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Structural equation modeling reveals decoupling of ecological and self-perceived outcomes in a garden box social-ecological system
<p><br></p><p>It is well known that green urban commons enhance mental and physical well-being and improve local biodiversity. We aim to investigate how these outcomes are related in an urban system and which variables are ...
Identifying the paths of climate effects on population dynamics: dynamic and multilevel structural equation model around the annual cycle
<p>How environmental factors influence population dynamics in long-distance migrants is complicated by the spatiotemporal diversity of the environment the individuals experience during the annual cycle. The effects of weather on several different aspects of life history have been well studied, but a better understanding is needed on how weather affects population dynamics through the different associated traits. We utilise 77 years of data from pied flycatcher (Ficedula hypoleuca), to identify the most relevant climate signals associated with population growth rate. The strongest signals on population growth were observed from climate during periods when the birds were not present in the focal location. The population decline was associated with increasing precipitation in the African non-breeding quarters in the autumn (near the arrival of migrants) and with increasing winter temperature along the migration route (before migration). The number of fledglings was associated positively with increasing winter temperature in non-breeding area and negatively with increasing winter temperature in Europe. These possible carry-over effects did not arise via timing of breeding or clutch size but the exact mechanism remains to be revealed in future studies. High population density and low fledgling production were the intrinsic factors reducing the breeding population. We conclude that weather during all seasons has the potential to affect the reproductive success or population growth rate of this species. Our results show how weather can influence the population dynamics of a migratory species through multiple pathways, even at times of the annual cycle when the birds are in a different location than the climate signal.</p>...
Will granny save me? Birth status, survival, and the role of grandmothers in historical Finland
<p>Grandmothers play a crucial role in families enhancing grandchild
wellbeing and survival but their effects can be context-dependent, and
the children born in poor conditions are most likely to benefit from the
investments made by helping grandmothers. In this study, we examined,
for the first time, whether grandmothers' presence modified associations
between adverse birth status and survival up to 5 years of age. In
detail, we verified, whether (i) firstborns, (ii) twins, (iii) children born within 24 months after their sibling, and (iv)
children followed by short interval (i.e. their younger sibling was
born within 24 months) survived better when either their maternal,
paternal, or both grandmothers were present. Moreover, we evaluated
whether illegitimate children survived better when the maternal
grandmother was present. We used an extensive and largely pre-industrial
demographic dataset collected from parish population registers kept by
the Lutheran Church of Finland from years 1730–1895. We show that
although grandmother presence cannot mitigate adverse effects of many
poorer birth conditions, grandchildren whose next sibling was born after
a short interval survived better when the maternal grandmother was
present. Taken together, these findings highlight an important role of
grandmothers in compensating the mother's investment in the new baby,
thus enabling overall faster successful reproductive rate of mothers.
Whilst the opportunity for grandmothers to mitigate the risks of adverse
birth statuses is limited, this study does show - through the
beneficial effect on survival for those with a short subsequent birth
interval - that grandmothers can increase their daughters' and their own
reproductive success.</p>...
Lack of anti-predator recognition in a marine isopod under the threat of an invasive predatory crab
The prey naivete hypothesis suggests that the failure of prey to recognize novel predators as a threat is caused by a lack of anti-predator adaptations. We tested this hypothesis in a unique natural setting, where the ...
Socio-cultural similarity with host population rather than ecological similarity predicts success and failure of human migrations
<p><br></p><p>Demographers argue that human migration patterns are shaped by people moving to better environments. More recently, however, evolutionary theorists have argued that people move to similar environments to which ...
Offspring fertility and grandchild survival enhanced by maternal grandmothers in a pre-industrial human society
<p>Help is directed towards kin in many cooperative species, but its nature and intensity can vary by context. Humans are one of few species in which grandmothers invest in grandchildren, and this may have served as an ...
Female-biased sex ratios in urban centers create a “fertility trap” in post-war Finland
<p>Because sex ratios are a key factor regulating mating success and
subsequent fitness both across and within species, there is widespread
interest in how population-wide sex ratio imbalances affect marriage
markets ...
Child volunteers in a women's paramilitary organization in World War II have accelerated reproductive schedules
Understanding how conditions experienced during development affect reproductive timing is of considerable cross-disciplinary interest. Life-history theory predicts that organisms will accelerate reproduction when future ...
Dead or alive: The interplay of grandparental investment according to the survival status of other grandparent types
<p>BACKGROUND According to the kin selection theory, grandparental investment has its evolutionary roots in the individuals’ aim to maximise their inclusive fitness. Owing to an increasing overlap between successive ...