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101.
Ability to assess nest predation risk in secondary hole-nesting birds: an experimental study 总被引:3,自引:0,他引:3
Because nest predation is the major source of nesting mortality in birds, site-specific predation risk may play an important role in determining birds' ability to select nest sites that reduce predation risk. This possibility has not been adequately tested. Here we report on 5-year experiments by which we studied, independently from birds' earlier experience with specific nest boxes, both the selection and predation risk of nest sites in the common goldeneye (Bucephala clangula). New, previously unoccupied nest boxes were erected in two habitat types on three study areas. Experimentally measured predation risk in the nest boxes varied between 0 and 1.0, i.e. goldeneye females could select a nest site along a wide gradient of possible predation-risk values. We did not find a difference in predation risk between occupied and unoccupied nest boxes, nor was the order of nest box occupation associated with predation risk. A power analysis revealed that our test had reasonably high power to reject a false null hypothesis. Our results suggest that common goldeneye females likely have not evolved an ability to assess predation risk of new, previously unoccupied nest sites. 相似文献
102.
Niinioja Riitta Holopainen Anna-Liisa Hämäläinen Heikki Heitto Lauri Luotonen Hannu Mononen Paula Rämö Anita 《Hydrobiologia》2003,506(1-3):773-780
Hydrobiologia - The deep mining of copper and nickel at Outokumpu, Eastern Finland, lasted from 1910 to the late 1980s, during which period metalliferous waste water of high conductivity and... 相似文献
103.
Effect of experimental nitrogen load on methane and nitrous oxide fluxes on ombrotrophic boreal peatland 总被引:8,自引:0,他引:8
Nykänen Hannu Vasander Harri Huttunen Jari T. Martikainen Pertti J. 《Plant and Soil》2002,242(1):147-155
Methane (CH4) and nitrous oxide (N2O) dynamics were studied in a boreal Sphagnum fuscum pine bog receiving annually (from 1991 to 1996) 30 or 100 kg NH4NO3-N ha–1. The gas emissions were measured during the last three growing seasons of the experiment. Nitrogen treatment did not affect the CH4 fluxes in the microsites where S. fuscum and S. angustifolium dominated. However, addition of 100 kg NH4NO3-N ha–1 yr–1 increased the CH4 emission from those microsites dominated by S. fuscum. This increase was associated with the increase in coverage of cotton grass (Eriophorum vaginatum) induced by the nitrogen treatment. The differences in the CH4 emissions were not related to the CH4 oxidation and production potentials in the peat profiles. The N2O fluxes were negligible from all microsites. Only minor short-term increases occurred after the nitrogen addition. 相似文献
104.
Sex-biased natal dispersal in long-lived species may resultin interactions between parents and mature young of the philopatricsex. To investigate the evolutionary basis of natal philopatryin a noncooperative species, the common goldeneye Bucephalaclangula, we studied possible costs and benefits of simultaneousbreeding of females and philopatric daughters. We did not find
any fitness consequences of a daughter's breeding on their mother'sbreeding in terms of nest-site selection, body weight, clutchsize, hatching date, or hatching success. Our results, therefore,did not support the assumption of the local resource competitionhypothesis, that the natally philopatric sex should be morecostly to a breeding parent. As possible benefits for daughters
returning to their natal area, we tested inheritance of nestsites from mothers and explored whether daughters utilize thepresence of their mother by parasitically sneaking into hermother's nest. Daughters' nest-site selection was not associatedwith the presence of their mothers. A comparison between daughtersand control females revealed that daughters chose their nestsite closer to their natal nest than expected by nest-siteavailability alone. Daughters could not expect to inherit anest site from their mother, and we did not find other indicationsof cooperation between relatives either. The mother's clutchsize did not increase in the year breeding with the daughter,
indicating daughters do not parasitize their mother's nest.We suggest that benefits such as decreased nest predation riskassociated with nesting close to the natal nest site may beimportant in the natal philopatric behavior of the species. 相似文献
105.
This study sought to evaluate the effect of cage space and earthen flooring on the behaviour of individually caged, farmed
blue foxes (Alopex lagopus). Three different cage sizes [80 cm long (CL80), 120 cm long (CL120), 240 cm long (CL240); each 105 cm wide×70 cm high] with
wire-mesh flooring, and one two-level cage (CL240E) with both wire-mesh (240 cm long×105 cm wide×70 cm high) and earthen flooring
(80 cm long×105 cm wide×70 cm high) were employed. Quantitative ethograms were obtained from ten males in each group by videotaping
the animals for 144 h monthly from August through November. Altogether 30 different behaviours were described. These were
rather similar in all study groups. Examples of behavioural differences included pacing around with a neighbour and the incidence
of scratching, which both declined with increasing cage space. Only the foxes in the cage with an earthen flooring (CL240E)
exhibited digging behaviour, which averaged 11 min/24 h. The wire-mesh section was distinctly preferred to the earthen-floor
section for most behaviours. Foxes in all groups were at their most active from 0800 to 1600 hours. Total activity, including
several separate behaviours, declined as winter approached. Locomotor and oral stereotypies were infrequent, and no significant
differences were found between the various cage options. For several hours before feeding, the foxes showed increasing levels
of stereotypies, but afterwards, stereotypies abruptly declined.
Received in revised form: 28 March 2001
Electronic Publication 相似文献
106.
Urban biodiversity in local newspapers: a historical perspective 总被引:3,自引:1,他引:2
Due to rapid urbanization the conservation and values of urban wildlife are becoming increasingly important study objects. Unfortunately, the lack of historical data makes it difficult to assess the effects of long-term urban land-use changes and human attitudes on local biodiversity. In this paper we show that old newspapers may in some cases provide useful historical data on both urban wildlife and local attitudes towards it. In the city of Turku, southwest Finland, the leading newspaper published 316 observations or reports on local urban mammals, birds and reptiles in 1890–1920, and in addition to these a lot of information on contemporary attitudes towards urban wildlife. At least 12 species of noncaptive mammals, 32 species of birds, and three reptile species were documented in newspapers. The newspaper data seem fairly reliable, and provide valuable information on the development of urban biodiversity. In the study period animals visiting urban areas were often persecuted, in which both adults and children (mainly schoolboys) participated actively. Birds were persecuted less frequently than mammals or reptiles. Some bird species, especially 'song-birds', were actively supported by winter-feeding and by constructing nest-boxes. According to newspapers local people were interested in local biodiversity, especially on phenological events, and benefited from it by getting esthetic pleasure, pet animals, and information on seasonal changes. 相似文献
107.
108.
109.
Kai Korpela Matti Laaksonen Arja Kallio Hans Söderlund Ulf Pettersson Hannu Kyrönseppä Marjut Ranki 《FEMS microbiology letters》1992,90(2):173-178
A rapid DNA-test, depending on the affinity based hybrid collection principle, was developed for the detection of Plasmodium falciparum DNA from clinical specimens. In this method, hybridization takes place in solution and the hybrids are collected onto a solid phase for measurement. Two probes are used, one labelled with an affinity tag (biotin) and the other with a detectable label (32P). In the present test a single oligonucleotide complementary to a 21-base pair sequence which is highly repeated in the parasite genome served both as capture and detector probe. The test is a 2-h hybridization performed in streptavidin coated microtitration plate wells, onto which the labelled hybrids simultaneously bind. The sensitivity of the assay with a crude erythrocyte lysate specimen was 1.6 x 10(9) repeat units corresponding to about 160 parasites in one microliter blood. The results allowed quantification of the repeat sequences and thus estimation of the degree of parasitemia in clinical specimens. 相似文献
110.