scholarly journals Environmental conditions during winter predict age- and sex-specific differences in reproductive success of a trans-Saharan migratory bird

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
C. López-Calderón ◽  
K. A. Hobson ◽  
A. Marzal ◽  
J. Balbontín ◽  
M. Reviriego ◽  
...  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Cynthia Reséndiz-Infante ◽  
Gilles Gauthier

AbstractMany avian migrants have not adjusted breeding phenology to climate warming resulting in negative consequences for their offspring. We studied seasonal changes in reproductive success of the greater snow goose (Anser caerulescens atlantica), a long-distance migrant. As the climate warms and plant phenology advances, the mismatch between the timing of gosling hatch and peak nutritive quality of plants will increase. We predicted that optimal laying date yielding highest reproductive success occurred earlier over time and that the seasonal decline in reproductive success increased. Over 25 years, reproductive success of early breeders increased by 42%, producing a steeper seasonal decline in reproductive success. The difference between the laying date producing highest reproductive success and the median laying date of the population increased, which suggests an increase in the selection pressure for that trait. Observed clutch size was lower than clutch size yielding the highest reproductive success for most laying dates. However, at the individual level, clutch size could still be optimal if the additional time required to acquire nutrients to lay extra eggs is compensated by a reduction in reproductive success due to a delayed laying date. Nonetheless, breeding phenology may not respond sufficiently to meet future environmental changes induced by warming temperatures.


2021 ◽  
Vol 11 (7) ◽  
pp. 3084-3092
Author(s):  
Pablo Capilla‐Lasheras ◽  
Blanca Bondía ◽  
José I. Aguirre

2004 ◽  
Vol 26 (1) ◽  
pp. 45 ◽  
Author(s):  
AD Bilton ◽  
DB Croft

Female reproductive success and the recruitment of offspring to the next generation are key components of animal population dynamics. With an annual commercial harvest of between 13 and 22% of the red kangaroo (Macropus rufus) population, it is increasingly important that these processes are understood. We used data on the reproductive success of 33 free-ranging female M. rufus on Fowlers Gap station in far western New South Wales to determine the expected lifetime reproductive success (LRS) of females within an unharvested population. We also designed a model to generate predictions about female LRS incorporating empirical relationships between a mother?s reproductive success and maternal age, environmental conditions and the sex and survivorship of a previous reproductive attempt. Results from observations on female LRS (calculated from annual weaning rates) and those generated by the model predict that female M. rufus on ?Fowlers Gap? wean, on average, 3.7 young in a lifetime (ranges 0 - 11 and 0 - 20, respectively); representing only 41% of their maximum reproductive potential. Manipulation of initial starting conditions allowed the effect of varying environmental conditions on female LRS to be explored. The condition of the environment when females commence breeding does not appear to significantly affect their overall lifetime reproductive output. However, the occurrence of drought does. Females experiencing two droughts in a lifetime did not live as long and weaned fewer offspring and grandoffspring (from their daughters) than those females experiencing only one drought in a lifetime. In addition to the adverse effect of drought on the reproductive success of female M. rufus in this study, we suggest that, given the relatively high and stable population densities of M. rufus on ?Fowlers Gap?, other mechanisms (acting primarily on juvenile survival) must exist which limit population growth.


2014 ◽  
Vol 286 ◽  
pp. 66-69
Author(s):  
Joanna Stojak ◽  

Forensic entomology uses insects to determine the time, cause and place of death. To this end, two entomological methods are used. The development-based method uses the patterns of insect larvae development under the specific thermal and environmental conditions. The succession-based method analyzes the sequence of insect succession on the body in various environmental conditions. The proper insect species identification is essential in both methods. In this article, the molecular methods of species, age and sex identification are presented such as DNA barcoding or DNA-HRM-PCR.


2020 ◽  
Vol 71 (9) ◽  
pp. 2490-2504 ◽  
Author(s):  
Atsuko Kinoshita ◽  
René Richter

Abstract Many plants synchronize their life cycles in response to changing seasons and initiate flowering under favourable environmental conditions to ensure reproductive success. To confer a robust seasonal response, plants use diverse genetic programmes that integrate environmental and endogenous cues and converge on central floral regulatory hubs. Technological advances have allowed us to understand these complex processes more completely. Here, we review recent progress in our understanding of genetic and molecular mechanisms that control flowering in Arabidopsis thaliana.


Oecologia ◽  
2009 ◽  
Vol 159 (4) ◽  
pp. 859-872 ◽  
Author(s):  
Javier Balbontín ◽  
Anders P. Møller ◽  
Ignacio G. Hermosell ◽  
Alfonso Marzal ◽  
Maribel Reviriego ◽  
...  

2018 ◽  
Vol XI ◽  
pp. 81-90
Author(s):  
Adam Mohr ◽  
Antoni Przybylski ◽  
Małgorzata Zimnicka – Pluskota ◽  
Damian Spieczyński

The paper presents the current methods of management and environmental conditions of the functioning of red deer population on the Wolin Island. The inventory carried out in 2014 using the drive census method revealed the prevalence of stags in the population (0.86 hinds/1stag) and the population density of 225 individuals/1,000 hectares of the forest, whereas harvest conducted in this season showed merely 22 individuals/1,000 hectares. In the analysed seasons before the inventory, harvest was also low (about 10% of the probable actual state) and despite harvesting mainly hinds, it did not curb the population growth. In the years 2006 – 2014, the yearly harvest in the largest hunting district fluctuated within the range of 14.5 to 60.5, x̅=27.0 individuals/1,000 hectares (n=9), while in the remaining four smaller population management units, the average yearly harvest amounted to only 0.2 to 9.8 individuals/1,000 hectares (n=9). The realized rate of population growth determined by the method of summer deer observation in 2015 amounted to 42.2% of the hinds number. Applying the simulation of the model population meeting the parameters indicated in the inventory, the researchers calculated and proposed the optimal indicators of harvesting individual age and sex groups. The proposed model of hunting monitoring and management assumes optimization of environmental conditions, structure and size of the actual population within the next 10 years.


2017 ◽  
Vol 4 (10) ◽  
pp. 170875 ◽  
Author(s):  
L. J. Henderson ◽  
N. P. Evans ◽  
B. J. Heidinger ◽  
K. A. Herborn ◽  
K. E. Arnold

Glucocorticoids, including corticosterone (CORT), have been suggested to provide a physiological link between ecological conditions and fitness. Specifically, CORT, which is elevated in response to harsh conditions, is predicted to be correlated with reduced fitness. Yet, empirical studies show that CORT can be non-significantly, positively and negatively linked with fitness. Divergent environmental conditions between years or study systems may influence whether CORT is linked to fitness. To test this, we monitored free-living blue tits ( Cyanistes caeruleus ) during breeding over 3 years. We quantified foraging conditions during brood rearing, and examined whether they were correlated with parental baseline CORT and reproductive success. We then tested whether CORT predicted fitness. Elevated parental CORT was associated with lower temperatures, greater rainfall and lower territory-scale oak density. Whereas asynchrony with the caterpillar food peak was correlated with reduced nestling mass and fledging success, but not parental CORT. Only low temperatures were associated with both reduced nestling mass and elevated parental CORT. Despite this, parents with elevated CORT had lighter offspring in all years. Contrarily, in 2009 parental CORT was positively correlated with the number fledged. The absence of a direct link between the foraging conditions that reduce nestling quality and elevate parental CORT suggests that parental CORT may provide a holistic measure of conditions where parents are working harder to meet the demands of developing young. As the positive correlation between parental CORT and fledging success differed between years, this suggests that contrasting conditions between years can influence correlations between parental CORT and fitness. Ultimately, as CORT concentrations are intrinsically variable and linked to the prevalent conditions, studies that incorporate environmental harshness will improve our understanding of evolutionary endocrinology.


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