Week 36 – Finding feathers

As we move into Autumn it signals the end of the breeding season for many (but not all) of our birds.  With no nests to build, eggs to incubate or hungry chicks to feed many of our birds are now taking the chance to moult.  As you walk around the park you will see several scruffy looking birds, particularly the Jays, Magpies & Thrushes at present
Moulting Kookaburra
Moulting is the periodic replacement of feathers by shedding the old while producing new ones. Feathers are dead structures at maturity, and they become gradually worn down and need to be replaced.  It is a comparatively slow process, as a bird never sheds all its feathers at once; it must keep enough of its feathers to regulate its body temperature and repel moisture.
The amount of shed feathers varies. In some moulting periods, a bird may renew only the feathers on the head and body, shedding the wing and tail feathers during a later moulting period.  Some species of wild bird become flightless during an annual “wing moult” and must seek protected habitat with a reliable food supply during that time. The Penguins tend to avoid swimming whilst in moult and will gain pre-moult weight to see them through this period when they fed very little
King Penguin in moult
 
The process of moulting in birds is as follows: First, the bird begins to shed some old feathers, then pin feathers grow in to replace the old feathers. As the pin feathers become full feathers, other feathers are shed.  Feathers can make up 4–12% of a bird’s body weight, so it takes a large amount of energy to replace them. This is why most birds moult after the breeding season as there is still abundant food available.  This is not always the case, the Kings moult pre breeding and some of the male pheasants need to look their best before the attract a female
Our male Blue Pie in moult, note the balding head and short tail
We will supplement the food whilst the birds are in moult with extra vitamins & calcium to help them through this time.
Young birds will also moult as the mature and gain adult plumage and this is particularly true of the waders, ducks and pheasants.  You can age some birds by looking at their feathers, this is the case when many UK species of Gull, but also with Blue Tit as well
 3 different stages of feather in a Bartlett’s Dove juvenile
 
As I said earlier, not everyone has stopped trying to breed.  Both the Bartlett’s & Emerald Doves have produced eggs this week as have the Roul Roul Partridge.
The young Roul Roul Partridge from June of this year has departed to a private breeder
The Lilac Breasted Rollers have been seen in their nest box & the King Penguins & Greater Flamingos continue to display so the incubators are on and ready to except any late eggs.
 
The warm weather this week seems to be playing havoc with the wildlife.  I don’t think I have ever seen a caterpillar in September but did this week with a Large White Butterfly caterpillar seen

 
 
We also watched a Comma Butterfly emerge from a chrysalis in the penguin shed

 
 
The Keepers staff room has seen some good wildlife this week with a Southern Hawker Dragonfly joining us on lunchbreak.  We’ve also had Speckled Wood butterfly (constantly avoiding being photographed), a group of Goldcrest and a Zebra Spider sitting by me at lunch time

 
 
A young Grass Snake was also seen by the staff room, only recently hatched as it was barely 6 inches long

 
 
We’ve had Kingfisher on the river practically every day, at least 3 present with juvenile Grey Wagtail also about.  Rob reported seeing a Sparrowhawk at the start of the week.  There are still a couple of Swallows around
 
Moth wise we had Old Lady again and a Brimstone Moth (not to be confused with the Brimstone Butterfly)

 
 
Thanks for reading, I can hopefully fit in one more blog before our own little chick emerges