scholarly journals Spacing Behavior of Eurasian Three-Toed Woodpeckers (Picoides Tridactylus) During the Breeding Season in Germany

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 58-67
Author(s):  
Peter Pechacek

Abstract Data on spacing behavior of the Eurasian Three-toed Woodpecker (Picoides tridactylus) are rare, and systematic observations are lacking. I used homing technique (>90%) and triangulation to document range use of 28 radiotagged birds in an alpine mountain forest in southeastern Germany between 1994 and 2000. Common home range of a pair (x ± SE, n = 10) identified by the adaptive kernel method (95% use distribution) during the nesting period averaged 86.4 ± 23.4 ha and varied a great deal between pairs (range 33.9–287.4 ha). Although ranges of females (69.4 ± 15.4 ha, n = 14) appeared larger than those of males (45.7 ± 10.3 ha, n = 10), the difference was not significant. Prior to nesting and during the postnesting period, both sexes used seemingly larger home ranges than during nesting (≤381.7 ha); but again, the difference was not significant. Home ranges of mates (n = 20) during the nesting period overlapped an average of 66.5 ± 5.7% (≤100.0%); female ranges and core areas overlapped male ranges to a significantly greater extent than male ranges overlapped those of females. Nearly all home ranges bordered or overlapped those of their neighbors. Ranges of neighboring male-female combinations (n = 11) overlapped by 17.6 ± 3.9% during the nesting period, with an increasing tendency to overlap toward the end of the breeding season. Because areas used by Eurasian Three-toed Woodpeckers remained stable over the breeding season, I propose consideration of home ranges during nesting as a reliable estimate of species area requirements for use in management plans.

2000 ◽  
Vol 6 (3) ◽  
pp. 229 ◽  
Author(s):  
Ty D. Smucker ◽  
Gerald D. Lindsey ◽  
Stephen M. Mosher

Feral cat Felis catus home range in a Hawaiian montane wet forest and their diet in three habitats - montane wet forest, subalpine dry forest, and lowland dry forest ? were determined to provide baseline ecological data and to assess potential impacts to native terrestrial fauna. Seven cats (three males and four females) were captured in 624 trap nights. Mean weight of adult cats was 2.85 � 0.27 (SE) kg for males and 1.87 � 0.03 kg for females. Mean diurnal home range using the adaptive kernel method was 5.74 � 2.73 km2 for three males and 2.23 � 0.44 km2 for two females. Daytime locations were always within the montane wet forest with the borders on one or more sides of the home ranges of all cats defined by open grassland pastures. Rodents comprised the majority of the cat diets in all three habitats, with the frequencies of occurrence between 0.88 and 0.91. Bird remains were a regular component of the diet of cats, with montane wet forest having the highest frequency of occurrence (0.68), followed by subalpine dry forest (0.53). and lowland dry forest (0.21).


1968 ◽  
Vol 46 (3) ◽  
pp. 405-408 ◽  
Author(s):  
Ian Stirling

In the field, nesting hen blue grouse (Dendragapus obscurus fuliginosus, Ridgway) show fidelity to home ranges and these are evenly spaced. Explanation of this is difficult. Hen blue grouse in an aviary were tested for aggressive behavior that might function to space them in the field. Reaction of hens to their mirror image was recorded and this was greatest during the period hens squatted and laid eggs, and decreased through incubation. The difference was statistically significant. Of the five acts which determined the index of activity, three were apparently aggressive, one was apparently investigative, and one was apparently conflict and fear. The results support the idea that dispersion of hens during the breeding season is caused by aggressive behavior.


1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.


2020 ◽  
Vol 7 (2) ◽  
pp. 107-112
Author(s):  
Marian Manciu ◽  
Sorour Hosseini ◽  
Joscelyne Guzman-Gonzalez

Background: Statistical methods commonly used in survival analysis typically provide the probability that the difference between groups is due to chance, but do not offer a reliable estimate of the average survival time difference between groups (the difference between median survival time is usually reported). Objective: We suggest a Maximum-Entropy estimator for the average Survival Time Difference (MESTD) between groups. Methods: The estimator is based on the extra survival time, which should be added to each member of the group, to produce the maximum entropy of the result (resulting in the groups becoming most similar). The estimator is calculated only from time to event data, does not necessarily assume hazard proportionality and provides the magnitude of the clinical differences between the groups. Results: Monte Carlo simulations show that, even at low sample numbers (much lower than the ones needed to prove that the two groups are statistically different), the MESTD estimator is a reliable predictor of the clinical differences between the groups, and therefore can be used to estimate from (low sample numbers) preliminary data whether or not the large sample number experiment is worth pursuing. Conclusion: By providing a reasonable estimate for the efficacy of a treatment (e.g., for cancer) even for low sample data, it might provide useful insight in testing new methods for treatment (for example, for quick testing of multiple combinations of cancer drugs).


2004 ◽  
Vol 16 (1) ◽  
pp. 45-49 ◽  
Author(s):  
P.Y. Lee ◽  
E.M. Khoo

70 patients presented with acute asthma exacerbation requiring nebulised bronchodilator treatment at the emergency department of a teaching hospital in Kuala Lumpur, Malaysia, were interviewed over a two-week period in July 2001. The results showed that 45 (64%) patients had not been educated on the nature of asthma; 30 (43%) had not been advised on preventive measures or avoidance of triggers; 54 (77%) were not advised about the medications used and their side effects; 42 (60%) patients did not know the difference between reliever and preventive medications; 37 (53%) were unable to recognize features of worsening asthma and 68 (97%) were not told about the danger of non-prescribed self-medication or traditional medications. Only six (9%) patients were using peak flow meters and were taught self-management plans. The multiple regression results suggest that patients who were followed up at teaching hospital based clinics were better educated on asthma. In conclusion, asthmatic patients are still not educated well about their disease. Health care providers need to put more emphasis on asthma education so that the number of emergency room visits can be reduced. Asia Pac J Public Health 2004; 16(1): 45-49.


2002 ◽  
Vol 8 (4) ◽  
pp. 271 ◽  
Author(s):  
Peter G. Cale

White-browed Babbler Pomatostomus superciliosus groups occupying linear strips of vegetation had breeding territories that were smaller in area and had longer linear dimensions than those occupying patches. A group's non-breeding home range was larger than its breeding territory. Groups occupying linear/patch home ranges expanded the linear extent and area of their home ranges more than those within other home range configurations. Some groups moved during the non-breeding season and this was more likely to occur if the group occupied a remnant with a low abundance of invertebrates during summer. Some groups that moved returned prior to the next breeding season, but the majority were never seen again. New groups moved into the study sites and established in vacant home ranges. This suggests that those groups that left the study sites may have established new home ranges elsewhere. Breeding site fidelity was lower in groups that had failed in previous breeding attempts. Therefore, group movements were influenced by the feeding and breeding quality of the habitat. However, the configuration of the local population also influenced group movements with those groups on the edge of a local population being more likely to move than those in the interior. New groups were formed by two processes; group dispersal, where groups generally filled a vacant home range, and group budding, which involved the splitting of a large group. Group dispersal maintained group densities while group budding increased the density of groups in a local population. These two processes were common, producing localized fluctuations in the density of groups. Since babbler groups contain only one breeding pair, changes in group density represent changes in effective population size. Therefore, group dynamics may be important to the persistence of local populations of White-browed Babblers, especially in landscapes that have suffered from habitat loss and fragmentation.


Koedoe ◽  
2004 ◽  
Vol 47 (2) ◽  
Author(s):  
G. Cleaver ◽  
L.R. Brown ◽  
G.J. Bredenkamp

The Kammanassie Mountain is a declared mountain catchment area and a Cape mountain zebra Equus zebra zebra population is preserved on the mountain. The high number of springs on the mountain not only provides water for the animal species but also contributes to overall ecosystem functioning. Long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. It was therefore decided that a classification, description and mapping of the spring vegetation of the Kammanassie Mountain be undertaken. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 11 major plant communities that could be related to geological origin. Habitat factors associated with differences in vegetation include topography, soil type and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers. The results also indicate a high species richness compared to similar regions and the difference between plant communities of wet and dry springs. This data is important for long-term monitoring of the spring ecosystems as well as for the compilation of management plans.


2021 ◽  
Vol 12 ◽  
Author(s):  
Hongju (Daisy) Chen ◽  
Bin Yi ◽  
Qiang Liu ◽  
Xia Xu ◽  
Lin Dai ◽  
...  

The human gut microbiome has been extensively studied, but its diversity scaling (changes or heterogeneities) along the digestive tract (DT) as well as their inter-individual heterogeneities have not been adequately addressed to the best of our knowledge. Here we fill the gap by applying the diversity-area relationship (DAR), a recent extension to the classic species-area relationship (SAR) in biogeography, by reanalyzing a dataset of over 2000 16s-rRNA microbiome samples obtained from 10 DT sites of over 200 individuals. We sketched out the biogeography “maps” for each of the 10 DT sites by cross-individual DAR analysis, and the intra-DT distribution pattern by cross-DT-site DAR analysis. Regarding the inter-individual biogeography, it was found that all DT sites have the invariant (constant) scaling parameter—all sites possessing the same diversity change rate across individuals, but most sites have different potential diversities, which include the portions of diversity that may be absent locally but present regionally. In the case of this study, the potential diversity of each DT site covers the total diversity of the respective site from all individuals in the cohort. In terms of the genus richness, an average individual hosts approximately 20% of the population-level genus richness (total bacterial genus of a human population). In contrast, in terms of community biodiversity, the percentages of individual over population may exceed 90%. This suggests that the differences between individuals in their DT microbiomes are predominantly in the composition of bacterial species, rather than how their abundances are distributed (i.e., biodiversity). Regarding the intra-DT patterns, the scaling parameter (z) is larger—suggesting that the intra-DT biodiversity changes are larger than inter-individual changes. The higher intra-DT heterogeneity of bacteria diversity, as suggested by larger intra-DT z than the inter-individual heterogeneity, should be expected since the intra-DT heterogeneity reflects the functional differentiations of the DT tract, while the inter-individual heterogeneity (z) reflects the difference of the same DT site across individuals. On average, each DT site contains 21–36% of the genus diversity of the whole DT, and the percentages are even higher in terms of higher taxon levels.


1989 ◽  
Vol 67 (4) ◽  
pp. 961-969 ◽  
Author(s):  
E. H. Hogg ◽  
J. K. Morton ◽  
Joan M. Venn

Species–area relations of vascular plants and the effect of nesting colonies of gulls on plant species composition were investigated for 77 islands in Georgian Bay and Lake Huron in the Great Lakes region of Canada. The percentage of plant species classed as alien, annual, or biennial was significantly greater on islands with gull colonies. The slope of the species–area curve was significantly steeper on islands supporting gull colonies compared with islands lacking gull colonies. The expected decline in species richness with increased island remoteness was not detected statistically using multiple regression analysis. The difference in species–area slopes does not appear to reflect a lower propagule immigration rate to islands with gull colonies, because gulls are important in the dispersal of alien plant species to these islands. Larger islands with gull colonies tended to have richer floras than islands of similar size without gull colonies. It is suggested that on these larger islands the presence of gull colonies produces a gradient of soil nutrient and disturbance regimes, thus increasing habitat heterogeneity and species richness.


Sign in / Sign up

Export Citation Format

Share Document