The Virginia Forum June 1992
The Virginia Forum June 1992
The presence of pair-bonds throughout the year appears to be common among most species of parrots. In A. albifrons [White-fronted Amazons] such pair-bonds are obvious and are characterized by allopreening, allofeeding, pair participation in aggressive interactions and a close spatial association. All pair bonds are heterosexual.
The exact mechanisms involved in pair formation in parrots are obscure. In A. albifrons, pair formation appears to be a slow process with a gradual strengthening of the bond over time by means of allopreening and allofeeding . . . Only paired birds that copulated and bred were birds that exhibited allofeeding. One pair that was engaged in allopreenings did not attempt to breed in 1978 but began allofeeding in 1980 and bred that year. It thus seems that in the development of the pair-bonds, allopreening precedes allofeeding . . . The death of a [White-fronted] male on Sept. 23, 1978, gave me the opportunity to observe whether its mate would acquire a new male. As of March 1979, the female had remained unpaired despite the presence of two unpaired males..
The females may be even more selective in choosing a mate than females of smaller parrots . . . It is therefore likely that my female A. albifrons did not find a desirable male in the aviary and that she will remain unpaired until a suitable male is introduced. In the wild, "widowed" females are of course more likely to find suitable males.
. . . Allopreening in A. Albifrons is confined to the head and neck region . . . Solicitation is common by both members of a pair. The soliciting parrot lowers its head and assumes a ruffled appearance. Once allopreening is initiated, the parrot being preened often alters the position of the head to indicate which area is to be preened. Solicitation of preening is apparently also used to appease or calm an excited male. The frequency of allopreening did not differ significantly during bouts in which mutual preening occurred (X5=2.4; df = 1; P.0.001). However, females initiated more allopreening bouts (X5= 19.88; df = 1; P<0.0001) than males.
In addition to the typical behaviors of feather nibbling and feather pulling, allopreening birds often exhibit a behavior that I have termed "bill nibbling." This behavior, which should not be confused with allofeeding, consists of two birds gently locking bills while flicking their tongues in a manner similar to feather nibbling.
|
Nine White-fronted Amazon parrots were observed for a total of 185 hours from June 1978 to January 1979 [in western Mexico]. The parrots were housed in an outdoor aviary which measured 19.7 x 8.2 x8.2 ft. and contained two wooden nest boxes 12.2 x 12.2 x 14.6 in. The birds were fed daily on a parrot mix, apples and oranges. The captive flock included four males and five females, and included one breeding pair. Individuals were easily identified by differences in plumage as a result of missing feathers and morphological [form and structure] variations. All observations were made from approximately 6.5 ft. in front of the aviary, and the aviary was entered only for feeding and maintenance. Feeding was carried out at about noon and was not done prior to or during observations. daily observations usually consisted of two or four hour periods throughout the morning and afternoon. During breeding, five 12 to 14 hour observations were conducted to determine incubation attentiveness. Observed behavior was recorded by written notes, 35mm camera and a Super 8 cine' camera. An ethogram was compiled by repeated observations of behavior. |
The term "Courtship feeding" in relation to parrots is really a misnomer, since the behavior is primarily a means of maintaining the pair-bond and is not sexually motivated . . . In A. albifrons, feeding is always by the males to females. While perched next to the female, the male typically lowers its body horizontally, raises the wings slightly away from the body, fluffs the malar region and fans the tail. The male then gives up to eight rapid head bobs with the mouth agape. These movements result in food being regurgitated into the mouth. During the display, the male exhibits serial pupil constrictions, a repeated series of dilations and contractions of the pupil associated with high levels of excitement. This behavior has been referred to as pupil-flexion and eye-blazing and is striking because of the contrasting light yellow iris and black pupil. The displaying male then grasps the female's bill so that they interlock at right angles and moves rapidly up and down, during which time regurgitated food is transferred to the female. The female often emits a low cough-like vocalization during the exchange. Allofeeding typically occurs while the pair are in close association, especially after allopreening.
The copulation stance in A. albifrons is typical of New World parrot species: the male's inner foot is lifted onto the back of the female while the other foot remains on the perch. The female initiates and solicits copulation by sidling up to the male, with body lowered horizontally, tail raised, head up with neck withdrawn from the body, wings elevated and quivering, while emitting a low intensity cackling vocalization. The male then sidles up to the female, lifts its inner foot onto her lower back and swings its tail under the tail of the female so that their cloacae touch. During copulation, the two birds continue to move close to each other with the male moving his tail in a pumping motion to maintain cloacal contact. Tail fanning and serial pupil constriction by the male also occurs during copulation . . .
Of 16 observed attempts at copulation, the longest was 7 minutes, 50 seconds, but most attempts lasted about 3 minutes (x=3.4 + 2.1). Unsuccessful bouts of copulation tended to be very short, lasting under one minute. Other behavior closely associated with copulation including allopreening, allofeeding and bill nibbling. Copulation attempts were observed from July 4 to August 8, 1978.
On July 30, 1978, a breeding pair was observed investigating and defending a nest box. Aggressive interactions between this pair and the remainder of the flock in the area of the nest box were common and intense. Prior to incubation, both the male and female spent short periods of time in the nest box. On
July 26, and egg was found in the nest box and a second egg was discovered the next day. As July 26 approached, the female spent longer periods of time in the nest box. Once the eggs were laid, the mail only occasionally entered the nest box and did not assist in incubation . . . During incubation, the male perched on a limb just outside the next box or in a nearby area. The female remained in the nest box for long periods and came out primarily to feed and preen. Only the female roosted in the nest box at night during incubation. Upon leaving the nest box, the male and female usually allofed and allopreened.
In 1978, breeding was unsuccessful, and the female abandoned the two unhatched eggs after 45 days. In a follow-up study in 1980 successful breeding was observed; two baby parrots hatched out on June 20 after an incubation period of 28 days . . . As during incubation only the female entered the next box and remained in the nest box for long periods of time. Both parents were observed regurgitating food to the young in a manner similar to allofeeding. At hatching, the young were naked. Pin feathers began to appear at about 25 days. The eyes of the young opened in 22 days; the irides were brown in comparison to the yellow irides of mature birds. It seems that the juveniles retain brown irides for over a year after hatching. After 28 days, the two young parrots were observed giving the Hissing display when I looked into the nest box.
One juvenile disappeared after 40 days. At 66 days the remaining juvenile appeared for the first time out of the nest box. It could not yet fly but could climb around the aviary using its beak and feet. Both parents were observed feeding the juvenile and both stayed near it. After 89 days, the juvenile flew and at 138 days fed itself from the food dishes. At 154 days, the juvenile was sexed as a male by the appearance of red primary coverts. After 150 days, neither parent was observed feeding the juvenile, although both stayed close to it and occasionally allopreened with it.
In 1989, I placed four White Fronts I had for several years in a large cage for them to select mates. The winners bred that year. The losers didn't breed until 1992, perhaps not mature enough in 1989, not pair-bonded, or stressed from the selection process, hatching three babies in May in the same nest box (cleaned) the others had bred in hanging outside on a 3' high standard parrot cage. The premier pair female has just begun going into a new box in May hanging outside a smaller cage the same size as used by the 1992 breeders.
They also engage in Aggressive Walk, which apparently is only performed by breeding pairs that are incubating and defending a nest box. The displaying bird walks slowly along a perch with the anterior portion of the body lowered horizontally, wings lifted out from the body and spread slightly, tail widely fanned, malar and forehead feathers fluffed and pupils rapidly constricted. This display has been observed in non-breeding Amazona aestiva and by personal observations of A. finschi and A. ochracephala [blue-fronted, lilac-crowned and yellow-crowned respectively] and may be a common display in the genus Amazona. G. A. Smith referred to it as a "parade" walk in Avicultural Magazine 83:21-27, Notes on some species of parrots in captivity and noted prevalence in other genus . . .
The Aggressive Walk appears to be a threat directed at individuals of other species what approach the nesting area of the displaying bird. If an unfamiliar person approaches the aviary, the breeding pair perform the Aggressive Walk and continue until the person leaves the area.
The female became very aggressive during incubation and often would attack me when I brought food into the cage. If I looked into the nest box while the female was incubating, she gave a "Hissing" display in which she spreads her remiges slightly and lifted the wings away from the body, fanned her tail, fluffed her body feathers, gaped her bill, swayed laterally and hissed. Both male and females were also very aggressive towards the other Amazons at this time.
* at the Department of Zoology, University of Florida, Gainesville, project funded by grants from California State University Fullerton Biology Dept. And the Dept. Assn. Council, and the Sea & Sage Audubon Soc., reprinted from the SPBE Journal, Vol. 1-1 and Vol. 3-4, which see for commonly known details, footnotes and bibliography. Other birds referred to in the paper are left out, and printed this way with the gracious indulgence of the author.
