This news from Natural England is very welcome – for two main reasons. First, it is good news, and second, it is fairly informative and doesn’t look as though it was written by the shooting industry.
119 Hen Harrier chicks fledged from 49 nests (actually from the 34 successful nests, and some nests were re-nests by the same pairs) – as the NE blog says, the most in England for over a century. That is fantastically good news to hear.
The distribution of nests:
Bowland/Lancashire – 18 nests
Yorkshire Dales/Nidderdale – 10 nests
Northumberland – 9 nests
North Pennines – 7 nests
Peak District – 5 nests
North York Moors – 0 nests
It is notable, though NE didn’t note it, that there were no nests in the North York Moors – the area with the highest death rate of Hen Harriers from the published satellite-tagging study (see here). The North York Moors still seem out of bounds for Hen Harriers.
It wouldn’t have taken NE much effort to annotate the list above with how many successful nests there were, and that would have been quite informative.
I’d be very interested to hear whether the Duke of Westminster struck lucky with Hen Harriers at last in Bowland – surely the birds can’t have shunned his land for another year? But at least the Bowland AONB now can keep its logo with some pride.
Fate of tagged birds: the NE blog says that six tagged birds have disappeared since their last update (early March) but then they only list five birds, and there do appear to be five of them if one consults the Excel table whose link is in the NE blog post. These five birds are Dru (female, tagged 2017, who was predated at her nest), Free (male, tagged 2020, who never bred and whose disappearance is the subject of a police investigation in Cumbria), Lydia (tagged 2021, disappeared near a Goshawk nest (though how the Gos persuaded the tag to stop working is unknown)), Harvey (tagged 2021, subject to a police investigation in the North Pennines) and R1M221 who died of infection and tested positive for bird flu in the Yorkshire Dales. Dru had a good innings but the other four failed to breed in their short lives.
The Hen Harrier which tested for bird flu is concerning – and I wonder what was the provenance of the other Hen Harrier that has been reported as having bird flu – maybe it’s a bird tagged by RSPB, maybe it was a chick, or maybe NE have forgotten it. Who knows?
Brood-meddling: 13 Hen Harriers ‘fledged’ from brood-meddled nests and 12 of these were satellite tagged – 9 from Yorkshire and 3 from Cumbria. It is, perhaps, tempting to try to assess the fledging success of brood-meddled nests with wild nests, and at first glance that looks like it is 13 fledged chicks from four brood-meddled nests (3.25 chicks/nest) compared with 116 fledged chicks from 45 wild nests (2.6 chicks/nest) but that isn’t the right comparison for two reasons. First, you can only be a brood-meddled nest if you have chicks or eggs close to hatching, but you can be a wild nest as soon as there is a single egg – thus wild nests are at jeopardy for far longer and that would have to be taken into account. To explain that further, if (and it might or might not be true) wild nests often are predated at the early egg stage then they enter the category of failed wild nest, but brood-meddled nests can’t fail at that stage because they have to get further through the season to qualify as brood-meddlable. Those data must exist, but they aren’t visible to me, and you’d have to take that into account. But in any case, second, each brood-meddled nest is, by definition, one of a pair of nests close together (that’s what the protocol is) and it is questionable whether the other nest should be regarded as a wild nest or in a separate category altogether. If, for instance, perish the thought, once brood-meddled chicks were removed, the other nest of the pair tended to fail for some reason, such as persecution, then those nest failures should not be ascribed to wild nests, in fact they ought to be part of the evaluation of brood-meddled nests. You see, it’s a bit complicated – let’s hope that the Steering Group have their heads around all this (maybe they do, I can’t tell). On the face of it, and not very surprisingly, brood-meddled nests seem quite productive. But as we know, Hen Harriers don’t seem to live very long.
The survival of satellite-tagged brood-meddled Hen Harriers does look higher (by eye-balling the data – small samples apply) than those of non-brood-meddled tagged birds – that’s interesting. Why might it be? It might be because being removed from the danger of the moors and brought up in a cage makes you particularly fit to survive once released again (possible – but I’m sceptical) or it might be that shooting estates know where brood-meddled Hen Harriers are and don’t kill them too often (possible and believable). Here again, the other nest in a pair of Hen Harrier nests, one of which is brood-meddled, should be used to compare survival of closely matched nests – but one can see from the locations of birds tagged each year by NE that isn’t done – that’s a shame.
If we imagine that shooting estates could be more likely to kill a satellite-tagged Hen Harrier that is not one of the brood-meddled birds, than one that is, then that adds some more complexity. The latter explanation is a bit of a difficulty for assessing this trial as a trial but it can certainly be used as a conservation measure.
With this number of nesting Hen Harriers I may become more relaxed about brood-meddling – although I’m not yet. My view has always been that brood-meddling should be a reward for good behaviour rather than a reward for bad behaviour, and maybe we are getting there. We’d all need to see a proper analysis of the data before we could make up our minds about any of this.
What has driven the increase?: there is so much that is still secret or unclear about the nesting population of Hen Harriers in England that it is difficult to assess what has gone on. However, we can be sure that relatively few broods have been meddled over the years and they are not enough, at my brief glance, to have driven this increase on their own, and I don’t think anyone is claiming that they are (this year, yet). Indeed, anything to do with brood meddling can only be a small part of the picture. I wonder how much of this very welcome increase in numbers is due to birds being tolerated if they arrive in spring and many of those birds might be heading for Scotland or maybe even Wales, and can thus be regarded as immigrants. Rather than increases in productivity, or survival, immigration coupled with greater tolerance on grouse moors may be the driving force.
Why should there be greater tolerance? There are so many moors with low Red Grouse numbers, due to weather and disease mainly, that it really isn’t worth taking the risk of breaking the law, and more Hen Harriers are being allowed to survive. As driven grouse shooting continues to decline then its impact on Hen Harrier numbers will also decline. I’d be very interested to see what would happen in a year when spring grouse numbers were high and everyone was looking forward to a big season – how many Hen Harriers will there be then?
It’s fun to speculate, but one way or another, Hen Harrier numbers are now much higher than any time in the last few decades. That has to be good news.
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It is at last some good news. A glimmer of hope and much needed.
Firstly this is very good news that 49 pairs attempted to nest and 34 fledged 119 chicks, that’s 2.42 chicks per attempt and 3.5 per successful nest. However those figures include I’m sure the brood meddled birds both in chicks and successful nests, (perhaps somebody should ask NE this in an FOI) So it is really 106 chicks from 45 attempts and 30 successes, 2.35 chicks per attempt and 3.53. Fifteen failures seems reasonable compared to natural figures but there is a lot of detail missing. How many nests were on tenanted ground with RSPB presence? on tenanted ground without RSPB wardens, on Non-grouse moors this I think will include all or almost all the Northumberland nests and possibly some in Cumbria, finally how many on private grouse moors with and separately without BM or feeding. That same data should be included for failures and how many of the failures were considered natural and on what category of moor?
The DGS lobby and their fellow travelers are crowing about this and of course saying most nests were on grouse moors, hardly surprising given that most indeed nearly all the suitable habitat is on grouse moors and should we really congratulate those with successful harrier nests for obeying the law for a change? Based on last years one success on RSPB Geltsdale at that same density there should have been 70 on the 348,300 ha of grouse moors or if you include the two failed nests at Geltsdale 210. So despite all the claims that RSPB reserves are failing Hen Harriers the truth is whilst the results this year are good, and they are Grouse moors could still do better and of course we are only 15 % of the way to what should be a fully operational population.
It is certainly more complicated than appears at first glance, to the critical reader at least.
Some further complication would be useful, as mr Irving says , in providing a breakdown in different land uses surrounding nest sites.
I suppose that some Scottish or Welsh birds could be involved in the recovery, but undoubtedly it is a greater tolerance being shown, year round, that is the driving force. Some of this is probably down to the brood management option being available, a large part also being a reaction to adverse publicity over illegal killings.
Regarding grouse numbers being a factor, if i was trying to build a moor back up i think i would be more bothered by what harriers were killing, rather than if my grouse were at bumper levels .
Mind you, a mate of mine was on the North York Moors early last week, and he says it was crawling with grouse, with a number dead on the roads. No Hen Harriers, but he did see a female Marsh.
I wonder, although one must assume so that the steering committee wil see a breakdown of the figures. There is a deal of difference between a tenanted moor, where a tenancy may well be lost if there is persecution , especially those with a wardening presence compared to the private grouse moor. It seems we are certainly winning the argument with tenants but as a colleague said, more involved these days than I am, most nests were where you would expect them, with relatively few on privately owned moors. If there is such a difference it certainly needs to be considered and it would have been good to see an overall breakdown so we could all see the progress being made. The same of course goes for the failures, indeed in many ways they may be more important than we think. The North york Moors once had nests near Scaling Dam and of course of Montagu’s Harriers but I suspect hell will freeze over first before they get more than a toe hold there if at all.Then again Durham had a similar reputation. All in all it is an improving situation and for that we should all be glad.
Of course all this breeding with virtually no VOLES! Next year looks like a bumper year for these 4 legged food items for harriers and especially SHORT EARED OWLS. So given food creates VOLES then VOLES create high numbers of breeding harriers and SHORT EARED OWLS. That would then suggested we can already start thinking of an even bigger number of Birds of Prey on these moors in 2023. This does not mean that predation of Red Grouse increases as seen on Geltsdale in 2020. Even waders will have a better breeding season as long as the sheep don’t eat their eggs!