The influence of lanscape on nest preferences and behavior of twig nesting Hymenoptera
The occurrence and behavior of insects is significantly affected by the environment they live in. In this thesis, I dealt with the influence of structure of landscape on nesting preferences of Hymenoptera. For this comparison I had chosen to work with twig-nesting Hymenoptera, for which I have placed artificial nest opportunities into four biotopes – heath, edge of a heath, country lanes between fields and field. The studied location is located south of Znojmo near Podyjí national park. Particularly, I have focused on small carpenter bees of genus Ceratina. My results show that there is a big difference in the species distribution between the habitates of field and heath. The habitats of edge of a heath and country lanes make up a gradient between these two biotopes. The ecosystem of fields was preferred by a sphecid wasp Pemphredon lethifer and Ceratina cyanea. On the other hand, the ecosystem of heath was preferred by Ceratina chalybea, Ceratina nigrolabiata and megachille bee Hoplitis tridentata. I had also found out that in species that are more abundant on heaths, there is higher mortality of offsprings. Heaths were a place of the highest competition between species, as a result of which species with a lower body weight (Ceratina nigrolabiata) have been pushed into narrower twigs by larger species (Ceratina chalybea). I recorded a high number of nests in biparental bee Ceratina nigrolabiata, which were guarded only by mother in fields and country lane habitats. This may indicate that Ceratina nigrolabiata is only facultatively biparental, not strictly biparental as was considered until now.
Territorial behaviour of the Eurasian Wren (Troglodytes troglodytes) during autumn migration and wintering in the urban environment of Hradec Králové, Czech Republic
In the present paper I studied the winter territories of the Eurasian Wren (Troglodytes troglodytes) in the urban environment of the city of Hradec Králové. The males of this species were detected through the aggressive reactions to the playback of its conspecific call. The Eurasian Wren territories were detected at seven out of the ten observation points in the city. The frequency of the territories decreased during the observation period from October to January and it was also affected by the structure of the biotope. It seemed that the wrens preferred trees and avoided lawns and isolated growths. That illustrates how important it is to maintain wildlife corridors in the cities. Individuals of seven other bird species were seen reacting to the playback of Eurasian Wren songs or warning calls. Eurasian Wren may be applied as an indicator species of the ecological value of the urban environment. Through this species, we can access such quality also for the human inhabitants.
高鹽飲食對果蠅學習與記憶能力的影響及其細胞與分子機制
先前論文指出高鹽飲食會造成果蠅睡眠間斷(Jiayu Xie et al., 2019)、減短果蠅壽命(Deng-Tai Wen et al., 2020)。而另一篇論文則以小鼠作為實驗對象，發現高鹽飲食會影響小鼠記憶和學習能力(Giuseppe Faraco et al., 2018)。根據上述，高鹽飲食在不同生物中可能影響神經系統的功能，但果蠅學習與記憶能力的影響還未被探討。因此，筆者以果蠅作為模式生物，研究高鹽飲食對其學習與記憶功能是否障礙及實驗其可能的細胞與分子機制。在將野生型果蠅進行測試後，選擇了Canton-S做後續實驗，並發現餵食Canton-S 四天的高鹽食物後學習及短期記憶表現下降，而進行實驗確認是由高鹽飲食導致此障礙，再研究了一系列相關研究。 本次實驗中，首次以餵食高鹽食物對果蠅學習與記憶障礙方面進行研究，並了解到高鹽飲食也會讓果蠅產生學習與短期記憶能力障礙。目前為了找出真正的細胞與分子機制提出可使用的方法，在實驗其他可能的機制。