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.
The presence of saprophagous millipede species showed a clear succession in parallel with mine-site development, but there is no species with true pioneer behaviour. Centipedes – with Lamyctes emarginatus as a true pioneer – as predators behave less predictably; Geophilomorphs, hunting in the subsoil, are the last to invade. 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.
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. Three examples are given for considerable changes of the annelid community due to land-use change or natural succession. The detection of substantial changes of the community is based mainly on the species composition, but is supported by quantitative parameters using the reference ranges.
- We draw attention to the high degree of inconsistency among empirical findings relating interindividual variation in innovativeness to interindividual variation in learning performance.
- If the temporal variation goes in the same direction throughout the time series, it is considered a trend.
- 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.
- The myriapod communities from the swampy alder woods (Ribeso nigri Alnetum) at Biebrza and in the BiaÂ³owieÅœa 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.
Karger AG, Basel. A further intensive study was made with millipedes and centipedes which need – like earthworms – a longer time for immigration.
Especially at sites that passed three investigations already, major changes become discernible. If the temporal variation goes in the same direction throughout the time series, it is considered a trend.
Our results demonstrate that birds are more frequent tool users than usually thought and that the complex cognitive processes involved in tool use may have repeatedly co-evolved with large brains in several orders of birds. 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. In recent years, much emphasis has been placed on the role of cognition. Here, we review briefly key findings from large-scale comparative research and, in more detail, those from experimental work on innovation.