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Scaling Patterns (scaling + pattern)
Selected AbstractsResting breathing frequency in aquatic birds: a comparative analysis with terrestrial speciesJOURNAL OF ZOOLOGY, Issue 2 2009J. P. Mortola Abstract Several studies have indicated that in birds breathing frequency (f, breaths min,1) scales to the ,1/3 of body weight (W, kg); this is different from the ,1/4 of mammals. We wondered if this discrepancy was due to the peculiar scaling pattern of aquatic birds, as is the case of aquatic mammals. In fact, we had noted previously that the allometric scaling of f differs considerably between aquatic and terrestrial mammals, respectively, W,0.42 and W,0.25. Measurements of f were obtained in 48 aquatic birds of 22 species and in 35 terrestrial birds of 27 species, during resting conditions on land. Additional data from 11 aquatic and 14 terrestrial species, different from the ones measured, were obtained from the literature. The allometric curve of all species combined (terrestrial and aquatic, n=74) was f=13.3W,0.36, similar to what is reported in previous studies. However, the allometric curve of the aquatic species (n=33, f=14.5W,0.56) differed greatly (P<0.001) from that of the terrestrial species (n=41, f=13.4W,0.26). On average, f of aquatic birds of the 3,5 kg range was 63%, and that of birds of larger size was 57%, of the values of terrestrial birds of similar W. We conclude that, as in mammals, also in terrestrial birds f scales to the ,1/4 exponent of W. The similarity of the scaling patterns of f between aquatic birds and mammals suggests a common breathing adaptation to life in the aquatic environment irrespective of phylogenetic relations. [source] Scaling of park trail length and visitation with park area: conservation implicationsANIMAL CONSERVATION, Issue 2 2005Michael L. McKinney Analysis of 688 state parks and 41 national parks shows that total trail length in a park has a significant decelerating scaling relationship with park area. Larger parks have much lower trail densities (less trail per acre) than smaller parks. A decelerating scaling pattern is also found when the number of annual visitors is regressed onto park area. Larger parks have fewer visitors per acre of park. Since trails and visitors are major sources of disturbance for many species of wildlife and plants in most reserves, these scaling patterns have important conservation implications. [source] Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae)ACTA ZOOLOGICA, Issue 2 2008Gabe S. Bever Abstract Bever, G.S. 2007. Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae). ,Acta Zoologica (Stockholm) 88: 000,000 Postnatal growth is one of the many aspects of developmental morphology that remains distinctly understudied in reptiles. Variation and ontogenetic scaling within the skull of the extant emydid turtle, Pseudemys texana is described based on 25 continuous characters. Results indicate that skull shape in this species changes little during postnatal growth relative to the only cryptodire taxa for which comparable datasets are available (Apalone ferox and Sternotherus odoratus). This relative lack of change results in the paedomorphic retention of a largely juvenile appearance in the adult form of P. texana. The skulls of males and females, despite the presence of distinct sexual dimorphism in size, grow with similar scaling patterns, and the few observed differences appear to reflect alteration of the male growth trajectory. Comparisons with A. ferox and S. odoratus reveal a number of similarities and differences that are here interpreted within a phylogenetic context. These preliminary hypotheses constitute predictive statements that phylogenetically bracket the majority of extant cryptodire species and provide baseline comparative data that are necessary for the future recognition of apomorphic transformations. Plasticity of ontogenetic scaling as a response to the homeostatic needs and behaviour of individuals commonly is evoked as a limitation of ontogenetic scaling as a means to inform phylogenetic studies. These evocations are largely unfounded considering that variability itself can evolve and thus be phylogenetically informative. [source] Measures, perceptions and scaling patterns of aggregated species distributionsECOGRAPHY, Issue 1 2010Cang Hui Non-random (aggregated) species distributions arise from habitat heterogeneity and nonlinear biotic processes. A comprehensive understanding of the concept of aggregation, as well as its measurement, is pivotal to our understanding of species distributions and macroecological patterns. Here, using an individual-based model, we analyzed opinions on the concept of aggregation from the public and experts (trained ecologists), in addition to those calculated from a variety of aggregation indices. Three forms of scaling patterns (logarithmic, power-law and lognormal) and four groups of scaling trajectories emerged. The experts showed no significant difference from the public, although with a much lower deviation. The public opinion was partially influenced by the abundance of individuals in the spatial map, which was not found in the experts. With the increase of resolution (decrease of grain), aggregation indices showed a general trend from significantly different to significantly similar to the expert opinion. The over-dispersion index (i.e. the clumping parameter k in the negative binomial distribution) performed, at certain scales, as the closest index to the expert opinion. Examining performance of aggregation measures from different groups of scaling patterns was proposed as a practical way of analyzing spatial structures. The categorization of the scaling patterns of aggregation measures, as well as their over- and in-sensitivity towards spatial structures, thus not only provides a potential solution to the modifiable areal unit problem, but also unveils the interrelationship among the concept, measures and perceptions of aggregated species distributions. [source] Resting breathing frequency in aquatic birds: a comparative analysis with terrestrial speciesJOURNAL OF ZOOLOGY, Issue 2 2009J. P. Mortola Abstract Several studies have indicated that in birds breathing frequency (f, breaths min,1) scales to the ,1/3 of body weight (W, kg); this is different from the ,1/4 of mammals. We wondered if this discrepancy was due to the peculiar scaling pattern of aquatic birds, as is the case of aquatic mammals. In fact, we had noted previously that the allometric scaling of f differs considerably between aquatic and terrestrial mammals, respectively, W,0.42 and W,0.25. Measurements of f were obtained in 48 aquatic birds of 22 species and in 35 terrestrial birds of 27 species, during resting conditions on land. Additional data from 11 aquatic and 14 terrestrial species, different from the ones measured, were obtained from the literature. The allometric curve of all species combined (terrestrial and aquatic, n=74) was f=13.3W,0.36, similar to what is reported in previous studies. However, the allometric curve of the aquatic species (n=33, f=14.5W,0.56) differed greatly (P<0.001) from that of the terrestrial species (n=41, f=13.4W,0.26). On average, f of aquatic birds of the 3,5 kg range was 63%, and that of birds of larger size was 57%, of the values of terrestrial birds of similar W. We conclude that, as in mammals, also in terrestrial birds f scales to the ,1/4 exponent of W. The similarity of the scaling patterns of f between aquatic birds and mammals suggests a common breathing adaptation to life in the aquatic environment irrespective of phylogenetic relations. [source] Scaling of park trail length and visitation with park area: conservation implicationsANIMAL CONSERVATION, Issue 2 2005Michael L. McKinney Analysis of 688 state parks and 41 national parks shows that total trail length in a park has a significant decelerating scaling relationship with park area. Larger parks have much lower trail densities (less trail per acre) than smaller parks. A decelerating scaling pattern is also found when the number of annual visitors is regressed onto park area. Larger parks have fewer visitors per acre of park. Since trails and visitors are major sources of disturbance for many species of wildlife and plants in most reserves, these scaling patterns have important conservation implications. [source] | ||||||||||