One of the tasks that school groups are given when they tour Zealandia is to complete a bird checklist. They carry a clipboard with a page showing 10 bird species that can be found in the sanctuary and, with the help of a guide, check off the birds as they encounter them. Every time I have accompanied a group into the Valley, the very first bird that makes an appearance is an English sparrow (aka tiu, house sparrow, and Passer domesticus).
It’s not surprising; these cosmopolitans bear the distinction of being one of, if not the most broadly distributed bird species in the world. Most of that is due to intentional introduction during the late 1800’s, when an era of exploration and colonization fueled the desire to spread both familiar and exotic species far and wide across the globe. Acclimatisation Societies were formed for the express purpose of bringing animals and plants into newly settled lands – lands that were perceived as empty or lacking in desirable game species and other familiar and supposedly essential wildlife. New Zealand’s Canterbury Acclimatisation Society released 40 English sparrows in 1867, ostensibly to eat pest insects; 20 years later, they had proven so successful at eating grain that they were themselves deemed a pest, and the Society tried to pin the blame on a foolhardy ship captain. Something similar happened in the US, but this introduction effort required several determined attempts before the sparrows finally acclimatized — again, just a little too well, ousting native species like bluebirds from nesting cavities and foraging heavily on grain crops.
Zealandia has been successful in restricting all introduced mammals in the sanctuary, and in reintroducing native birds on the brink of extinction, but it has no recourse when it comes to excluding sparrows and other non-native birds like starlings, blackbirds, California quail, mallards, and magpies. As far as I can tell, these birds, which frequent the sanctuary in large numbers, are usually simply ignored. School children will spot a sparrow and eagerly go to check it off, only to find that it doesn’t appear on the checklist. “Oh, it’s just a sparrow,” is the guide’s usual response. “Not important.” Then their attention is directed to the rare takahe, the inquisitive robin, the warbling tui. Guides are usually careful when talking to children to identify, but not vilify, any of the other invasive species that have been excluded from the sanctuary. That message usually goes, “Not bad – just not supposed to be here.” Even the introduced California quail receives some respect, as a ground-dwelling bird whose habits resemble those of native (though locally extirpated) weka closely enough that it is considered an analogue species and tolerated in Zealandia.
On one of my weekend hikes around Zealandia, I met a volunteer guide at a bird feeding station. His name was James, and he was eager to show me the different species that frequent the station: the kaka and bellbird drinking nectar, and the red-capped kakariki eating millet. We searched the trees around the millet feeder, but no parakeets showed themselves. I noted the abundance of sparrows, and the guide gave an exasperated groan. “Oh yes, there are more than enough of those. But you’re an American – you must know how invasive they are! Do you know, I had a nice British couple here just a few minutes ago, and all they could do was admire the English sparrows! I told them, But they’re just sparrows! And they don’t belong here! But they just went on about how lovely they were. Sparrows – can you imagine?” Just then a pair of kakariki arrived to capture our attention, and the offending sparrows were quickly forgotten.
What the British couple may have been expressing, a perspective difficult for people living in sparrow-introduced parts of the world to accept, is that English sparrows have been severely declining in their home territory. They suffered a 60% reduction in the past two decades and have been placed on the red list for conservation efforts in Great Britain. Lack of insects for feeding nestlings has been targeted as the primary cause, blamed on the use of pesticides and gardening practices that have eliminated foraging areas. I can well imagine that encountering your disappearing backyard birds in abundance halfway around the world would be a thrill.
That afternoon, a flock of sparrows showed up in my back yard, perched in a line along the wooden fence. One flew down and began to pull vigorously at a dried dandelion seed head, while the others spread out, some snapping up the prolific passonvine hoppers and others foraging in the grass. A few juveniles followed adults, begging to be fed. I sat and watched this family whose survival success because of and in spite of humans has rendered them insignificant – or, in terms of biodiversity, a concern – in the places where they were once so eagerly introduced. They have a story here. At the very least, don’t they deserve a spot on the bird checklist?