Correspondence From J. Denis Summers-Smith

Below is the text of an excellent email I received from J. Denis Summers-Smith, the renowned authority on sparrows who has written several books about them:

House Sparrow by J D Summers-Smith
Published by Collins (1967) ISBN: 0002130939

In Search of Sparrows by J. Denis Summers-Smith.
Published by T. & A. D. Poyser Ltd (1992) ISBN: 0856610739

The Sparrows: A Study of the Genus Passer by J. Denis Summers-Smith.
Published by T. & A. D. Poyser Ltd (1988) ISBN: 0856610488

The Tree Sparrow by J. Denis Summers-Smith
Published by the Author (1995) ISBN: 095253830X

I found the content of his email intriguing and sought his permission to publish it on my website. This is followed by the full text of my response, and then his reply.

I know my views on the importance of hedges as necessary cover are at odds with current thinking on house sparrow decline, but if you have read all my previous essays on the subject, you’ll see I’m adamant in my opinion and until proved otherwise, I shall maintain by belief that Sparrows Need Hedges.

The current rapid removal of cover from many of our towns and cities, namely from front garden loss, has eliminated vital urban hedgerow and habitat from many of our streets. In the London Borough of Ealing, the Council received over 900 applications last year for dropped curbs outside people’s properties. The concern with flooding from extra rainwater run-off, during downpours has prompted the local Agenda 21 group to undertake a survey to calculate the total percentage loss of front gardens in their Borough.

This type of practical survey will reveal in facts and figures what we can plainly see around us; how the character of our suburbs are changing from leafy-green to red block paving and grey concrete. Along with vermin-proof roofs, a dislike for ivy clad walls and new apartment-style developments without gardens, any creature that liked nesting in holes, using gardens to find food and hedges for cover, will find it an increasing struggle to live near us in our stupid desire to eradicate green spaces from our city environments.

Here is J. Denis Summers-Smith’s letter:

12th November, 2004

Dear Mr Lyven,
I find your argument interesting, though I do not agree with it. I have been studying House Sparrows since 1948 and am still unable to define a ‘House Sparrow Habitat’. You assert that ‘hedges’ are a necessary component of this habitat, but that is not my experience. Let me give you some examples.

I built a new house on a site with existing hedges (hawthorn) on the outskirts of Guisborough in 1960-61. Almost immediately after I occupied the house, House Sparrows moved in and took over nest boxes that I had put up. I planted additional hedges (beech, hornbeam, thuya). House Sparrows bred from 1962-78; they continued to visit the garden up to 1996 though there was no further breeding. After that visits ceased.

Guisborough, the small town where I live, has currently a population of 18,100 and covers an area of 541 ha. In the spring of 1998 I carried out a census in 120 ha of the old town (Guisborough dates back to Domesday Book, though the ‘old’ part I censused was more probably built in the 1920s), consisting of shops, commercial buildings and inner residential areas (mainly back-to-back terrace houses opening directly on the street with no front gardens, but a small yard at the back, the rows of houses being separated by a lane. The back yards are mostly used as drying areas or rubbish dumps with little attempt at cultivating them. There were no hedges in this area and yet there was a thriving sparrow population (5.3 birds/ha). This population is still present today.

House Sparrows breed on sea cliffs on the island of St Mary’s in the Scillies (Penhallurick British Birds 1993 86: 435-436). Similarly, I have seen House Sparrows breeding in holes in the banks of roadside cuttings on Cyprus and, even more extreme, in a similar situation in Afghanistan, far away from human habitation with no cultivation and no trees or bushes.

House Sparrows are common in India and live in the bazaars of many Indian towns where there is little, if any, vegetation.

House Sparrow colonised Ushuaia on Tierra del Fuega, the most southerly town in the world, early in the 20th century. I visited Ushuaia in 2002 (not to study birds but on an engineering consultancy trip) and was very keen to see how the sparrows were faring. This was in July, at the height of the Austral winter. They seemed quite at home with about a foot of packed snow in the streets. There are no hedges, even few bushes, in Ushuaia.

The House Sparrow is a tough and resourceful bird; it takes more than the absence of a few hedges to prevent it colonising an area. In my view we have to look further than loss of hedges to account for its decline in our cities. I do not think that hedges are an essential part of its habitat, though that is not to say that hedges are not a valuable addition to the habitat; House Sparrows, as you say, make much use of them, if they are there, as a safe refuge, and possibly also a source of food, but they are not essential.

You make a number of critical remarks about scientists. I must tell you that I am a scientist with a PhD (not in biology but in physics). I was involved in the chemical industry for 30 years and after that for another 21 years as an independent consultant until I finally gave up at the end of last year when I was 83, not I must add because of my age, but my wife died and I thought it was time to concentrate on other things, such as sparrows. In my professional life I was concerned with problem solving. This involved what is called the ‘scientific method’. This is an essential technique if one is going to convince one’s employer and, as a consultant, one’s client.

This is precisely the situation the biologists are in trying to solve the problem of urban House Sparrow decline. (Very simplistically, the scientific method consists of collecting data, analysing it and establishing associations/correlations and then, most importantly, making predictions of what will happen under some particular set of circumstances.) You have established an association between House Sparrows and hedges, but not a correlation that implies a cause and effect relationship.

Our masters - the politicians - tend to react to public pressure - potential voters - and will only take action (if at all) about resolving the urban House Sparrow decline on recommendations based on conclusions reached by application of the scientific method. Whether you like it or not, this is the reality of the situation. We (fortunately) live in a democracy; however imperfect this is, it is infinitely better than an autocracy, and whether politicians take action or not depends to some degree on public choice. Even if it were established that urban sparrows could be saved by reverting from using our front gardens as car parks and turning them into suitable habitats, there is no guarantee which way the vote would go if this was put to the general public. I suspect a lot of people would rather have convenient car parks than sparrows.

(You make mention of Chairman Mau and the sparrows in China - incidentally, Tree Sparrows not House Sparrows. Mau made the decision, not based on any scientific investigation, that sparrows were inimical to man’s interests by eating rice that could otherwise be food for man. This led to a major extermination campaign, but the consequence of this was a fall in rice production. The reason was that Mau had not allowed for the useful contribution made by the sparrows in controlling harmful insects. The campaign against the sparrows was quietly forgotten and the birds quickly recovered! This shows what can go wrong if you do not investigate the situation comprehensively.)

Unfortunately, application of the scientific method tends to be slow and leads to frustration in people thinking it is a reason for the authorities dragging their feet, but this is a fact we have to put up with. I fully sympathise with your frustration, but I am sending you this long comment in the hope of giving you some idea of the real situation, as I perceive it. Believe me, I am also very frustrated.

Now let me come to my ideas about the reasons for urban House Sparrow decline. I think this is complicated by a number of factors rather than there being one simple cause. My view is that the basic underlying factor is lack of invertebrate food on which the adults depend to rear the young. There is some good evidence to support this view: Simon Bower showed that failures of 1st broods in Hamburg in 1999 coincided with lack of insects; Kate Vincent in Leicester found that the poor success of late broods was associated with the absence of aphids; the BTO has shown from an analysis of nest record cards that the average number of chicks reared per brood has fallen from 3.5 in 1980 to 2.5 in 2003 (a decrease of almost 30%!). Breeding success has been evolved over a long period in balance with losses by disease, predation, etc. The fact that predation has increased (more Sparrowhawks and cats in cities) must have some significance when viewed in the light of this fall in breeding success. House Sparrows have been gradually adapting themselves to man and his environment for the 10,000 years in which they have been associated. There is a real problem in that the current rate of change in this environment is so rapid that it may well be beyond the capacity of the House Sparrow to keep pace.

Don’t just laugh off green petrol as a possible factor. There is some circumstantial evidence to suggest it could be having a negative effect on House Sparrows (the major onset of urban decline coincides with the introduction of unleaded petrol in the UK in 1989; NY State authorities attributed a major kill of birds, including sparrows, in New York in 1999, to an outbreak of disease caused by West Nile Virus, but Jim West, an independent environmental researcher showed that deaths correlated better with traffic density - incidentally House Sparrows are immune to WNV, though they can be carriers; Peter Joseph in Philadelphia showed that toxic gases are emitted from the exhausts of automobiles running on unleaded petrol, such gases could be responsible for insect deaths. What frustrates me is that having drawn attention to the possibility that unleaded petrol could be a factor none of the scientists looking at House Sparrow decline have bothered to put it to the test.

Again, let me apologise for having gone to such lengths, but I have done this because I think what you have been doing - providing actual observations from the field - is valuable. My one criticism is that you should be careful to separate the observational facts from your interpretations (this tends to antagonise people, as does the current trend in newspapers of blurring news and opinion). Don’t take my criticisms too much to heart; they are intended to be constructive, not merely destructive and dismissive. It takes a long time to get the message across. Darwin published his hypothesis on evolution by natural selection in 1859; almost 150 years later there are large numbers of people in the USA calling themselves creationists that still do not accept Darwin’s ideas.

Keep the flag flying!

Regards
J Denis Summers-Smith

14th November, 2004

Dear Mr. Summers-Smith,
Thank you very much for taking the time to look at my Sparrow Website and the comments you’ve made. My wife, Miranda was quite impressed with the length and depth of your reply and says you are very kind. She takes an interest in the subject, but I have tended to ‘go on’ about sparrows these past few years and she’s been feeling the strain!

We’ve enjoyed two glorious days in London, cold yes, but it’s great to see the sun after the incessant gloom of much of last week. The Remembrance ceremony at our local War Memorial was well attended today, and our son impressed us both with his drumming in the Air Cadet band.

You are correct in that I’m frustrated at the seemingly slow progress being made by scientists trying to discover the cause of house sparrow decline. I am not a scientist myself and can only report on what I’ve experienced and seen with my own eyes over the last forty-five years. I’ve come to the conclusion there is a bit of rivalry between the RSPB and BTO over the subject of house sparrows, neither wanting to make a definitive statement until absolutely sure. Meanwhile, both organisations are still busily working on yet more surveys and research.

I read your observations of sparrows around the world with extreme interest, for I have never left these shores. Is it not possible localised conditions experienced by sparrows world-wide, coupled with learned behaviour, enables them to adapt over time to regional differences? Human beings live in many different parts of the world; Eskimos in Northern Canada and Aborigines in Australia, but each would find the other’s environment intolerable and difficult to survive in, without a period of training and acclimatisation.

A few months ago when Tony Blair and Col. Gadaffi appeared at their open-air news conference in Libya, I was delighted at the great chorus of sparrow chirruping in the background. I was listening to the radio in my van and eating my lunch at the time. It was only later, I saw on television where the news conference took place, in a walled garden with a lot of greenery around. The way they described the location on the radio, as a camp in the desert was quite misleading.

All the house sparrows I’ve witnessed in Southern England utilise hedges, trees etc. for cover and dive into them when disturbed. If these are removed, I would not expect them to instantly adapt to the locally new bare conditions without a great deal of disorientation and stress. Tough the bird may be, but sudden change to what it’s used to cannot be healthy. If they cannot find a new nest site, if the house they’ve been in has been demolished, or the area they’ve fed in has been eradicated, they may not survive long enough to relocate. Especially as they are acknowledged for their lack of desire to venture far.

It must be known at what rate house sparrows colonise a new area - say a housing estate. They would surely spend time looking for new nest sites and food sources adjacent to where they are already, as the family expands over the years. Possibly more research needs to be done on this. Conversely, I feel the bird does not get the time to retreat out of an area at the speed they originally colonised it, leaving family groups trapped.

With the ‘isolated’ colonies I’m aware of locally, the areas between them consist of long stretches of paved-over hedge-less front gardens, or new housing developments that have little green space for anything to feed on. This sudden cutting-off of adjacent nesting sites, and foraging areas stops inter-colony exchange and colony expansion. Supposition maybe, but if hedges and cover were rail lines, how would a train travel if there were great gaps in them?

The destruction of front gardens in London has been dramatic and rapid. They first started to disappear in the road where I lived in the mid 70s. There are two photographs of my father’s house on my website showing how desolate the front looks since the new owners removed the hedge and garden. I’m quite sure the people who’ve done it prefer to park their cars rather than provide habitat for birds. Sadly most people don’t see it as important. We don’t see dead hedgehogs in our local roads anymore either, I can only hope they are still surviving in people’s rear gardens, though I haven’t heard reports of any locally for over a year.

In London I honestly believe few people really care for their city environment anymore, and most are blind to its degradation. It’s the reason house sparrow loss went unnoticed for so many years. Why else would supermarket trolleys be abandoned on our streets, or a sofa suddenly appear on the pavement, being dumped in the middle of the night! Wheelie bins are left overflowing with rubbish while empty recycle-boxes blow around in the wind.

Water leaks go unreported, and all of London’s drains are slowly filling with flattened plastic and aluminium drinks containers. When it rains, all the localised flooding in London is caused by blocked drains - yet no action is taken to clear them, and the same areas repeatedly flood - because no organisation takes the responsibility or has the equipment to empty them. This general apathy towards our surroundings has undoubtedly contributed to the sparrows’ fate, why else did society not react quicker to stop sparrow decline.

I find your concern over unleaded petrol and its possible effects on insects intriguing. I think it’s a scandal that in this country, motorists are exposed to the benzene and other hazardous compounds every time they fill their fuel tanks at petrol stations, whereas in America there is an additional outer covering to the fuel pump nozzle that sucks away any fumes escaping from the filler pipe, that’s sent back into the main holding tank. I cannot understand why there has not been an outcry about this in the rest of the world. The fuel companies know there’s a potential health problem with the fumes yet treat their customers with scant regard.

Personally I’ve noticed no reduction in greenfly population. The undersides of the sycamore and oak tree leaves, were again covered in the creatures this year, as witnessed by the great volumes of sticky ’sap’ they cover my van in, if unfortunately I have to park under them!

Thankfully, the local numbers of insectivorous birds like Goldcrest, long-tailed tit, pied wagtail and dunnock, have remained constant over the years, as have the local greenfinch, chaffinch, robin, blackbird, great and blue tit etc. All but one of the local house sparrow colonies I’ve kept an eye on these past six years are still in place. The one to disappear was from a house that had it’s dense leylandii trees removed from the front garden, leaving the area completely exposed, then the garden removed and paved over - however, the stumps remain! This was very noticeable as it was the last house sparrow colony in that street; it also bred successfully for the previous five years I knew it.

Incidentally, one of my earliest memories of the family house I moved into when I was eight, (in the mid 60s) was the occasional dead young sparrow that would be on the ground under where the house sparrows nested. This seemed to occur every summer, but they always bred, as they did the last time I was able to observe them closely in 1999 before my father moved. It makes sense for sparrows to try and breed again after the first brood, (to hedge their bets so to speak) to assure the colony’s survival.

The sparrows that currently visit my allotment always sit in the hedged area that divides the plot in two. They have never been seen feeding on the ground of the neighbouring allotments, which lack any dense cover. They arrive at our plot by travelling along the hedgerow at the end of the gardens that borders the allotment site. That seems to be the edge of their foraging range, about 250 yards from the house they nest in.

I find it particularly maddening that the correlation between the reduction of available ground in a given suburban area, primarily due to front garden loss, patios etc., and therefore the decrease of food available has not been studied more. Simply put, if the area for plants and weeds to produce seeds and harbour insects is physically covered with concrete, where is the natural food for house sparrows to come from? Back gardens traditionally utilise wooden fences as borders. Not much use to hide in when escaping a pouncing moggy or eager Sparrowhawk.

My brother witnessed at close range a sparrow being taken by a sparrowhawk about 30 years ago. From out the sky the hawk suddenly appeared, grabbing a young sparrow as it took off and crashing unceremoniously into the garden fence! It picked itself up, shook its head, looked at my brother, grabbed its meal and took off. I missed the incident myself by seconds, but the fluffy feathers left behind and my brothers stunned expression were an indication to the dramatic event...

I’ve never seen sparrows feeding off paved driveways that seem such a feature of much of North London now, whereas they are still seen in traditional front gardens. I’ve always reckoned house sparrows were so bold in their loud chirruping because they felt immune from attack, knowing there was a hedge nearby to dive into. A bird supposedly so vulnerable to predation from cats, magpies and sparrowhawks would surely have learnt to be more quite! The sparrows of the successful large colony nearest to my home are as noisy as ever, despite the many local cats and prominent gang of magpies. They also make great use of the dense hedges that borders their safe enclave.

Sparrows need hedges, not just because the hedge is for sitting, resting, digesting, preening and socialising in, (the larger and wilder the hedge is, the better to fit a larger flock into) but the hedge usually represents a garden. Few people have paved front gardens and a hedge. The hedge is also seen as too much bother to maintain. But if people have a hedge they usually have an associated garden, because they like the greenery and gardening - it is not seen as a time consuming problem. A garden can provides food, whereas a block-paved driveway does not. The hedge indicates a potential food source next to it, and that’s why sparrows need hedges, in addition to the necessary cover they also provide.

House sparrows do not take dust baths on concrete, and can drink from rain soaked leaves.

I will be adding a few more articles and photographs over the next few weeks to my website when I get time, and then I will relax, knowing I have permanently time-stamped and stated my position and feelings on this matter. If some organisation eventually comes up with a definitive answer to the sparrows’ plight that differs from my own, I’ll be extremely pleased, but more than that, I’ll be very, very, very surprised...

Would you be so kind as to allow me put your last e-mail to me on my website? I feel it would be healthy to publish your counter argument. I quite understand if you do not agree to this.

I too am very sorry for going on so long, my wife was expecting me at the allotment this afternoon! Am I in trouble...

All the best, and please keep in touch,

Donald E Lyven donaldelyven@aol.com
please visit: www.sparrowsneedhedges.com

P.S. For over a year ‘The Independent’ did not acknowledge the letters, articles and photographs I‘ve sent them. All I’ve received are two phone calls from Michael McCarthy himself, one in July 2003, the other in October 2004.

16th November, 2004

Dear Mr Lyven
Thank you for your comprehensive response. In giving you examples of situations where sparrows were apparently happy without hedges, or for that matter, little shrubby vegetation, I was merely reacting to your generalisation that 'sparrows need hedges'. In the particular situation in London the problem may be, as you say, that the rate of removal of front gardens is too fast for the sparrows to have been able to adapt to the change.

Are you aware of Jennifer Partridge? She is a teacher (and a determined New Zealander) in a secondary modern school in Bermondsey. She has created a bird haven (with sparrows!) in a courtyard in the Purbeck Estate and took on the Southwark County Council when they demanded that the feeders be removed on the grounds that they were encouraging vermin. By raising a lot of outside support, she got them to retract.

I find our big cities, particularly London, very depressing. They are frankly dirty and untidy with fast food containers dumped willy-nilly. Nobody seems to care. The contrast with the Continent is striking. There, people seem to take a pride in their towns. This was not always so: Belgium, France and Spain used to be scruffy, but how things have changed and Britain is now at the bottom of the heap. I suppose in this context it is not surprising that few people seem to be interested in sparrows, far less doing something about trying to encourage them.

I did not mention before that, as with you, DEFRA had a problem with my name badge at the meeting, as I was not representing any organisation. Finally they came up with 'Private Expert'! Like you, the Private Expert had to pay his own way to attend.
Best wishes
Denis

Donald E Lyven © 2004 donaldelyven@aol.com