Sunday 31 January 2016

First sight of juvenile Goshawk in flight!

Juvenile Goshawk, N Apennines, 29.viii.12. 
Getting to the end of summer 2012, with Goshawk nesting now a couple of months past, I was not optimistic about the chances of catching sight of a Goshawk again until the next breeding season.  Although still hot in direct sunshine there was a new autumnal feel to the days: cooler, breezy, and misty.

On 29 August I'd got out to the end of the 'spur' watchpoint quite late and was systematically looking around over the slopes and valleys below, hoping to find a Honey-buzzard.  I tried to keep an eye also on the sky behind me, over the spur ridge and the valleys either side.  At 10.55, when completing another quick scan behind me, through a helpful gap in the ridgeline trees I just saw a medium-large raptor lift fast into sight from the adjacent narrow wooded valley.  First impression was of a possible Honey-buzzard, with a typical large well spread tail; but as it began to gain height in fast circles, putting evident power into the tight turns, I saw the streaked breast of a juvenile Goshawk!

Juvenile Goshawk Accipiter gentilis, N Apennines, 29.viii.2012. Panasonic FZ45
It was very soon too high for such detail, and too distant for more prolonged study of appearance in flight, but this felt like an important step.  Not only had I just had a decent look at a fresh juvenile, I realised belatedly that even if the adult birds resume their cryptic behaviour there might be further opportunities at this time of year to see young Goshawks exploring their surroundings.  Could this bird have been from the nest whose breeding male I saw several times earlier in the year (about 2 kms to the southeast of the spur end), or from another nest in the local area?

Wednesday 20 January 2016

A foraging male, a little less distant

Local Goshawk habitat: wooded hills & small meadows
Same time of the season but the following year, 17.vi.2013, late afternoon I was on the side of the valley opposite my 'white edge' watchpoint.

Looking over the valley from the watchpoint in the morning the sun is rising behind your back in the east.  It is better to be on the opposite side at the end of the day and looking back over the valley toward the morning watchpoint, because the sun will again be low behind your back.  Any birder will know the radical difference in appearance between a bird illuminated by direct low sunlight, and one reduced to a dark silhouette by strong backlight.

Choosing the appropriate slope certainly paid off that afternoon.  The depths of the wooded valley in front were darkening but most of the airspace above was still in full sun.  I had not heard any signs of activity around the Goshawk site, off to my right up the valley, when I caught sight of a hawk rising fast out of the woods, probably not much more than 100 metres away.  I was so surprised I just stood looking, transfixed by the hawk suddenly supercharging the quietening day with energy, and did not consciously tick off recognition points. But I knew it was a Goshawk, and before it headed decisively away up the valley toward the ridges and peaks above I managed to grab a few images.  Happily, although the hawk was as usual too distant, the low direct sun gave the images a bit of detail (instead of being just a distant grey blur).  See composite image below.

Adult male Goshawk, 17.vi.2013, N Apennines.  Heavy crops from Panasonic FZ45.
If viewing this illustration at larger size (left-click) the characteristic dark mask behind the eye is visible on a couple of images (eg. far left, 2nd from right); this dark patch appears more prominent because of the white supercilium separating it from the dark crown.  The step between broad secondaries and narrow hand is almost exaggerated in this individual.  Two typical tail shapes appear in the two images at right, the image 2nd from right shows a closed tail during powered flight, broad at the rump and tapering toward the rounded tip; the tail on image far right is open somewhat, perhaps preparatory to a turning manoeuvre. The image at far left shows the heavy body well, with maximum depth at the belly rather than the breast.  Also note the white undertail coverts, slightly flared here, shown in the image at 2nd left.

Adult male Goshawk (possibly the same individual as 2013), 10.vi.2014, N Appenines. 
I soon learnt to keep an attentive eye on the airspace over the lower stretch of this side valley during the breeding season, and while I could never count on it, I did see a male several times in recent years when the Goshawk nest was active (eg. above, 2014).  It seems he would tend to glide fast down the valley below the nest after leaving the site, sometimes at canopy level for some distance (or below?), before gaining a little height, often skimming the western slopes and then moving purposefully up along the ridge above toward the extensive woods surrounding the local peak.  Curiously, that day back in mid-June 2012 (mentioned in the previous post) remains the only time I have seen the male on his way toward the nest site rather than leaving after food delivery.  I'm convinced that when he brings prey to the nest area he must often approach at or below canopy level.

Tuesday 19 January 2016

First strategy: looking for the breeding male

On 13 June 2012 I was waiting at my usual 'white edge' watchpoint (at the top of a near vertical exposure of slumped shaley rock, without trees and so giving a wide view across the valley to the opposite ridge and hills beyond), hoping to catch sight of one of the local  Honey-buzzards.  Suddenly a medium sized raptor flew fast and low overhead parallel with the edge I was sitting on.  Dark against the bright sky I could only see it was an Accipiter and that it was clutching prey, possibly a Blackbird Turdus merula.  Although I didn't get a firm ID I guessed, because of the apparent size relative to the prey, and the fact that it was heading up the valley toward the Goshawk nest site just a couple of hundred metres away (but out of sight), that the hawk was possibly the male of the breeding pair.

Just a few minutes later I was still enjoying the satisfaction of a close encounter with a raptor, while inwardly wishing I'd seen more detail of it, when a medium sized raptor rocketed down the valley in front of me, rose in fast circles above the skyline of the opposite ridge, and meandered in widening arcs - clearly craning its head around looking for potential prey - before dwindling to a dot over the next valley.

Male Goshawk sets off foraging (FZ45, heavy crops, distant bird). 13.vi.2012. Photos show the long-winged appearance, with narrower 'hand' (2nd left) and distinct neck (right).
The shape in flight was different from raptors I was familiar with, but seemed to combine some aspects of both Sparrowhawk and Honey-buzzard.  But the wings looked longer than any Sparrowhawk Accipiter nisus and narrower than Honey-buzzard although the fairly long tail was half-spread and sometimes twisted in flight in Honey-buzzard style.  I was able to get a few low quality images when the bird was already much too distant but these showed enough information for me to conclude that I'd just seen an adult Goshawk - probably the same individual I'd seen not long before heading toward the nest with prey.

That's when the penny finally dropped: I could probably give myself a decent chance of seeing a Goshawk again by observing from the same spot and looking specifically for the male leaving the nest area after a food drop.  Definitely a plan, although it could be confounded by several variables: I didn't know how often food might be delivered, the male might set off foraging on any compass bearing instead of heading down-valley, and he might not fly off above the canopy.

Next day, I did not see him flying toward the nest area but again he suddenly appeared in the mid-valley airspace in front of my watchpoint (left image below), rose fast on a headwind and was soon out of sight over the head of the main valley.  Apart from the relatively long wings, compared with Sparrowhawk, the narrow 'hand' relative to the broad secondaries really stood out in the few images I had time to take.

Adult male Goshawk, the same bird, next day. 14.vi.2012.  Photo on right shows the narrow hand, white undertail coverts, hint of the head pattern (and missing secondary). 
Just having a clue about where to look for a male Goshawk felt like a real step forward.  But a sighting was by no means guaranteed, and if he did show he was always more distant than ideal, too fast, and soon out of sight. And during many watches he did not show at all.  The other obvious constraint was that this approach is only viable when the male is compelled by the needs of his mate and their brood, or subsequent fledglings, to be out and about foraging for food, ie. potentially from late May through to early August.  No doubt the local micro-topography, the availability of an effective watchpoint, and the nest location itself (see pages 'Location' and 'Nesting site' on tabs above) all contributed to the relative effectiveness of this approach.



Sunday 17 January 2016

Next steps: moving on from random Goshawk sightings

Adult Goshawk leaving nest area, N. Apennines, 17.vi.2015
Back in 2008, although elated for days after finding an active Goshawk nest within easy reach, just an hour's climb up the hillside behind the village, it slowly dawned on me that seeing goshawks might not be any easier than before the discovery.

I briefly thought about setting up a hide before the next breeding season but soon abandoned the idea: the literature suggested a high likelihood that the birds would use a different site if they bred again, and any obvious structure left up in the woods could perhaps attract unwanted attention.  Although desperate to be able to watch the birds, I was even more desperate not to cause breeding failure or provoke the adults to move to another site.

So, during visits to the area over the next few years after 2008, amounting to a couple of weeks annually at first (and two or three months more recently), I essentially relied just on luck to catch sight of Goshawks again.  I was focused almost exclusively on Honey-buzzards and did not set aside the time needed to get in touch with Goshawks or develop a particular strategy aiming to see them more regularly until the 2015 season.  Not surprisingly, encounters were few and far between.  Here are a few extracts from field notebooks to give some flavour of the occasional and typically fleeting and/or distant encounters with probable Goshawks.

14 October 2008, from the local mountain top: "Hawk mobbed by Kestrel (!), at least 2x size but not quite CBuzz size and slimmer, tail faint barred, darker at end, body dark barred under and heavy 'hanging' appearance.  Mostly 'lazy' flight, floating close to treetops, few wingbeats, at times gliding in and out of canopy".  This was a lateral/posterior view of a bird that came past at eye level then a shrinking dorsal view as it dropped down to a wooded saddle far below connecting one peak with another.

19 March 2010, at foot of local mountain: "From distance medium-large bop, c CBuzz size, rising very rapidly above peak, soaring in circles but seeming to speed up in one direction, almost 'dashing' soaring until very quickly dot in sky; prob Gos, poss same bird as yesterday?  Much snow."

2 June 2010, on small mountain road: "From treetop height on left suddenly across road c 20m in front of car and low over treetops on steep downslope on right.  Medium-dark brown upper with 'sooty' tinge, massive barrel-like body, clear flash white under rump.  Prob. Gos (was it perched or already gliding down mountainside?)"

26 September 2010, from ridge of local mountain: "Watching 2 brown-grey presume juvenile Sparrowhawks duelling around top peak, suddenly another hawk appears, but at least twice size, 2 Spar vanish instantly and other - must be Gos - zooms off to mountain block across valley.  Suddenly 2 others in air with Gos.  White under rump and pale underwings prominent at distance (only sign visible when below treeline).  Separated, lost."

16 May 2011, 'white edge' watchpoint: "Suddenly saw heading direct toward me from opposite  ridge, almost immediately overhead, to side, disappeared over trees behind; brief 2nd view as circled and disappeared upslope toward white scar.  Noted very slow shallow wingbeats, but fast airspeed. Noted underwings quite uniform pale but barring vis on base outer primaries; narrower hand, broad across secondaries. Tail tip dark. Prominent white undertail coverts, slightly flared."  Had been looking up the valley and only saw bird as turned to look across; almost too surprised to take in all details.

10 June 2012.  "Windy, crept to Gos nest. Saw underside rear end of adult tipped up, body moving as if tearing at food; head of one small white chick visible."


It took a surprisingly long time to wake up to the fact that hoping to get a lucky sighting while concentrating on other species was just never going to bring results.  And I can't quite understand why it took me so long to find one practical way to gain more regular views (providing the location of an active nest is known).  One of my habitual watchpoints while seeking Honey-buzzards is downstream in the same side valley as the Goshawk nest site, and it was only after seeing a male Goshawk three times one week in June, streaking down the valley past my watchpoint, or rising abruptly over the ridge opposite, that I realised he would have been leaving the valley after bringing food for the female.  So there should be a chance to see him in flight one or a few times every day at this time of year.

The second key realisation, that came a little later, was that accurate interpretation of hawk calls from the nest area could allow prediction of when the male is still awaited, when he has brought prey, and when (approximately) he might be expected in flight having just left the nest site after delivery.