Comparisons between myriapod assemblages at mine sites in Upper and Lower Lusatia that had different soil and age conditions revealed that myriapods are good indicators of biological soil quality and are reliable and easy to use. Using soil sampling and subsequent heat extraction of animals, four alder stands in the wetlands of the Biebrza, Narew and Bia³owieŜa national parks, north-eastern Poland, were surveyed for millipedes and centipedes. Among 12 millipede species revealed, Xestoiulus laeticollis, Polydesmus complanatus and Craspedosoma rawlinsii occurred and predominated in all alder woods.
Karger AG, Basel. A further intensive study was made with millipedes and centipedes which need – like earthworms – a longer time for immigration.
The centipede fauna was very poor, altogether represented by four species, only Lithobius curtipes being shared by all sites. The myriapod communities from the swampy alder woods (Ribeso nigri Alnetum) at Biebrza and in the Bia³owieŜa Primeval Forest were mainly under the influence of fertility soil parameters (available and total phosphorus contents) while the assemblage from an alder swamp at Narew was largely affected by soil humidity. Apparently, the community from an ash-alder alluvial wood (Fraxino-Alnetum) sampled in the Bia³owieŜa Primeval Forest mostly depended on soil pH. Comparing all available information, the structure of myriapod assemblages seems to be quite similar even over distant regions in Central Europe.
We tested the hypothesis that sexual selection for complex motor displays has selected for larger brains across the Pipridae. We found that display complexity positively predicts relative brain weight (adjusted for body size) after controlling for phylogeny in 12 manakin species and a closely related flycatcher. This evidence suggests that brain size has evolved in response to sexual selection to facilitate aspects of display such as motor, sensorimotor, perceptual, and cognitive abilities. We show, for the first time, that sexual selection for acrobatic motor behaviour can drive brain size evolution in avian species and, in particular, a family of suboscine birds. © 2015 S.
By these standards, a vulture breaking an egg by hitting it with a stone uses a tool, but a gull dropping an egg on a rock does not. This distinction between true and borderline (or proto-tool) cases has been criticized for its arbitrariness and anthropocentrism.
Discussions of the evolution of intelligence have focused on monkeys and apes because of their close evolutionary relationship to humans. Other large-brained social animals, such as corvids, also understand their physical and social worlds. Here we review recent studies of tool manufacture, mental time travel, and social cognition in corvids, and suggest that complex cognition depends on a “tool kit” consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems.
- When a value shifts substantially out of its reference range, a change of the system state is probable, especially if this applies for two or more parameters simultaneously.
- Behavioral innovations, the invention of new behaviors or the use of preexisting ones in new contexts, are increasingly considered an essential source of behavioral plasticity, yet the mechanisms by which they arise are poorly understood.
- After 50 years of development of mine-site woodlands, five species of millipedes and six species of centipedes, though common in adjacent reference woodlands, had not yet colonised the mine sites.
Manakin displays vary across species in terms of behavioural complexity, differing in number of unique motor elements, production of mechanical sounds, cooperation between displaying males, and construction of the display site. Historically, research emphasis has been placed on neurological specializations for vocal aspects of courtship, and less is known about the control of physical, non-vocal displays. By examining brain evolution in relation to extreme acrobatic feats such as manakin displays, we can vastly expand our knowledge of how sexual selection acts on motor behaviour.
We show here that relative size of the neostriatum and whole brain distinguish the true and borderline categories in birds using tools to obtain food or water. From two sources, the specialized literature on tools and an innovation data base gathered in the short note sections of 68 journals in 7 areas of the world, we collected 39 true (e.g. use of probes, hammers, sponges, scoops) and 86 borderline (e.g. bait fishing, battering and dropping on anvils, holding with wedges and skewers) cases of tool use in 104 species from 15 parvorders. True tool users have a larger mean residual brain size (regressed against body weight) than do users of borderline tools, confirming the distinction in the literature. In multiple regressions, residual brain size and residual size of the neostriatum (one of the areas in the avian telencephalon thought to be equivalent to the mammalian neocortex) are the best predictors of true tool use reports per taxon.
We draw attention to the high degree of inconsistency among empirical findings relating interindividual variation in innovativeness to interindividual variation in learning performance. We go on to propose a model that reconciles the possible (but perhaps controversial) existence of positive associations between cognition and innovation at the cross-taxon level with inconsistent associations at the within-species level.
We test the hypothesis that the relative sizes of the different parts of the brain (brain stem, optic lobes, cerebellum and cerebral hemispheres), measured after body size effects have been removed, are associated with differences in behaviour and ecology across bird species. Tools are traditionally defined as objects that are used as an extension of the body and held directly in the hand or mouth.
Furthermore, motor diversity constitutes a proximate link between diet generalism and innovativeness. Acrobatic display behaviour is sexually selected in manakins (Pipridae) and can place high demands on many neural systems.