The jacky winter (Microeca fascinans) is a small grey-brown robin found commonly throughout Australia and also in Papua New Guinea.
[2][7][11][12] Microeca fascinans zimmeri is a subspecies of jacky winter found in Papua New Guinea[13] The jacky winter is around 12 – 14 cm in length (including the tail) and its weight varies from 14 – 18 g.[14] The plumage of M. f. fascinans includes a greyish breast with white on the bottom half, its head and back is greyish-brown, while its wings are a darker brown with white edges.
[17][18][19] In many species of birds, the male plumage is quite bright and flamboyant to attract the opposite sex in hope of finding a partner to mate with.
[15] In the eastern states of Australia, the jacky winter breeds mostly to the west of the Great Dividing Range, where a suitable habitat of eucalyptus woodland is present.
They build a small, open cup-shaped nest, which is often made from grass and bark strips held together by spider webs.
[14] The jacky winter holds these territories by perching on top of these eucalyptus trees and keeping a regular sustained call.
Like many other small woodland birds in Australia, the jacky winter populations are declining and are considered to be a common species but decreasing.
[12] A number of species of woodland birds, such as the jacky winter, are declining and going locally extinct, due to the fragmentation and degradation of their habitats.
[22][23][24] Since European settlement in Australia, much of the woodlands have been converted to arable land and pasture, for crops to grow and for livestock to graze.
This bare ground disadvantages the ground-pouncing jacky winter because a decrease in the larger terrestrial arthropods that they feed upon occurs.
The noisy miner (Manorina melanocephala) is a winner of these human-altered landscapes, and is quite aggressive towards other small insectivores, such as the jacky winter.
The noisy miner has quite a negative impact on tree health, which also limits the availability of suitable nesting material for the jacky winter.
A changing climate caused by anthropogenic sources has already been determined to affect the breeding activity, the timing of migration, and also the geographical and elevation range of birds quite significantly.
[28][29][30][31] What threatens the jacky winter in Australia is rising temperature and evapotranspiration, causing more droughts and increasing fire severity and frequency.
This has been interpreted as a micro-evolutionary response to global climate warming, and to the changes in nutrition associated with declining food availability and habitat quality, which the jacky winter is undergoing in southeastern Australia.