Tag: hen harrier

Yesterday, Natural England (NE) published some information about their hen harrier satellite tagging programme, which has been running since 2007. Their press release, entitled: “Initial findings of Natural England’s hen harrier tracking programme 2007 to 2014” can be read here.

The key word here is “initial”. What they’ve released is extremely limited and to be frank, doesn’t tell us much that we don’t already know.

It’s a difficult situation for them, because part of the funding for this project has come from us (tax payers) and so NE has an obligation to inform us how our money has been spent and the results of the research that we’ve helped fund. However, this research has been undertaken as part of a PhD study and so the doctoral candidate (Stephen Murphy) is entitled to retain his data until he’s ready to submit his thesis and, ideally, has produced some peer-reviewed papers. No researcher worth his/her salt would wish to release their data, prematurely, in to the public domain, in case someone nicks the data and takes intellectual credit for the work.

The problem in this case is exacerbated by the controversial topic (and thus the high level of public interest and clamour for information), the poor survival rate of the study species (which is bound to have impacted on the research design seeing as the research is specifically aimed at examining hen harrier dispersal ecology; quite hard to assess if your harriers are killed just a few months after fledging), and also the length of time it has taken for this PhD study to be completed. We understand Mr Murphy’s studies began in 2006 – that’s eight years ago. That’s a very long time. We do have some sympathy with Mr Murphy, for the first two reasons outline above – but, we do know that he has given numerous public presentations on his research over the years and so we should have seen at least SOME of his findings published by NE well before now.

So, what information did NE release yesterday? Or more to the point, what information didn’t they release?

We now know that NE has attached sat tags to 47 young hen harriers between 2007-2014. There are at least a further six tags that have been fitted and monitored by other organisations. Of NE’s 47 harriers, only four are known to be still alive. That’s a pathetic 8.7%.

Of the 47 harriers, six have been found dead.

Of the 47 harriers, a staggering 37 (78.7%) are listed as ‘missing’.

Of the 37 ‘missing’ harriers, 34 were under a year old when their sat tag stopped functioning. Two were between 1-2 years old, and only one was more than two years of age. The vast majority went ‘missing’ in the months of September and October, with a smaller peak in July and August.

NE has provided some technical information about the sat tags, stating that they are programmed to emit signals on a ten hour cycle with a subsequent 48-hour re-charging cycle. They point out that just because a harrier’s last signal came from a particular location, the harrier could have subsequently moved a considerable distance (within that 48-hour period).

Viewing the case of each ‘missing’ harrier in isolation, that’s quite a plausible possibility. However, when you combine ALL the cases of ALL the missing harriers, it’s not quite so plausible. NE states that tag failure is “uncommon”. Incidentally, so did the Dutch researchers who were commenting on the ‘missing’ sat tagged Montagu’s harrier earlier this year, whose last signal came from the Queen’s Sandringham Estate in Norfolk (see here). Sure, you might expect the odd one to fail, but when you’ve got a 78.7% failure rate, and you’re told that tag failure is “uncommon”, it’s very hard to conclude anything other than foul play.

When you also add in the known fact that breeding hen harriers are missing from almost every driven grouse moor in England and Scotland, it becomes blindingly obvious what’s going on.

Unfortunately, the newly-released data provided by NE don’t include detail of where these hen harriers have gone ‘missing’. They’ve given 100km2 grid references, which are utterly meaningless. They say they don’t want to release any finer detail because there is concern from the raptor study groups that sensitive locations will be publicised. That’s a little ironic (clearly the harrier killers know where to find these birds) but it’s also understandable. However, NE could have easily provided a column showing the habitat type of where these birds went ‘missing’ without compromising site security. Those data would have been very interesting and, we think, pretty damning. Perhaps that’s why they were excluded?

As NE quite rightly points out, the circumstances that led to the loss of these harriers’ tag signals can only be ascertained if the bird’s corpse is recovered. That’s also a statement that has repeatedly been put out by the game-shooting lobby – “No dead bird, no evidence of persecution”. Now, we expect some natural mortality – not all the sat-tagged harriers are going to survive, that’s basic biology. But wouldn’t you think, if all these sat-tagged harriers had died a natural death, their corpses (or at least part of a corpse) would be found, as would the tags?

Of those 37 ‘missing’ harriers, only one tag has been recovered. Amazing, eh?

So what have we learned? Not much. 78.7% of sat tagged hen harriers are ‘missing’. ‘Somewhere’.

Here’s a reminder of what happens to some hen harriers on some driven grouse moors. Please sign the petition to ban driven grouse shooting here.

Following on from the news story nine days ago of a successful hen harrier breeding attempt in the Derbyshire Peak District (see here), it has been announced that three of the five chicks are already dead.

The following press statement has been released by The National Trust:

Newsflash 12 September 2014: We are very saddened by the deaths of three of the hen harrier chicks. All indications are that two of the birds were killed by a natural predator. The body of the third has been recovered and, along with the remains of the other two, has been sent for post-mortem (as is usual practice), but there is no evidence of suspicious activity at this stage. Two chicks are still doing well. This news reinforces the need to have a strong and healthy population of hen harriers in the Peak District and England: one nest is not enough as there will always be natural losses. We will continue to work with our partners to protect the remaining chicks and create an environment where hen harriers can thrive in the future.

Predation, if that’s what this is, is a natural phenomenon; most species are particularly vulnerable during their first year. Raptor populations in general are especially sensitive to high mortality as many bird of prey species take several years to reach breeding maturity and then only produce a few offspring in any given year. This is why the additional illegal killing of raptors can have such a devastating impact at the population level – once the population level has dropped it can take a long time for it to recover.

This year’s Peak District hen harrier chicks were also at a disadvantage having fledged relatively late in the breeding season. It’s a well established ecological concept that the offspring of early breeders generally have a much better survival rate than those of late breeders.

Having said that, there are many examples of fake ‘natural’ deaths, set up in an attempt to hide a crime. The most prominent one that springs to mind is the case of the Deeside eagle, believed to have been caught in an illegal trap on an Angus grouse moor and then taken by vehicle, overnight, to be dumped at a roadside location 15 km away from the moor to make it look like the bird had had an ‘accident’ (see here and here).

Given the notoriety of the Peak District as a hotspot for crimes against raptors, we hope that the post mortem results of the three dead birds will be published, along with their locations, to allay any suspicions that they were the victims of illegal persecution.

Photo of one of this year’s hen harrier chicks by Tim Birch (Derbyshire Wildlife Trust).

UPDATE: The Peak District Raptor Monitoring Group (PDRMG) has put out a statement that includes this:

“Early post-mortem results indicate that disease is most likely cause of death for all three birds”.

PDRMG statement here

A press release has been issued to announce the discovery of a fourth active hen harrier nest in England this year.

The nest was discovered on National Trust land in Derbyshire’s Upper Derwent Valley in August and was found to contain five healthy chicks, which have now fledged.

Read the full press release on the Peak District Raptor Monitoring Group’s website here.

In part, this is a good news story. In fact, in part, it’s a very good news story. These are the first hen harriers to successfully breed in the Peak District in eight years, and ironically, the nest site wasn’t far from the location of the Hen Harrier Day gathering on 10th August; had it been better weather, we might have had the rare opportunity to see one of the adults flying overhead. That would have been quite something!

What makes it a very good news story though are the circumstances of the nest discovery. According to the press release, the nest was found and then reported by someone called Geoff Eyre. This name might ring a bell for some readers – Mr Eyre was the shooting tenant on the National Trust’s Howden Moor in 2011 and had employed gamekeeper Glenn Brown, who was subsequently convicted of operating an illegal cage trap on the moor. Mr Eyre, who was not implicated in the criminal activities of his gamekeeper, was nevertheless at the receiving end of some less-than-complimentary comments by the judge at Brown’s trial, including the following:

“I found Mr Eyre on occasion to be evasive in his evidence. He seemed reluctant to give a direct answer to questions. He is a man who clearly distrusts RSPB officials and singled out Mark Thomas [RSPB Investigator] in particular. He cites the issue of the dead falcon in 2006 as the basis for that together with a vague assertion of misleading press releases. He told me that the results of the post mortem of the dead falcon in 2006 had never been released to him although he had paid for the investigation and then had to concede that he had not in fact done so“. [To read the full judgement notes from the trial click here].

Why is this relevant now? Well, Mr Eyre reported this year’s harrier nest to the recently-formed Peak District Bird of Prey Initiative – a partnership of organisations including the RSPB (as well as the National Trust, Moorland Association, Natural England and the Peak District National Park Authority) which was established in 2011 to try and address concerns about unnaturally small raptor populations in the region. That’s got to be seen as very welcome progress and an indication that trust can be rebuilt, at least in some circumstances.

So why would we consider this only partly a good news story? Well, that depends on your perspective. If you look at this successful breeding attempt at a local scale then of course, it’s excellent and very welcome news  and ALL the partners involved in the monitoring and protection of the nest deserve recognition for their efforts. But what about at a national scale? This successful breeding attempt brings the grand total of known breeding harriers in England this year to four pairs. Not three, as we had previously thought, but four.

Count them. One, two, three, four.

Four successful pairs in the entire English uplands which have been estimated to have the capacity for 330 pairs.

Those four pairs represent just over 1% of the estimated potential hen harrier breeding population.

That’s a lot of ‘missing’ hen harriers. 98-and-a-bit% of the English hen harrier breeding population is ‘missing’.

That’s not a figure we think to be worthy of celebration.

However, according to DEFRA’s response to Mark Avery’s petition to ban driven grouse shooting, “It is encouraging to learn that there are four hen harrier nests this year which have chicks, given that in 2013 there were no known hen harrier fledglings in England“.

‘Encouraging‘? How about embarrassing? How about shameful? How about an apology for failing this so-called protected species?

Some of this year’s fledglings have been fitted with satellite tags – will their journeys be made public, including those whose signals un-mysteriously stop transmitting when the birds visit a driven grouse moor? It’s been 12 years since Natural England started tracking hen harriers (partly paid for by us taxpayers) – we’re still waiting to see the full results.

 Photograph of one of the Peak District hen harrier chicks by T. Birch (Derbyshire Wildlife Trust).