ASPECTS OF THE BREEDING BIOLOGY OF THE FIERYNECKED NIGHTJAR

Jackson H. D. 1985. Aspects of the breeding biology of the Fierynecked Nightjar. Ostrich 56: 263–276.

A marked population of nightjars in Zimbabwe was studied intensively for four breeding seasons. This paper covers certain aspects of the breeding biology of the Fierynecked Nightjar Caprimulgus pectoralis. The male shows strong site fidelity during the breeding season (September to December), singing, feeding and breeding within an area of about 5,8 ha. There is some evidence of site defence by the male. The female shows strong mate fidelity, resulting in a pair bond for life. Egg laying starts with full moon in September and is further stimulated by the next two full moon periods. The eggs are laid directly on dense leaf litter at a site overhung by foliage. The normal clutch is two eggs (12S % are one egg) laid on successive days during the afternoon. Incubation starts with the first egg and is by the male at night and the female by day. The incubation period is 18 days. The birds respond to undue disturbance by deserting the eggs and laying a replacement clutch. The chicks usually hatch on successive afternoons; they are mobile on the first day and will move to a parent if called. Both parents feed and brood the young during twilight and moonlight; the male broods them on dark nights and the female does so by day. The species is double-brooded when time permits, the female laying again once the first brood has reached independence; she may even lay a third clutch if the second one comes to grief. There is no evidence of adults transporting eggs or young.     

OBSERVATIONS ON THE BREEDING BIOLOGY OF THE FISCAL SHRIKE

Ward, D. 1989. Behaviour associated with breeding of Crowned, Blackwinged and Lesser Blackwinged Plovers. Ostrich 60: 141–150.

The behaviour of Crowned Plovers Vanellus coronatus, Blackwinged Plovers V. melanopterus and Lesser Blackwinged Plovers V. lugubris in mate and territory acquisition and defence was documented and related to the habitats these birds occupy. The open habitat occupied by vanelline plovers makes them particularly vulnerable to predation and as a result, they have a highly-developed ability to detect potential predators and have developed a number of behavioural strategies to avoid predation. This has resulted in these birds having a higher reproductive success than that documented for other precocial birds.     

BREEDING BIOLOGY OF THE EDIBLE-NEST SWIFTLET AERODRAMUS FUCIPHAGUS

A colony of the Edible-nest Swiftlet Aerodramus fuciphagus nesting in a Chinese shophouse in Penang, Peninsular Malaysia, was studied for seven months. Birds bred throughout, but laying was concentrated in the period October to February. Incubation and fledging periods were 23 ± 3 days and 43 + 6 days, respectively. Most young hatched during the dry season. The normal clutch size was two, with many birds laying second clutches (75%) and some third clutches (15-4%) using the same nest. Clutch size showed no variation with clutch order or month. The overall hatching success was 69-0 %, most losses caused by eggs falling from or with the nest. Fledging success was similar for broods of two (625%) and broods of one (59-4%), so that the former were twice as productive. The main loss of chicks occurred when they fell from the nest and were eaten by mammalian predators. There was a tendency for breeding success to decline with successive clutches, but not with month, being highest in November (53-6 %) and February (55-6 %). The growth rate of single chicks and successful broods of two was similar, except that the second chick was more prone to fluctuations in weight. Some second chicks showed evidence of starvation before falling from the nest. Diet was examined by analysis of foodballs regurgitated by mist-netted adults. Foodballs weighed 0–13-1 08 g and, on average, contained over 500 prey items. The main arthropods caught were Hymenoptera (40-8%), Ephemeroptera (26-4%), Homoptera (15-4%) and Diptera (7-7%). Flying ants and mayflies contributed most by weight, although figwasps and mayflies were the most numerous prey items. Only in December did the percentage of moulting mist-netted adult swiftlets fall below 70 %. It appeared that many birds were moulting and breeding simultaneously, although 21% of birds had primaries moulting in two places, suggesting arrested moult. Diurnal activity showed a normal high dawn exodus and dusk inflow of birds, although there was evidence of an increase of birds flying out prior to the dusk inflow. Nest harvesting was continued throughout the study, but most of the marked nests under study were left undisturbed.     

BREEDING BIOLOGY OF THE MANX SHEARWATER PUFFINUS PUFFINUS

Studies on the breeding biology of Puffinus puffinus were carried out in 1963 and 1964 at the large colony on Skokholm, Wales. During the six weeks before laying the birds spent up to a quarter of the days in the burrows, but the ten days immediately prior to laying were normally spent at sea. There is a prolonged laying period, with a marked peak in the first half of May. Details are given of a second egg being laid when the first was deserted immediately after being laid. The male took the first incubation spell. The incubation spells ranged from one to 26 days and averaged six. The incubation period was about 51 days. The frequency of visits to land by breeding birds, unlike those by non-breeders, was not affected by the moon. On hatching, the chicks grew rapidly and reached maximum weights of between 505 and 755 gm. sometime between 39 and 61 days. There was a variable desertion period, usually eight or nine days, before the chicks left the island about 70 days after hatching. During the feeding period the chick received about two feeds every three days. There is evidence that adults visited the chicks more frequently than this. There was no correlation between growth of the chicks, their feeding rates or fledging weights and the time of laying. There was a high survival (about 95 %) of chicks during the fledging period but some eggs were lost in disputes for burrows. Nine pairs in 1964 were unable to raise two young simultaneously. Parents altered their feeding rhythms to try to feed two young but did not themselves lose weight. It is suggested that the critical factor in the production of young is the availability of food for the young immediately after they leave the colonies.     

SOME NOTES ON THE BREEDING BIOLOGY OF THE STRIPED CUCKOO

Steyn, P. 1973. Some notes on the breeding biology of the Striped Cuckoo. Ostrich 44: 163–169.

Information is presented on the breeding biology of the Striped Cuckoo, a species for which little authentic material exists. A number of cases of parasitism of the Arrow-marked Babbler are given. Pre-laying behaviour is similar to that of the Jacobin Cuckoo. The blue egg of the cuckoo may be distinguished on several minor points, but mainly because it is rounder and broader than those of the host species. The growth and development of a nestling is outlined up to its ninth day when it was killed by a snake. It was reared to this stage with three babbler chicks, probably because several babblers contribute to feeding the nestlings. The cuckoo gains weight very rapidly, and it is suggested that this is because of its brighter gape and more intense gaping response which ensure that it is fed preferentially. Anti-predator devices such as open-gaped lunges, jerking movements of the body and the exudation of a vile-smelling brown fluid are described. The nestling cuckoo's call is identical to that of the babblers. The juvenal may be fed by its foster parents For at least 36 days after leaving the nest.     

BREEDING BIOLOGY OF THE GREY-FACED PETREL PTERODROMA MACROPTERA GOVLDI

The Grey-faced Petrel is a non-migratory winter breeder whose reproductive season occupies 9–10 months. Males spend more time in the burrows than females during the courtship period. Some females keep company with strange males, and may be fertilized by them, but subsequently share incubation with their mate of the previous year. The duration of the pre-laying absence of females is about two months, and of the pre-incubation absence of males about seven weeks. Since copulation is presumed to occur before this absence, these petrels seem to have evolved prolonged viability of the spermatozoa, though ovulation may take place some time before laying. Eggs are laid in late June or July but chicks are rarely reared from eggs laid after 14 July; effective laying thus lasts three weeks. The single egg is about 15·5% of the female's weight; she may be able to exert slight control over timing of oviposition. She may be required to incubate, if capable, for up to 14 days from laying but the male takes over, on average, after four days. There are three main incubation spells of 17 days' average duration, two by the male. These are of a duration such that there is usually a change-over near hatching. Incubation lasts about 55 days. There is competition for burrows, resulting in two-egg nests. Norway Rats take unattended eggs and young chicks and scavenge, but their predation (less than 10–35% of chicks per year) is not considered to be endangering the population. After initially more frequent feeds, chicks are fed approximately once a week by each parent. They do not become much heavier than adults and the growth rate is slow: about 120 days to departure. The ability to begin breeding in winter, atypical of petrels in this region, may be facilitated by three factors: improved availability of food resulting from longer nocturnal feeding time and reduced inter-specific competition; the ability to lay fertile eggs two months or more after copulation; and the brevity of the non-breeding season due to the relative proximity of a sufficient food supply.     

THE EFFECT OF AGE ON THE BREEDING BIOLOGY OF THE KITTTWAKE RISSA TRIDACTYLA

1. From 1954 to 1956 inclusive, the biology of individual marked Kittiwakes was studied at North Shields, Northumberland.
2. It was concluded that older Kittiwakes reacted to the breeding stimulus earlier, more intensively and with greater success than younger breeding birds.
3. Birds with previous breeding experience returned to the colony before birds breeding for the first time and these before non-breeders.
4. Before breeding started, birds which had bred previously spent more of their time at the colony than those about to breed for the first time.
5. Birds breeding for at least the second time laid the first egg 7·5 days earlier than those breeding for the first time.
6. Breeding started one day later for every four days the return to the colony was postponed.
7. Older breeding birds showed greater nest-site tenacity, laid larger clutches and had greater breeding success than younger birds.
8. The chicks in broods of two (but not of one) increased in weight more rapidly where the parents had previous experience.
9. Breeding Kittiwakes showed strong colony tenacity, but 24% of the marked non-breeding birds were subsequently seen in other colonies.
10. Over half the birds retained the same mate as in the previous year.     

THE BREEDING BIOLOGY OF THE BLACK-FACED DIOCH QUELEA QUELEA IN NIGERIA

A study of the breeding biology of Quelea quelea in Nigeria, and particularly at a large breeding colony near Lake Chad, showed that losses of eggs and young were extremely small. 95% of eggs laid hatched successfully, and 87% give rise to fledglings. Nestling deaths were density-dependent and apparently due to starvation.
The incubation period was 10 days or less. By day, eggs were heated to 34°- 37° C. by the sun; at night the females incubated. The nestlings were initially fed mainly on insects, their diet gradually changing to one of seeds—mostly of the grass Echinochloa pyramidalis . The deep body temperatures of young birds were determined. It is suggested that the nestlings left the nest after, on average, 11¹/₂ days to escape intolerable temperature conditions in the nest.
Fat reserves were accumulated by nestlings and fledglings, and were utilized when the young became independent. The adults put on fat during the incubation period and lost it during the time spent feeding nestlings.
It is concluded that the most common clutch-size of Q. quelea , which is everywhere three, corresponds to the largest number of young the parents can normally nourish. This conforms to Lack's theory on the significance of clutch-size, and gives no support to Skutch's opinion that the theory does not apply to tropical birds.     

NOTES ON THE BREEDING BIOLOGY OF THE AFRICAN SPOONBILL PLATALEA ALBA

Silbernagl, H. P. 1982. Seasonal and spatial distribution of the American Purple Gallinule in South Africa. Ostrich 53:236-240.

The American Purple Gallinule Porphyrula martinica has been recorded 21 times in the southwestern Cape Province of South Africa. Nearly all records fall in the period 22 April to 2 July and nearly all birds were juveniles. The majority of dated records for which weather data are available appear to be of birds starting their northward migration in Buenos Aires Province, Argentina, or Uruguay and caught by strong westerly winds which carry them downwind to South Africa in about five days. Most birds arrive in South Africa in an exhausted condition and markedly below normal weight. Thus it is unlikely that the American Purple Gallinule will establish a breeding population in Africa.     

BREEDING BIOLOGY OF THE DARTFORD WARBLER SYLVIA UNDATA IN ENGLAND

The breeding biology of Dartford Warblers was studied during 1975–1976 in 1010 ha of heathland on the Purbeck peninsula, Dorset; comparisons are drawn from other areas of the species' range. Clutches were of 3,4 or 5 eggs, with the mean clutch size increasing progressively from early May to mid-June, declining thereafter. Incubation and brooding of the young were shared unequally between the sexes, with the female taking the greater part. In the number of feeding visits to nestlings there was no difference between the sexes until the last four days of nest-life, when the male greatly increased his share. Nesting was comparatively successful (about 80% of nests producing some young), though the incidence of single infertile eggs was high. There were large variations between years and sites in the timing of the starting of laying. Late-laying pairs reared only one brood, while early starters could rear two. Timing of starting, influencing the number of broods reared, appeared to be the most important factor causing variation in breeding productivity. No vegetational characteristics were entirely adequate to explain variation in starting dates. Past data, however, showed earlier starting in Sussex and Jersey where gorse was a more abundant component of the vegetation of Dartford Warbler habitat than in Dorset. It is suggested that the abundance of gorse is directly related to the quality of the habitat for Dartford Warblers, and hence to breeding productivity.     

BREEDING BIOLOGY AND BEHAVIOUR OF THE QUAIL FINCH ORTYGOSPIZA ATRICOLUS

Summary

Nuttall, R.J. 1992. Breeding biology and behaviour of the Quail Finch Ortygospiza atricollis. Ostrich 63:110-117.

During a study of the breeding biology of the Quail Finch Ortygospiza atricollis, observations of nest-building, egg-laying, incubation and nestling periods, and nestling development in a grassland near Pietermaritzburg, South Africa were supplemented with observations of breeding behaviour in captivity. Mean clutch size was 4,5 and eggs were laid at intervals of approximately one day. Incubation began after the third or fourth egg was laid. An incubation period of 15–16 days and an estimated nestling period of 18–19 days was recorded. Incubation and brooding are shared by both sexes. Breeding success was low (26,7% ?28,6%), with most losses resulting from predation during either the egg-laying or incubation stages.