[Dave Kennedy]

This sighting was originally posted in "Your Local Patch - Kintyre Birds". However there was not a single response, so I am trying again in a forum which may be more appropriate.

On Sunday 15th June 2008 I managed a quick visit to the Seabird and Wildlife Observatory at Machrihanish, Kintyre, where Eddie Maguire, the Observatory's custodian and I observed a peregrine flying determinedly northwards up the Sound of Jura. Above and behind it, and possibly undetected by the peregrine, was an Arctic skua, holding the same course. Suddenly the skua tipped over and dive-bombed the peregrine, causing the falcon to take rapid evasive action.
I have seen Arctic skuas at Machrihanish using the same technique to force terns to disgorge their catch, which is then snapped up by the skua. My questions are as follows:

Was the skua simply doing what skuas do, and, failing to distinguish between a falcon and a tern, looking for a quick meal?

Did it recognise the falcon as a possible threat, so was this an aggressive display?

I would appreciate your comments on this incident.

Thank you,
Dave Kennedy

[RecoveringScot]

Originally Posted by Dave Kennedy

This sighting was originally posted in "Your Local Patch - Kintyre Birds". However there was not a single response, so I am trying again in a forum which may be more appropriate.

On Sunday 15th June I managed a quick visit to the Seabird and Wildlife Observatory at Machrihanish, Kintyre, where Eddie Maguire, the Observatory's custodian and I observed a peregrine flying determinedly northwards up the Sound of Jura. Above and behind it, and possibly undetected by the peregrine, was an Arctic skua, holding the same course. Suddenly the skua tipped over and dive-bombed the peregrine, causing the falcon to take rapid evasive action.
I have seen Arctic skuas at Machrihanish using the same technique to force terns to disgorge their catch, which is then snapped up by the skua. My questions are as follows:

Was the skua simply doing what skuas do, and, failing to distinguish between a falcon and a tern, looking for a quick meal?

Did it recognise the falcon as a possible threat, so was this an aggressive display?

I would appreciate your comments on this incident.

Thank you,
Dave Kennedy

I'm almost certain this was mobbing behaviour. Skuas will be well aware of the Peregrine's ability to predate their young. I've seen Common Gulls mob Peregrine from behind (although the Peregrine was carrying prey at the time, so was not liable to turn predator on its pursuer).

Here in Aberdeen Peregrines are warily watched by Gulls but not mobbed very often that I've seen. The gulls seem to be able to distinguish when a raptor is in hunting mode, and will ignore passing Peregrines that are obviously, to them, intent on other things.

Cheers,

[Dave Kennedy]

Originally Posted by RecoveringScot

I'm almost certain this was mobbing behaviour. Skuas will be well aware of the Peregrine's ability to predate their young. I've seen Common Gulls mob Peregrine from behind (although the Peregrine was carrying prey at the time, so was not liable to turn predator on its pursuer).

Here in Aberdeen Peregrines are warily watched by Gulls but not mobbed very often that I've seen. The gulls seem to be able to distinguish when a raptor is in hunting mode, and will ignore passing Peregrines that are obviously, to them, intent on other things.

Cheers,

Phil,

Many thanks for your prompt response. Mobbing would certainly fit the behaviour observed. I suppose the next question is whether birds recognise particular threat species instinctively, or whether this incident results from some personal experience by that particular skua?

Best wishes,
Dave

[scuba0095]

ive heard of bonxies going after gryfalcons to steal their prey

[Himalaya]

what are the odds that a great skua could predate a pregrine?

[scuba0095]

if it got a hold of a p falcon it could kill it

but i dont see it getting a hold of one

[Gentoo]

Most birds recognize their avian predators instinctively. I think the Skua in this case saw a potential rival as well as a potential predator. This sounds like the same interaction I've seen between Peregrines and Cooper's Hawks.

[scuba0095]

According to my new info the great skua can be a serious threat to gyrfalcons and smash into gryfalcons with such force that the falcon will sometimes crash!! Falcons dont seem to pose any threat to great skuas however, its always the skua thats the aggressor!

After a bonxie teaches a gyrfalcon a lesson the falcon often never goes anywhere near the skua again!

Falcons prey on gulls so sometimes have a run in with a skua and often wish they never have !

[scuba0095]

Also id like to mention large skuas attack falcons out becasue of territory the falcon is invading the skuas space when its hunting and the skua gets pissed!

[Dave Kennedy]

Thanks to all the recent posters to this thread. I thought it had died a death in the middle of 2008, so I never saw your interesting posts. I appreciate your input.

Best wishes,
Dave Kennedy

[eiderman]

In support of the mobbing theory, I recall arctic skua remains being found in a peregrine nest on a sealoch in Argyll.

[Himalaya]

whena peregrine stoops i think a skua would be easy prey....

Originally Posted by eiderman

In support of the mobbing theory, I recall arctic skua remains being found in a peregrine nest on a sealoch in Argyll.

[scuba0095]

actually a skua is faster in level flight than a falcon and also is more agile, being caught up in a falcon stoop would be rare.

Id also like to mention that bonxies pose more of a danger to falcons than vice versa as i have read a few accounts in regards to falcons almost getting killed from territorial skirmishes with BOnxies, never have i read a single account of any falcon taking a bonxie though.

[BrownnishSkua]

Originally Posted by scuba0095

actually a skua is faster in level flight than a falcon and also is more agile, being caught up in a falcon stoop would be rare.

Id also like to mention that bonxies pose more of a danger to falcons than vice versa as i have read a few accounts in regards to falcons almost getting killed from territorial skirmishes with BOnxies, never have i read a single account of any falcon taking a bonxie though.

Thinking about it again, this is impressive and you said you have said its from the book 'Sea birds of the World' if not mistaken.
i hope to be able to borrow or at least read that.
Who is the author?

[BrownnishSkua]

Originally Posted by Himalaya

whena peregrine stoops i think a skua would be easy prey....

In 'Raptors of the World', a pom skua seems to be included in the list of gryfalcon's food item. However, the pom skua is said to have better flying ability than the falcon.

[Himalaya]

what about if you read books written about pergrine falcons? surely people who have studied the peregrine or gyrfalcon could tell you a different story. as their attention is more focused on what the falcon eats surely that could give a different perspective?

Originally Posted by TheCrow

Thinking about it again, this is impressive and you said you have said its from the book 'Sea birds of the World' if not mistaken.
i hope to be able to borrow or at least read that.
Who is the author?

[scuba0095]

the people who study falcons will tell you that they are deathly afraid of great skuas and will flee the area as fast as they can if a great skua is around or they will end up paying the price

[purple highflyer]

Just found this thread, on saturday 17th oct I saw an artic skua mobbing a juv peregrine in the thames estuary from canvey island,strangly it was also being half heartedly mobed by some larger gulls aswell.

PH

[Dave Kennedy]

Originally Posted by purple highflyer

Just found this thread, on saturday 17th oct I saw an artic skua mobbing a juv peregrine in the thames estuary from canvey island,strangly it was also being half heartedly mobed by some larger gulls aswell.

PH

This is the second time this thread has been resurrected, so thanks to all the post-February contributors! I think February wa the last time I bothered to look, because I thought the thread had surely died a death.

If I could just query the above quote, was it the skua or the juvenile peregrine that was being half-heartedly mobbed by the gulls?

Best wishes,
Dave

[purple highflyer]

If I could just query the above quote, was it the skua or the juvenile peregrine that was being half-heartedly mobbed by the gulls?

Best wishes,
Dave[/quote]

Hi Dave

It was the Peregrine.

PH