scholarly journals Nestling Development of Jackdaws Corvus monedula in Agricultural Landscape

2015 ◽  
Vol 39 (1) ◽  
pp. 4-23
Author(s):  
Piotr Kamiński ◽  
Leszek Jerzak ◽  
Joerg Boehner
Keyword(s):  
Mortality Rate ◽  
Ambient Temperature ◽  
Clutch Size ◽  
Agricultural Landscape ◽  
Hatching Success ◽  
Egg Laying ◽  
Point Of View ◽  
Ne Poland ◽  
Temperature And Precipitation ◽  
Nestling Development

Abstract A Jackdaw colony of over 200 nests, built in cavities of old willow trees along 3 km of a small road running through meadows next to the river Narew in an agricultural landscape (15 km southwest of Białystok, NE Poland), was studied to determine nest locations and construction, onset of egg laying, incubation period, egg parameters, clutch size and hatching success, nestling growth and mortality, breeding success as well as predation. The onset of laying and clutch size were correlated with ambient temperature and precipitation (p < 0.001). Hatching success was also determined by these environmental factors as well as by the degree of predation (p < 0,001). There was a statistically significant correlation between clutch size and hatching success (p < 0.001) as well as fledging success (p < 0.001). Nestlings hatching first or second grew faster, reached a higher body weight, and had a lower mortality rate than those hatching last or second to last. There was also a statistically significant correlation between nestling survival and clutch size as well as ambient temperature (p < 0.001 each). Nestling mortality caused by predators, i. e. mainly by martens Martes foina and domestic cats Felis domestica, was high in periods of intensive burning of the meadows surrounding the Jackdaw colony. However, mortality rate of the youngest nestlings was almost 100% lower in periods of high predation compared to times of low predatory activity. Several groups of insects constituted a high amount of nestling food, e. g. 60% of all Orthoptera occurring in the meadows next to the breeding colony. In that area the total dry body mass of phytophagous invertebrates amounted to 1.4-2.0 g per m2, of which 0.3 g were fed to the nestlings. The percentage of zoophagous invertebrates delivered to the offspring was high with about 30-35%. From an economical point of view, Jackdaws during the breeding season are advantageous in an agricultural landscape because they reduce pest insects significantly while consuming only an insignificant amount of all seeds applied.

Variation in incubation length and hatching asynchrony in Eastern Kingbirds: Weather eclipses female effects

The Auk ◽  
2021 ◽  
Author(s):  
Samantha M Gillette ◽  
Amanda L Klehr ◽  
Michael T Murphy
Keyword(s):  
New York ◽  
Clutch Size ◽  
Egg Laying ◽  
Hatching Asynchrony ◽  
Ambient Temperatures ◽  
Temperature And Precipitation ◽  
Incubation Periods ◽  
Tyrannus Tyrannus ◽  
Eastern Kingbird ◽  
Small Clutch

Abstract Incubation length and hatching asynchrony are integral elements of the evolved reproductive strategies of birds. We examined intra- and interpopulation variation in both traits for Eastern Kingbird (Tyrannus tyrannus) populations from New York (NY), Kansas (KS), and Oregon (OR) and found that both incubation length and hatching asynchrony were not repeatable among females, after controlling for a repeatable trait, clutch size. Instead, incubation length and clutch size were influenced by ambient temperature and precipitation. Incubation length exhibited the same median (15 days) and range (13–17 days) at all sites. Model selection results indicated that incubation periods for the smallest and largest clutches were longer in NY than KS when rain was frequent throughout incubation, in replacement nests, and likely when ambient temperatures were low during egg-laying. Full hatching usually required 2 days (but up to 3), with synchronous hatching associated with small clutch sizes, short incubation periods, frequent rain during the egg-laying period, and low ambient temperatures during the first half of incubation. Nestling starvation was uncommon (5–9% of nestlings monitored) and not associated with greater hatching asynchrony. These results indicate that while clutch size, a repeatable female trait, contributed to variation in incubation length and hatching asynchrony in Eastern Kingbirds, weather was a greater source of variation, especially for incubation length.

Reproduction du Grand Cormoran (Phalacrocorax carbo) et du Cormoran à aigrettes (P. auritus) aux îles de la Madeleine, Québec

1983 ◽  
Vol 61 (3) ◽  
pp. 524-530 ◽  
Author(s):  
Christian Pilon ◽  
Jean Burton ◽  
Raymond McNeil
Keyword(s):  
Mortality Rate ◽  
Clutch Size ◽  
Hatching Success ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Different Types ◽  
Nesting Sites ◽  
The Mean ◽  
Great Cormorants ◽  
La Madeleine

The Great Cormorant (Phalacrocorax carbo) and the Double-crested Cormorant (P. auritus) on the Magdalen Islands (Québec) nest in different types of habitat; all Great Cormorants nest on the ground either on cliff ledges or on the flat tops of rocky islands, while all Double-crested Cormorants nest in coniferous trees. No mixed colonies were seen in 1977 and 1978. Most Great Cormorants laid their eggs some 10 days before the Double-crested Cormorants. The mean clutch size was 4.4 for the Great Cormorant in 1978 and 3.2 and 3.6 for the Double-crested Cormorant in 1977 and 1978. The hatching success was similar for both species, 69.2% for the Great Cormorant in 1978 and 74.5 and 71.8% for the Double-crested Cormorant in 1977 and 1978. Great Cormorant chicks had a higher mortality rate mainly during their first 2 weeks of like. This resulted in a similar ratio of young fledged for both species of cormorant, about 2.0 fledglings per clutch for the Great Cormorant and 2.1 and 2.4 fledglings per clutch for the Double-crested Cormorant in 1977 and 1978. The greater mortality rate of young Great Cormorants reflects differences in nesting sites' conditions.

scholarly journals Nest characteristics and breeding success of Black Kites (Milvus migrans migrans) in the High Plateau (Algeria)

2019 ◽  
Vol 29 (2) ◽  
pp. 79-85
Author(s):  
Sarra Messabhia ◽  
Ettayib Bensaci ◽  
Salah Telailia ◽  
Abderraouf Chouaib Rebbah ◽  
Menouar Saheb
Keyword(s):  
Clutch Size ◽  
Hatching Success ◽  
Egg Laying ◽  
Breeding Ecology ◽  
Nearest Neighbour ◽  
Breeding Parameters ◽  
Milvus Migrans ◽  
Black Kite ◽  
The Mean ◽  
The Mediterranean Basin

The breeding ecology of the Black Kite Milvus migrans migrans in Algeria was first studied in 2014 and 2015 on Tarf Mountain in the semi-arid High Plateaus region. The nearest-neighbour nest distance was found to range from 130 to 550 m for colonial pairs and from 1,730 to 2,390 m for the solitary ones. All 12 monitored nests were placed on cliffs at different heights ranging from 149 to 155 m. The mean egg laying period was 15 days, and the mean clutch size was 2.83 ± 0.31 and 3 ± 00 eggs per nest in 2014 and 2015, respectively. The mean hatching success was 83% and that of fledging 75%. Only 2 nests were predated. Our results disagree with those of the previous studies that were carried out mainly in the Mediterranean basin and Asia, differing in such nest characteristics as the nearest - neighbour nest distance, cliff and nesting heights, egg laying period and hatching success. Otherwise, no consistent differences in clutch size and fledging success were revealed. Finally, we determined that Black Kites tend to build their nest on the eastern side of cliffs. However, our analysis showed no effect of nest placement on breeding parameters and success.

scholarly journals Reproductive Parameters and Productivity of the Yellow-Shouldered Parrot on Margarita Island, Venezuela: a Long-Term Study

The Condor ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 178-192 ◽  
Author(s):  
Virginia Sanz ◽  
Adriana Rodriguez-Ferraro
Keyword(s):  
Clutch Size ◽  
Human Disturbance ◽  
Hatching Success ◽  
Reproductive Potential ◽  
Reproductive Investment ◽  
Egg Laying ◽  
Reproductive Parameters ◽  
Term Study ◽  
Long Term Study

AbstractWe studied the breeding biology of the Yellow-shouldered Parrot (Amazona barbadensis) on Margarita Island from March-August, 1990 to 1999. The timing of the different phases (egg-laying, hatching, fledging) was consistent over the years, except during 1998 when all phases were delayed. The average clutch size was 3.38 ± 0.78 eggs per nest, with a range of one to five eggs per clutch, and most eggs survived until hatching (3.36 ± 0.80 eggs per nest). Total clutch size and hatching success of this species on Margarita Island are among the highest in the genus Amazona, suggesting the Yellow-shouldered Parrot has a higher reproductive potential than other species of the genus. We detected interannual differences for some of the reproductive parameters, all in 1998, a year with an extreme drought. Egg losses totaled 20% and were caused by hatching failure, predation, and human disturbance. Forty-nine percent of nestlings were lost, mainly due to poaching. The number of fledglings per nesting pair averaged 1.27 ± 1.61, but varied greatly among years. Thus, in relation to the average total clutch laid, each pair lost an average of 62% of its initial reproductive investment.

Territorial Distribution of Alcohol and Drug Addictions Mortality Concerning Regional Disparities in the Slovak Republic from Year 1996 to Year 2015

2020 ◽  
Keyword(s):  
Mortality Rate ◽  
Slovak Republic ◽  
Regional Disparities ◽  
Point Of View ◽  
Extreme Position ◽  
Data Set ◽  
Female Sex ◽  
Male Sex ◽  
The Individual ◽  
High Level

BACKGROUND: This paper deals with territorial distribution of the alcohol and drug addictions mortality at a level of the districts of the Slovak Republic. AIM: The aim of the paper is to explore the relations within the administrative territorial division of the Slovak Republic, that is, between the individual districts and hence, to reveal possibly hidden relation in alcohol and drug mortality. METHODS: The analysis is divided and executed into the two fragments – one belongs to the female sex, the other one belongs to the male sex. The standardised mortality rate is computed according to a sequence of the mathematical relations. The Euclidean distance is employed to compute the similarity within each pair of a whole data set. The cluster analysis examines is performed. The clusters are created by means of the mutual distances of the districts. The data is collected from the database of the Statistical Office of the Slovak Republic for all the districts of the Slovak Republic. The covered time span begins in the year 1996 and ends in the year 2015. RESULTS: The most substantial point is that the Slovak Republic possesses the regional disparities in a field of mortality expressed by the standardised mortality rate computed particularly for the diagnoses assigned to the alcohol and drug addictions at a considerably high level. However, the female sex and the male sex have the different outcome. The Bratislava III District keeps absolutely the most extreme position. It forms an own cluster for the both sexes too. The Topoľčany District bears a similar extreme position from a point of view of the male sex. All the Bratislava districts keep their mutual notable dissimilarity. Contrariwise, evaluation of a development of the regional disparities among the districts looks like notably heterogeneously. CONCLUSIONS: There are considerable regional discrepancies throughout the districts of the Slovak Republic. Hence, it is necessary to create a common platform how to proceed with the solution of this issue.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

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.

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

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.

THYROID ACTIVITY AND OXIDATIVE METABOLISM IN A SPECIES OF GECKO (HEMIDACTYLUS FLAVIVIRIDIS RÜPPELL) IN RELATION TO SEX HORMONES

1974 ◽  
Vol 63 (1) ◽  
pp. 191-199 ◽  
Author(s):  
ASHA CHANDOLA ◽  
D. SURESH KUMAR ◽  
J. P. THAPLIYAL
Keyword(s):  
Thyroid Function ◽  
Oxidative Metabolism ◽  
Egg Laying ◽  
Point Of View ◽  
Phylogenetic Position ◽  
Physiological Importance ◽  
Functional Aspects ◽  
Energy Consuming ◽  
Metabolic Activities ◽  
Hemidactylus Flaviviridis

SUMMARY Orchidectomy in Hemidactylus flaviviridis led to significant reduction of thyroidal 131I uptake, thyroidal content of thyroxine, plasma protein-bound iodine and oxygen consumption of isolated liver and skeletal muscle (at 30 °C). Administration of testosterone to orchidectomized lizards restored these parameters to normal levels. Dependence of thyroid function and oxidative metabolism on male hormone may be a general feature in reptiles. This hormone may, therefore, be of greater physiological importance in these animals than in other vertebrates. Since reptiles occupy a crucial phylogenetic position in the animal kingdom these findings are important from the point of view of evolution of the functional aspects of hormones in vertebrates. The results also show that thyroid function is inhibited by oestrogen(s) in this lizard. This may be an adaptive compensatory measure to control (through effects of the thyroid on metabolic activities) the extra expenditure of energy usually associated with such energy-consuming functions as ovulation and egg-laying.

Sign in / Sign up

Export Citation Format

Share Document