SHORT NOTES

Earlé, R. A. 1981. Factors governing avian breeding in Acacia savanna, Pietermaritzburg, Part 3: Breeding success, recruitment and clutch size. Ostrich 52:235-243.

The clutch size and breeding success of eight species of birds were monitored over a two year period in Acacia savanna. The mean clutch size fluctuated within the breeding season and four patterns of clutch size variation were noted. A smaller proportion of large clutches were laid in the 1979 season when less food was available. Breeding success was higher in the dry 1979 season but fewer breeding attempts were made and the overall recruitment was thus lower. At the peak of the breeding season, in mid-November, breeding success was at its lowest. Predation on nests was the greatest factor reducing breeding success although rain and strong winds affected some species.     

Breeding systems of New Zealand Snipe Coenocorypha aucklandica and Chatham Island Snipe C. pusilla; are they food limited?

New Zealand Snipe Coenocorypha aucklandica were studied over six breeding seasons on the Snares Islands. The study area (7.5 ha) held about 20 pairs at a density of 3.2 ± O.5 pairs/ha, plus 5 to 25 nonterritorial birds. Most matings were monogamous but simultaneous polygyny was recorded in one territory (by two different males) in four consecutive seasons. Males courtship fed females before egg-laying. The typical clutch was two eggs, laid three days apart. Incubation was shared equally by the sexes in monogamous pairs and took 22 days. Some females with polygynous mates attempted to incubate unaided, which took about 38 days. Broods were split at hatching, with the male caring for the first chick to leave the nest. Chicks were fed by adults for at least 41 days, and did not become independent until about 65 days old. Growth rates were slow compared to Common Snipe Gallinago gallinago and full plumage took about 54 days to attain. No pairs were double-brooded but 43% of pairs that failed during incubation or early chick-rearing renested together. Some breeders of both sexes who had lost their dependent chick bred a second time with a new mate while their first mate continued rearing the surviving chick (sequential polygyny and polyandry). Hatching success was 80%, and fledging success was 48%. Each pair produced, on average, O.6 fledglings per year. Chatham Island Snipe C. pusilla were studied on Rangatira Island during the 1983–84 breeding season. Breeding density was about 5.6 pairs/ha. The breeding system was very similar to that for C. aucklandica but chicks became independent at about 41 days old. Hatching success was 89%. Compared to Common Snipe, Coenocorypha snipes occurred at high densities, had courtship feeding, large eggs, a long interegy interval, a small clutch, shared incubation and a long incubation period. Nest desertion rates were high, but overall hatching success was also high, chick growth rates were slow, there was a long period of chick dependence and a long relaying interval following nest failure or chick loss. Survival rates of both adults and chicks were high. These differences are attributed to the absence of predation, and to intense intraspecific competition for food in a stable environment.     

绿翅鸭繁殖生态初报

2007～2009年在黑龙江中南部地区对绿翅鸭(Anas crecca)繁殖生态习性进行了观察。绿翅鸭在黑龙江属夏候鸟,每年3月末4月初迁来,10月上旬迁离,所观察的4对绿翅鸭居留期约6个月。迁来时成群停留在湖泊及江的冰面上,开江以后散去,繁殖期间,绿翅鸭的配偶关系为一雄一雌,巢址多选择离水域较近的草丛或灌木丛中,所观察的4巢,巢都比较简单,筑巢时间为(5.5±1.0)d(n=4)。巢筑成后的(3.25±0.50)d开始产卵。每窝70～12枚不等,平均(9.80±2.21)枚(n=4)。卵重平均(28.70±0.72)g(n=39),最后一枚卵产出后(2.50±0.577)d(n=4),开始孵卵,孵卵期约为22～26 d不等,平均孵卵期为(24.25±1.17)d(n=4),平均孵化率为79.5%±29.98%。幼鸟为早成鸟,育雏期为(29.75±1.70)d。     

The biology of the Yellowthroated Sandgrouse Pterocles gutturalis in a South African agricultural landscape

Tarboton, W.R., Blane, S. & Lloyd, P. 1999. The biology of the Yellowthroated Sandgrouse Pterocles gutturalis in a South African agricultural landscape. Ostrich 70 (3&4): 214–219.

A local population of Yellowthroated Sandgrouse was monitored from 1988–1992 at Northam, Northern Province, South Africa, a region in which this species was previously an irruptive, non-breeding visitor. Yellowthroated Sandgrouse were found to be year-round residents, foraging and nesting exclusively in areas cleared for agriculture, particularly one-year fallow lands. They ate the dry seeds of a variety of weedy plants, especially Amaranthus and Crotalaria spp. Males outnumbered females 1.35:1. Egg-laying occurred from April-October, with a peak in June. Clutch size (2–3) averaged 2.85 (n=26), and the incubation period for one nest was 26 days after clutch completion. Nesting success was estimated at 24.8% (n=19 nests, 176 nest days), and the daily nest predation rate at 2.55%; predation and ploughing accounted for most nest losses. Average annual productivity was estimated to be within the range 0.42–0.85 young/pair/year. We suggest that the Yellowthroated Sandgrouse depends on the seeds of early successional plants for food and that the recent agricultural development of the region maintains sufficient areas of fallow land to allow this otherwise nomadic species to become a breeding resident.     

THE INFLUENCE OF THE ENVIRONMENT ON BREEDING SUCCESS OF A SUBURBAN POPULATION OF CRESTED BARBETS TRACHYPHONUS VAILLANTII

Van Zyl, A.J. 1994. The influence of the environment on the breeding success of a suburban population of Crested Barbets Trachyphonus vaillantii. Ostrich 65: 291–296.

I studied the breeding biology of the Crested Barbet Trachyphonus vaillantii in Colbyn, a suburb east of Pretoria, South Africa, for nine breeding seasons from 1981 to 1989 to examine patterns in annual breeding success, breeding attempt success in multiple broods, and rainfall. The modal incubation period was 14 days and the nestling period ranged from 28 to 31 days. Average clutch size for all the years was 3,3 eggs/clutch and there was no significant difference in clutch size or number of young fledged/nest between years. On average, Crested Barbet pairs made 2,4 breeding attempts/season. There was no difference in clutch size or breeding success between the breeding attempts. Crested Barbets nesting in natural nests laid on average larger clutches than those in artificial nestboxes, but had non-signficantly lower breeding success. Failure to raise Crested Barbet chicks was attributed to parasitism by Lesser Honeyguides Indicator minor, bee swarms occupying nestboxes, and flooding of natural nests. Breeding performance was not correlated with rainfall or adult body size. The suburban environment may be less variable than a natural environment, resulting in a stable breeding Crested Barbet population.     

Proceedings of the New Zealand Society for Parasitology Inc.

Abstract

A study of the nesting habits and breeding biology of blue penguin Eudyptula minor was undertaken over the 1995–96 and 1996–97 breeding seasons on Matiu‐Somes Island, Wellington, New Zealand. Male and female blue penguins tended to be faithful to both mates and nest sites, although there was insufficient evidence to detect any association between a bird's breeding success in 1995 and a subsequent change of mate or nest in 1996. Over the 1995 and 1996 seasons the recorded hatching success (0.51 ±0.11 and 0.63 ± 0.10 respectively), fledging success (0.81 ±0.12 and 0.85 ±0.10 respectively) and reproductive success (0.41 + 0.11 and 0.54 ± 0.11 respectively) were similar each season. There was no significant difference between the proportion of eggs laid, or eggs hatched and chicks fledged, between the two seasons. The mean number of chicks raised over the two seasons was 0.94 ± 0.05 per nest. Replacement clutches were laid by 11 per cent of failed breeders in each season, but only in 1996 were they successful in fledging chicks.

No significant difference was found between the breeding success of the Matiu‐Somes Island blue penguin colony recorded during this study and a previous study undertaken on the island 40 years ago.     

四川南充市区珠颈斑鸠的繁殖生态学和巢址选择

2002年11月~2004年4月在四川省南充市区内对珠颈斑鸠(Streptopelia chinensis)繁殖生态和巢址选择进行了研究。结果表明:珠颈斑鸠3月初开始求偶交配,求偶行为复杂,有“婚飞”行为;雌雄参与筑巢,营巢期7~8 d。影响巢址选择的主要因素有6种:栖位与巢周隐蔽因子、巢下隐蔽因子、光照因子、人为活动因子、食物因子和营巢树因子;窝卵数2枚,雌雄轮流孵卵,孵卵期17~18 d,孵化率86.67%;雌雄均参与育雏,育雏期18~20 d,雏离巢率73.08%,繁殖生产力1.82,种群育雏高峰期为7月和8月中上旬。     

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.     

Reproductive tactics of the ringed plover Charadrius hiaticula

Reproductive tactics of ringed plovers Charadrius hiaticula were studied at three localities in SW Sweden during five seasons. The usual clutch size is four, but removal experiments showed that females can produce five eggs in succession, with similar intervals between all eggs. High predation made mean breeding success per clutch low, 6.3% of eggs resulting in fledged young. Replacement clutches were common, and many pairs laid again after rearing their first brood to fledging. Egg laying spanned three months, much longer than for other waders in this region. Between years, reproductive success varied unpredictably with time of the season, but averaged over several years, the expected success was low and similar for the different parts of the breeding season. Chicks from late clutches had similar survival and recruitment as others. Because of the long breeding season and high rate of nest failure a female may produce up to five clutches of four eggs per season, containing in total about 3.7 times her own mass. Yearly local survival of adult females and males was estimated to 84.6 and 88.6%, respectively. Ability to produce many clutches with similar expected success throughout the season favours a long reproductive period, sometimes leading to double-brooding. Possible life-history trade-offs are discussed.     

THE BIRDS OF LANGEBAAN LAGOON

Data are presented on breeding success of Red Bishops (Euplectes orix) collected over four breeding seasons at a colony in the Addo Elephant National Park, Eastern Cape, South Africa. Overall hatching and fledging success were 53.8% and 26.0% of all eggs laid, respectively, and the overall mean number of fledglings per breeding attempt was 0.77. Hatching and fledging success varied significantly among seasons, with both clutch and brood losses due to predation being the main reason for the observed differences. Hatching success also differed significantly among clutch sizes, being highest for four-egg clutches (63.2%), intermediate for three-egg clutches (55.5%) and lowest for two-egg clutches and five-egg clutches (33.2% and 34.3%, respectively). However, fledging success was not significantly different among clutch sizes. The mean number of fledglings per breeding attempt was 0.44 for two-egg clutches, 0.80 for three-egg clutches, 1.10 for four-egg clutches, and 0.57 for five-egg clutches. The height of accepted nests (i.e.nests in which at least one egg was laid) was significantly lower than the height of nests not accepted. In addition, accepted nests in which eggs hatched and young fledged were significantly lower than accepted nests in which no eggs hatched and no young fledged. These overall effects of nest height on nest acceptance and hatching and fledging success were, however, due only to nests built above water, since no such effects were found when nests built above ground (i.e.on dry land) were analysed separately. I detected no effect of nest coverage on the probability of a nest being accepted, nor was there any effect of nest coverage on hatching or fledging success. Nests above water were significantly more likely to be accepted than nests above ground; however, hatching and fledging success of nests that were accepted did not differ significantly between nests built above water and those built above ground.     

The breeding biology of the Pacific Swallow Hirundo tahitica in Malaysia

The breeding biology of the Pacific Swallow was studied in Malaysia. Time-budgets and preliminary energy-budgets were calculated for different stages of the breeding cycle. Breeding was seasonal, the first eggs were laid in the first week of March from 1978 to 1982. The nest was a mud cup built under an overhang, often on man-made structures over water. The mean clutch size was 2.98 eggs. So more than two successful clutches were ever raised, although up to four sets of eggs can be laid if clutches are lost. The incubation period was 16.2 days and the nestling period 19–21 days. Nestling weights showed the typical hirundine recession before fledging. The mean brood size was 2.32 and there was no evidence of undernourishment in larger broods. Nesting success was lower than for temperate hirundines but high for a tropical passerine. Incubation duties were carried out by the female alone but both parents fed the brood. The male never delivered more than 44% of the total feeds. Daily energy expenditure varied from 3.44–4.9×BMR depending upon the stage of the breeding cycle.     

THE BREEDING BIOLOGY OF AN URBAN POPULATION OF ROCK PIGEONS COLUMBA GUINEA

Elliott, C. C. H. & Cooper, J. 1980. The breeding biology of an urban population of Rock Pigeons Columba guinea. Ostrich 51:198-203.

The breeding biology of the Rock Pigeon Columba guinea was studied for three seasons from 1972 to 1975 at the University of Cape Town, southwestern Cape, South Africa. Nests were visited at approximately weekly intervals. The breeding season (September to February) coincided with the end of the winter rainy season and the presence of cereal crops. Clutch size was two eggs in 99% of cases. Mean incubation period was 14,8 days. Incubation was shared as two continuous shifts per day. Growth rate was similar to that in other studies. The mean nestling period was 23,6 days. Second broods after the successful departure of chicks were frequent, the interval between nest departure and re-laying being as little as five days. Hatching success was 66%, chick rearing success 83% and overall breeding success 49%, similar to other Columba pigeons. It is suggested that the production of pigeon's milk is the limiting factor controlling the invariable clutch size.     

Relationship between breeding activity and rainfall for Swainson's Spurfowl,Pternistis swainsonii,within southern Africa,with specific reference to the Springbok Flats,Limpopo Province,South Africa

We collated the literature available on the breeding activity of the Swainson's Spurfowl Pternistis swainsonii and made use of reliable unpublished reports, nest record cards and field observations within the Springbok Flats, Limpopo Province, South Africa to establish breeding seasons and pairing behaviour. The onset of breeding (egg laying) is closely associated with rainfall, with male gonad development, population density and covey size (pairing behaviour), all correlated with rainfall. Peak breeding activity is from January–April in South Africa, February–May in Zimbabwe and March–June in Botswana. Egg laying has been recorded in all months and sporadic egg laying in the winter months is most likely the result of isolated rainfall. Mean clutch size is 5.2 eggs/hen (n = 140) with an incubation period of 23 days and brood hatching success and chick survival of 69.4% over the southern African sub-region. Current hunting seasons within Limpopo Province are in line with the recommended hunting season for this region and should remain unchanged: 15 June–30 September. The success of this phasianid can be attributed to its extended breeding season, high survival rate of hatchlings and the potential of birds to breed within their first year.     

Weight change and the body reserves of female blue tits, Parus caeruleus, during the breeding season

A female blue tit lays a large clutch that is commonly heavier than her own body weight. Body reserves cannot provide for the entire clutch and little is known of the importance of these reserves during the breeding season. This study reports on weight changes in adult female blue tits during the breeding season, observed by the use of electronic balances. In addition, data from dissecting 67 adult female blue tits, at different stages of the breeding cycle, were used to investigate the changes in body weight. There was a rapid increase in body weight during a period of 4–5 days before the first egg was laid, which was explained mostly by the development of the oviduct and the production of an egg on the final day. Body weight remained constant during the laying period, before decreasing by approximately one gram after clutch completion, owing to the absence of an egg and the absorption of the oviduct. Body reserves increased during the day after clutch completion, were maintained throughout the incubation period and were mobilized during the first five days of the nestling period. Breeding female blue tits appear to deposit small body reserves to act as a short-term buffer against adverse conditions or to support the brooding phase.     

Body condition dynamics and the cost‐of‐delay hypothesis in a temperate‐breeding duck

Pre‐breeding body condition is an important determinant of reproductive success in birds, largely through its influence on timing of breeding. Declines in clutch size and recruitment probability within breeding seasons indicate a tradeoff may exist between the number of young (clutch size) and quality of young (recruitment probability). We explored local drivers of pre‐breeding body condition and tested predictions of the cost‐of‐delay hypothesis in female lesser scaup Aythya affinis. Yearling females arrived on the study site in lower body condition than older females, but both age classes had similar rates of body condition gain on the breeding grounds prior to nesting. Rates of body condition gain were positively influenced by water temperature, a proxy for wetland phenology. The effect of water level was asymptotic and interacted with water temperature, with greater rates of gain in body condition occurring in years with low water levels. Our results supported the predicted response of clutch size to the rate of pre‐breeding body condition gain. After accounting for lay date, clutch size was positively related to the rate of body condition gain (= 0.08 ± 0.039). We did not find support for a predicted interaction between rate of body condition gain and intra‐seasonal decline in clutch size (= 0.01 ± 0.01). Our results indicate that local conditions during pre‐breeding influence body condition dynamics in female lesser scaup, which subsequently affects clutch size.     

Breeding biology aspects of spotted flapshell Turtle,Lissemys punctata (Lacepede 1788), in Bangladesh

This study was conducted to determine the breeding season, gonadal development, egg laying period, clutch size and other biological aspects of spotted flapshell turtle, Lissemys punctata, of Bangladesh between January 1997 and December 2001. The egg laying period of L. punctata, was found between August and March. The nesting sites were elevated fallow lands in secluded areas. The female turtle laid all the mature eggs at a time for each clutch at night. A gravid female turtle laid three clutches of eggs in each year and the mean clutch size was 13.0 ± 1.9 eggs and mean weight of each egg was 10.3 ± 1.3 g. The eggs are spherical in shape and whitish in color. The mean incubation period was 173 ± 34 days (range 119–225 days). The incubation period of first clutch was the longest than the second and third clutches. Hatching success was found 41%. Maximum hatching was observed in June. The present investigation was made to explore the possibility to raise turtle farming in captive condition. The findings would, hopefully, help to rear the species and to assess the commercial potentiality of turtle farming in captive condition, that is, in the eco-climatic condition of Bangladesh.     

On a Poorly Known Rookery of Green Turtles (<Emphasis Type="Italic">Chelonia mydas</Emphasis>) Nesting at the Chabahar Beach,Northeastern Gulf of Oman

There is a poorly known rookery of green turtles (Chelonia mydas) nesting in sandy beaches of Chabahar town, northeastern Gulf of Oman, Iran.This study has been carried out to evaluate nesting activity of this small rookery in 2014 nesting season (June to October). In this study, total clutches were collected and transferred to an artificial hatchery. The peak of nesting occurred from the third parts of August to the end of September. Mean CCL was 106.3 ± 6 cm and mean CCW was 94.5 ± 5 cm. Females laid on average of 99.42 ± 47.8 eggs per clutch. The mean inter-nesting interval was 18.5 days. The observed clutch frequency was 3.4. Mean hatching success was 36.63 ± 4.1%. The incubation period was 61.07 ± 5.4 days. Nest status evaluation represented that major causes for the failure was unhatched egg with no obvious embryo followed by unhatched eggs with obvious but undeveloped embryos > unhatched eggs with developed embryos > hatched eggs but dead embryos. The results achieved in this study are a valuable contribution to cognition of the reproductive ecology of the green turtle population globally and regionally.     

Female coloration indicates female reproductive capacity in blue tits

It is poorly understood whether female morphological and behavioural traits can be used as 'signals'. In particular, experimental tests of the hypothesis that female ornaments reflect quality are scarce. Here, we experimentally examine whether female plumage coloration might signal maternal quality in the blue tit, Cyanistes caeruleus by forcing half of the females breeding in our population to produce a replacement clutch. Using statistical models that controlled for the effects of male coloration, and the effects of age and condition of both parents, we found that carotenoid-based female coloration was positively linked to key proxies of bird lifetime reproductive success: clutch size, fledgling success and recruitment. Importantly, the relationships between maternal yellow carotenoid coloration and both clutch size and recruitment were stronger in the experimental group than in the control group, indicating that breeding females with higher values of yellow coloration were better able to handle the cost of producing a second clutch. Finally, UV-blue female coloration was positively linked to female survival and marginally linked to laying date. Taken together, these results show for the first time in a natural population that female coloration can indicate individual and maternal quality under natural and adverse reproductive conditions. They highlight the potential for the evolution of female ornamental traits through sexual selection.     

栗苇(升鸟)繁殖生态的初步研究

关于栗苇(升鸟)(Ixobrychus cinnamomeus)繁殖生态的研究,国内只有过零星的报道(寿振黄,1936;郑作新等,1959),资料较缺乏。我们于1972—1974年5—10月,在太原市西里解村汾河畔(海拔760米),对栗苇(升鸟)的繁殖生态进行了调查研究。1981年6—7月在代县西旺村滹沱河滩(海拔880米)又作了补充调查。现将资料整理报道。     

Population growth confounds phylogeographic inference in Namaqua sandgrouse

The Namaqua sandgrouse, Pterocles namaqua, is a highly nomadic granivore of semiarid to arid habitats. As a result of nomadic movements in response to rainfall, the size of the breeding population in any one area fluctuates dramatically between breeding seasons. This high mobility in response to spatial and temporal abundance of food resources is expected to result in little population genetic structuring. Namaqua sandgrouse also shows a seasonally predictable partial migration between the southeast and northwest regions of South Africa, and a further possible north-south migration between southwestern South Africa and central Namibia. It is unclear whether birds migrating between these regions breed in only one or both regions. If populations breed in only one region of their migratory range, then population genetic structuring is predicted to occur. This study addresses Namaqua sandgrouse movements with the analysis of mitochondrial DNA control region sequences. In general, little population genetic structure was evident, yet strong signals of population growth were detected. Several populations have private alleles, which is in direct contradiction to the spatial genetic pattern expected under high levels of gene flow. We suggest that the inference of high levels of female gene flow could be an artifact of population growth and that additional loci will allow a greater understanding of Namaqua sandgrouse movements.