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)