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

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.

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

Avian Research ◽

10.1186/s40657-021-00249-6 ◽

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.

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

Ornis Norvegica ◽

10.15845/on.v43i0.2977 ◽

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.

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Clutch Enlargement in Lesser Gray Shrikes (Lanius Minor) in Slovakia When Food is Superabundant: A Maladaptive Response?

The Auk ◽

10.1093/auk/121.2.557 ◽

2004 ◽

Vol 121 (2) ◽

pp. 557-564

Author(s):

Herbert Hoi ◽

Anton Kristin ◽

Francisco Valera ◽

Christine Hoi

Keyword(s):

Clutch Size ◽

Egg Laying ◽

Laying Date ◽

Breeding Ecology ◽

Long Distance ◽

Fledging Success ◽

Melolontha Melolontha ◽

Nestling Diet ◽

Study Population ◽

Maladaptive Response

Abstract Food abundance influences various aspects of birds' breeding ecology, such as onset of laying, clutch size, and reproductive success. Here, we examine the effects of a natural superabundance of food—cockchafers (Melolontha melolontha, Coleoptera)—on nesting success of a monogamous long-distance migrant, the Lesser Gray Shrike (Lanius minor). In that species, cockchafers make up 88% of adult and 48% of nestling diet in years with cockchafer outbreaks. We compared timing of egg laying, clutch size, and fledging success in three years and chick development in two years with and without cockchafer outbreaks. In cockchafer years, laying date was advanced by about one day, clutch size increased by about one egg, and heavier chicks were produced. Fledging success, however, did not change (fledgling number in non-cockchafer years: 5.3 ± 0.2, 5.0 ± 0.2, and 4.0 ± 0.5; in cockchafer years: 4.1 ± 0.7, 5.4 ± 0.2, and 4.2 ± 0.5), because more eggs failed to hatch during cockchafer years. Thus, increased clutch size in periods of superabundant food do not always result in increased fledgling production. Limited incubation ability or intrinsic physical egg properties, resulting in inefficient incubation, are the most likely explanations for increased hatching failure in years of food superabundance in our study population of Lesser Gray Shrikes.

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

Journal of Bioresource Management ◽

10.35691/jbm.4102.0010 ◽

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.

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Maguari Stork Nesting: Juvenile Growth and Behavior

The Auk ◽

10.2307/4086908 ◽

1984 ◽

Vol 101 (4) ◽

pp. 812-823 ◽

Cited By ~ 8

Author(s):

Betsy Trent Thomas

Keyword(s):

South America ◽

Clutch Size ◽

Breeding Biology ◽

Brood Reduction ◽

Juvenile Growth ◽

Fledging Success ◽

Wide Range ◽

The Mean ◽

And Behavior ◽

Tropical South America

Abstract Although it has a wide range in tropical South America, the Maguari Stork (Ciconia maguari) is poorly known. In an 11-yr study of its breeding biology in the llanos of Venezuela I found the mean clutch size for 3 yr to be 3.2 eggs. The young hatched asynchronously at 29-32 days and usually made their first flight at 60-72 days. Data on egg sizes, weights, and a probable dump egg are given. The weight and growth of two siblings, plumage succession, and nestling and fledgling behaviors are described. The fledging success of eggs from 55 nests, over 9 yr, was 61%. Loss of eggs (presumably from snake predation) was higher than nestling loss. Although the asynchronously hatched young in a clutch varied greatly in weight and continued this difference throughout nestling life, no case of brood reduction was found in 123 nests during the study. Nestlings were fed mainly frogs and tadpoles, fish, eels, and aquatic rats; food classes and food sizes brought by adults varied with the age of their young. Maguari Stork nestlings do not grasp with their hallux and so are confined to their nests until they can fly. I suggest that the two black plumages of nestlings, between the white hatching down and the white first basic plumage, are for crypsis of the nest-bound young.

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Reproductive suppression in female cooperatively breeding cichlids

Biology Letters ◽

10.1098/rsbl.2008.0365 ◽

2008 ◽

Vol 4 (6) ◽

pp. 606-609 ◽

Cited By ~ 27

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.

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

Bird Conservation International ◽

10.1017/s095927091700048x ◽

2017 ◽

Vol 28 (4) ◽

pp. 606-619 ◽

Cited By ~ 1

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.

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From individual to population level: Temperature and snow cover modulate fledging success through breeding phenology in greylag geese (Anser anser)

Scientific Reports ◽

10.1038/s41598-021-95011-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Didone Frigerio ◽

Petra Sumasgutner ◽

Kurt Kotrschal ◽

Sonia Kleindorfer ◽

Josef Hemetsberger

Keyword(s):

Ambient Temperature ◽

Reproductive Output ◽

Population Level ◽

Egg Laying ◽

Future Research ◽

Breeding Phenology ◽

Anser Anser ◽

Fledging Success ◽

Average Annual Temperature ◽

Greylag Geese

AbstractLocal weather conditions may be used as environmental cues by animals to optimize their breeding behaviour, and could be affected by climate change. We measured associations between climate, breeding phenology, and reproductive output in greylag geese (Anser anser) across 29 years (1990–2018). The birds are individually marked, which allows accurate long-term monitoring of life-history parameters for all pairs within the flock. We had three aims: (1) identify climate patterns at a local scale in Upper Austria, (2) measure the association between climate and greylag goose breeding phenology, and (3) measure the relationship between climate and both clutch size and fledging success. Ambient temperature increased 2 °C across the 29-years study period, and higher winter temperature was associated with earlier onset of egg-laying. Using the hatch-fledge ratio, average annual temperature was the strongest predictor for the proportion of fledged goslings per season. There is evidence for an optimum time window for egg-laying (the earliest and latest eggs laid had the lowest fledging success). These findings broaden our understanding of environmental effects and population-level shifts which could be associated with increased ambient temperature and can thus inform future research about the ecological consequences of climate changes and reproductive output in avian systems.

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

University Journal of Zoology Rajshahi University ◽

10.3329/ujzru.v31i0.15397 ◽

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

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Factors influencing fledgling production in little penguins (Eudyptula minor)

Wildlife Research ◽

10.1071/wr03071 ◽

2004 ◽

Vol 31 (3) ◽

pp. 339 ◽

Cited By ~ 3

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.

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