The Goshawk and the Dormouse

Goshawk prey: Edible Dormouse Glis glis, 12.ix.2012

2012, 12 September.  So far as I could tell, the local Honey-buzzards had all gone south and I was returning from an end-of-season walk in the woods with no particular objective beyond the ever-present wish for a good long look at a Goshawk.

I headed back home via the Goshawk nest site, thinking that now the young have long since fledged, I'd have a look under the nest tree in case wind, rain and other agents had left behind any moulted feathers or prey remains.

No feathers this year, but there was a clean and quite robust  cat skull with a large irregular hole in the base of the cranium.  I'm pretty sure this had been one of the semi-ferals that spread out from the villages, rather than Wild Cat Felis silvestris which is probably now absent from the northern Apennines. I carried on home taking my usual route through the hill woodland, wondering if the cat could possibly have been Goshawk prey or if another predator had by chance left it near the nest tree (this latter seemed far more probable).

Predation site: the Goshawk was behind vertical stems,
left of centre. 12.ix.2012. N Apennines

I'd gone around 300 metres on a diagonal down from the nest tree, across a stream and up the other hillside, idly speculating on what the usual prey may be here, and where the post-nesting adult Gos are now, when a large bird suddenly came up from the ground a few metres away (image above left).  Partly hidden by branches and creepers it was gone in an instant, away downhill through the valley woods. It happened so fast, initially just a vague grey blur, but I managed to retain one imprecise image before the bird disappeared behind vegetation: big, approaching buzzard size, a hint of  dark grey and a white stripe along the head, hint of barring in the tail, flash of white somewhere near the tail base, looking medium-dark grey overall but somewhat variegated and with a brownish tinge. The large size was the main feature. Different colour, different proportions, but approaching Common Buzzard Buteo buteo in size. No question it was a Goshawk, possibly the adult female from the nearby nest.

Goshawk prey: Edible Dormouse Glis glis remains, half
mandible (top), palate (centre). 20.ix.2012. N Apennines

Given that the bird came up from the ground, it seemed likely that I had disturbed it while on prey, and sure enough, a metre or two up the slope were the remains of a small mammal. A still-warm dormouse in fact, which, on the basis of colour and tail shape, was a Fat or Edible Dormouse Glis glis. The upper jaw and two halves of the mandible were discarded to one side but the cranium seemed to be missing, presumably consumed.  A considerable amount of grey-white fur was scattered around the remains.

The strongly arboreal Edible Dormouse is noted for laying down fat during autumn before hibernation , so would presumably be a valuable food source for a Goshawk needing to improve its nutritional status after breeding and before winter.  The dormouse hibernates over winter (between October and May, depending on local conditions) but would in principle be available throughout the summer.  In a long-term study of Goshawk in the central Apennines by Penteriani (1997) this species formed 12% of prey biomass.

So, a close but fleeting sight of a Goshawk rather than a "good long look", but more importantly, a fascinating glimpse into part of the bird's daily life in the woodland! Sooner or later I'll get a good long look at a Gos soaring or displaying, but it's sure to be a very long time before I see one on the ground again. My only regret is that I accidentally made the bird leave a good meal; I hope she returned to the kill after I left.

Penteriani V. 1997. Long-term study of a Goshawk breeding population on a Mediterranean mountain (Abruzzi Apennines, Central Italy): density, breeding performance and diet. Journal of Raptor Research 31: 308–312

(expanded from material first posted to BirdForum)

A longer look at a juvenile Goshawk

Juvenile Goshawk, same location as 2012, 29.viii.2014

Same date plus two years (29 August 2014) and same place, the 'spur' watchpoint, but this time I was looking across the short and narrow valley to the south rather than the long view down the main valley from the spur end.  The day had started hazy and cloud cover was quite extensive by late morning.  Raptors showed early (Common Buzzards, Honey-buzzards and a  Sparrowhawk) but there had been no visible activity for some time when, my attention wandering, I poured a cup of tea from the flask.  I was happily anticipating the first sip when suddenly there were two raptors quite close overhead, evidently they had just crossed from the valley behind me on the other side of the spur ridge.  One large and one a little smaller but definitely bigger than the large Sparrowhawk seen earlier.  Some frustration at first because glare from the bright cloudy sky made it impossible to see colour and pattern, and my camera chose that moment to malfunction.

Juvenile Goshawk (far right!) mobbing Short-toed Eagle, 29.viii.2014

The smaller bird dived at the larger several times but without making contact and without evident aggression; the larger evaded contact but maintained a fairly steady course while looking around as if nervous.  The smaller turned out to be a juvenile Goshawk, the dark-streaked buff breast showing clearly as the pair crossed a patch of blue sky.  The larger was a Short-toed Eagle Circaetus gallicus!  This species seems to provoke quite intense mobbing behaviour in other smaller raptors, but without presenting any obvious threat to them.

My camera finally decided to work again when the two were moving away, but only in time for one image of the birds close together.  Fortunately, the young Goshawk soon left the eagle and came back overhead; the (badly exposed) images show the overall shape quite well but only a hint of colour and pattern.

The long-winged appearance of Goshawk compared to Sparrowhawk, and the long 'hand', narrow compared to the secondaries, are shown clearly; note also the prominent tail, long and spatulate when closed, and the somewhat more prominent bill, head and neck.

The same juvenile Goshawk. Note long wings and narrow hand relative to Sparrowhawk (less clear in image at far right because wings are raised above horizontal); also bill, head and neck more prominent than in Sparrowhawk (again less clear in right-most image because head is elevated). N Apennines. 29,viii.2014.

I could not be certain, but strongly suspected that it was the same juvenile seen soon afterwards in company with a Honey-buzzard Pernis apivorus and a Marsh Harrier Circus aeruginosus (possibly starting southward migration from one of the Po valley breeding sites), but this transient group, although at only moderate height, was several hundred metres distant over the opposite slopes of the side valley.  I was struck then by the strong similiarity in general shape between the Goshawk and the Honey-buzzard, and on several occasions since, when a medium sized raptor has just appeared over a distant ridge, I've been undecided at first between these two species .