Search results for "Nesting"
showing 10 items of 87 documents
Prehatching maternal investment and offspring immunity in the pied flycatcher (Ficedula hypoleuca).
2007
Maternal investment in offspring immunity via egg quality may be an adaptive evolutionary strategy shaped by natural selection. We investigated how maternal investment in eggs can influence offspring immunity by conducting two experiments. First, we manipulated foraging performance of the mothers before egg laying by attaching a small weight to their back feathers. During the nestling period, we investigated offspring total antibody production at the age of 7 days and after antibody challenge, and conducted a partial cross-fostering design to separate the effects of the experiment and rearing-related variation on offspring immunity. In a separate experiment, partial cross-fostering with ant…
Nesting self-employment in education, work and family trajectories of Romanian migrant returnees
2019
Challenging a biased view towards self-employed returnees as neoliberal selves, as the normalized approach of the migration–development nexus tends to depict them, this article builds an alternative conceptual framework to unpack the variegated experiences of migrant returnees’ self-employment trajectories in post-socialist Romania. The authors argue that the overemphasis on the benefits of return migration for origin countries through the skewed focus on the migrants’ accrual of human and financial capital and their ostensible entrepreneurial orientation has resulted in disregarding more influential biographical and cultural aspects. Life story interviews with middle-aged participants reve…
Nest modifications by the acorn ant Temnothorax crassispinus (Hymenoptera: Formicidae)
2019
Many ant species construct nests and during the process considerably influence the environment such as by changing soil structure and creating new habitat for other species. However, other ant species dwell in ready-for-use cavities. Ants of the genus Temnothorax inhabit small cavities such as acorns and under rocks, but under natural conditions, good nest sites are limited resources. During field and laboratory experiments, I studied how the acorn ant Temnothorax crassispinus (Karawajew, 1926) modifies nesting sites. Temnothorax crassispinus is a forest species, which typically lives in cavities in fallen twigs and acorns; colonies usually number from a few dozen to about 200 workers. Alth…
High winter survival rate of acorn ants inside artificial nest sites (Hymenoptera: Formicidae)
2022
Although most species of ants overwinter underground to avoid low temperatures, the acorn ants of the genus Temnothorax remain in nests situated at ground level. During a field experiment, I studied the winter mortality of acorn ants in nest sites situated aboveground, as well as in sites experimentally buried in the soil. Despite the low air temperatures (even reaching –19°C, recorded 1.5 m above the ground), the survivorship was very high: all of the 18 queens used in the experiment survived, while the survival rate of workers was 61.9-100%, and for most colonies it exceeded 95%. The rate of survival in the nest sites aboveground and those experimentally buried in the soil was similar. Su…
Acorn Ants May Create and Use Two Entrances to the Nest Cavity
2021
Many ant species construct large nests that are inhabited by numerous workers, but other species dwell in ready-for-use cavities and live in small colonies. Ants of the genus Temnothorax inhabit small cavities, e.g., in acorns, twigs, and under rocks. Although a preference for nest sites with a narrower entrance is known, recent studies have shown that they also use cavities with wider entrances and may modify the size of such entrances. As good cavities for nest sites are a limited resource, the possibility to modify a potential nest site, including a reduction in the size of the hole, should be a favorable matter for the ants. Through field and laboratory experiments, I studied the acorn …
CO2 EFFECTS ON SPAWNING RATES OF A MEDITERRANEAN NESTING WRASSE
2014
Some aspects of the reproductive behaviour of the ocellated wrasse Symphodus ocellatus (Forsskål 1775) were investigated in wild conditions along a pCO2 gradient. Our results show no differences in the number of females, sneakers and satellite males involved in the spawning phase under two pCO2 conditions. However, the spawning rate of nesting males was negatively affected in high pCO2, whilst exerted a normal reproductive pattern in ambient pCO2.
The 1-way on-line coupled atmospheric chemistry model system MECO(n) – Part 2: On-line coupling with the Multi-Model-Driver (MMD)
2012
A new, highly flexible model system for the seamless dynamical down-scaling of meteorological and chemical processes from the global to the meso-γ scale is presented. A global model and a cascade of an arbitrary number of limited-area model instances run concurrently in the same parallel environment, in which the coarser grained instances provide the boundary data for the finer grained instances. Thus, disk-space intensive and time consuming intermediate and pre-processing steps are entirely avoided and the time interpolation errors of common off-line nesting approaches are minimised. More specifically, the regional model COSMO of the German Weather Service (DWD) is nested on-line into the …
Effects of harvesting timber stands on goshawk nesting in two European areas
2001
We evaluated the effects of harvesting timber stands on goshawk (Accipiter gentilis) nesting in two European areas (central Italy and eastern France), by studying their occupancy and reproductive performance. We found no difference in the productivity of goshawk pairs reproducing in unlogged vs. logged stands. When considering the same nesting stand, before and after timber harvesting, we noted no differences in the number of young per breeding pair nora year effect. We observed that 87.5% of goshawk pairs nesting in logged stands moved away only when the original stand structure was altered by > 30%, and then only to the nearest neighbouring mature stand (maximum distance ca. 1.5 km). The …
Preliminary observation on use of nest boxes in protected areas of Southern Sicily
2011
In this short note we summarize the data self-made nesting in nest boxes in two areas of NATURA 2000 in southern Sicily. The models of nest boxes considered host species during the study the following period: Falco naumanni, Falco tinnunculus, Athene noctua, Strix aluco, Sturnus unicolor, Parus major, Certhia brachydactyla, Corvus monedula, Passer montanus.