Pine Martens (1 Viewer)

People seem to have different opinions on this subject, being a scientist I looked at the latest research I could find on the subject. The report's (I think it is the one referred to apologies if not) discussion was interesting, I quote two passages that sum up its findings.


"Despite Summers et al., (2009) finding that martens were the major predator of capercaillie clutches at Abernethy, this study found no evidence of a relationship between the marten index and any of the three measures of capercaillie breeding success in either period of observation3. Indeed, the marten index was positively correlated with hen densities in 2005-09. This lack of agreement could result from marten abundance not yet being fully restored in many of the study forests. To this end, marten indices in 2009 were on average almost five-fold higher in Abernethy than amongst other study forests, with increase rates subsequent to 1995 being on average eight–fold higher than in other forests. At what level of abundance marten start to impact upon capercaillie breeding success, akin to that described at Abernethy, remains undetermined. The findings of this study would suggest that other predators, in particular crows, may be more important in determining breeding success, probably through predation of
clutches, and that foxes and raptors may be linked to changes in breeding densities, possibly through predation of hens."

"This study, whilst not finding any correlation between marten indices and breeding success, found that crows, and to a lesser extent foxes, were linked to poor breeding success, whilst fewer hens in 2005-09 were found where predator (fox, crow and raptor) indices were higher"


http://www.snh.org.uk/pdfs/publications/commissioned_reports/415.pdf

This report seems to suggest that crows and foxes were the major culprits in Caper lack of breeding success.
If there is any other research plese post links so I can take a look

Thanks

Mark

Ben Nevis said:

A National Survey conducted by Scottish Natural Heritage (A Government body) of Capercaillie,from 2004 until 2012,reports that 45% of Capercaille were lost due to Pine Marten.I would Imagine that the SNH properly conducted their research and I rest my case.

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Do you have a reference for that study? I search the SNH website and did a more general Google search, and couldn't come up with anything. They don't even claim to have done a survey over that period (there have been a couple of separate population surveys within that period). My search did come up with the same paper that Mark linked, which is definitely by SNH and which clearly draws precisely the opposite conclusion about the importance of pine martens to what you're suggesting.

The following is from SNH's Species Action Framework. If they had evidence that 45% of mortality of capercaillie was due to pine martens, then this would be a very strange list of priorities indeed.

"The principal threat to the capercaillie is thought to be loss of suitable woodland habitat, partly due to over-grazing of blaeberry by sheep and deer.
Increased predation from crows and foxes, especially on breeding females.
Increased adult mortality through collisions with deer fences.
An increase in adverse weather conditions during June when chicks are newly hatched resulting in reduced breeding success.
Human disturbance, in part due to forestry operations and the recreational use of forest tracks, may also be involved in the species' decline."

I read the article In the Press and Journal,which Is the north of Scotland's leading morning newspaper.The only link of any kind I can find Is this;

www.pressandjournal.co.uk/Article.aspx/3470478

Since these studies have been done the Caper population has declined significantly. Therefore the effect of any predator is going to have a greater effect on a smaller population. Also as the main study was carried out in a large forest and the main stronghold of Caper, so fails to assess the impact on other smaller woodlands which hold birds..in these the Pine Marten may well be having a greater impact. With such a small and fragmented population I would think each woodland needs to be assessed individually as to the effect of Pine Martens?
It's possible the Caper population has reached such a critical level that little can be done to help other than removal of all predators to kick start it which of course just wouldn't happen.

Fair point John and as you are based In the core Caper/Marten habitat area and have an excellent knowledge of the species there,I fully accept what you are saying.

jpoyner said:

It's possible the Caper population has reached such a critical level that little can be done to help other than removal of all predators to kick start it which of course just wouldn't happen.

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Again, shouldn't removal of the human-made obstacles take priority over "removal of all predators", the latter of which would be difficult if not impossible (good luck removing foxes from anywhere), not to mention controversial? If there's shooting to be done, why not get rid of excess numbers of competitors like, for example, deer (I seem to remember they were cited as such).

Or is it a strict case of "they make take our capers, but they'll never take our deer fence"? (substitute deer fences for mountain bikes etc. pp.)

For anyone interested, I popped over to this B&B at the weekend, where Pine Martens are fed every evening. Easy success, with great views!
http://www.ardnamurchan-bed-breakfast.co.uk/

Also had a half-hearted try for wildcats, but no joy...

Well done JP. Another sure thang for martens.

Stayed 2 nights at Glen Loy Lodge a couple of weeks ago. First pine marten turned up 10 minutes after we arrived and we saw two on both evenings (down to about 10 cm as they ran along the outside window ledge!).
All credit to my younger son who asked to see pine marten for his 6th birthday treat!

Rob

https://mobile.twitter.com/BBCSpringwatch

How many generations before they become truly wild, if at all. Same criteria as White tailed Eagles I'd imagine and down to the individual.

PYRTLE said:

https://mobile.twitter.com/BBCSpringwatch

How many generations before they become truly wild, if at all. Same criteria as White tailed Eagles I'd imagine and down to the individual.

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I'd imagine that it would be quite fast Pat, they breed a lot faster than W-tE. How many litters per year, John?

Far as I know, one: but usual rules apply, provided there are no serious negative factors breeding success should be pretty good and with a native species expanding into unexploited suitable habitat new territories should be generated quickly. Main hazards - potentially limiting factors - will be cars, foxes and (perhaps) unfriendly locals.

Litters will perhaps be on average larger then for WTE which would accelerate the process if survival is good and I suspect breeding age for Pine Martens is also younger (probably second year onwards), another accelerant. My foxes seem to disappear quite quickly, what between cars, territoriality and so on: a four-year fox would be very unusual. I've no idea how Pine Martens compare but usually smaller animal = shorter life.

John

So in progress, more like Red Kite reintroduction than WTE reintroduction . . .