DEFRA licence farce (2 Viewers)

[KnockerNorton]

In studies of marsh Tit, both in Britain and Poland, jays have been found to be serious nest predators. See papers by Wesolowski for details (other figues I know of are unpublished as yet). This year, Jays predated significant numbers of marsh tit nests in both Oxfordshire and Cambridgeshire study sites (particularly the former). They're right up there in the top 3 nest predators for that species.

 

[Strandman]

What objective evidence is there that Jay is a serious nest predator? This behaviour is deemed common knowledge -everybody "knows" it but have there been any effective studies? -I suspect not!
Jays are common in many parts of continental Europe & are a major "vector" of acorns for a number of Oak species (indeed they are longterm Oakwood architects). In my limited experience of such woodlands there has been no shortage of small passerines. The recolonisation of for example, large parts of Argyll by Jays coupled with sheep exclusion would go a long way to encouraging the recurrence of the once extensive & species-rich sessile Oak woods of that area.

I should have added in my previous posting that I am also a sceptic in relation to the justification for controlling Jays.

As it happens, my experience around these parts is that corvid control is much more focussed on Carrion Crow and Magpie, as those two species are easier to control (with Larsen traps) and are perceived as having much more of an impact than Jays.

 

[Brian Stone]

In studies of marsh Tit, both in Britain and Poland, jays have been found to be serious nest predators. See papers by Wesolowski for details (other figues I know of are unpublished as yet). This year, Jays predated significant numbers of marsh tit nests in both Oxfordshire and Cambridgeshire study sites (particularly the former). They're right up there in the top 3 nest predators for that species.

So what?! The two must have co-existed in woods for millennia. This in itself is a complete non-starter as justification for killing Jays. The justification is that they conflict with human commercial activity.

 

[Steve G]

Whilst I am not in a position to argue about Jay nest predation of Marsh Tits in any given locality I'm not sure that one can then infer that Jays are the principal agent of Marsh Tit decline either. In summarising the sad & worrying status of Marsh Tit in the UK (& indeed in Europe) it seems that the BTO feel that habitat fragmentation is the major issue :- "Marsh Tit abundance has declined rapidly, despite improvements in breeding performance. The species' UK conservation listing has recently been upgraded from amber to red. Detailed demographic work suggests that the decline may have been driven by low annual survival and that neither increased nest predation nor interspecific competition is responsible (G.M. Siriwardena, unpubl.). Marsh Tits nest in woods as small as half a hectare (Hinsley et al. 1995), but there is evidence from CBC that declines are steeper on smaller plots (G.M. Siriwardena, unpubl.). Increased woodland isolation, loss of woodland understorey due to grazing, and reductions in the availability of dead wood may all have contributed to the decline (Vanhinsbergh et al. 2001, Perrins 2003). Following declines in France and elsewhere in northwest Europe during the 1990s, the European status of this species is no longer considered 'secure'."


However Corvids are admittedly more effective nest predators in fragmented degraded habitat & especially in habitat greatly disturbed by human activity (which is why Crow predation of Dotterel nests is thought to be on the increase on the Cairngorm plateau).

 

[Jos Stratford]

In studies of marsh Tit, both in Britain and Poland, jays have been found to be serious nest predators. See papers by Wesolowski for details (other figues I know of are unpublished as yet). This year, Jays predated significant numbers of marsh tit nests in both Oxfordshire and Cambridgeshire study sites (particularly the former). They're right up there in the top 3 nest predators for that species.

Is it shown that the Jay predation is having any impact on their population (as opposed to other factors)? Perhaps in isolated populations already in decline, but Marsh Tit is second (third) most abundant tit species in both garden and my forest, Jay is by far the most abundant member of the crow family (have 12 coming to my peanut feeders alone). In the last eight years, Marsh Tit population has not declined.

Additionally, as is said by Steve, offsetting any possible negative impacts, it has to be asked how beneficial have Jays been in recreating habitat for woodland species? As Poland, my neighbouring country, is mentioned above, it is worth mentioning that in this part of the world, very little tree replanting occurs in a conservation sense, though with the fall of Soviet farming practises, a lot of idle land exists, both within traditionally farmed areas and former commercial pine forest land. Across these areas, it is now common to see oak saplings growing across the meadows and in cleared pine clearings. On my own land, for example, there are quite a number of fine oak saplings which are now developing into good little trees in their own right. Reckon the ol' Jays are doing an okay job.

On the other issue, Jays as a heath risk, I can't find anything whatsoever to support this in pages and pages of websearches, so my gut feeling remains - DEFRA are in error to include it on that category of the license.

 

[KnockerNorton]

Is it shown that the Jay predation is having any impact on their population (as opposed to other factors)? Perhaps in isolated populations already in decline, but Marsh Tit is second (third) most abundant tit species in both garden and my forest, Jay is by far the most abundant member of the crow family (have 12 coming to my peanut feeders). In the last eight years, Marsh Tit population has not declined.

On the other issue, Jays as a heath risk, I can't find anything whatsoever to support this in pages and pages of websearches, so my gut feeling remains - DEFRA are in error to include it on that category of the license.

Marsh Tits have declined by about 2/3 in Britain since the 60s. It's unclear why. As Jays mainly predate the nests in soft dead wood, they are also possibly significant predators of Willow Tit nests, which have declined by even more and are at risk of extinction in many parts of the island (and this form is found nowhere else). Whether the predation has any impact or not was not the question, the question was whwther they are significant nest predators, and they are. With a single-brooded, fragmented population that may already be under pressure from other sources, nest predation is clearly not desireable. havign said that, Great Spots take more than Jays, and are probably the main nest predator in Britain.

Re jays and health, why not email Defra and ask them?

 

[s.g.]

Watch out all you G. S. W.s your next on the list......

S. G.

 

[Andrew]

If we meddle in the balance of nature by protecting certain species from predation we are effecting artifical evolution and that is not really acceptable in the long run/bigger picture. Let things run their natural cause and limit man's impact on nature is the way to go about it.

 

[Jos Stratford]

Re jays and health, why not email Defra and ask them?

I have, if they reply I'll post it up here.

 

[alcedo.atthis]

The seemingly total lack of understanding of the General Lisences and their constraints, does not come as a surprise, especially, as it is being shown in the realms of a Wild Bird Forum.

It's sad.


Regards

Malky

 

[Percy]

Canada Geese should be top of the hit list in South Northants, the bank erosion and plant destruction on many lakes in the area is shocking and lots of mess!!!!!!!
The Coots on one lake have moved on as food became scarce.

In my view it should be easy applying for the relevent licenses as some areas have problems that need sorting sooner rather than later, and legally.

 

[alcedo.atthis]

"Canada Geese should be top of the hit list in South Northants, the bank erosion and plant destruction on many lakes in the area is shocking and lots of mess!!!!!!!"

Well Percy, it is quite easy. Just get the permission of the landowner, where these geese are, catch them using any of the legal methods, and cull them, again using any of the legal methods, noting that it would illegal to re-release them back into the wild.

Regards

Malky.

 

[Gus Horsley]

I've been for a couple of days so I'm going to wade in again.

I don't think attitudes towards wildlife have changed significantly in the past hundred years or so. True, there has been a lessening of egg collecting, but to counterweight that there has been an increase in poisonings, such as the 16 red kites that were killed this way in 2003, one of the worst years for this kind of activity. I do agree with those who think that we're shifting the blame for ecological disturbance from ourselves to other species, when we should really be addressing the root cause.

As far as jays are concerned - I can't say they're common at all around here. They predate on other birds' nests. This surely isn't a recent thing - they've always done it. Why the persecution for something which is inherently following its own instincts? What about cuckoos? I sometimes get the feeling that we dislike species which most closely resemble our own...

And finally, maybe at the end of the day all this rhetoric is futile, because I'm fairly certain we're well on the way to an accelerated mass extinction due to our poor planet management. Look at what's happening in the Siberian tundra.

Gus

 

[KnockerNorton]

Canada Geese should be top of the hit list in South Northants, the bank erosion and plant destruction on many lakes in the area is shocking and lots of mess!!!!!!!
The Coots on one lake have moved on as food became scarce.

In my view it should be easy applying for the relevent licenses as some areas have problems that need sorting sooner rather than later, and legally.

I did some research on the issue of canada geese and pollution a few years ago - the study found that they're the most significant waterbird contributing N and P to stillwaters. They can have a significant impact on eutrophication and water quality over time.

Steve, re Marsh Tit research, please take it from me that the BTO stuff is largely conjecture. They haven't actually carried out any research except on the CBc and ringing etc returns, which isn't very representative (only about 700 birds are ringed each year, which is very few, and few CBC etc plots have them. They get less than 50 nest record returns every year, which is minute, and certainly not big enough to draw firm conclusions - especially seeing as most of those are from only a couple of sites). In fact, nobody has yet published any in-depth studies of British Marsh Tits since 1953. In short, nobody has a clue as to why they're declining. The same is true os LSW, Spotted Flycatcher and Willow Tit.

 

[Brian Stone]

In short, nobody has a clue as to why they're declining.

Maybe, but it certainly won't be Jays!

 

[KnockerNorton]

Not just Jays, no, that's unlikely, I agree. But if increased nest predation IS a factor, perhaps partly due to the boom in GSW, then Jays aren't going to be helping at all as, like I said, they're in the top 3 nest predators.

However, saying that, there is a scenario whereby increases in Great and Blue Tits could be forcing Marsh Tits to nest in more vulnerable sites by nicking all the good ones. In that turn of events (which is a scenario that is actually on the table), then Jays could be a proprtionately more important nest predator than historically, and thereby increasing their role in Marsh Tit decline.

There's plenty that you could argue about with that, but that is about the level of insight we've got on Marsh Tit decline at the moment.

 

[Strandman]

Not just Jays, no, that's unlikely, I agree. But if increased nest predation IS a factor, perhaps partly due to the boom in GSW, then Jays aren't going to be helping at all as, like I said, they're in the top 3 nest predators.

Is that top 3 avian nest predators, with Grey Squirrel predation separate, or top 3 of feathered and furred predators?

I have a bit of a downer on Grey Squirrels and my uninformed guess is that they are a factor in the decline of some of the scarcer tree nesters like Hawfinch and Bullfinch. But I realise that it is just an assumption on my part that they are a bigger factor than increased avian predation.

 

[KnockerNorton]

That's fur and feather. I've never known a squirrel rob a Marsh Tit nest or, at least, I have no evidence that it's happened in the 2 study sites I'm looking at. The top 3 seem to to be GSW, Jay and Weasel. Stoats, rats, feral cats and possibly mice are also predators. In fact, I've never known of a squirrel robbing a tit nest, but what i have seen is a stoat 9m up a tree, attacking a MT nest. One wonders how many times squirrels get blamed when it may be something else, just because the nest was high? Weasels will also happily rob nests up to 2m off the ground, and rats even higher. It is, however, often difficuly to be absolutely certain what has robbed a nest, as a lot of the time the evidence is circumstantial (GSW are the easiest, for obvious reasons). A squirrel attack on live wood would be quite easy to infer, I'd imagine, as you'd have clear knaw marks. But I've never seen it yet.

 

[Strandman]

That's fur and feather. I've never known a squirrel rob a Marsh Tit nest or, at least, I have no evidence that it's happened in the 2 study sites I'm looking at. The top 3 seem to to be GSW, Jay and Weasel. Stoats, rats, feral cats and possibly mice are also predators. In fact, I've never known of a squirrel robbing a tit nest, but what i have seen is a stoat 9m up a tree, attacking a MT nest. One wonders how many times squirrels get blamed when it may be something else, just because the nest was high? Weasels will also happily rob nests up to 2m off the ground, and rats even higher. It is, however, often difficuly to be absolutely certain what has robbed a nest, as a lot of the time the evidence is circumstantial (GSW are the easiest, for obvious reasons). A squirrel attack on live wood would be quite easy to infer, I'd imagine, as you'd have clear knaw marks. But I've never seen it yet.

That is interesting- not the top 3 I would have guessed. I know Kokako conservationists in New Zealand in the 1980s were surprised (and worried) to find Stoats up at 20 metres plus in the canopy..

I assume you don't have Pine Martins to contend with in your area- from experience elsewhere they seem to be top dog as it were of the furred nest predators. I think I read somewhere that over half of woodpecker fledglings in Bialowieza are taken by P Martins. I don't think that makes P Martins population limiting for woodpeckers, but it is an impressive rate of take.

 

[KnockerNorton]

No martens here, but I do know that they're the top Marsh Tit nest predator in Jan-Ake Nilsson's study area around Lund (Sweden). Most of his birds are in nestboxes, and they have to put tunnels on the front to create an entrance that is too long for a marten to get its paw in and fish out the nest - their usual tactic.

Here, we get weasels entering (27mm holes) and dismembering or carrying off the young. They also kill adults at night, leaving characteristic feather remnants where they've dragged them out.