Three metres from my front door, in a dense Ceanothus bush with its halo of bright blue flowers, sits a Common Blackbird on its nest. It has been brooding for a couple of weeks now, and it is used to my comings and goings. The male sings on his territory all hours of the day and night, most unfailingly just before dawn to wake me up. I’ll put up with it – Spring won’t last for ever. He likes to raid my bird table for seeds. I watched during winter as four or five male and female Blackbirds regularly visited my garden, variously feeding, chasing and squabbling. I guess he and his mate were the winners. I feel attached to them.
Blackbirds are not the only introduced species in my Australian garden. Others include Spotted Doves, Common Starlings and Common Mynas. The latter, like so many others (including the Common Blackbird), were brought to Australia in the second half of the 19th Century. Mynas are native to Central, South and South-east Asia – another name for them is Indian Myna. Those responsible hoped they would control agricultural pests. In my garden and surrounds, they are loud and go mob-handed. I chuck things at them whenever they land in range.
Perhaps my preference for welcoming Blackbirds but not Mynas into my garden has aesthetic and cultural roots. I find the song of the Blackbird to be more attractive than that of the Myna and it is a reminder of my childhood in England. In general, I have nothing against Mynas; indeed, I admire their resourcefulness and adaptability. They have an appealingly cocky, in-your-face demeanour. In Hong Kong, where I lived for nearly twenty tears, they were common (they are not native there, either). I used to drive past a party of them every morning on a stretch of highway where they would perch on the central barrier and dart down to pick up roadkill from under the wheels of the passing traffic. Very impressive!
But I have it in for my Canberra Mynas because they compete with local species for nesting sites and territories. More often than not, they seem to win. They are ‘invasive’ and, according to some legislation concerning the harm that some animals and plants can do, they are potential ‘pests’.
I’m fully on song with the ‘invasive’ description, but not so in tune with the ‘pest’ bit. Invasive species alter the local ecology. They thrive by out-competing native species, which may be driven towards extinction. But the concept of ‘pests’ is a different kettle of fish altogether. A whole of lot of plants and creatures (both introduced and native) are put into this category simply because they cause inconvenience to humans, at which I tend to say, as a knee-jerk response: ‘good for them’. OK, there are exceptions, but I certainly feel this way over the classification in Australia of Sulphur-crested Cockatoos and Galahs as agricultural pests and, hence, fair game for the bird-scarer or worse. I admire them for taking advantage of this evolutionary opportunity when, for some other indigenous creatures, agricultural activity has brought actual or impending doom.
Mynas are classed by the International Union for the Conservation of Nature (IUCN) as one of three bird species in the top 100 list of most damaging invasive species world-wide. The other two are Red-vented Bulbul and Common Starling. Ornithologists have provided evidence that Canberra’s Common Mynas cause damage to populations of native bird species, particularly Parrots (which also like nesting in tree holes and cavities). They strongly advocate control measures, including extermination.
Less than ten minutes’ walk from where I live, in Heritage Park in the suburb of Forde, a nice stand of weather-beaten (and well-lopped) eucalypts provides numerous nesting holes for Red-rumped Parrots and Eastern and Crimson Rosellas. The Mynas have headed over there to breed. A decent-size colony hangs out, some already occupying holes, others eyeing likely ones along with the Parrots, all the while making a fair old racket in the branches. On the face of it, there seems to be an abundance of riches for all, but if the research is accurate, the Mynas could be taking over.
With the support and encouragement of local ornithologists, a community organisation exists whose sole purpose is to combat the invasion of Mynas in Canberra’s streets, parks and gardens. Formed in 2006, the Canberra Indian Myna Action Group proudly proclaims in its 2019 Annual Report that they have achieved remarkable success. In the annual Garden Bird Survey, the Common Myna fell from 3rd to 17th as the most common garden bird in Canberra.
The Action Group undertakes community education, helps provide traps so that Mynas can be captured and trains residents in how to use them. They have persuaded the local correctional centre to manufacture the purpose-designed wire cage traps, as a useful work activity for the inmates. The devices are designed in a way not to entrap native birds – it helps that Mynas are unique in their strong liking for a diet of dried dog food.
The final step in the trapping process after rounding them up in a wire cage is to gas the captives. You just put a cover over the trap and connect it to a vehicle’s exhaust pipe. If done properly, asphyxiation is very rapid. From their meticulous records, the Action Group claims to have been responsible for the death of 72,200 Mynas.
I have not come across anyone who seriously suggests we should gas Common Blackbirds, although their habits cause a lot of irritation among gardeners. By their standards, Blackbirds are pests. They throw soil and mulch around with gay abandon in all directions and they dig deep holes if they think a juicy morsel is to be had. The collateral damage to carefully planted rows of seedlings can be annoying. But I am OK just sweeping the paths now and again. And if you plant seedlings, they have to be protected against all sorts of digging and trampling, not just from Blackbirds.
On an excursion into western New South Wales, I came across a private garden open to the public, in the main street of a small country town. The owner proudly showed off a spectacular display of roses and other exotic flowering plants. We chatted, sharing notes on waging chemical warfare on aphids. During the conversation, the subject turned to Blackbirds as one hopped across a path in front of us. To him, they were pests just like the aphids. They dig up any seedlings he plants and strew dirt and dead leaves across his neatly tended lawns and paths. He advised me to try an old-fashioned wooden rat trap, suitably baited. He claimed great success: ‘You just bang ’em on the head when you catch one’.
Blackbirds were introduced to Melbourne and Adelaide for decorative and sentimental reasons by the European settlers, under the auspices of the local Acclimatisation Societies. The main purpose was to make Australian gardens, parks and rural landscapes more familiar and congenial to the new settlers. They later spread north into New South Wales on their own accord.
They have arrived quite recently in southern Queensland. There, the State agricultural authorities have looked into their potential as a ‘pest species’ and have raised warnings about their possible impact on horticultural crops and orchards. Pest control companies recommend sonic devices to scare Blackbirds off the fruit. They haven’t spread to Western Australia, where the State authorities proclaim them to be ‘prohibited’. It helps that they can’t cross the Nullarbor Desert on their own.
Blackbirds are not generally considered to be a significant threat to native birds in mainland Australia. Two distant Australian relatives, the Bassian Thrush and the Russet-tailed Thrush, live a bit like Blackbirds – foraging on the ground in leaf litter and nesting in bushes. But they rarely compete; the native thrushes prefer rainforest gullies, while the Blackbird is an open woodland and garden bird. The state agricultural departments that like to call Blackbirds ‘pests’ repeat the line that they ‘may compete’ with native birds such as the local thrushes, but they don’t present evidence.
I am not going to trap Blackbirds in my garden, but I have seriously considered joining the Canberra Indian Myna Action Group and installing a Myna trap. So far I have held back, primarily out of squeamishness. I have no objection in principle to their extermination, aside from a personal preference (all other things being equal) for not putting birds in cages and killing them. But if I could overcome these sentiments, I could justify to myself the act of killing my garden Mynas.
The basic animal welfare principle of not causing suffering to any animal can be trumped in many contexts. The most obvious case would be when a lion is about to eat you. In the instance of the Mynas and many other invasive species, the case for extermination is an ecological one. While culling can be cruel and involve mass slaughter, the value of maintaining biodiversity in itself may legitimately trump the case for not perpetrating this harm on the individual members of introduced species and on a whole population.
There will be contextual, often practical, considerations that may stay the hand, such as whether the culling effort is feasible and will bring the desired result. And there is also a contrarian ecological argument. One inescapable effect of humans spreading to every corner of the globe and in such large numbers has been a process of ecological homogenisation. This has been going on for centuries. Human transportation of plants, animals and other living forms has resulted in a smaller number of species dominating the environment just about everywhere. Introduced species in the wild include many that turn out to be the fittest in their new homes, diminishing the local wildlife.
Perhaps we should accept that there is nothing special or prior in the rights of indigenous or native species. There is a new, irreversible condition of existence on the planet and we should just get on with it. So, the argument goes, it is an arbitrary choice, a matter of taste, to prefer indigenous to introduced species, or to afford them privilege and lend them a hand in the battle for survival.
Without going into all the weeds of these arguments, let me say my strong preference is for diversity over homogeneity. I prefer a variety of local habitats and bio-systems over the uniformity of pets, feral scavengers and plantations. When pets and plantations or other fauna and flora transported by humans replace local indigenous populations and threaten them with extinction, a wanton form of destruction occurs, not just an evolutionary process of succession.
Of course, humans survive in their current numbers in part through such processes, especially through the farming of non-native crops and livestock. We don’t usually think of these as ‘invasive’, but clearly in one sense they are, even if this doesn’t mean we want to exterminate them. The exception is when some of them escape, propagate and do damage.
Ironically, when invasive species ‘go feral’ they can do harm to introduced agricultural crops and livestock as well as to native flora and fauna. A case in Australia is the flowering plant Paterson’s Curse, originally planted in a settler’s garden for decoration but now found all over the paddocks and open woodlands of southern Australia. In flowering season, it covers some outback landscapes in a sea of purple. Not only does it smother the local vegetation, it is also poisonous to livestock – hence the ‘curse’.
Halting or checking a process of ecological destruction that is clearly due to invasive species does require cruelty and destruction against some of the invaders, but this would be far from wanton. Properly done, it would be soundly based in science, as in the case of Canberra’s Mynas. It is a matter of making case-by-case judgments abut what to do with introduced species.
I’ll be leaving my garden Blackbirds alone, keenly anticipating a successful breeding season; I shall throw things at the neighbour’s cat if I see it in my garden for the sake, in equal measure, of both the introduced Blackbirds and the native Wattlebirds who feed on my grevillia bushes; and every now and then I will wonder if I should give the Myna Action Group a call.