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Message: <blockquote data-quote="Jos Stratford" data-source="post: 1751301" data-attributes="member: 12449">The Mysterious Case of......the Missing Nuthatch.Lithuania appears to lie on the cline of the caesia and europaea races of Eurasian Nuthatch, the division a broad zone running north of the capital, warmer-coloured birds more reminiscent of caesia to the south and west, paler birds closer to europaea to the north-east. Over the last decade, suggesting this zone of convergence is edging northwards, warmer-coloured birds have gradually edged out the pale birds in my Vilnius garden, the latter now the exception rather than rule. At my Labanoras feeding station, however, just 80 km further north, pale birds still predominate ...or at least they did, literally overnight they vanished! So, to the mysterious case of the missing Nuthatch. A resident species, Nuthatches have been a year-round feature at my feeders, both Labanoras and Vilnius, ever since they were established. The Labanoras birds, as well as breeding in the woodland, visited the feeders on a daily basis. Winter 2009/2010 began much as usual -two or three pairs in and out throughout the day, frequently taking nuts and storing them in nearby nestboxes. All continued without sign of decline, then on a single weekend in mid-November, the birds disappeared. Not a single bird since, not at the feeders, not in the forest.Populations in my Vilnius garden, and elsewhere as far as I can tell, remain unchanged, so what happened to the birds?They dispersed or migrated? Possible, but why? Largely a sedentary species, birds have never left the forest before. Indeed, if anything, winter usually sees numbers slightly higher as occasional birds arrive with roving tit flocks.They succuumbed? A distinct possibility, but the cause?Disease? No signs of illness were noted, could a sudden catastrophic illness remove all the local birds in the space of one week?Food poisoning? Had toxins been present in the peanuts? A visiting Lesser Spotted Woodpecker also disappeared in December, but toxins seem unlikely - no other birds have been affected and the same food is used in Vilnius, the Nuthatches there unaffected.Predation? Sparrowhawk, Great Grey Shrike and Pygmy Owl have all been hunting at the feeders this winter. Did one of these find Nuthatches easy to catch, possibly also taking the Lesser Spotted Woodpecker? It seems unlikely however that any predator would catch all the birds in a single week.Weather? Nothing untoward at the time of disappearance, rather typical November mildness. In past years, regardless of severity of the winter, birds have not dispersed. So I have no answer. Vanishing into thin air without explanation, my feeding station is left a quieter place, a vacant spot remaining for their return. I hope, as the breeding season approaches, I am able to report on the 'Mysterious Case of the Returning Nuthatch'!</blockquote>

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