]Marginal value theorem states that a forager should leave a patch when intake rate falls to the average. A patch with high food availability will be depleted more slowly, so foragers should stay there for a longer period. Alternatively, ideal free theory states that foragers should distribute themselves across the landscape so as to equalise their intake rate, which declines as forager density increases. Patches with high food availability will provide a higher intake rate for a given density, and so should support higher forager density than patches with lower food availability.
The important thing to bear in mind in both cases is that the rules still hold when poorer quality patches provide a more than adequate food supply, so aggregation of foragers in food rich patches doesn’t mean that they would suffer any detriment if those patches were removed. However studies showing that birds are attracted to improved habitat is constantly spun as evidence for general food shortage, as in the above press release. It’s either ignorant or dishonest – probably a bit of both.
And totally ignores other BTO research (sorry, cannot cite where) showing that foragers flock up, presumably as defence against predators, even when the "optimum" feeding strategy would be for them to disperse. That also suggests that both those theorems do not apply to granivorous passerines in winter in general.
It also suggests that the patches of wild bird cover may be offering birds better feeding conditions even when adequate food is distributed thinly across the countryside. Why ? because the birds benefit from being flocked up as a defence against predators.
As a farmer (and committed conservationist) I have been very critical of the RSPB over the years. However, I have always respected the fact that they are trying to _do_ something which is apparently far beyond the imagination of so many. I am also aware that I have made many of the same mistakes as RSPB, have learnt and adapted and I have seen the RSPB doing the same. In particular, I too started (25 years ago) with a species centred approach. I have moved on gradually from that to the state where I am today - with a general principle of generating as much diversity of habitat and opportunity for all different types of wildlife and letting that wildlife exploit the opportunities. The RSPB are quite clearly moving in the same direction - and earning my respect in the process even though I wish they could move faster, achieve more. We should help them. I am not saying criticism is out - but we should accept the limitations such a large organization faces.
My criticisms of the RSPB have centred like CP Bell on the "upper" management being too focussed on fund generation rather than actually doing the conservation work. I would be quick to say that I think that RSPB staff in general do an excellent job despite poor pay (typical of rural workers !) though you will find exceptions in any generalization. However, it must be difficult, in senior RSPB management, not to become obsessed with money. Imagine the furore if they failed to keep the funds rolling in. It is not inconceivable that they could end up in prison for mis-managing such a flagship charity if things went wrong. Consider - how many bread-winners are torn between their urge to keep the bread on the table and the need to spend time with their family ? It is not a dissimilar position, and has the same difficulty in trying to see the bigger picture from inside the situation.
I haven't been aware of the BTO being too focussed on fund raising.
As for agri-environment schemes failing. Yes, there has been a study done in Scotland comparing farms in schemes and farms outside schemes. It found, basically, that schemes achieved little, that some farms were good and some were poor regardless of whether they were in schemes or not. I can't remember but I think they pointed to farmer attitude. This did not surprise me as I and any similar minded farmers would be classified as "not in scheme" and all organic farmers, who are generally only in it for financial reasons, were classified as "in scheme". When you set targets (in the latter case financial) you tend to focus on them and achieve them, everything else tends to get forgotten.
In that sense I am lucky. My business, like any other, has to make money. However, to achieve that I use a contract farmer who concentrates on farming profitably (with considerable backup from me) freeing me to focus more effort on conservation, especially now that I have lost my outside job !
So, I would accept that agri-environment schemes are not doing well - though I would question whether we have good enough information to say they have achieved nothing. For instance, the education information put out to farmers has probably affected many farmers thinking even if they are not in schemes - perhaps the good farmers found by the Scottish study have done better because they know what is being advised under these schemes. I almost certainly fall into that category.
I believe that agri-environment schemes could work, probably already have, and that continuing them is not "flogging a dead horse". However, to justify the amount of money put in, they need to change, we need to up our game.
What do I think schemes need to do to perform better ?
They need to become part of the profit picture for farmers. Remember the farmers maxim - "live for today, farm as if you will be farming for 1000 years". Many. probably most, farmers do dream of passing on their businesses to future generation ad infinitum, and to do that the business must be financially sound. If farmers generally are focussing on making profit, conservation is always going to take last priority if it is perceived as a loss leader.
Is conservation a loss leader ? In immediate financial terms, most definitely. EU policy is that direct agri-environment scheme payments should not cover more than 75% of costs. So, a 25% loss guaranteed, in the bureaucrats eyes. To the farmer things are much worse - because scheme rules value the farmer's time at £0. Yep - we are slaves. Add to that the high rate of inflation we are experiencing (well above RPI for critical inputs such as energy) and that 75% of costs becomes a joke.
My suggestion is that agri-environment payments should be set at a level which gives a decent profit to the farmer. There are already excellent, excessive, bureaucratic controls in place to make sure that work gets done properly. Where does the money to pay farmers come from ? Reduce direct payments, so called Pillar 1 or Single Farm Payments to fund this. To her credit Caroline Spellman publicly supported similar moves, though without the profit for agri-environment work. Unfortunately in the face of blind panic amongst the industry lobby (fear of the unknown amongst subsidy junkies), she backed down.
What can you all do ?
Criticism is good. Criticise the agri-environment schemes for under performing. We might get some improvements eventually, even if not what I would consider the best ones ... but then I am a farmer ! Oh, and please keep your criticisms calm and to the point. Anything else tends to be dismissed out of hand as ignorant bluster from "those with an agenda"
Mike.