Saturday, 11 January 2014

Four Thrush Species in a Morning - Back at Manor Farm

For the second weekend running it was back to Manor Farm in the hope of catching some of the redwings and fieldfares that were there last week. We arrived early to set the nets, putting up two rows of three 18 metre nets and a single 9 metre net. Pre dawn there were redwing and fieldfare calling and moving around, and it wasn't long before we had our first birds. Our first bird was a species that I have only caught a handful of times before........a fieldfare.

Fieldfare Turdus pilaris

As I previously mentioned, fieldfare is a species that I catch extremely infrequently despite it being an annual winter visitor to the site in good numbers. For ageing and sexing I referred to my trusty Swennson and Jenni and Winkler, so here goes. Adult fieldfares undergo a complete post breeding moult, whereas juveniles only undergo a partial moult. However, Svensson states that many birds (though not all) do not complete the moult of their juvenile greater coverts. There was no obvious break in the greater coverts on this bird which was an indication that it was an adult.


As with many species the shape of the tail feathers is a useful indication, with adult feathers being broad and rounded, whereas first year feathers are pointed. This bird had very broad and rounded tail feathers and therefore due to the combination of features it was aged as an adult.

Broad Adult Type Tail Feathers of the Fieldfare

For sexing fieldfares Svensson describes the pattern of the crown feathers as a useful feature; male feathers are generally dark centred, whereas female feathers have the dark area restricted to the central shaft, and the base, where it is slightly broader. Svensson also states that where this is ambiguous the colouration of the tail feathers is useful. In males the tail feathers are black to blackish whereas female tail feathers are dull dark brownish-olive.

Head of Fieldfare

Given the black colouration of the tail feathers on this bird and the extent of black in the crown feathers, we sexed it as a male. The numbers of birds present was nowhere near those recorded last week, nonetheless the next round did produce a retrap blackbird, the first two redwing of the year and a new song thrush. 


There was still a mixed flock of finches feeding in the top fields of which single greenfinch and goldfinch were caught, and a small mixed tit flock boosted the numbers a little. Another species that we don't catch very often is collared dove, and today one bird was caught. The eye of this bird was bright ruby red, the legs bright red and there were no pale fringed feathers present in the plumage, we therefore aged it as an adult. I used to catch quite a few collared doves in my garden, but in recent years they seem to have declined, probably as a result of the local sparrowhawk which used to be a regular visitor.

Male Collared Dove

By the end of the session we had caught 18 birds, 15 new and three retraps, of 13 species. The three retraps were an adult male blackbird that was originally ringed on the 15th September 2013, a long-tailed tit that was originally ringed on the 11th April 2010, and a blue tit that was originally ringed on the 3rd January 2011. The complete list of species was blackbird (1), redwing (2), fieldfare (1), blue tit (5), great tit (1), song thrush (1), dunnock (1), long-tailed tit (1), goldfinch (1), greenfinch (1), collared dove (1), carrion crow (1) and robin (1).

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