Breeding Rufous-backed Mannikins

Abstract

In the fall of 1988, I was in a local pet shop and spotted an odd, unfamiliar bird in a cage of Bronze-winged Mannikins (Lonchura cucullata). After returning home, with mental notes on the bird's coloration and markings for reference, I searched through Goodwin's (1982) Estrildid Finches of the World until I found the species whose description matched the bird in the shop - the Rufousb a ck e d Mannikin. I promptly returned to the shop and purchased the bird, which was sold as a ''miniature Tri-colored Nun;' which, indeed, they do resemble. By August 1989, I had managed to obtain four more of these birds at another shop.

Bates and Busenbark (1970) indicated that the Rufous-backed Mannikin was rarely imported into the United States and gave this species only cursory treatment in their book. Similarly, other general avicultural texts give only a brief mention of this bird (Rogers, 1975; Martin, 1983). Goodwin ( 1982) provided some notes on captive breeding that occurred in Germany, but the most extensive descriptions of courtship behavior, nesting and other breeding characteristics, as well as management of this species, were provided by Borlase (1987), based on his breeding success in New Zealand.

Here I describe my own experience in breeding this species, which may constitute a first U.S. breeding.

Taxomony and Distribution

According to Goodwin (1982), Rufous-backed Mannikins include three subspecies: L. b. nigriceps, L. b. uioltersi, and L. b. minor. The latter two are distinguished from the first by a darker coloration and smaller size, respectively. These subspecies share species status with the Black and White Mannikins, L.b. bi color, L. b. poensis, and L. b. stigmatothorax, which resemble the Rufous-backed Mannikin except that black replaces all brown coloration. Other close relatives are the Bronzew i ng ed Mannikin and the much larger Magpie Mannikin, L. fringillo ides.

Rufous-backed Mannikins generally inhabit open areas such as grasslands, marshes, and other clearings, although they may be found in palm groves and forested areas adjacent to open areas. Geographically, they extend from southern Somalia and Kenya southward to South Africa in eastern Africa. Lonchura bicolor nigriceps is more widely distributed than the other two subspecies (Goodwin, 1982). Although it is most likely that my birds belong to the nigriceps subspecies, this is not a certainty.

Description

The Rufous-backed Mannikin is slightly over three inches long and is similar in size and shape to the more common Bronze-winged Mannikin. The mantle, back, wing coverts, and parts of the secondaries are a dark, rich, chestnut brown. Wing coverts have straw-colored streaks along the feather shafts that vary in intensity from bird to bird. The exposed edges of the secondaries are barred with dull white, reminiscent of the wing coloration of the Owl Finch (Poepbila bichenovii). The head, upper breast, and tail are black, and the lower breast, abdomen, and vent area are white. The flanks are scalloped in black and white. The irides are dark brown. Legs and feet are blackish, and the bill is blue-grey, almost silvery in appearance. Sexes are alike. Before they molt into adult plumage, juveniles are a grey-buff color on the underparts and brown above; flight feathers and the tail are an even darker brown. The bill of young birds is also a dull black rather than the adult color.

Diet

The birds receive a diet of a standard, commercial finch seed mix and an eggfood mixture. The eggfood consists of three hard-boiled ( or microwaved) eggs, three slices of whole-wheat bread, two heaping teaspoons of 95% soy protein powder, and two teaspoons of Vionate powdered vitamin supplement. These ingredients are combined and chopped to a fine, crumbly consistency in a food processor. Cuttlebone and crushed oyster shell are both provided as sources of calcium for laying females and are available at all times. Fresh water is provided daily and is available continuously.

Breeding

The greatest difficulty in breeding Rufous-backed Mannikins is distinguishing the sexes. Although the males do sing and perform a courtship ritual in the presence of the females, these activities can be difficult to observe and may not be exhibited by the birds in the presence of humans. I have attempted to sex the birds on the basis of bill size - male mannikins reputedly have a stouter, larger bill, although this can be difficult to distinguish in birds this small. A female in breeding condition can also look fuller in the abdominal area, indicating the expansion of the reproductive tract in preparation for egglaying. However, these indicators are not always reliable, and a presumed pair may never lay because they are two males, or may lay lots of infertile eggs because they are both females.

The breeding cage I used was a large, wire-fronted, box-type cage with a 20-watt fluorescent light in the top. The cage measures four feet wide by three feet high by two feet deep. The light is on a timer set for 15 hours of light per day (7 a.m. to 10 p.m.) year-round. Juniper branches were placed in one end to provide cover and potential nest sites. Large and small domed wicker nests were also placed in the cage to provide additional nest sites. Fine dried grasses and strands of burlap were placed in the cage for nesting material. The cage bottom was covered with about one inch of small, hardwood chips.

Three wild-caught birds were placed in the cage together in the fall of 1989. I believed these to be two males and a female. After a couple of weeks, one of the males appeared to be harassing the other male, and the subordinate male was removed. The remaining birds promptly began nestbuilding and constructed a nest in the juniper branches. The nest was essentially a grass shell lined with burlap and was covered over with an entrance hole on one side.

 

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References

Bates, H., and R. Busenbark. 1970. Finches and Softbilled Birds. T.F.H. Publications, Neptune City, New Jersey.

Borlase, S. 1 987. The Rufo us-backed Mannikin. National Finch and Softbill Society Bulletin 4(2): 36-39.

Goodwin, D. 1982. Estrildid Finches of the World. Cornell University Press, Ithaca, New York.

Martin, R.M. 1983. Encyclopedia of Aviculture. Arco Publishing, Inc., New York.

Rogers, C.H. 1975. Encyclopedia of Cage and Aviary Birds. Macmillan Publishing Co., Inc., New York.