Sparrowhawks responsible for House Sparrow decline says scientist (1 Viewer)

[Nightranger]

Has anyone ever tracked the spread of trichomonosis?

Dr Kirsi Peck at the RSPB was collecting reports but I am not sure if anything more definite has been done in the four + years since I left.

 

[fugl]

Here's a paragraph from an article linked to in another thread (http://www.smithsonianmag.com/scien...Most-Common-Bird-in-the-World.html?c=y&page=1)

"In the United Kingdom . . the house sparrow is now considered a species of conservation concern. Newspapers ran series on the birds’ benefits. One newspaper offered a reward for anyone who could find out “what was killing our sparrows.” Was it pesticides, some asked? Global warming? Cellphones? Then just this year a plausible (though probably incomplete) answer seems to have emerged. The Eurasian sparrowhawk (Accipiter nisus), a hawk that feeds almost exclusively on sparrows, has become common in cities across Europe and is eating the sparrows. Some people have begun to hate the hawk."

Just this year? What's being referred to here, I wonder? It can't be Bell's article surely which must be a lot earlier than that!

 

[Jane Turner]

Its probably as accurate in its date as it is in the "almost exclusively"

 

[PhilW]

Interesting that recent news release fro mBT Oshows House Sparrow populations in some areas now increasing.

 

[Amarillo]

Interesting that recent news release fro mBT Oshows House Sparrow populations in some areas now increasing.

I joking commented a while back that I wonder whether sparrows will recover before this thread finishes...

I've noticed a huge increase recently and have never seen so many sparrows in the garden as this year.

 

[Jane Turner]

Greenficnhes too... perhaps it really was trichomoniasis after all. Can I claim the money?

 

[tittletattler]

I joking commented a while back that I wonder whether sparrows will recover before this thread finishes...

I've noticed a huge increase recently and have never seen so many sparrows in the garden as this year.

Yup. This was bound to happen.

With the recession, people are less inclined to spend money clearing their gardens of sprog friendly habbo and replacing it with decking. Hurrah for the banking global economic crisis!

 

[robinm]

I've also noticed that my local council is not sending round the hack merchants to "tidy up" the verges. There are even complaints about it in the local rag.

I have never had so many House Sparrows in the garden despite regular visits from the local Sparrowhawk.

 

[angusmcoatup]

I've also noticed that my local council is not sending round the hack merchants to "tidy up" the verges. There are even complaints about it in the local rag.

I have never had so many House Sparrows in the garden despite regular visits from the local Sparrowhawk.

I was thinking the same thing recently. The local council estate greens are looking nicely overgrown at present, when usually they've been cut and strimmed to bowling green length at regular intervals. House Sparrow numbers have been slowly creeping up close to my home over the last 4 years I've been here. This year they've spread out a little and I can hear them throughout a fairly wide area.

 

[Wildmoreway]

Another factor is perhaps that because of this thread some of us are looking and listening for house sparrows more, I have certainly noticed more since this thread started. Other factors are that the population dip could have resulted from house sparrows adapting to new conditions or moving into more suitable but different situations that were not previously available to them. Indeed perhaps their population did not actually dip but that they simply drifted slowly into other habitat situations but we failed to adapt our own observation methods to accomodate this, in the meantime we saw a decline in the populations their older habitats without observing them in their new habitats.

One point is that profesional researchers often have more rigid ideas of where a species will occur than an amateur observer might, this is certainly something that I have observed with butterfly watchers.

On the sparrowhawk issue, just watch the outrage at an Osprey chick being taken by a Buzzard and the (ironic) flailing of arms by members of the anti raptor camp.

 

[KenM]

During a 5 day trip to NYC in early May this year...I noticed how ''superb'' the plumage conditioning was on Central Park's abundant House Sparrow and Starling population.

Last week at the Tower of London I was able to watch a handful of Starlings in very poor condition, not unlike some of the residing feral pigeons..equally tawdry. It has been suggested that salt impregnated processed foods are to blame for this condition..just a coincidence that NYC posseses healthy stock as opposed to our own ailing and dwindling populations ?

Perhaps the BTO in conjunction with a US counterpart, might consider importing and releasing these once common species, particularly into urban centres where they once thrived (pers.obs.London parks early '50's).

If any degree of success was achieved (the US populations may well have developed a superior dynamic to our existing stock..and thus might be able to reverse the trend?)...on the basis of ''nothing ventured''..after all...If the conservation bodies can do it for White-tailed sea eagles and Bitterns..why not House Sparrows and Starlings..a more difficult project?

 

[Nightranger]

Perhaps the BTO in conjunction with a US counterpart, might consider importing and releasing these once common species, particularly into urban centres where they once thrived (pers.obs.London parks early '50's).

If any degree of success was achieved (the US populations may well have developed a superior dynamic to our existing stock..and thus might be able to reverse the trend?)...on the basis of ''nothing ventured''..after all...If the conservation bodies can do it for White-tailed sea eagles and Bitterns..why not House Sparrows and Starlings..a more difficult project?

This is an interesting idea Ken although some of the populations are known to have declined as a result of nest habitat loss. I think there are two problems though I am not sure either is insurrmountable:
1. Transportation would be costly and possibly questionable on the grounds of welfare although it is true to say that sparrows did not get to NYC by flying of their own accord.
2. Releasing the birds into an environment that had all their needs such as nest sites or put in a nutshell, the reasoin that the sparrows declined had been removed.

I like the idea that US sparrows may have developed along a different line and have acquired a resistance to salty food. As a geographical isolation, we probably should expect a little change and I wonder how Australian sparrows have developed.

Starlings are a little different even though some of the reasons behind the decline may be similar. Unfortunately, starlings prefer to nest in urban environments rather than in woodland unless the population is high enough to overflow. It is now rare to find starlings nesting in woods but the continued decline of the species points at the fact that the problem lies in urban areas. It now looks like we could be turning the clock back 250 years and seeing the end of breeding starlings in the UK although we will continue to see winter migrants. Having said that, some alarming statistics have been noted about declines in winter roosts with the same trend being mirrored across Europe.

 

[Jos Stratford]

Starlings are a little different even though some of the reasons behind the decline may be similar. Unfortunately, starlings prefer to nest in urban environments rather than in woodland unless the population is high enough to overflow. It is now rare to find starlings nesting in woods but the continued decline of the species points at the fact that the problem lies in urban areas. It now looks like we could be turning the clock back 250 years and seeing the end of breeding starlings in the UK although we will continue to see winter migrants. Having said that, some alarming statistics have been noted about declines in winter roosts with the same trend being mirrored across Europe.

Beyond the UK setting, I am not sure the overflow idea holds true - at least here in eastern Europe, Starlings are abundant and, whilst present in urban areas, the higher densities are certainly in semi-rural and rural areas, nesting commonly in farmsteads and rural gardens, as well as completely natural locations. In urban areas and even in the rural human-orientated areas, Starlings are frequently spring birds only, moving into the open countryside as soon as young fledge. Eg in my garden, rural by my definition, two-three pairs appear in late March or early April, breed, then depart the very day the young fledge in late May. Summer records are near non-existent, winter absolutely not (all out of the country). On my land, a mix of meadow and forest, about 15 pairs breed - both on provided nestboxes and in natural tree sites - birds are present from spring through to autumn migration, with much roving.

 

[Jos Stratford]

Having said that, some alarming statistics have been noted about declines in winter roosts with the same trend being mirrored across Europe.

Winter roost counts in Britain, if declining, could also reflect a growing tendency of Starlings to winter on the continent.

 

[JTweedie]

Beyond the UK setting, I am not sure the overflow idea holds true - at least here in eastern Europe, Starlings are abundant and, whilst present in urban areas, the higher densities are certainly in semi-rural and rural areas, nesting commonly in farmsteads and rural gardens, as well as completely natural locations.

I was surprised how widespread they were when I was in Shetland recently. I saw them everyday and this even after travelling from south to north and east to west over the islands. They were found on beaches, on top of hills, on moorland, around inland lochans, on seacliffs, in gardens and behind walls, on quaysides and on buildings, ducking in and out of breakwaters, in the few areas of woodland, hanging out with the Shetland wren and wheatears around lighthouses, they were in quarries which had nesting fulmars.

Some of the birds I saw must have nesting near to where I saw them, but I only saw actual nesting birds once - behind a wall behind my cabin in Baltasound, Unst, but even so, I got a real sense of a highly resourceful and very successful bird.

 

[Nightranger]

Beyond the UK setting, I am not sure the overflow idea holds true - at least here in eastern Europe, Starlings are abundant and, whilst present in urban areas, the higher densities are certainly in semi-rural and rural areas, nesting commonly in farmsteads and rural gardens, as well as completely natural locations.

I think you are right Jos, the UK breeding birds seem to be slightly different in their habits. I can only imagine that this is in some way linked to the fact that they only became established as UK breeding bird around 250 years ago.

Winter roost counts in Britain, if declining, could also reflect a growing tendency of Starlings to winter on the continent.

Again, there is certainly a lot of truth in this idea, after all why migrate if you don't have to? However, I am sure I read that starlings had declined in parts of their continental range. Unfortunately, I am no longer at the RSPB so I have no way of checking what the source was.

 

[CPBell]

Salt eh? Well I never..

I’ve had the pleasure of reading the BTO’s latest House Sparrow offering in the form of a “factsheet”, which I’ll attach to this post. It’s not available for download - you have to request it so they can get your details for their marketing database.

Needless to say the word ‘Sparrowhawk’ doesn’t appear in the document, though there are grave reservations expressed about the effect of cats, woodpigeons and collared doves on sparrow numbers. Nevertheless the first recommendation offered is to provide thick cover so that sparrows can ‘escape from predators, rest, roost and socialize’ (for which read ‘escape from predators’ – otherwise why not rest, roost and socialize out in the open?). So as not to frighten the horses (or is it the RSPB?) they quickly qualify this with a genuflection to Peach’s dodgy PCA analysis in his Animal Conservation paper showing a marginal relationship between shrubbery and breeding success.

They also recite the usual RSPB-approved liturgy about loss of stubbles and spilled grain in the countryside (forgetting their own research which indicates to the contrary), and off-road parking spaces and plastic fascia boards in the cities. They then go on to recommend you let your lawn go to pot (nice for the neighbourhood – haven’t they heard of the broken-windows theory?) and put up ‘terrace’ nestboxes (which don’t work).

The British Trust for Ornithology – impartial, objective, scientific.

http://www.cpbell.co.uk
http://www.youtube.com/CultoftheAmateur

 

[Amarillo]

Good to see this thread evolving (until the last post, anyway)

Maybe a new one should be started to discuss the real reasons for sparrow decline, rather than allow Bell to continue keeping this one going in order to promote his own interests?

 

[bluechaffinch]

An interesting new piece of the puzzle...

Firstly, whatever one thinks (or perhaps believes is more appropriate) about the merits of Dr Bell's thesis, it is surely to be welcomed that posters on this forum have had the rare, if not unique, opportunity to really grill the author of a paper about the fine details of their research over an extended time period- has this been done with any other sparrow/farmland bird papers on here? I don't believe so.

Secondly, the posts 'against' Dr Bell have been based entirely on the context that 'no, you are wrong, it's not sparrowhawks but a range of other anthropogenic reasons such as building design, changes to 'good old' farming practices etc etc'. Now we have BTO research which suggests that HS are actually increasing - so which way is it? Are these various reasons now not an issue? Are there no more plastic soffits and fascias being installed? Are our gardens all messy because we have no money to tend them well due to the downturn? When exactly did these factors stop being an issue? Is it the dreaded cats???

I find it frustrating that on the one hand people are more than happy to go to town on Dr Bell's paper and espouse various factors which are far more likely causes for HS declines, and yet when BTO research shows that HS are increasing fail to acknowledge that maybe this flies in the face of the 'all is doom' hypothesis. Can't have it both ways!

Carry on...

 

[AlfArbuthnot]

Nevertheless the first recommendation offered is to provide thick cover so that sparrows can ‘escape from predators, rest, roost and socialize’ (for which read ‘escape from predators’ – otherwise why not rest, roost and socialize out in the open?).

Do you mean just like Blackbirds rest, roost and socialize in the middle of lakes, and Mallards rest, roost and socialise in woods?

They also recite the usual RSPB-approved liturgy about loss of stubbles and spilled grain in the countryside (forgetting their own research which indicates to the contrary),

Before you think you have got away with this, please point us to the research showing that increased herbicide application and a switch from autumn to spring sowing since the 1980s has NOT led to a decrease in the seed stock available on farmland. To argue against this is delusional.

and off-road parking spaces and plastic fascia boards in the cities.

lest we let dismissive assumptions get in the way of the facts, there are some numbers for you here http://www.bbc.co.uk/news/uk-18623096

Showing that 3200 ha of London gardens have been paved over, and in NE England nearly half of gardens are more than 3/4 covered.

The British Trust for Ornithology – impartial, objective, scientific.

It certainly looks that way. Can you yourself claim to be impartial and objective? We'll leave 'scientific' to the judegment of viewers of your videos and readers of your papers.