Flight behaviour of the juvenile Goshawks

One of the two juvenile Goshawks now flying freely in open airspace. 29.vii.2016. N Apennines, Italy. The pale buff ground colour and dark-streaked chest and belly are characteristic of juvenile Goshawk.

It takes a lot to get me up at 6 o'clock in the morning, but the chance of close contact with young Goshawks flying around above the woods in their home valley does the trick.  The plan has been to climb up to the nest site, more specifically, to my 'edge' watchpoint that overlooks the valley below the nest site, before one of the parents makes a first food delivery.  The hope then is that, as seems to be usual, the juveniles will take to the air after eating.  As the previous post noted, 25 July was the first time this year I had seen the juveniles in flight in open airspace above the woods, and I've been up to the valley every morning since (writing on 3 August).  During each of those ten days, there have been phases of 'wee-oo' calling from juveniles, moving in the woods between about 200 metres above the nest location and 500 metres below, and my visit has coincided with flights on seven mornings.

Juvenile Goshawk Accipiter gentilis

The morning of the 29th was fairly typical of the first few days (apart from the possible adult hawk arriving).  I had heard no sounds from down in the valley as I walked up on the path through the woods on the eastern slopes.  At about 8.00, through the screen of branches extending over my head from the woods behind, I glimpsed a bird fly quite fast above the 'edge' heading toward the nest site; this is out of view upstream, behind a buttress of rock and screen of trees to my left.  I had the impression it was the adult male Goshawk, although I did not get a good view of  it. Whatever that bird was, a couple of minutes later a wild cacophony of screaming from at least two juveniles broke out.  I could hear them, rather than see them, moving through the treetops below me, uphill toward the nest area. Then the calls seemed to return to near the original position below me.  Frantic screams followed for a few seconds, then one source of calls moved position up the valley again. Then there was silence again.  I did not see an adult leave (it was typical, back in June, to see the male leave, but has been very unusual in July).  It seemed almost certain from the calls that there had been some animated discussion about a food item, but that both juveniles may have got some.

The quiet lasted nearly an hour, then there were a couple of wailing calls below.  They seemed to indicate an excited state, but not the hunger-driven desperate sounding calls around the assumed food delivery.  Then a few more calls, then suddenly a juvenile launched from the woods and flew fast across the opposite valley slopes.  In hindsight, the characteristic pace and pitch of the calls suggested that the bird was working itself up toward flying out of the woods, but that could be entirely fanciful!

One of the juveniles in mid call. 

The first bird was soon joined by a second, and, as on previous mornings, they began to soar up, alone or in synchrony, or fly in pursuit of one another, soon covering the full width of the valley (around 700 metres at this point) and gaining height until they broke above the skyline.  Their frequent wild screaming calls helped make the occasion just unforgettable. While rising up in this way they would often fly past my 'edge' watchpoint at eye level, sometimes at very close range, and then disappear for a few moments over the woods behind me before reappearing, and perhaps diving down to the bottom of the valley, grappling in a whirling tumble of pale underwings and spread tails.  They would then vanish, but I couldn't tell if they had flown off for a greater distance or returned down to the woodland canopy closer to the nest site.

Sequential images of juvenile Goshawks grappling during an early flight, 1st frame on left. 25.vii.2016. N Apennines

Once, I could just follow one young Gos as it flew a sinuous track among the higher tree crowns below, small birds scattering ahead; then it flew directly into an opening of a tunnel-like enclosure of trees arching over a stony track through the woods, and I could hear its calls as it followed the path up along the western slope! Which, if habitual, perhaps a foraging route for adults, could explain why I once found a Goshawk feather on that track.

Juvenile Goshawk, July, N Apennines

This basic pattern was extended on the following (sixth) day.  Some while after they had flown together around the valley and then gone out of sight, one bird appeared from the direction of the nest site, calling.  On its own still, it soared quickly up, well above the valley, and kept going up until it was barely visible without binoculars.  From a height it then moved off uphill toward the rocky peaks of the local mountain, just over 2 kms distant.  Exactly the flight pattern the provisioning male often took after a food delivery, and I had to check carefully while still within range to make sure it was a juvenile.  About 45 minutes later (around 11.00)  I started hearing persistent but distant Goshawk calls, they gradually became less distant, and eventually I picked up a high hawk approaching.  It came closer, crossed the valley and started flying uphill again following the ridgetop opposite.  This bird turned out to be a juvenile and quite possibly the same one that earlier set off in the direction whence this one appeared.

Juvenile Goshawks: part of one interaction

Since that sixth day (30 July), one or both juveniles have been seen to fly higher and/or longer distances from the nest valley, and in one instance at least, to behave more 'confidently' in flight.

On August 2nd, for example, one of  the juveniles had soared to medium height above the lower end of the home valley, moved across to the valley on the far side of the western boundary ridge, then abruptly and strongly powered upward towards a higher approaching raptor. This turned out to be a Honey-buzzard, and a couple of fast swooping dives by the Goshawk encouraged on its way.

Today (3 August) was interesting.  While at the 'edge' watchpoint I managed to glimpse an adult Goshawk, that I presumed was the male after a food delivery.  He soared high from close to the nest site, then headed toward the rocky local mountain and was soon lost.  As he left there was a phase of penetrating screaming wail calls from the juveniles, and they burst out of the woods, flew downhill, soared quite slowly in widening arcs, and went separate ways.  One crossed the adjacent side valley, heading for a prominent wooded mountain; the other headed uphill along the western ridge of the valley where I soon lost it (while tracking it's sibling).  So, three of the Goshawk family had gone their separate ways.

Juvenile Goshawk harried by Kestrel Falco tinnunculus
3.viii,2016. N Apennines

I then left the side valley where the Goshawk nest is and walked through the woods to a small high meadow giving extensive views over the main valley itself.  I was hoping to pick up one of the local Honey-buzzards in flight, but the main bird of note was a Goshawk.  I heard what sounded like the same juvenile wailing calls I'd been listening to in the morning.  Then the source came into view, rising  from the far unseen side of the convex slope below, it was indeed a juvenile Goshawk, probably one of the valley two: it was being harried by a Kestrel, and headed towards perhaps more familiar terrain just over one kilometre away.

So, picturesque details aside, the basic pattern of early juvenile flight behaviour (of this brood) seems to have been:

1) Remain mainly under and within the tree canopy for something like four weeks once able to fly (I do not know the actual fledging, branching and flying dates because I have not directly observed the active nest or the woodland immediately around it).

2) The first few flights in open airspace above the canopy tend to be limited to a radius of a few hundred metres from the nest site, with both juveniles remaining relatively close (estimated up to about 200 metres apart).  (I'm not certain if there is a third less advanced bird).

3) Flights have been distinctly more ambitious after day 6, and each of the two juveniles has started to take their own course.  Birds have soared higher, almost out of (binocular-aided) sight; they have been seen to overfly adjacent valleys and mountain blocks; they have interacted with other raptors.