Mysterious Disappearance

Male house sparrow (photo by David Lofink via Wikimedia Commons)
Male house sparrow (photo by David Lofink via Wikimedia Commons)

If you live in North America this fact is amazing:  House sparrows are an endangered species in Britain.

I learned this when I read John Metcalfe’s article called Making Cities More Bird Friendly With Nesting Bricks.  In it he describes a new brick specially designed by Aaron Dunkerton and manufactured in England to provide habitat for nesting house sparrows.  Before mortar is applied it looks like this.  (Click on the bricks to read about them.)

Bird brick by Aaron Dunkerton (image from Aaron Dunkerton's website)

House sparrows are the most widely distributed wild bird on earth.  Why are they so endangered in the U.K. that people invent ways to help them?  Here’s what I found out.

Since 1977 house sparrows have declined by 71% in Britain.  In some locations they are nearly extirpated.  London’s Kensington Park had 2,603 house sparrows in 1925.  By 2000 there were only 18.

Despite many studies a single cause has not been found and no other urban/suburban bird has experienced a similar decline.

In 2005 Kate E. Vincent published a house sparrow population study.  In 2009 Lorna Margaret Shaw investigated the role of neighborhood socio-economic status in house sparrow abundance.  These studies found:

  • The greatest house sparrow declines occurred where nestlings starved within a week of hatching or had low fledging weight, both due to lack of insect prey.  The best success occurred where they ate plenty of aphids or spiders.  (Aphids come up again!)
  • Because house sparrows nest in holes in buildings, they did well in neighborhoods built before 1919, in neighborhoods where soffitt and fascia were made of wood, and in distressed neighborhoods where the buildings needed repairs.  They avoided neighborhoods built after 1985 because of new construction standards and lack of deterioration.  That’s why Aaron Dunkerton invented the bird brick for new homes.
  • House sparrows did poorly in tidy neighborhoods with lots of paving.  Over the years Britons have paved their front yards and removed trees and shrubs so they can park their cars.  This has reduced house sparrow habitat.
  • All habitat was not equal.  House sparrows preferred deciduous plants and the insects associated with them.
  • House sparrows did not use ornamentals or evergreens.  This lead to a headline that Leylandii hedges were to blame for the house sparrow decline.  (A fascinating topic…more on that tomorrow.)

With so many factors in play there’s no simple answer to the house sparrow’s mysterious disappearance.  In the meantime they continue to decline and Britons miss them terribly.

If it would work I’d package some of ours and send them to England.  We have a house sparrow surplus right now.


(photo of a house sparrow in California from Wikimedia Commons. Nesting bricks by Aaron Dunkerton.  Click on the images to see their originals.)

7 thoughts on “Mysterious Disappearance

  1. In the tidy neighborhoods they could be ingesting more harmful chemicals, weed killers and pesticides. Thus instead of starving they may be not eating cause their ill. The newly hatched being more sensitive to the chemicals just can not take it while the adults are possibly more able to take them. Just a thought.

    They certainly thrive well in my old neighborhood.


  2. Who knew?!! We certainly have a lot of them out here in California. They take over whatever bird houses are put out for other birds, and we have to chase them away in order to allow our bluebirds to have any chance at all. They mob the feeders, just as they did when we lived back east. As you said, too bad we can’t bag some up and send them to Britain.

  3. I became aware of the decline of the house sparrow population in Britain when we traveled to Europe a few years ago. I suppose there are all sorts of problems with reintroducing house sparrows from America to Britain, but other species have been successfully repopulated this way. (Musk ox from Greenland to Alaska, for example) Is this a possibility for house sparrows?

  4. Interesting! I often think that some of our really common birds would be thrilling to see if they were only rare! European starlings, and mourning doves …..

  5. Dear Folks,
    I have been an avid watcher of birds most of my life. I learned bird calls as well as physical identity and migration habits of many birds. I am now 66 and still take a 2 mile walk in Cuyahoga Valley National Park, Ohio every day. I do not see a disappearance of House Sparrows here at all!!!! In fact, they are quite abundant here. I feed them 6 table spoons of seeds every day. If I fill the feeder they dump the entire contents on the ground in one or two days creating a messy weed problem. I am surprised to hear your report; yet, I can find no report whatsoever on line about the disappearance of the House Finch in this area of the United States. I lived in Salem, Ohio in the 1980’s and set up a feeder to attract Sparrows, Nuthatches, Cardinals, and Downey Woodpeckers and I got an abundance of House Finches equal to the House Sparrow who has the black chest(bib) on the male. The tablespoon method of feeding works quite well. I moved from Salem, Ohio to Northfield, Ohio about 1982 and then an apartment in Northfield in 1995. Something strange happened around 1995. I no longer had any House Finches whatsoever. I know the difference between the two birds except females can be tricky without binoculars or a feeder near the window. The House Sparrows are friendly and good birds except when there is an argument between several birds. Then the fuss begins for 10 or 15 minutes in a bush or tree nearby. Sometimes there’s a struggle between two birds on the ground. House Finches were everywhere in the 1980’s yet I have not seen any since 1995 in the Cleveland, Ohio area. I spend a lot of time outdoors and know a lot of birds. I spend hours per day in the national park. What is going on?!?!?
    Here is my point since 1982 until 1995 I watched birds both at home and in the wild with binoculars very carefully and probably know about 25-30 bird calls of local and some migrating species without hesitation. I became aware of a disappearance of the very similar looking bird, the House Finch in the 1990’s. I have not seen a House Finch at my feeder since 1995 when I move to my apartment in Northfield, Ohio; however, when I look up bird disappearance of House Finch I get absolutely nothing in my search. What in the world is going On!
    Thank you for listening,
    Mr. Jan C. Ebert, retired.

    1. Mr. Ebert, thanks for asking about House Finches. Yes, they were very abundant until the mid-1990s when everyone noticed they declined rapidly. Their decline was caused by an eye disease that they are susceptible to and House Sparrows are not. In places where many birds feed together and the area is not kept clean, the disease spreads rapidly among the House Finches and they die off.

      Here’s an article from the Washington Post from this February that talks about what happened. I’m sure you’re seeing this in Ohio.

      I have not written about this issue… perhaps I should.

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