When best laid plans go wrong
text and photos by Brian Morin
When we think of the term exotic, it might conjure up an image of something exciting, alluring, and fascinating, but when it comes to birds, exotics have a dark side. In the bird world, exotics are introduced species that have taken hold in a place they don’t naturally occur. They are considered by many birders to be like foreign weeds that take root and crowd out native species. That is what often happens when exotic birds appear.
Take the European starling for instance. This species was among the first avian ‘immigrants’ to our shores. In 1890 to 1891, the American Acclimatization Society released close to 100 birds in New York City’s Central Park to help European settlers feel more at home.The plan was to bring in every bird mentioned in Shakespearean plays. That misguided effort was followed over the next 50 years by their rapid expansion across the continent in numbers that today exceed 200 million. Perhaps not the best idea.
The issue is that this bird is adaptive and will take over natural nest cavities that native species such as bluebirds, purple martins,and woodpeckers occupy. Any structure or natural site with a hole is fair game. Because they thrive in cities, starlings have been able to multiply exponentially at the expense of our own species.
Backyard bird feeders have no love for them either. In flocks, they can quickly take over, competing with our local birds. Fortunately, they are migrants that head south in the millions, so in normal winters our numbers are usually low. Because last winter was milder, more birds remained behind and quickly discovered local sources of food. They can wipe out a suet block in a day.
On the plus side, the starling is an amazing mimic. It can repeat, with a fair degree of accuracy, a significant number of songs and calls. If you hear a flicker or killdeer in mid-January, you’d better look twice.They are highly gregarious and will gather in flocks of thousands, moving at high speed in swarms, much like gnats. If you ever see a starling ‘ball’ – a dense, erratically moving flock of birds – scan the sky for a predator.This is a highly effective defense mechanism. If a hundred descend on your yard, let’s at least hope they pick up some of those lawn-destroying grubs.
A less annoying species,but still an issue, is the house sparrow. It actually arrived earlier than the starling, in 1851, in New York City, but was subsequently introduced in numerous locations in the decades which followed.There are few benefits to having this species present, and some problems. It is also competitive for nest sites in and around communities, and is highly aggressive towards tree swallows and purple martins. It is also aggressive at feeders.
The house sparrow nests early, occupying potential nest sites of native birds, and will destroy eggs, chicks, and even adults on the nest. On a positive note, something has happened to the population in recent years, reducing their numbers.Too bad the same thing doesn’t happen to starlings.
Sometimes, a thing of beauty can be deceptive.The mute swan, a bird we associate with zoos, urban parks, waterfowl collections and royalty, is a striking species. Its curved neck presents a classic swan-like profile even young children recognize. In fact, it is a favourite with kids of all ages.Unlike the name suggests,the bird is not actually mute, but does make a muffled bugle call as well as snorts and hisses when disturbed.
A small number of birds were brought over from England and Europe to New England in the late 1800s for their size, colour, and graceful appearance. Most had wings clipped to discourage movement from local areas,but some escaped and eventually expanded their range. They are prolific in parts of New England today, as well as along the lower Great Lakes. They are common along the waterfront in places like Hamilton, Toronto, and east to Presqu’ile Provincial Park near Brighton.
The issue with this species is its aggressive behaviour towards other waterfowl. It is fiercely territorial during breeding, forcing ducks and other waterbirds to move elsewhere.With virtually no predators as adults,they have been slowly multiplying.They will never rise to the stature other exotics have achieved, but the mute swan is yet another example of what can happen when the best-intentioned plans go awry.
The moral of the story is sometimes it is better to leave well enough alone. Mother Nature does pretty well on her own.When we interfere, we can often do more harm than good, and nature itself pays the highest price. n
Brian Morin is the publisher of Ontario Birding News, a newsletter for birding enthusiasts.He has been actively involved in watching and photographing birds in Ontario for more than 40 years.