Search results for "Animal Ecology"
showing 10 items of 120 documents
Macroecology meets global change research
2007
Diphyllobothriids (Cestoda: Pseudophyllidea) from the long-finned pilot whale Globicephala melas (Traill, 1809) off the Faroe Islands, with comments …
1993
The taxonomy of marine species of the genus Diphyllobothrium, particularly those parasitic in cetaceans, is rather confused. During parasitological investigations of long-finned pilot whales Globicephala melas from waters off the Faroe Islands, five diphyllobothriid species were detected: Diphyllobothrium sp. (possibly D. polyrugosum), D. stemmacephalum, Diphyllobothrium sp. A, Diphyllobothrium sp. B and Diphyllobothriidae sp. D. stemmacephalum is reported for the first time from G. melas. The stituation regarding the taxonomy of Diphylobothrium species from cetaceans is briefly reviewed. It is concluded that the recent development of genetic techniques may be of great value in relation to …
Zooloģijas muzeja raksti, Nr. 2 Vertebrata
1968
Delayed maturation in plumage colour: Evidence for the female-mimicry hypothesis in the kestrel
1993
In many sexually dichromatic species, young males have female-like plumage during their first potential breeding year. The female-mimicry hypothesis (FMH) supposes that by possessing female-like plumage young males deceive older conspicuous males into believing that they are females, thus reducing competition from adult males. The status-signalling hypothesis (SSH) supposes that adult males can distinguish sex, but postulates that young males reduce competition from adult males by reliably signaling low status with their dull plumage. We tested these hypotheses in the European kestrel (Falco tinnunculus). Female-like young males settled to breed closer to adult males than did other adult ma…
Ground-level predation on artificial caterpillars indicates no enemy-free time for lepidopteran larvae
2017
Lepidoptera is one of the most diverse orders of insects, their larvae are very abundant in many habitats, and frequent prey of various predators. To decrease predation risk, caterpillars developed several means of defence, among them timing their activity to avoid predators (seeking enemy-free time). Although the enemy-free time hypothesis is often invoked to explain caterpillar behaviour, empirical evidence for it is scarce. We tested whether such enemy-free time exists in a temperate forest by comparing predation pressure on artificial caterpillars during day and night on the ground in forest fragments in Denmark. We found a high predation rate, 23.9% d(-1), and higher predation rate at …
New insights into the taxonomy and phylogeny of social voles inferred from mitochondrial cytochrome b sequences
2012
We sequenced the entire cytochrome b gene in Microtus paradoxus from Turkmenistan and Microtus socialis from Crimea and Kalmykia. Phylogenetic relationships among social voles were reconstructed by the inclusion into analyses of a further 23 published haplotypes belonging to six species. The two probabilistic methods which were used in phylogenetic analyses, the Bayesian inference and Maximum Likelihood, yielded very similar results. Both trees showed two highly divergent lineages which were further subdivided into seven species. The socialis lineage encompassed four species (M. socialis, M. irani, M. anatolicus, and M. paradoxus), and the remaining three species clustered into the guenther…
Costs of courtship and mating in a sexually cannibalistic orb-web spider: female mating strategies and their consequences for males
2002
The costs of courtship and mating may include increased risks of predation, the transmission of pathogens, and a loss of foraging opportunities. Thus, a female's decision to tolerate a courting male will depend upon how these costs offset the benefits of mating, which will depend on her reproductive and nutritional status. While these costs may be similar for mated and unmated females, the benefits of mating will be less for mated than virgin females. However, the cost of lost foraging opportunities may be higher for females with fewer nutritional reserves necessary for forming eggs. We examined how these costs and benefits influence the courtship and mating behaviour of male and female orb…
Intraguild interactions between two egg parasitoids exploring host patches
2010
Intraguild interactions between two egg parasitoids, Trissolcus basalis (Hymenoptera: Scelionidae) and Ooencyrtus telenomicida (Hymenoptera: Encyrtidae), exploring egg masses of the Southern Green Stink Bug (SGSB) Nezara viridula (Heteroptera: Pentatomidae), were investigated in laboratory conditions by single, simultaneous and sequential host attack experiments. Mortality of N. viridula eggs was higher in simultaneous and sequential releases compared to single species releases. In simultaneous host exploitations, T. basalis females displayed an aggressive behavior against O. telenomicida females. The outcome of multiparasitism showed that interspecific larval competition was dominated by O…
The genus Scaphiostomum Braun, 1901 (Trematoda: Brachylaimidae): A systematic review and description of Scaphiostomum palaearcticum n. sp.
1986
A systematic review of the genus Scaphiostomum Braun, 1901 (Trematoda: Brachylaimidae) is presented. Its diagnosis is emended and its position within the subfamily Brachylaiminae Joyeux & Foley, 1930 is established. The subfamily Scaphiostominae Yamaguti, 1958 is considered a synonym of the Brachy-laiminae. Scaphiostomum comprises the following species: S. illatabile Braun, 1901 (type species) from birds in South America, S. pancreaticum McIntosh, 1934 and S. microti (Kruidenier & Gallicchio, 1959) n. comb., both from rodents in North America, and S. palaearcticum n. sp. from rodents in the Balearic Islands (Spain). Scaphiostomum sp. of Lim, 1967 from rodents in Malaysia probably constitute…
A new species of the genus Zalophotrema (Digenea: Campulidae), Zalophotrema atlanticum n. sp., from the liver of the striped dolphin Stenella coerule…
1991
Zalophotrema atlanticum n. sp. from the liver of a striped dolphin, Stenella coeruleoalba (Meyen, 1833), stranded in the Canary Islands is described. This new species differs from the other Zalophotrema species in body dimensions and relative size and position of the suckers and cirrus-sac. This is the first record of a species of the genus Zalophotrema in the striped dolphin, and the Atlantic Ocean constitutes a new locality record for this genus.