At this time of year our gardens seem to be populated by sickly looking birds such as ragged robins, bedraggled blackbirds, shabby starlings, jaded jays, mussed magpies and tatty tits. The subject of feather moult is fraught with variation by species, birds within species, frequency, timing, duration, life-style and is full of exceptions but most go through a post-breeding moult, hence the “pulled through a hedge backwards” look.

 

The wear and tear of parenthood; tattered adult blue tit at right.

Like human hair, feathers grow from follicles and are made of keratin. Fully formed they are basically dead and cannot be repaired, so must be replaced. Individual feathers are replaced as required whereas moult takes lots of energy and usually serves a purpose. In general these include: Non breeding to breeding to bring out the catwalk display plumage for courtship; breeding to non-breeding which tends to be more camouflaging and insulating for autumn/winter; juvenile to adult and if no colour change is required, general replacement to maintain health and quality.

And so, at the close of the breeding season, energy-intensive song disappears as do some birds while they are vulnerable. For instance ducks, swans, geese, divers and grebes become flightless during their moult. Male ducks take on an ‘eclipse’ plumage as they adopt a more female look for camouflage and a male mallard is so convincing the plain yellow bill is the main giveaway (the female’s has dark blotches). Some, such as most waders, defer losing their all their summer finery until completing migration to their winter home.

Courtship colours of returning black-tailed godwit, admittedly accentuated by sunset.

Juvenile birds that differ from their parents start to replace their feathers to look no different from their parents by autumn-winter. Others who are a “mini-me” of their parents will also replace sub-adult feathers for more durable ones. In larger birds growing a feather takes longer so replacement is more gradual and more or less continuous or it will go through various immature stages (e.g. gulls, gannets). Where a blue tit will take six weeks to fully moult, an albatross takes two years. And on top of all this some birds can suspend moult; osprey suspend for migration, sparrowhawk and peregrine defer until their young no longer need feeding.


Juvenile robin loses its streaky camouflage look at about 6-7 weeks old.

Which is why we can all help by feeding birds all year round; their frenetic lives are beset with one major task after another. Plus, you can get to see some frightful sights visiting feeders and bird-baths.


Is it me or does this baldy blackbird look like it regrets taking a bath?

Recent Sightings:

Juvenile spoonbill; apparently dwarfed by black-headed gull in moult, due to ‘illusion of proximity’.

Now is a good time to visit and see spoonbills (most probably from Fairburn) as they are more frequent on the reedbeds or Astley lake. Catching them awake is another matter because they also feed after dark (“didn’t expect that did you Mr fish/beetle/larvae/snail/frog!” - they have a wide diet) and use parts of the day to roost. More grey heron and little egret are around the site. Continuing to make flights are the bitterns over the reedbeds, reservoir, Astley lake and the ridge & furrow. Also all over are great-crested grebes with juveniles of various ages.

Also at Astley lake are loads of adult and juvenile common tern, and the now not so black black tern, is flitting between Astley, the reservoir and Skelton lake (outside the reserve). The common tern adults can be seen performing their acrobatic fishing techniques all over the site as they rush to plump up their young.


At right; black tern with mostly white head. Note how much smaller than common tern.


Adult and juvenile common tern; adult is losing black forehead, youngster is getting black head.

Along the hillside/pastures and opposite ditch: yellowhammer, willow warbler, reed bunting, sedge warbler, meadow pipit, whinchat and wheatear. In the same area plus over the ridge & furrow and reedbeds are kestrel (up to 9 one day), red kite, peregrine, sparrowhawk, buzzard, hobby and marsh harrier. Plus hares are making appearances to feed on the new shoots in the recently cut grass.


Patrolling red kite.

Returning from their northerly breeding grounds are waders including black-tailed godwit (up to 25), redshank, spotted redshank, oystercatcher, dunlin, greenshank, ruff, snipe, little ringed plover and common/wood/green sandpiper. Seen mostly on the ridge & furrow, Main and Astley lakes. Very mobile are sand martin and lapwing.

Ducks in eclipse being seen are gadwall, pochard, shoveler, teal, garganey, wigeon on the reedbeds, Astley and a goldeneye on the Main lake.

 In the tree-lined areas (behind the lakes Lemonroyd and Main and around Lowther) smaller parties of birds are roaming; bullfinch, treecreeper, blackcap, whitethroat, lesser whitethroat, willow warbler. Also sightings of green woodpecker at Lemonroyd and Main lakes.


Male faded bullfinch with his partner showing off behind.

The ridge & furrow seems the preference of yellow wagtails (up to 20) that have even been seen sat atop the predator fence. And kingfisher are returning to perch on it by the causeway. A more unusual sighting at this time of year was a brief sojourn by a short-eared owl on the 30th July.

In the reedbeds water rail screams and sightings are becoming more frequent, the odd black-necked grebe, linnet and cetti’s warbler. The juvenile starlings are still flocking in during evenings to murmurate over the reedbeds before sunset.


Male linnet; moults once in autumn and the winter feather tips are worn off to reveal spring colour.

Near the visitor centre, in the dragline compound, the little owl adults and juveniles continue to entertain. The juveniles have less flecking on their heads and unlike their disgruntled looking parents, they look more surprised; their eyebrows must be less weighty.


With a sticky out feather at left; the male little owl starts to moult before the female.

Around the site, still plenty of damsel and dragonflies (e.g. darters ruddy & common, brown hawker) and butterflies/moths (e.g. common & holly blue, brown argus, speckled brown).

Common blue butterfly.

And finally:

 

A back seat driver.

At foot of the field by the dragline; female hare lets a male know what she thinks of his attentions.

Yours, K Sp-8 (18/08)

 

 

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