scholarly journals The Breeding Biology of Pheasant Tailed Jacana, Hydrophasianus chirurgus in Wetlands of Pakistan

2014 ◽  
Vol 1 (2) ◽  
Author(s):  
Zahid Iqbal Khan ◽  
Mohammad Shareef Mughal
Keyword(s):  
Clutch Size ◽  
Egg Laying ◽  
Breeding Biology ◽  
General Behaviour ◽  
Defensive Responses

Pheasant Tailed Jacana, Hydrophasianus chirurgus is an attractive bird sustaining its presence in wetlands of Pakistan during summers. To facilitate conservation, the breeding biology of specific birds was recorded during 2004-07. According to the observations, the clutch size remains between 1-4 eggs, and most of the fertile females laid 2 consecutive clutches to hand over to two different males for hatching and chick rearing. Incubation calculated between 25-29 days hatchability was found to be around 80%. Defensive responses, egg laying, and chick care were observed to better understand the general behaviour of the species.

scholarly journals The breeding biology of the Coal Tit Periparus ater in South Central Sweden

Ornis Svecica ◽  
2013 ◽  
Vol 23 (3–4) ◽  
pp. 151-158
Author(s):  
Karl Gustav Schölin ◽  
Hans Källander
Keyword(s):  
Clutch Size ◽  
Egg Laying ◽  
Breeding Biology ◽  
Fledging Success ◽  
South Central ◽  
Coal Tit ◽  
Mean Size

In a nestbox study started in 1948 and still ongoing, the number of breeding Coal Tits Periparus ater was always low. Here we present data on time of egg laying and its advancement during the last three decades, clutch size, fledging success and proportion of second broods. Laying dates varied between 18 April and 10 May, with an overall mean of 5 May, and advanced by 0.36 days per year during the second half of the study. Mean clutch size was 8.55 (first clutches). A mean of 7.25 young fledged (all first broods) or 7.78 (failed first broods excluded). Second broods (12.6%) were often not checked but seven clutches had a mean size of 7.23 eggs and fledged 6.71 young.

scholarly journals Breeding biology of a relictual Maghreb Magpie (Pica mauritanica) population in Tunisia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aymen Nefla ◽  
Ridha Ouni ◽  
Slaheddine Selmi ◽  
Saïd Nouira
Keyword(s):  
Clutch Size ◽  
Rattus Rattus ◽  
Egg Laying ◽  
Breeding Biology ◽  
Laying Date ◽  
Rank Test ◽  
Detailed Data ◽  
Egg Volume ◽  
Fledging Success ◽  
Relic Population

Abstract Background The Maghreb Magpie (Pica mauritanica) is an endemic North African species. Available knowledge on this species is limited to historic descriptive data with no ecological information provided. Populations continue to dramatically decline in Tunisia, where only one relic population survives. Investigating the breeding biology of this species is essential for conservation purposes. The purpose of this study was to increase our understanding of the Tunisian relic population and provide detailed data on breeding biology over two breeding seasons (2017 and 2018). Methods This study occurred on a private farm of 650 ha, located 10 km from Dhorbania village at Kairouan Governorate, in central Tunisia. Active nests were monitored weekly during egg laying period and twice a week during hatching period. The Ivlev’s electivity index was used to assess whether the frequency of use of nesting trees and bushes matched their availability in the study area. We recorded nest measurements and positions, and compared them using Wilcoxon signed-rank test. Variations of breeding parameters as number of eggs laid, hatchlings, and fledglings over years were performed using Mann–Whitney U-test and χ2 tests. We used a Generalized Linear Mixed Model (GLMM) to investigate how egg volume varied with clutch size and laying date. Results We investigated clutch size, egg size, hatching and fledging success, and evaluated how these parameters varied according to laying date and nest characteristics. Clutch size averaged 5.00 ± 0.19 but was significantly greater in 2017. Hatching success was 2.78 ± 0.34 eggs hatched per nest and fledging success reached 1.69 ± 0.30 young/nest. Causes of nest failure included the depredation of nestlings by shrikes, cobras and rats (e.g. Lanius meridionalis, Naja haje and Rattus rattus), death of parents by the Black-shouldered Kite (Elanus caeruleus) and nest parasitism by the Great Spotted Cuckoo (Clamator glandarius). Clutch size, brood size and fledgling success were unaffected by laying date, nest volume and nest elevation. Egg volume decreased with laying date but was unaffected by clutch. Conclusion Our study provides the first and only detailed data on reproductive parameters of the Maghreb Magpie in its entire geographic range (North Africa). Information gleaned from this study provides valuable information for monitoring and long-term conservation plans of the endangered Tunisian Magpie population. Additionally, our data provide an avenue of large-scale comparative studies of the reproductive ecology of the magpie complex.

scholarly journals Breeding biology and long-term population dynamics of the Pied Flycatcher Ficedula hypoleuca in Skibotn, Northern Norway

2020 ◽  
Vol 43 ◽  
pp. 17-27
Author(s):  
Antero Järvinen
Keyword(s):  
Population Dynamics ◽  
Clutch Size ◽  
Ficedula Hypoleuca ◽  
Egg Laying ◽  
Breeding Biology ◽  
Deciduous Forests ◽  
Pied Flycatcher ◽  
Source Population ◽  
Northern Norway ◽  
Long Run

Abstract. The breeding biology and population dynamics of the Pied Flycatcher Ficedula hypoleuca in pine, mixed and deciduous forests in Skibotn, Northern Norway (69°20’N, 20°20’E), was studied during 33 years (1987–2019; in total 1775 completed first clutches). It was a period during which summer temperatures remained relatively stable, but late spring (May) temperatures tended to become warmer. The number of breeding pairs declined over the study period but varied less than in populations living in more harsh subalpine environments. In spite of the northern location, females started to lay eggs in a relatively late phenological phase of the environment and in relatively warm weather. The date of birch leafing and the date of egg-laying advanced during the study period, and they correlated with each other. Mean clutch size was 6.4 eggs, and mean number of fledglings/nest 4.6. Date of egg-laying was earlier and clutch size larger in deciduous forests than in pine and mixed forests, but this did not translate into better fledgling productivity. The main causes of nesting failure were predation by small mustelids and starvation in warm and dry summers. However, in the long run the population seemed to be able to maintain itself without immigration, i.e., act as a source population. The possibility that during warm climate periods of the past, breeding biology and population dynamics of Pied Flycatchers over large geographical areas might have resembled those in Skibotn is discussed.

scholarly journals Reproductive suppression in female cooperatively breeding cichlids

2008 ◽  
Vol 4 (6) ◽  
pp. 606-609 ◽  
Author(s):  
Dik Heg
Keyword(s):  
Clutch Size ◽  
Group Living ◽  
Egg Laying ◽  
Alloparental Care ◽  
Large Female ◽  
Egg Mass ◽  
Small Female ◽  
Reproductive Suppression ◽  
Cooperatively Breeding ◽  
Female Subordinate

Suppression by dominants of female subordinate reproduction has been found in many vertebrate social groups, but has rarely been shown experimentally. Here experimental evidence is provided for reproductive suppression in the group-living Lake Tanganyika cichlid Neolamprologus pulcher . Within groups of three unrelated females, suppression was due to medium- and small-sized females laying less frequently compared with large females, and compared with medium females in control pairs. Clutch size and average egg mass of all females depended on body size, but not on rank. In a second step, a large female was removed from the group and a very small female was added to keep the group size constant. The medium females immediately seized the dominant breeding position in the group and started to reproduce as frequently as control pairs, whereas clutch size and egg mass did not change. These results show that female subordinate cichlids are reproductively capable, but apparently suppressed with respect to egg laying. Nevertheless, some reproduction is tolerated, possibly to ensure continued alloparental care by subordinate females.

Breeding biology of the Critically Endangered Tahiti MonarchPomarea nigra, a bird with a low productivity

2017 ◽  
Vol 28 (4) ◽  
pp. 606-619 ◽  
Author(s):  
CAROLINE BLANVILLAIN ◽  
THOMAS GHESTEMME ◽  
TEHANI WITHERS ◽  
MARK O’BRIEN
Keyword(s):  
Reproductive Success ◽  
French Polynesia ◽  
Egg Laying ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Tropical Island ◽  
Island Endemics ◽  
Nest Activity ◽  
Considerable Length ◽  
One Year

SummaryWe studied the breeding biology of Tahiti MonarchPomarea nigra, a ‘Critically Endangered’ forest bird endemic to Tahiti (French Polynesia). Nest activity was monitored from 1998 to 2002, and again from 2008 to 2015. During these 12 years, only 2–13 breeding pairs per year produced hatchlings. Egg-laying occurred all year, but usually increased between August and January, peaking around November. Of the 200 nests monitored, 33 (16%) were abandoned shortly after construction, 71 had an egg laid immediately after the nest were completed (34 %) and 96 nests (46 %) had a pre-incubation phase of 18.9 ± 1.9 days (3–62 days;n= 47 nests), during which the birds visited the nest on an irregular basis. Half (49 of 96) of these nests were abandoned before an egg was laid, with incubation subsequently commencing at the remaining nests (n= 47). Although both sexes incubated for an average of 13.6 ± 0.3 days (range 13–15), the female usually spent more time incubating than the male. Only one young per nest was ever observed. The average nestling phase was 15.5 ± 0.7 days (range 13 to 20 days). Parents continue to feed the young after fledging for 74 ± 4.7 days (range 42–174). As with many tropical island endemics, the Tahiti Monarch has low reproductive productivity as indicated by the fact that: 1) only 56% of pairs attempt to lay an egg in any one year, 2) most pairs attempt only one brood per year and 3) the considerable length of the nesting and fledging phases. Because of its low productivity, maximising the reproductive success of the Tahiti Monarch is essential to secure its recovery.

scholarly journals Breeding biology of coppersmith barbet, Megalaima haemacephala (Müller, 1776)

2013 ◽  
Vol 31 ◽  
pp. 31-34
Author(s):  
Noor Jahan Sarker ◽  
M Firoj Jaman ◽  
Shariar Mustafa ◽  
Md Saidur Rahman
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Breeding Success ◽  
Brood Size ◽  
Botanical Garden ◽  
Egg Laying ◽  
Breeding Biology ◽  
Average Weight ◽  
Average Height ◽  
Average Depth

Breeding biology of the Coppersmith barbet, Megalaima haemacephala (Müller, 1776) was carried out between February, 2006 and January, 2007 at Sharawardy Uddyan, Ramna Park, Curzon Hall and National Botanical Garden. The breeding season started from December and ended in June. In total 20 nests were observed, of which 10 nests were studied in details in four study areas. The coppersmith barbet mostly preferred to make holes on the branches of koroi (Albizzia procera) for nesting. Egg laying started on 15th February in the study areas. Average height of nests from the ground was 9.7m and average depth and diameter of the holes was 29.20cm and 4.46cm respectively. New holes were constructed yearly or the old one was reused. Both the sexes took part in incubation of eggs, brooding and feeding to the nestlings. A total of 30 eggs were laid in 10 nests. Clutch size varied from 2 – 4 eggs (average: 3 eggs). Among them, 20 (66.67%) eggs were hatched and the rest 10 (33.33%) were unhatched and lost. Average incubation period was 14 days. The male and the female incubated the eggs for an average of 27.44 minutes/ hours and 32.56 minutes/ hours, respectively. Average number of nestlings (brood size) per nest was 2. Out of 20 nestlings, 16 left their nests successively. The breeding success was 53.33% in relation to the number of eggs laid and 80% in relation to nestlings hatched. The average weight of eggs and nestlings was 3.59g and 9.33g, respectively. The main causes of loss of the eggs and nestlings were human interference, predation and ectoparasitic infections. Insects and fruits were fed to the nestlings by their parents.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15397Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 31-34 

Factors influencing fledgling production in little penguins (Eudyptula minor)

2004 ◽  
Vol 31 (3) ◽  
pp. 339 ◽  
Author(s):  
C. Knight ◽  
T. Rogers
Keyword(s):  
Breeding Season ◽  
Egg Laying ◽  
Breeding Biology ◽  
Single Variable ◽  
Nesting Habitat ◽  
High Quality ◽  
Factors Influencing ◽  
Little Penguin ◽  
Significant Model

An eight-year study was conducted on the breeding biology of the little penguin population at Lion Island. Forwards-selection Poisson regressions were used to determine whether variables such as year, date of lay, years since banding of each parent (indicator of age) and habitat influenced the fledgling numbers and average fledgling weight for adult pairs. 'Date of lay' provided the most significant model of fledgling numbers, while 'habitat' and 'year' as single-variable models also significantly influenced fledgling numbers. 'Date of lay' provided the most significant model of average fledgling weight. Future monitoring of the Lion Island colony therefore should focus on monitoring egg laying at the start of the breeding season, and maintaining high-quality nesting habitat.

Breeding biology of the critically endangered Malherbe's parakeet on Maud Island, New Zealand, following the release of captive-bred individuals

2009 ◽  
Vol 57 (6) ◽  
pp. 433 ◽  
Author(s):  
Luis Ortiz-Catedral ◽  
Jonathan C. Kearvell ◽  
Mark E. Hauber ◽  
Dianne H. Brunton
Keyword(s):  
New Zealand ◽  
Clutch Size ◽  
Captive Breeding ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Limiting Factor ◽  
Early Age ◽  
Small Islands ◽  
Austral Spring ◽  
Nesting Sites

We studied a population of the critically endangered Malherbe’s parakeet (Cyanoramphus malherbi), following the release of 62 captive-bred individuals on Maud Island, New Zealand, to identify and characterise nesting sites in a novel island environment. Previous work on Malherbe’s parakeets consisted of limited observations on remnant mainland populations. The age of breeding pairs on Maud Island was 7.2 ± 4.7 months and included both captive-bred individuals of the first release flock and individuals hatched on Maud Island within a year of the first release. Nests were found in hollows of mamaku (Cyathea medullaris), vacant nests of sacred kingfisher (Todiramphus sanctus), a hole in the ground and a hollow in a kohekohe (Disoxylum spectabile). Active nests were found in the austral spring, summer and autumn. Clutch size was 5 eggs. The fledging of three Malherbe’s parakeets was confirmed for one nest 43 days after hatching. Observations of newly fledged individuals around the island indicate that at least seven successful nesting attempts occurred. Consistent with other studies in Cyanoramphus parakeets, our results suggest that availability of nesting sites on small islands may not be a limiting factor for the establishment of additional populations of Malherbe’s parakeets via captive breeding and translocation. The formation of breeding pairs at an early age, the use of diverse nesting sites in regenerating vegetation, and the evidence of successful breeding shortly after release on an island represent encouraging prospects for the conservation of New Zealand’s rarest parakeet.

Annual variation in common eider egg size: effects of temperature, clutch size, laying date, and laying sequence

1995 ◽  
Vol 73 (9) ◽  
pp. 1579-1587 ◽  
Author(s):  
Gregory J. Robertson
Keyword(s):  
Clutch Size ◽  
Egg Size ◽  
Annual Variation ◽  
Size Variation ◽  
Egg Laying ◽  
Laying Date ◽  
Somateria Mollissima ◽  
Ambient Temperatures ◽  
Common Eiders ◽  
N 93

Annual variation in volumes of eggs laid by common eiders (Somateria mollissima sedentaria) nesting at La Pérouse Bay, Manitoba (58°43′N, 93°27′W), was studied over 3 years (1991–1993). Temperatures during the egg-laying period were higher in 1991 than in 1992 and 1993. However, the eiders began nesting in 1993 at the same time as in 1991, whereas in 1992 the eiders began laying approximately 2 weeks later. Eiders laid significantly smaller clutches in 1992 than in the other 2 years. Egg size did not correlate with clutch size or laying date in any year. However, eiders laid smaller eggs in 1992 and 1993 than in 1991. In five egg clutches, the pattern of intraclutch egg-size variation was different among years. The last laid eggs of five egg clutches were disproportionately smaller in 1992 and 1993 (cold years) than those laid in 1991. Minimum daily temperatures before the egg-laying period (during rapid yolk development) were positively correlated with egg size. However, this effect was not significant when year and egg sequence were controlled for. Egg-size variation was correlated with the overall ambient temperatures during the laying period, whereas annual clutch-size variation was correlated with laying date, suggesting that the proximate mechanisms affecting clutch and egg size are different.

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