Search results for " nest"
showing 10 items of 81 documents
Exceptional sea turtle nest records in 2011 suggest an underestimated nesting potential in Sicily (Italy)
2012
We report seven nesting events by loggerhead sea turtles in Sicily (Italy) in 2011. In comparison to past records, this number is relatively high and may be at least in part due to an awareness campaign carried out in 2011 to solicit such reports. This suggests that Sicily may host a much higher nesting activity than previously thought and higher monitoring effort is recommended, especially in certain coastal tracts. Sand temperatures and incubation periods indicate that the beaches monitored so far in the southern coast are not optimal for development, resulting in low hatching success, and produce a majority of males. Five 2011 nests and two past nests from the same area had mtDNA haploty…
Geostatistical techniques for runoff mapping: an application to Sicily, Italy
2011
The availability of reliable and long time series of runoff data is fundamental for most of the hydrological analyses and for the assessment and the management of water resources even in condition of global climatic change. However, hydrologic data sets are often characterized by a short duration and also suffer from missing data values, mainly due to malfunctioning of gauging stations for a specific period. In order to overcome this problem and obtain long and continuous runoff time series, different models and methods have been previously developed and proposed. While some models, used to extent the streamflow record, are conceptual, empirical, regressive models based on the rainfall inpu…
Geoestadística en regiones heterogéneas con distancia basada en el coste
2012
El germen de la presente tesis consistió en un problema aplicado, de ingeniería, al que pensamos que la Estadística como disciplina puede contribuir de manera significativa. Concretamente, se trata de la elaboración de mapas acústicos en entornos urbanos. Resuelto habitualmente de una manera determinista y aproximada, la valoración de la incertidumbre de los resultados es extremadamente deficiente en la mayoría de los casos reales. Este problema, siendo de naturaleza espacial, se puede ver como un problema de predicción geoestadística, a partir de un conjunto de observaciones de campo. La dificultad radica en que el fenómeno se sitúa en un entorno urbano, que posee una importante heterogene…
The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)
2020
Abstract Aim: Nest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors—temperature, nest predation and interspecific information utilization—shaping geographical variation in a specific nest structure—hair and feather cover of eggs—and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes …
Breeding success of the Great Tit Parus major in relation to attributes of natural nest cavities in a primeval forest
2015
An overlap in attributes of nest cavities used by Great Tit Parus major across Eurasia suggests similar nest site preferences within the geographical range, although the drivers of these preferences are unclear. To determine whether preferred cavities provide conditions enhancing successful reproduction, we investigated the breeding performance of Great Tits in relation to tree cavity characteristics using data collected during 2008–2011 in primeval conditions (Białowieża National Park, Poland). Here, tree cavities are diverse and superabundant but nesting birds are at risk from a variety of predators. According to expectations, nest losses were high (60 % of Great Tit nests failed), mostly…
Optiski inducētas magnētiskās nestabilitātes magnētiskajos Šķidrumos
2015
Šī maģistra darba mērķis ir izpētīt magnētiskās nestabilitātes plānos ferokoloīdu slāņos, optiski inducējot tajos koncentrācijas režģi un pakļaujot tos ārējam magnētiskajam laukam. Paraugos ierosina temperatūras režģi ar Nd:Yag (λ=532) lāzerstaru inetrferences ainu, kas, savukārt, spēcīga Sorē efekta dēļ inducē paraugos koncentrācijas režģi. Ar He-Ne lāzera staru (λ=633nm), izmantojot hologrāfiskā attēla veidošanās efektu, optiski tiek vizualizēts daļiņu koncentrācijas sadalījums paraugā. Eksperimentos pamanāms kā ferokoloīda slāņa biezums un ārējā magnētiskā lauka virziens ietekmē paraugā optiski inducēto koncentrācijas režģi (t.i. kā mainās nestabilitāšu daba). Tika novērotas konvektīvas …
Ptiliolum marginatum (Aube, 1850) (Coleoptera: Ptiliidae)– gatunek nowy dla Polski z Białowieskiego Parku Narodowego
2021
We present the first record of Ptiliolum marginatum for Poland. The specimens have been extracted from two nests of the wood warbler Phylloscopus sibilatrix in 2020, during investigations of the invertebrate fauna inhabiting bird nests. The samples were collected in the strictly protected part of the Białowieża National Park, in eastern Poland. We provide general information on the geographical distribution of Ptiliolum marginatum in Europe, the state of knowledge of the genus Ptiliolum in Poland, and further documentation including colour photographs of dorsal and ventral habitus, and characteristic features of hind femora and spermatheca of females.
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.
Avoiding perceived past resource use of potential competitors affects niche dynamics in a bird community
2014
Abstract. Background: Social information use is usually considered to lead to ecological convergence among involved con- or heterospecific individuals. However, recent results demonstrate that observers can also actively avoid behaving as those individuals being observed, leading to ecological divergence. This phenomenon has been little explored so far, yet it can have significant impact on resource use, realized niches and species co-existence. In particular, the time-scale and the ecological context over which such shifts can occur are unknown. We examined with a long-term (four years) field experiment whether experimentally manipulated, species-specific, nest-site feature preferences (sy…
Ekonomikas ciklu lejupslīdes fāzes salīdzinājums - politisko lēmumu ietekme uz cikla lejupslīdes un depresijas fāzēm
2019
Pētnieciskā darba tēma ir: ekonomikas ciklu lejupslīdes fāzes salīdzinājums – politisko lēmumu ietekme uz cikla lejupslīdes un depresijas fāzēm. Pētījumā iekļautā problēma ir, līdzšinējo darbību trūkumā, nesasaistot politisko lēmumu nozīmību ar ekonomikas cikliskās attīstības prognozēšanu un svārstību mazināšanu. Pētnieciskā darba mērķis ir izpētīt ekonomikas cikliskās attīstības makroekonomiskās nestabilitātes (ekonomikas lejupslīdes) ietekmējošos faktorus un to mijiedarbību – analizējot galvenos makroekonomikas statistiskos rādītājus un politiski ekonomiskos lēmumus laika posmā no 2005. gada līdz 2018. gadam. Atbilstoši darba mērķim tika izvirzīts izpētes jautājums: Vai pastāv mijiedarbīb…