CO-OPERATIVE BREEDING IN THE PIED STARLING

Craig, A. J. F. K. 1987. Co-operative breeding in the Pied Starling. Ostrich 58:176-180.

Pairs of Pied Starlings Spreo bicolor build the nest, but only the female incubates. After the chicks hatch, subadult and juvenile birds help feed the young. Helpers also feed young after they leave the nest. In most cases parents contribute more than the helpers which may attend several different nests. Associations between members of the same breeding group may persist for up to three successive seasons.     

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.     

SOME OBSERVATIONS ON THE DIDRIC CUCKOO

Earlé R. A. 1986. The breeding biology of the South African Cliff Swallow. Ostrich 57: 138–156.

The South African Cliff Swallow Hirundo spilodera breeds in dense colonies usually under man-made concrete bridges. The clutch size is 1–4 eggs but most 4-egg clutches are probably the result of conspecific brood parasitism. The incubation period averages 14,6 days and the fledling period 24,1 days. Although only the female Cliff Swallow has a featherless brood-patch, both males and females incubate effectively. Nestlings reach a maximum weight of up to 31 g between 19 and 22 days, about 10 g more than average adult weights. This weight increase of nestlings is mostly the result of an increase in water content of the body. Both parents feed the chicks, with the highest rate of feeding during the midday hours. In all, 56% of all eggs laid produced flying young, with a recruitment rate of 0,9 young: 1 adult per season.     

OBSERVATIONS ON THE BREEDING BEHAVIOUR OF GREY AND RED-NECKED PHALAROPES

Observations were made on Grey and Red-Necked Phalaropes near Chesterfield Inlet, N.W.T., Canada, from the date of their local arrival, 13 June, until 21 July 1967. The similarity of the colour of the Grey Phalarope nuptial plumage to that of dead seaweed among which the birds often feed is suggested as possibly relevant to the evolution of this plumage. A mutual Head Up pre-copulatory display, first given by the female, is described in Grey Phalaropes. It is suggested to have the function of assuaging fear in the prospective partner and to be a prelude of only the first copulation between any two birds. Other displays are described and figured. Three full copulations, including their preliminaries, were observed in this species and two others in which the preliminary actions escaped observation. Three copulations took place on land and two on water. Of the three copulations observed with their preliminaries, two were initiated by some form of display by the female, and one, without any display, by the male. Eight attempted copulations were observed; all were initiated by males and all but one took place while the female was on land. One male which had just copulated was observed to attempt copulation with another female. In the course of three full or attempted copulations, another Grey Phalarope fluttered up against the mating pair. All Grey Phalarope copulations took place in a collective feeding area; little intra-species antagonism was seen and no evidence of territorial behaviour. All female Grey Phalaropes left the colony under observation on the night of 9–10 July; only two eggs had by then been laid in one nest and the female of one pair had not laid at all. Six copulations and six attempted copulations were observed in Red-necked Phalaropes; all took place on the water. Only in two of the copulations were the preliminaries observed; one was initiated by a display of the female, the other without any preliminary display by the male. Preliminary observations suggest specific differences in rate of spinning and in the preferred direction of spin. The functions and factors associated with spinning are discussed. Accelerated spinning with reduced frequency of pecks at the water by both members of a pair of Red-necked Phalaropes was observed once and may have been a form of display. Head scratching, observed once in a Red-necked Phalarope and several times in Wilson's, is by the direct method, supporting the view, based on the colour pattern of the downy young, that phalaropes are more akin to the sandpipers than to the avocets.     

OBSERVATIONS ON THE BREEDING OF THE WOOLLYNECKED STORK

Scott, J. A. 1975. Observations on the breeding of the Woollynecked Stork. Ostrich 46: 201–207.

Little is known about the breeding of the Woollynecked Stork Ciconia episcopus in Africa. This paper discusses breeding, adult and nestling behaviour, nests and sites. Seasonal movements are discussed briefly. Eight nests were studied during 1970 to 1974. At one nest incubation was established at 30 to 31 days and the fledging period 55 to 65 days. No feeding of the young was observed at any time, though one eight hour observation period was undertaken. Few mating displays were seen and none away from the nest.     

COOPERATIVE BREEDING OF THE NORTHWESTERN CROW CORVUS CAURINUS IN BRITISH COLUMBIA

The behaviour of helpers at nests of Northwestern Crows was studied on Mandarte Island and Mitlenatch Island, British Columbia. Not all nests had a helper and there was only one helper per nest. Helpers participated in varying degrees in the defence of the territory and nest, feeding of the nestlings and fledglings and they cached food on the territory. Adult males fed helpers, and helpers obtained most of their food on the adults' territory. Adults with helpers laid larger clutches and produced more fledglings per nest than adults without helpers. It is suggested that cooperative breeding in the Northwestern Crow is of recent origin.     

SUPPLEMENTARY OBSERVATIONS ON THE BREEDING BIOLOGY OF THE BOOTED EAGLE IN SOUTHERN AFRICA

Steyn, P. & Grobler, J. H. 1985. Supplementary observations on the breeding biology of the Booted Eagle in Southern Africa. Ostrich 56:151-156

Further observations on the biology of the Booted Eagle Hieraaetus pennatus in southern Africa are presented. Several nest sites in trees are described, and details of behaviour during the incubation and early nestling period are given. The down colour of nestlings is discussed. One juvenile returned to its natal area the following breeding season. In ninepair-years the replacement rate was 1,0 young/pair/year. Prey records confirm that birds predominate. The implications of the recent discovery of breeding in mid-winter in Namibia are discussed; there may be three Booted Eagle populations in southern Africa.     

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.     

THE BREEDING OF THE GREATER FLAMINGO AND GREAT WHITE PELICAN IN EAST AFRICA

This paper brings together observations on the breeding of the Greater Flamingo Phoenicopterus ruber and Great White Pelican Pelecanus onocrotalus, mainly at Lake Elmenteita, Kenya, 1951–1971. The Greater Flamingo bred at Lakes Elmenteita and Nakuru in 11/21 observed years and at Lakes Natron and Magadi in 5/12 observed years. On average, it breeds about every second year, but a succession of breeding years is followed by several years in which no breeding occurs. A history of 21 years' breeding at Lakes Nakuru and Elmenteita is given. At Elmenteita three sites have been used, the main site in every breeding year, the others less often. The number of pairs breeding in any year has varied from 500–9,250, but in 1968 flamingos bred three times, involving perhaps 8,500 pairs which made about 15,700 nests, some pairs perhaps laying twice or even thrice in a year. Losses of eggs (38.2% overall) were caused by rising water (16.2%), competition for nest space with Great White Pelicans (6.9%, after 1968 only), human interference (3.5%), Marabou Stork predation (1.8%) and other natural causes (9.8%). Losses among chicks totalled 68.3% overall and were mainly due to Marabou Storks (36.5%), undiagnosed disease (8.6%), and rising water (6.6%). Disease caused serious loss only in 1966, and after 1968 losses from Marabous rose from 2.7% to 76.5%, resulting in an increase in overall mortality from 48.7 to 92%. This was perhaps associated with the establishment of a fish factory at Lake Naivasha. When attacking flamingo colonies Marabous did not actually eat many eggs or chicks, but simply caused wholesale desertion by alarming the flamingos. In 1968 total desertion of a colony of 4,500 pairs was caused between 18 and 26 March by a maximum of 17 Marabous, and similar wholesale desertion was caused in later years. The overall breeding success among Greater Flamingos at Elmenteita was about 19% of eggs laid, but without the excessive post-1968 Marabou predation would have been about 30%. At such a rate Greater Flamingos require at least 24 years of adult life to replace themselves, but if the mortality caused by Marabous since 1968 continues they will require about 58 years, and the population will inevitably decline. Breeding success at Lakes Magadi and Natron has been higher, about 44% of eggs laid; but figures available are much more approximate than at Elmenteita. Some new data on display, nest-site selection, laying dates, clutch-size, hatching and creche behaviour are given for the Greater Flamingo. The Great White Pelican bred at Lake Elmenteita from 1968 to 1971 without a break, some birds laying in every month, but with reduced laying November–December. They bred on the same islands as, and in association with the Greater Flamingo, and caused heavy losses among the latter, not through aggressiveness, but simply because of their superior size and weight. Although food supply must ultimately have controlled the pelican's ability to breed, an adequate food supply was available for 6 years before they did and continued after they had ceased. Their breeding was finally triggered by the Greater Flamingo colonies, with which the pelicans associated. When a flamingo colony was deserted because of Marabou Storks the pelicans, unafraid themselves of the Marabous, also deserted. They also associated with, and wiped out, a colony of Sacred Ibis. From July 1968 to June 1969 about 2,600 pairs of pelicans bred at Elmenteita, rearing about 2,200 young to the flying stage. The breeding colony apparently comprised most of the adults from Lake Nakuru and Lake Naivasha, the main feeding areas. From July 1968 to January 1971 certainly 7,200 and probably 8,000 pairs of pelicans bred at Elmenteita. Some pairs may have bred twice or thrice in this period. Breeding ceased suddenly in January 1971, eggs, and small and large young being alike abandoned for no established reason, although food supply was certainly still plentiful. Additional information on pair formation, incubation and fledging periods, nest-relief, etc. is given. The best available record of the incubation period is 35–36 days. Nest relief takes place on average about once every 48 hrs, and is dependent on thermal activity enabling the pelicans to soar. At Elmenteita large young ate quantities of putrefying matter, including the corpses of other young pelicans. They also ate living young hatching from eggs, and up to 14 days old. Touch probably plays an important part in helping them to locate possible food in opaque water.     

〔蒙古〕百灵繁殖生态的研究

本文报道了蒙古百灵的繁殖生态、食性及数量,并对其叫声的声谱进行了分析。     

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.