How Kangaroo and Bird Keep Pouch/Nest Clean

choi

(1) C Claiborne Ray, Marsupial Maintenance. New York Times, Aug 14, 2012.
http://www.nytimes.com/2012/08/1 ... -pouches-clean.html
("'A female kangaroo cleans her pouch by licking it out,' said Colleen McCann, curator of mammals with the Wildlife Conservation Society at the Bronx Zoo. 'She is able to push her long snout in to clean it effectively, removing the urine and feces of the young joey by using her tongue'”)

Note:
(a) joey (n; origin unknown; First Known Use 1839):
"Australian : a baby animal; especially: a baby kangaroo"
http://www.merriam-webster.com/dictionary/joey
(b) kangaroo
http://en.wikipedia.org/wiki/Kangaroo
(a marsupial from the family Macropodidae (macropods, meaning 'large foot'); Kangaroos are the only large animals to use hopping as a means of locomotion; Like most marsupials, [only] female kangaroos have a pouch called a marsupium in which joeys complete postnatal development; section 3.2 Diet; When the joey is born, it is about the size of a lima bean; section 3.8 Reproduction and life cycle)
(c) The NYT column says, "Most species of kangaroo can harbor a partly developed embryo in a state of suspended development, then return to active gestation when an older joey makes room by leaving the pouch."

Section 3.6 Adaptations of the above link states, "The female kangaroo is usually pregnant in permanence, except on the day she gives birth; however, she has the ability to freeze the development of an embryo until the previous joey is able to leave the pouch. This is known as diapause, and will occur in times of drought and in areas with poor food sources. The composition of the milk produced by the mother varies according to the needs of the joey. In addition, the mother is able to produce two different kinds of milk simultaneously for the newborn and the older joey still in the pouch."
(d)
(i) diapause (n; Greek diapausis pause, from diapauein to pause, from dia- + pauein to stop; First Known Use 1893):
"a period of physiologically enforced dormancy between periods of activity"
http://www.merriam-webster.com/dictionary/diapause
(ii) embryonic diapause
http://en.wikipedia.org/wiki/Embryonic_diapause


(2) bird
(a) Disposable Diapers for Birds: The scoop on poop. Journey North, undated.
http://www.learner.org/jnorth/tm/spring/FecalSacs.html
(b) fecal sac
http://en.wikipedia.org/wiki/Fecal_sac
(The nestling usually produces a fecal sac within seconds of being fed; Not all species generate fecal sacs)

The video clip in the Wiki page does not work. But I have one for you:
House Wren (Day 10). YouTube.com, uploaded by faunascope on Apr 12, 2008.
http://www.youtube.com/watch?v=fGpeAuo8pPg
, where the parent picked up the fecal sac at seconds 14-15 of the entire 55 seconds (0:55).