crow vs magpie

[Dogghound]

Originally Posted by Sawsicksteve

Really? Any references for this?

Its widely mentioned in the (BWPI).

Witherby et al. 1939,
Dementiev and Gladkov 1951a,
Uttendörfer 1952,
Mebs 1964b,
Thiollay 1967a,
Melde 1971,
Glutz von Blotzheim et al. 1971,
Brown 1976a.

Additionally a study in france looking at 6146 prey items references it Thiollay J.M 1967, Terre et Ve 21, 116-85. Although you need to translate this journal, and some above.

Its also mentioned in other wider references.

Originally Posted by Sawsicksteve

In my experience, Buzzards tend to err on the side of caution when it comes to prey items. Not unnaturally if you think about it, as if a predator is damaged in an attack it has a lot more to lose.
It would have to be a pretty desperate Buzzard that took on a healthy adult Rook, especially as the Rook would be unlikely to be alone. In fact, the only predation at a rookery I've witnessed is by a Carrion crow who snuck in to grab a couple of eggs from a peripheral nest when the rest of the colony was distracted and mobbing - yes - a Buzzard!

I said occassionally adults, I didnt specifiy if they were healthy, injured, part of a group alone, in a rookery, in an open field... They will quite happily predate nests and nestlings a more prevelant occurance than adult birds. Rooks and other Corvids form a small part of the diet, its not a frequently occuring event and smaller birds like starlings and thrushes naturally make up a larger part of the diet in context of birds predated, which is small compared to mammals, invertebrates and carrion.

Other birds such as Red kite have been documented raiding rook nests for fledglings (recent) and nestlings.

Regarding never seeing it occur, I have never seen a mink kill a water vole, does that mean it doesnt happen?

[anderson123]

Not much violent fight but some have seen many usual battles between birds in my garden. These were usually after food.

[Sawsicksteve]

Originally Posted by Dogghound

Its widely mentioned in the (BWPI).

Witherby et al. 1939,
Dementiev and Gladkov 1951a,
Uttendörfer 1952,
Mebs 1964b,
Thiollay 1967a,
Melde 1971,
Glutz von Blotzheim et al. 1971,
Brown 1976a.

Additionally a study in france looking at 6146 prey items references it Thiollay J.M 1967, Terre et Ve 21, 116-85. Although you need to translate this journal, and some above.




Other birds such as Red kite have been documented raiding rook nests for fledglings (recent) and nestlings.

Regarding never seeing it occur, I have never seen a mink kill a water vole, does that mean it doesnt happen?

So, mainly European references then, not UK? Interesting stuff though, unfortunately the release of BWP coincided with a time of extreme budget constraint (mortgage,kids etc etc..) and I could never justify the outlay.

Dr Franklin Coombs, in his book 'The Crows, A study of the Corvids of Europe' mentions an unsuccessful attempt by a buzzard to catch a rook back in the late 50's, when myxomatosis was at it's height. This bird he describes as 'starving', due to the decimation of the rabbit population.
I'm not saying it's never happened, just that it's extremely rare - certainly in Britain. Far too many easier options - road kill, small mammals, earthworms, beetles, carrion and the absolute abundance of rabbits this last few years. I did witness a buzzard kill a grey squirrel once though.

Regarding Red Kite, yes, never in doubt and well documented. But we're talking buzzard here.

Your last point seems a bit of a strange analogy - we know mink kill water vole as it's been well documented in Britain. I bet you've never seen a 'big cat' in the UK either, but would probably equate absence of evidence with evidence of absence in that instance.
Kind regards,
Steve.

[Dogghound]

Originally Posted by Sawsicksteve

So, mainly European references then, not UK? Interesting stuff though, unfortunately the release of BWP coincided with a time of extreme budget constraint (mortgage,kids etc etc..) and I could never justify the outlay.

Ok, upto you if believe it or not, I could'nt care less. Its unlikely that buzzards in other parts of europe behave in such a different way to British ones in respect to this this kind of activity.

Originally Posted by Sawsicksteve

Dr Franklin Coombs, in his book 'The Crows, A study of the Corvids of Europe' mentions an unsuccessful attempt by a buzzard to catch a rook back in the late 50's, when myxomatosis was at it's height. This bird he describes as 'starving', due to the decimation of the rabbit population.
I'm not saying it's never happened, just that it's extremely rare - certainly in Britain. Far too many easier options - road kill, small mammals, earthworms, beetles, carrion and the absolute abundance of rabbits this last few years. I did witness a buzzard kill a grey squirrel once though.

Originally Posted by Sawsicksteve

Regarding Red Kite, yes, never in doubt and well documented. But we're talking buzzard here.

Even though buzzards predate more birds? Its well documented in Buzzards as I just stated about 9 references which you chose to ignore.

Originally Posted by Sawsicksteve

Your last point seems a bit of a strange analogy - we know mink kill water vole as it's been well documented in Britain. I bet you've never seen a 'big cat' in the UK either, but would probably equate absence of evidence with evidence of absence in that instance.

Whatever, I cant be bothered to get into another disagreement on this forum, ive made my opinion you can believe it or not it makes no difference to me.

[Jonathan]

Originally Posted by Sawsicksteve

I'm not saying it's never happened, just that it's extremely rare - certainly in Britain.

I thought it was common knowledge that buzzards occasionally kill corvids?

Taylor & Francis Online :: Correlates of Common Buzzard Buteo buteo density and breeding success in the West Midlands - Bird Study - Volume 48, Issue 3

"Fledgling corvids also appear to have been an important prey item, especially during chick-rearing. Some nests were almost completely covered in corvid remains, eight legs being found in one nest".

"As in our study area, corvids were found to be a common prey item in north Scotland and Wales (Swann & Etheridge 1995, Newton et al. 1982, Dare
1989)".

Cheers
Jonathan

[Sawsicksteve]

Re: crow vs magpie

Ok, upto you if believe it or not, I could'nt care less. Its unlikely that buzzards in other parts of europe behave in such a different way to British ones in respect to this this kind of activity.

Your tone implies that you could.

Even though buzzards predate more birds? Its well documented in Buzzards as I just stated about 9 references which you chose to ignore.

Ignore, or couldn't access, as I've already stated I can't afford BWPi.

Whatever, I cant be bothered to get into another disagreement on this forum, ive made my opinion you can believe it or not it makes no difference to me.

Had a few have you? Cant think why with that attitude (insert sarcastic smiley here). And that's twice you've emphasised that you don't care.
I haven't made too many postings here and I can see that you're one of the 'senior' board members, so forgive a 'newby' for forgetting his place.

I thought it was common knowledge that buzzards occasionally kill corvids?

Taylor & Francis Online :: Correlates of Common Buzzard Buteo buteo density and breeding success in the West Midlands - Bird Study - Volume 48, Issue 3

"Fledgling corvids also appear to have been an important prey item, especially during chick-rearing. Some nests were almost completely covered in corvid remains, eight legs being found in one nest".

We were referring to adults though.

[Dogghound]

Originally Posted by Sawsicksteve

Your tone implies that you could.

No.

Originally Posted by Sawsicksteve

Ignore, or couldn't access, as I've already stated I can't afford BWPi.

If you want I will give you the full reference to any of these reports however they are unlikely to make much of a difference in this respect. As I have stated Buzzards will predate adult, juvenile and fledgling corvids. Juveniles make up the bulk age group of corvids predated (same as with most other large nest raiding raptors i.e. red kite). Then fledgling birds make up a smaller portion of the diet (predominantly due to them roosting close to the nest site initially after fledging). Then a small portion of adults are taken, predominantly ill, old or dying birds. In no way do adult corvids constitute a large part of a buzzards diet, infact the number taken is insignificant in resect to other prey. However as I initially said they will on occassions predate them. Hence one of the mobbing causes of corvids (others being to drive them from nest sites, pirate food from raptors etc).