are released into appropriate habitats after they hatch.
Besides turtles, the Wildlife Clinic treats many other animals that have been hit by cars, including raccoons and red-tailed hawks, and even an eagle, a bear, and a bobcat.
Most people are aware that birds are often injured or killed when they fly into windows, misled by reflections.
“To minimize the risk,” Dr. Pokras suggests, “place your bird feeders either quite close to a window, or far away.” He notes that there are now special architectural designs for windows to help prevent bird strikes.
Plastic items that don’t readily degrade in the environment are another human-made hazard to wildlife. Plastic fishing line and gill nets entangle animals. For example, a common loon recently got tangled in fishing line at Wachusett Reservoir and starved. Every year the Wildlife Clinic sees a number of owls that have been caught in soccer nets. Also, plastic six-pack containers can harm marine mammals and sea turtles.
“Recycle – keep the plastic out of the environment,” Dr. Pokras advises, “and fold or roll up soccer nets when they’re not in use.”
Besides roads, windows, and plastic items, are there other hazards to wildlife that due to humans? Toxins that humans put into the environment are another source of trouble for wildlife, according to Dr. Pokras. Rat poison, for example, takes hours or even days to kill a mouse or rat. During that time, the dying and confused animal wanders out of the house or garage and eventually gets eaten by a fox, owl, hawk, or eagle, which in turn is poisoned. As a result, our environment loses wild predators that are far better at controlling rats and mice than poison is.
For example, Dr. Pokras notes that one red-tailed hawk eats about 4 mice per day. That means a pair of hawks eats 2,920 mice a year (8 mice x 365 days = 2,920). A family with 3 chicks will eat 9,800 mice per year.
“Don’t poison the mice that then poison the red-tails,” Dr. Pokras advises. Instead of poisoning mice, he suggests trapping them and “putting them out for the foxes.”
Lead in the environment also poisons animals. A significant number of road-killed deer have lead in their bodies from being shot in the past, Dr. Pokras reports. This lead gets into bald eagles and other scavengers that feed on the road kill and poisons them.
Dr. Pokras’s own research includes common loons, which sometimes swallow fishing gear. Acid in their stomach dissolves fishing sinkers and jigs, releasing lead that then poisons the loon. To avoid putting lead into the environment, people need to switch to copper and other metals for bullets, to iron, tungsten, or other metals for fishing gear, and to nontoxic shot for hunting waterfowl or skeet and trap shooting.
Can anything be done about problems that humans cause for wildlife? Overall, Dr. Pokras believes humans can reverse the problems they cause. He cites the example of bald eagles, osprey, and other birds of prey whose populations are rebounding now that DDT is finally disappearing from the U.S. environment after having been banned in the 1970s.
Dr. Pokras also believes strongly that it’s in people’s own best interest to pay attention to problems that affect animals. The reason is that problems in wildlife can warn of environmental problems that potentially affect humans. For example, X-rays and necropsies of local great blue herons have revealed abnormal fat in their bodies, indicating a possible new disease (steatitis) that may be caused by water pollution and toxins from an overgrowth of algae.
Cancer in wild animals is another example.
“Any living thing can get cancer,” Dr. Pokras says, “and when we start seeing it in many animals, maybe the problem is in our shared environment.”
What can ordinary people do to help wildlife and the environment?
“Live greener,” Dr. Pokras suggests. “Reduce water use and energy use, and decrease lawns. Plant for wildlife, using native species of plants. Take part in citizen science, such as feeder-watch projects and vernal pool studies, to provide data for science. And pass environmental awareness and knowledge on to young people – the next generations.”