Secondary users of Great Spotted Woodpecker (Dendrocopos major) nest cavities in urban and suburban forests in Sapporo City, northern Japan

2002 ◽  
Vol 1 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Nobuhiko Kotaka ◽  
Shigeru Matsuoka
2019 ◽  
Vol 16 (1) ◽  
pp. 25-35 ◽  
Author(s):  
N.A. Komaromi ◽  
A.V. Putchkov ◽  
V.Yu. Nazarenko

A total of 54 species in 35 genera of Curculionidae are registered in the urbocenoses of Kharkiv city. Only three species, Exomias pellucidus, Otiorhynchus raucus and Ot. ovatus, are recorded as dominants. Some other species (Urometopus nemorum, Sciaphobus squalidus and Glocianus punctiger) are sporadically noted in some sites as subdominants. The total number of species turned out to be higher in the herpetobios of plantings at periphery (31), slightly lower in private farmlands of the city (21), parks and plantings of the center (17 each), but minimal in suburban forests (11 species). The highest quantity of specimens were observed for the plantations of the center and margins of city: nevertheless, minimal quantity of specimens was registered at parks and woods. The maximum number of species (including all cenoses) was recorded from the end of April to first decade of May (28 species). From May to the end of June 15–18 species were registered. Ten species were recorded at July, and only six species at August. A slight rise was noted from the end of August to mid-September (11 species). In biotopes where Exomias pellucidus appeared to be the monodominant, the seasonal dynamic density of weevils reached a peak at late May or early June, but the significant decline was observed from early June to July. At the sites with several dominants, two or three peaks were registered: at spring (May) and at mid-summer (end of June or beginning of July). Furthermore, the number of weevils decreased gradually, but some species of Curculionidae were rather abundant even from the end of summer to September–October. The spring increase is reasoned by high density of species in the genus Otiorhynchus; the peak in early summer (maximum) is caused by the increased activity of majority of dominant species; the autumn peak is also caused by the high number of species of the genus Otiorhynchus. The level of sex index (by the example of E. pellucidus) differed significantly at all plots. It was higher for the plantations at the periphery of the city (0.70), and it was minimal at private farmlands (0.20). Relative conjugacy of sex index and dynamic density were not observed: the maximum abundances of quantity of Curculionidae were recorded 20–30 days earlier than the maximal numbers of the sex index.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
S. Tephillah ◽  
J. Martin Leo Manickam

Security is a pending challenge in cooperative spectrum sensing (CSS) as it employs a common channel and a controller. Spectrum sensing data falsification (SSDF) attacks are challenging as different types of attackers use them. To address this issue, the sifting and evaluation trust management algorithm (SETM) is proposed. The necessity of computing the trust for all the secondary users (SUs) is eliminated based on the use of the first phase of the algorithm. The second phase is executed to differentiate the random attacker and the genuine SUs. This reduces the computation and overhead costs. Simulations and complexity analyses have been performed to prove the efficiency and appropriateness of the proposed algorithm for combating SSDF attacks.


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