alan_rymer
Well-known member
Which are?
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Magpies and crows to be culled to protect songbirds (1 Viewer)
- Thread starter John B (not the sloop)
- Start date
YourBirdOasis
Well-known member
Crows killing lambs? Say what!
Very newly born lambs, yes. Individual birds will also attack the ewe when she lies down to give birth. I've personally seen a ewe die of shock after having her eyes pecked out when she was giving birth. Nature isn't always pretty.
These days though, the majority of sheep are lambed inside.
Mike Price
Well-known member
I can't find this. I assume you mean the program of 28/1/11 at http://www.bbc.co.uk/programmes/b00xwpkb
John B (not the sloop)
Don't blame me I didn't vote for 'em
Goshawks spring to mind, and Peregrines are perfectly capable.
Perhaps we could interest GWCT and SS in a conservation programme for both species in the interests of corvid population management. No doubt they'd be very receptive.
Oh, and female Sparrowhawks are proven Magpie killers too. Maybe SS should adopt one as their logo.
chris butterworth
aka The Person Named Above
It's a shame more people don't realise this. There are too many uninformed, anthropocentric or biased views concerning the reality of the natural world being promoted by those who should, or could, if they made an effort, know better.
Chris
Marcus Lawson
I've had to have a few of these!
KenM
Well-known member
Clearly there is no single answer to songbird decline!...having been at my present abode for a 'nano second 53 year! blink'...witnessing the dissappearance completely at local level of those invertebrates that I can recognise...namely House Flies and TigerMoths!
Speaking as a birder with almost no knowledge of insects..the latter vanished perhaps 30-40 years ago...and the former possibly 30 years ago..the exact timing of their demise has probably been chronicled (I hope) by those that know better.
I can recall at the end of a 'Summer days driving' during the '70's be it on
M2/M4, A30 etc. having to scrub the 'film' of invertebrates off the grill and bonnet of the car...something we don't encounter now!..probably a 90% decrease.
When I arrived in '57, the 'London Corporation' which controls the 6000 acres that I live adjacent to, 'controlled' Corvids and Grey Squirrels...Pesticides had wiped out the Sparrowhawk to the extent that I didn't see my first
till '72 there weren't any locally until the mid '70's.
Prior to which RBShrike, Woodlark,Turtle Dove, and Tree Sparrow were already gone!
Then from perhaps the '70's onwards these declines were followed by Linnet, Yellow Hammer, WillowTit and Com.Redstart.
During the '80's the underlying decline of Cuckoo,Tree Pipit, Spotted Flycatcher and MarshTit began to gain momentum.
During the early '80's Hobbies became more frequent ( I didn't have to drive down to SW Surrey to see them anymore!) and saw my first Little Egret on Corfu...I thought what a magnificent creature..imagine seeing it in the UK..one can dream! ....also seeing my first and only Firecrest on Majorca during the same period. These 3 species now occur around my locale...just 30years after!!!
It was the late '90's that I noticed the decline of Reed Bunting, Skylark, Lesser Spotted Woodpecker, Hawfinch, Bullfinch, Kestrel and Yellow Bunting from a wider locale radius, with the loss of House Sparrow and Starling from my garden plus a noticeable decline in Song Thrush, Tree Creeper, and Greenfinch...
Yes there has been an increase in Corvids/Sprawks and Squirrels and they may have had a measurable impact on certain species, but overall the problem I believe is not down to the direct balance between song bird and accipter, that's a balance that is purely natural, and should be seen in that context.
What concerns me apart from the sirens of Global Warming/Farming practices etc. is the lack of natural or human control on those predators that are only there because of man's hand (or lack of) ie Squirrels introduced without any natural predator! and the Corvid (likewise)...whose increase has been brought about by Man's activities...garden handouts, waste dumps adding even more pressure! to an already dwindling Songbird base.
Perhaps more Goshawk introduction (which are more functional) than 'pretty' Red Kites, but I suspect any 'game rearing' local estate owners might just not agree....however our 'Songbird fabric' should take president over all and sunder! The sound of our Songbirds should be enshrined in statute...for future generations.
Otherwise in another 30 years, it might not just be!..a silent Spring that we need to worry about..If that scenario sounds far fetched...how do you think this present situation would have seemed...yes...30 years ago?
Speaking as a birder with almost no knowledge of insects..the latter vanished perhaps 30-40 years ago...and the former possibly 30 years ago..the exact timing of their demise has probably been chronicled (I hope) by those that know better.
I can recall at the end of a 'Summer days driving' during the '70's be it on
M2/M4, A30 etc. having to scrub the 'film' of invertebrates off the grill and bonnet of the car...something we don't encounter now!..probably a 90% decrease.
When I arrived in '57, the 'London Corporation' which controls the 6000 acres that I live adjacent to, 'controlled' Corvids and Grey Squirrels...Pesticides had wiped out the Sparrowhawk to the extent that I didn't see my first
till '72 there weren't any locally until the mid '70's.
Prior to which RBShrike, Woodlark,Turtle Dove, and Tree Sparrow were already gone!
Then from perhaps the '70's onwards these declines were followed by Linnet, Yellow Hammer, WillowTit and Com.Redstart.
During the '80's the underlying decline of Cuckoo,Tree Pipit, Spotted Flycatcher and MarshTit began to gain momentum.
During the early '80's Hobbies became more frequent ( I didn't have to drive down to SW Surrey to see them anymore!) and saw my first Little Egret on Corfu...I thought what a magnificent creature..imagine seeing it in the UK..one can dream! ....also seeing my first and only Firecrest on Majorca during the same period. These 3 species now occur around my locale...just 30years after!!!
It was the late '90's that I noticed the decline of Reed Bunting, Skylark, Lesser Spotted Woodpecker, Hawfinch, Bullfinch, Kestrel and Yellow Bunting from a wider locale radius, with the loss of House Sparrow and Starling from my garden plus a noticeable decline in Song Thrush, Tree Creeper, and Greenfinch...
Yes there has been an increase in Corvids/Sprawks and Squirrels and they may have had a measurable impact on certain species, but overall the problem I believe is not down to the direct balance between song bird and accipter, that's a balance that is purely natural, and should be seen in that context.
What concerns me apart from the sirens of Global Warming/Farming practices etc. is the lack of natural or human control on those predators that are only there because of man's hand (or lack of) ie Squirrels introduced without any natural predator! and the Corvid (likewise)...whose increase has been brought about by Man's activities...garden handouts, waste dumps adding even more pressure! to an already dwindling Songbird base.
Perhaps more Goshawk introduction (which are more functional) than 'pretty' Red Kites, but I suspect any 'game rearing' local estate owners might just not agree....however our 'Songbird fabric' should take president over all and sunder! The sound of our Songbirds should be enshrined in statute...for future generations.
Otherwise in another 30 years, it might not just be!..a silent Spring that we need to worry about..If that scenario sounds far fetched...how do you think this present situation would have seemed...yes...30 years ago?
alan_rymer
Well-known member
Havn't included the full quoted post. However, Corvids used to be "managed", they are not now, My local site , an ex rubbish tip, now a Gravel pit and grassed over fields grazed by sheep Autumn/Winter, then Hay summer. Its a place where the local Jackdaws/Crows come to have a wash and brush up and to play. Well play if your'e a corvid, anything else gets mercilessly harried except when the Common Terns arrive and breed in any number. Anything else, LRP, Lapwing, Common Sand, Redshank etc have no chance, they are hardly given a chance to land, and are usually chased around and around , any that do try to breed are eventually discoved. surrounded by a dozen Jackdaws and driven off, any eggs/chicks devoured.
Numbers, 1000 corvids are not out of the ordinary, some are Rooks which do not seems to cause a problem. Raptors: Lots of Kites, Buzzards, and Sparrowhawks with the occaisional Peregrine and Kestrel, Barn and Tawny Owl, recent reports of Merlin and possible transitional Goshawk. Certainly nothing that could control the numbers of Jackdaws and Crows.
I would dearly love to have the ability to reduce the corvid numbers.
KenM
Well-known member
Alan Hi,
It sounds like we are 'kinda' singing from a similar song sheet! although I must admit that 'waders' were not at risk from Corvids on my radar!, and I never realised that Jackdaws were/could be a problem...isn't note swopping good!
A number of years ago during mid-winter...I did a 400m walk through the deciduous wood behind my house and counted c50 Grey Squirrels!...having witnessed how long it takes...for 2 Grey Squirrels to devour all the Hawthorn berries on an old 20' Hawthorn (sustenance for Winter thrushes..and Hawfinches)...the answer is less than 2 days!!!
Fast forward to Dec.'10...I witnessed 2 Squirrels 'taking out' a c100m stretch of mature woodland edge, seeded Hornbeams, extrapolate that throughout UK deciduous woodland, and it is positively frightening!!!
That is without monitoring the compound effect that they would have, on nestlings/eggs etc....and thats without Corvids!...You would think that the RSPB could throw it's weight behind 'corvid/Squirrel control' wouldn't you?....I suspect that they are 'Legacy sensitive'....must not upset the hand that feeds!...well that can work both ways....they won't be getting my small legacy...and hopefully...not just mine!
ChrisKten
It's true, I quite like Pigeons
Already said my bit about this "study" and SBS, but just a bit of anecdotal evidence that doesn't seem to fit with other posters' experience:
Visiting my garden are Crows (3+), Magpies (4+), Jays (6+), Squirrels (6+), and Sparrowhawks (4+ recently). There are also House Sparrows (40+), Starlings (20 - 70+), Great Tits (5+), Blue Tits (4+), Robins (2+), Dunnocks (2+), Chaffinches (4+), Wrens (2), Blackbirds (3+), Collared Doves (14+), Feral Pigeons (60+), Great Spotted Woodpecker, Goldcrests (2+) and a few Mice. There are also Greenfinches, Goldfinches, and Song Thrushes, that don't visit often due to the amount of other birds in the garden.
I've seen no decline in anything, especially over the last 4 years that I've been observing my garden each day. Oh, and my garden is a 20ft square patch of mud with two trees, and I'm on a Housing Esatate in London.
My local Reservoirs (a large 10 Reservoir complex) has 100s of Corvids, 100s of Squirrels, Peregrines, Sparrowhawks, and Kestrels, and many Foxes. There are 1000s of small birds (loads of waders too), species too many to type. Also 100s of Cormorants, but not relevant to this. Although the Reservoirs is an SSSI, there's been no management of any predators during the 30+ years that I've been going there, at least not that I'm aware of. Although I should say that there is regular cutting back of bankside vegetation (it's a Fishery). Like my garden and local area, I've seen no decline in Songbirds at the Reservoirs, but maybe a study would prove otherwise.
As to why everything seems fine in my garden and locally, and at the Reservoirs; I've no idea. But I find it interesting that no management of predators hasn't reduced Songbird numbers, quite the opposite in fact.
I would be interested to know why my experience appears to be at odds with many other posters' (what's different about my local area?).
Visiting my garden are Crows (3+), Magpies (4+), Jays (6+), Squirrels (6+), and Sparrowhawks (4+ recently). There are also House Sparrows (40+), Starlings (20 - 70+), Great Tits (5+), Blue Tits (4+), Robins (2+), Dunnocks (2+), Chaffinches (4+), Wrens (2), Blackbirds (3+), Collared Doves (14+), Feral Pigeons (60+), Great Spotted Woodpecker, Goldcrests (2+) and a few Mice. There are also Greenfinches, Goldfinches, and Song Thrushes, that don't visit often due to the amount of other birds in the garden.
I've seen no decline in anything, especially over the last 4 years that I've been observing my garden each day. Oh, and my garden is a 20ft square patch of mud with two trees, and I'm on a Housing Esatate in London.
My local Reservoirs (a large 10 Reservoir complex) has 100s of Corvids, 100s of Squirrels, Peregrines, Sparrowhawks, and Kestrels, and many Foxes. There are 1000s of small birds (loads of waders too), species too many to type. Also 100s of Cormorants, but not relevant to this. Although the Reservoirs is an SSSI, there's been no management of any predators during the 30+ years that I've been going there, at least not that I'm aware of. Although I should say that there is regular cutting back of bankside vegetation (it's a Fishery). Like my garden and local area, I've seen no decline in Songbirds at the Reservoirs, but maybe a study would prove otherwise.
As to why everything seems fine in my garden and locally, and at the Reservoirs; I've no idea. But I find it interesting that no management of predators hasn't reduced Songbird numbers, quite the opposite in fact.
I would be interested to know why my experience appears to be at odds with many other posters' (what's different about my local area?).
KenM
Well-known member
I don't know about Alan?....but for me a '53 year' shutter speed...is longer and more accurate than a 3-5 year monitoring study as far as recording the presence and decline of individual species is concerned!
Your avifauna/mammal figures for your patch are more or less what one might expect for an urban situation...I see no surprises..save perhaps Song Thrush presence?...I would find their RA (Relative Abundance) on your patch of interest, as of yet..I have not recorded them in my garden yet!..this year.
If I care to walk 4/5 hundred metres, I can make contact with a local House Sparrow group....and they will be chirping within deep cover ie Privet/Hawthorn..no longer confiding!...Starlings again, can be found a not dissimilar distance, often in association with!...10 years ago both species were 'daily present' in my garden.
cheers
ChrisKten
It's true, I quite like Pigeons
Yes, it was early, I think I've replied to posts in another thread as well (concerning House Sparrows). |=)|
Obviously longer term observations will give a more accurate picture, especially if those observations are recorded. My short term observations are just based on watching the garden every day, no records taken, just pictures.
The Reservoirs is another matter, although again, no records. There is one species that completely disappeared about 30 years ago (I'll have to check the year), and that was Tree Sparrows. There was a small flock of them at the Reservoirs for years, but alas, no more. No idea what happened, though I suspect it wasn't due to Corvids.|=)|
Anyway, like I said, some of what I typed wasn't really meant for this thread, but I'll leave it all in; it might interest someone.
For those assuming that there is a major impact of crows on lambs - from BWP: Scottish study, only c. 0.1% of lambs born estimated to have died as a result of attacks and great majority of those probably dead or already dying. [so presumably the figure could be considered to be <0.1%]
Also worth remembering that there is a need for caution when dealing with observations like that in post 63. I would have thought that the trauma of birth is much more likely to induce a lethal shock than loss of eyes. In any case it is not possible to reach a firm conclusion re the cause of death it could be illness, or related to poor husbandry, etc etc.
Geoff
Also worth remembering that there is a need for caution when dealing with observations like that in post 63. I would have thought that the trauma of birth is much more likely to induce a lethal shock than loss of eyes. In any case it is not possible to reach a firm conclusion re the cause of death it could be illness, or related to poor husbandry, etc etc.
Geoff
Shadow-watcher
Well-known member
I farm sheep on carngafallt, and that number is wrong. It is definitly a great minority, but >0.1% is way off. Even though I have seen crows 'blinding' a ewe while she's giving birth, I am of the mind that lambs are generally dead or dying from some birth defect before the crows get at them. I plan on doing my own study this spring.
How many lambs are injured or possibly killed by crows has many variables, but Id like to think that they are mostly natural. Farmers have to start accepting that loss to nature is an integral part of farming, there are those of us pioneering a more compliant, clean, and sustainable approach.
The vice chair of SBS lives on carngafallt too, Im pretty sure he wants to kill the Red kites, which clear the afterbirth of lambing. He genuinly see's the BoP as threatening to songbirds. This cull is about opening up the legislation to warrant their control, which of course is good for the game shooters as well. Its rubbish, complied by uneducated landowners hell bent on controlling the countryside.
The big danger is that culling corvids will increase songbirds, that will be enough to deem their test a success, and it will probably work out that way.
How many lambs are injured or possibly killed by crows has many variables, but Id like to think that they are mostly natural. Farmers have to start accepting that loss to nature is an integral part of farming, there are those of us pioneering a more compliant, clean, and sustainable approach.
The vice chair of SBS lives on carngafallt too, Im pretty sure he wants to kill the Red kites, which clear the afterbirth of lambing. He genuinly see's the BoP as threatening to songbirds. This cull is about opening up the legislation to warrant their control, which of course is good for the game shooters as well. Its rubbish, complied by uneducated landowners hell bent on controlling the countryside.
The big danger is that culling corvids will increase songbirds, that will be enough to deem their test a success, and it will probably work out that way.
Adam W
Well-known member
Well presumably because an increase in songbirds as a direct result of the cull would be pretty hard eveidence that it was a success or am i missing something?
black kite 1964
Well-known member
I suspect the vice chair of SBS kills Red Kites already!!!
MJB
Well-known member
Whatever the results of a single study, as biological and medical researchers well know, correlation of results and circumstances is always difficult to turn into a case for causation, even when studies are numerous, sample sizes are large, and variables have been taken into account; subsequent in-house critiques and the mandatory pre-publication peer-review critiques of studies are the norm in organisations such as the BTO just to test how strong or how weak the links between correlation and causation are.
Post-publication criticism gnerally comes in two kinds: that based on the strength or shortcomings of the science, and that based on opinion, misunderstanding of the science, whether genuine or wilful (eg the conspiracy theory approach resorted to when commissioned research does not fulfil preconceptions), or an inability to perceive the context in which the research took place.
In terms of scientific ethics (not the ethics of killing or not killing), any organisation claiming scientific respectability has to start out from the position outlined above and not evade questions about methodoly and data. Songbird Survival decided not to accept findings from research they commissioned - that's their right - but their refusal to argue their case for their rejection on the grounds of flawed scientific or statistical method by citing appropriate published authorities suggests that their approach is less likely to be valid.
I'll go back a couple of decades for an illustrative example. When Song Thrush numbers plummeted, there were any number of well-meaning groups that 'knew' (and campaigned hard on the basis of that knowledge) why this was. The claimed reasons given (there were several, some incompatible) rubbished reasoned arguments that no one could explain any correlation as causation, but being largely pre-Web, vituperative condemnation of the science was by snail-mail (Ah, the nostalgic days when loonies obligingly wrote in green ink!) to the research organisations or to the newspapers.
Patient research of 50 years of data showed: no reduction in clutch size; no reduction in hatching rate; no reduction in fledging rate and no reduction in adult survival rate, all factors that would have been affected by poisoning or reduced reproduction by chemical ingestion. The context of the main critics was that spraying of crops 'was poisoning our birds', the kind of hysteria that occurs even more often today from belief in opinion and not in evidence.
It was a double irony that chemical usage on crops was actually involved, but that that usage was as a result of the replacement of broad-spectrum sprays by non-persistent targeted sprays or pellets. Narrow-spectrum molluscicides had become extremely effective, but only adult Song Thrushes had sufficient adaptability to seek an alternative diet in alternative habitats. First-year birds were endogenously 'programmed' to the ideal diet of slugs and snails in semi-open or open habitats and so starved. I seem to remember that first-year mortality was about 97%, unsustainable.
Extraordinarily careful research resulted in a recovery strategy, but I still find people who not only remain angry about 'pesticides poisoning out Song Thrushes', but also are convinced that 'they' just did another cover-up.
So Adam, a long, illustrative answer to your query. In short, you are completely wrong to 'presume' at this early stage that a correlation between an increase in numbers and culling would represent a causal link. My reasons lie in that part of my motto, 'Biology is messy', and so almost always demand a long answer, no matter how many people want an instant 'yes' or 'no', and it won't always be the answer you (or I) want,
MJB
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