Little quantitative information on the development and behaviour of chicks and young is available for many species, despite the crucial importance of such data and the sensitivity of this stage in a bird's life. For Eagle Owls Bubo bubo, despite the large amount of scientific literature on this species, much basic information is lacking. This study provides a photographic and morphometric guide for age estimation of nestlings and fledglings, as well as data on the call behaviour of young, and patterns of movements during the post-fledging dependence period. The most remarkable event in chick development is the rapid increase in mass, and size gain, during the first 30 and 40-45 days, respectively. Because after this time morphometric differences become less evident, young-feather development is more useful for ageing. Patterns of chick call behaviour showed that the time spent calling increased with age and, from 110 days of age, chick vocalizations were usually uniformly distributed through the whole night and most synchronized at sunset and sunrise (the maximum recorded number of vocalizations per chick and per night was 1106 calls). During the post-fledging dependence period, radiotagged Owls moved widely, up to 1500 m from the nest after the age of 80-90 days. During such movements, the mean distance among siblings increased with age, from 168 m on average for juveniles less than 100 days old, to 489 m for those older than 100 days. Definitive dispersal started when young were about 150-160 days old. Information on chick call behaviour and movements is crucial for unbiased census and nest checking, as well as for the definition of young post-fledging areas. Knowledge of the latter is very important in terms of conservation and management (especially for those species that move largely around their nest before dispersal) owing to the high mortality that can occur during this period.

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Summary 1.Fat reserves are stored energy that may help birds survive periods of harsh winter weather. This hypothesis predicts that annual apparent survival is higher for birds with large fat reserves than for birds with few or no fat reserves in winter. 2. Blackbirds ( Turdus merula Linnaeus) were ringed in central Italy from 16 November to 20 February during 1990February during -2001. Fat scores were recorded for each bird. We used these capture-mark-recapture data for 1703 blackbirds to estimate the effect of large fat reserves on annual apparent survival, while controlling for transients, using computer programs  and  . Probability of birds retaining large fat reserves, or retaining few fat reserves, over 2 successive years was also estimated. 3. Birds with large fat reserves did not have higher estimated annual apparent survival than birds with few fat reserves ( 2 large = 2 few = 0·595, SE = 0·043), inconsistent with our prediction. No effects of age, sex or year were detected on annual apparent survival. Birds with few fat reserves in any given year tended to have few fat reserves the following year ( -few → large = 0·332, SE = 0·052). Birds with large fat reserves in any given year were unlikely to have large fat reserves the next year ( -large → few = 0·585, SE = 0·080). 4. Large fat reserves may not increase annual survival of blackbirds wintering in central Italy. Winter weather in our study area may be too mild to effect survival. Alternatively, increased predation risk associated with large fat reserves may counteract any benefits of reduced starvation risk.

Authors examined the autumn-winter diet of the woodcock Scolopax rusticola from 407 gizzard samples originating from Crimea and Italy, resulting in a high number of millipedes (Diplopoda) in all the samples; this prey item was particularly important in terms of weight percentage. The authors consider that calcium, highly present in millipedes, should be an important source for the woodcocks' metabolism during the autumn-winter seasons.

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