Thursday 27 April 2017

Four days,one unforgettable Goshawk sighting

Adult Goshawk Accipiter gentilis 
N Apennines, 21.04.2017
Olympus e-m1 (I), 75-300 II
The pale underside of a large bird glimpsed in fragments between leaves as it moved over the canopy, time interrupted in the instant it crossed a gap high overhead, big chest fine-barred: an adult Goshawk!  Actually that was just an imaginary Goshawk in a recurrent daydream (the mind tends to wander after a few hours scanning the wooded slopes on high alert for calls or a hawk in flight), but a real encounter during a recent mid-April visit to the valley in the northern Apennines was much better.

I had been sitting on a rock outcrop amid a high landslip scar in the wooded hills since mid-afternoon, the warmth on my face fading as the sun declined toward the distant hilltops, and the air getting colder as the freezing wind strengthened with evening.  Shadow covered the slopes opposite and the valley below filled with darkness.  For just the second time during the afternoon a distinct 'kek-kek-kek' call came from woods about a hundred metres up-valley from the nest site, then a stronger call from the nest area out of sight below.

It seemed that nothing more would develop and, with eyes streaming in the cold, I decided enough was enough and started to head down.  I had just paused to stand in the clearing at the base of my rock, enjoying the silence and the clear blue sky overhead, when there were suddenly two urgent 'wee-oo' calls from the nest area.  Immediately, through the treetops circling the patch of open ground, I saw the dark profile of a large bird powering up from the slopes below.  Camera and binoculars were just packed away for the steep track downhill  but I knew it was a Goshawk, probably the male, and as it flew low around the edge of the landslip scar and out of sight behind higher trees I cursed for giving up my vigil at the worst time possible.  Once or twice in the past I'd seen hawks flying along the wood edge around the open ground and decided to wait just in case it reappeared (meanwhile trying not to panic as I scrabbled to extract my camera).  And, as if by magic, it came into view from over the higher woods above the landslip zone, soared at speed in widening arcs almost directly overhead, then moved higher and across until it must have been over the patch of woods whence the first kek-kek-kek call came.  Soon more distant, it set into a fast gliding descent out of sight beyond the higher ground above.

Adult Goshawk Accipiter gentilis 
N Apennines, 21.04.2017
The bird was overhead, at only moderate height, for at least twenty seconds and in sight but more distant for about a minute.  While closer it was dramatically sidelit by the last rays of sunlight, soon to leave even the higher treetops on this side of the valley but still filling the blue sky above.  Probably the most sustained view of an adult Goshawk I'd experienced, and certainly in the best lighting!

So that was one great Goshawk sighting for an investment of about 24 hours of observation time over four days, and much serious discomfort from the cold of early morning or late afternoon.  Light-headed with the thrill of the encounter, that seemed like an excellent outcome, and I skipped down through the darkening woods without even trying to restrain what must have looked like a mindless grin on my face.  Less intensely exciting, but certainly more significant, was the fact that rare calls over the four days demonstrated that two Goshawk were still present in the nesting valley and apparently centred on the same nest site (as suspected back in March, see previous post).


Any lessons?

OK, never mind the romance, what has been learnt?  Next year, despite that stroke of good fortune, I probably will not plan a visit in April.  It seemed to me that the male restricted almost all his activity to the woodland proper, but of course he may have appeared above the canopy when I was not on lookout (eg. at dawn, when I have to admit the cold deterred my ageing bones).  If sightings are exceptional, audible calling was also very infrequent, in marked contrast to the month before and the month following.  In March, pairing, mating and nest preparation involve much activity and lots of excited calling.  In May, assuming chicks are present, the male should be in active flight for hunting more often, and vocal communication between the pair becomes vigorous around prey delivery; later on there can be high-intensity calling as the female ensures the male keeps his distance from the nest.

Tuesday 4 April 2017

Mist, mud, and Goshawks nesting again!

Male Goshawk, 24.iii.2017
(for basic background information on the locality, click on the separate page tabs above: 'Location' and 'Nesting site')

The 23rd of March 2017.  For my first visit to the site since autumn 2016, I went up to one of my usual watchpoints, a high and open former landslip scar that gives a useful view over the valley woodland, including the airspace above the nest site, itself deeper in the valley centre, hidden by the slope and by the trees edging the landslip.  Calls from the nesting woods can easily be heard, and hawks in flight can sometimes be seen if above the canopy.

Sitting out in the rain on an Apennine hillside, hunched up under a not quite waterproof cape  was not exactly the scenario I'd imagined while struggling to endure  the dull cold Cambridgeshire winter.

The steep track up was difficult in parts; slippery stones and glutinous mud where a tractor had recently been labouring up to a small patch of hillside cultivation. Grey cloud off the cold Ligurian Sea streamed over the mountains to the west, grey cloud crept up the valley from the Po plains to the east, and the very air seemed made of water, misting the landscape of leafless grey-brown woods (photo left).  But the wind was gentle and the damp air was mild.  Soon an occasional relaxed ke-ke-ke call, or quiet wee-oo wail, came up from the unseen valley woods in front of me to confirm the happy fact that at least one Goshawk was present near the old nest site.

From my notes

24 March 2017. Saw high accipiter, possible Goshawk, from stream crossing ca 11.30.  12.15 heard calls around white edge area.  Ca. 13.00 k-k-k and wee-oo calls near site, then together from above and below site, ie. definitely 2 birds present.  Soon two birds calling at same time, loud and fast, "weooweeoo", probable mating; then occasional k-k-k and wee-oo calls. More sporadic over next half hour.

13.25 couple more weeoo calls, louder, apparently higher in canopy and so suggesting imminent flight, then bird up from patch above nest site; fast direct powered flight downstream, just above treetops, passed near white edge watchpoint, then around uphill toward principal ridge above C., out of sight behind higher ground.  Now 13.33.

14.25 Sparrowhawk across old landslip scar: instant impression small and fluttery, marked contrast to Goshawk just seen (adjective 'moth like' came to mind at the time but not an exact resemblance).

Goshawk, probably adult male. Not much colour visible in the dull conditions but some typical structural features can be seen. 1: head and neck prominent, 2: bill distinct, looking deep at base, 3: wing appearing relatively long, tapering hand, 4: body somewhat bulky, deep at belly. 24.iii.2017, N Apennines.

25 March 2017.  08.55 weeoo call heard near fork to white edge watchpoint. Continued uphill through scrub at base of landslip scar.  More calling with some apparent changes in bird's position.  Then 2 birds together, then bit quiet, then slight increase in frequency and volume, bird promptly up.  Circled down valley just above trees, past white edge area then across valley and back upstream along opposite slope and then lost, apparently down among trees.  10.37 high raptor over, probable Peregrine?  11.00 2 x Common Buzzard around peak at top of valley.  Occasional quiet k-k uphill from site.  11.40 Gos crossing lower valley apparently from area where earlier bird lost, Sparrowhawk following apparently encouraging Gos to keep moving, Gos gliding on as if unconcerned (very obviously larger, bigger mass of flared white undertail coverts).

Goshawk, adult male, probably same bird as above.  Note prominent white supercilium, broader posteriorly, also bulky body and distinct white undertail coverts (not flared out).  Exposure in some images emphasises contrast of wing barring although wings appear largely pale grey to white in live view. 25.iii.2017, N Apennines.
So, - wonderfully - everything looks good for another nesting attempt!  Same nest, two birds, lots of vocalisation, apparent mating, same flight movements as last year.  I don't know if the hawks are the same individuals as last year, and never will know for sure, but because they are based at the usual nesting patch it seems likely that one or both of the pair has used the nest site in previous seasons.  In some populations, breeding pairs rarely use the same nest in succeeding seasons, but may use alternative nests in the same territory (see Kenward, 2006); however, at this location the same nest seems to be used more often than not (but I cannot confirm the same birds are involved).  This has been vital in allowing me to gain a little more experience with the species, because although I have walked extensively through the hill woodland in this area I have not yet succeeded in locating another Goshawk nest site.  My guess is that there are very few nearby areas with the preferred slope, aspect, degree of disturbance, and open structure, ie. tall trees and clear flight channels.   Whatever the ecology, it really is so exciting to know that, potentially, another season of being close to Goshawks lies ahead.

I had been watching webcam images of the urban pair in Riga (Latvia) visiting their previous nest from early January, sometimes bringing twigs or rearranging those already present, and listening to mating events in March, apparently all on nearby trees, not on the nest itself (ie. off camera).  The live stream is HERE, and an active message board is HERE.  Four eggs have now been laid, between 24 March and 1st April.  One salutary lesson from this webcam has been that adult birds can be at the nest, if only briefly, or in its immediate surroundings, from mid-winter onward whereas, in my ignorance,  I had assumed from the lack of evidence at my few short winter visits that "my" nest area is usually deserted until spring.

Kenward, R. 2006. The Goshawk. T & A D Poyser, London. (reprinted 2007).
(Links referenced above were verified on 4 April 2017).