Ground-dwelling sciurids, including prairie dogs (Cynomys), marmots (Marmota) and several genera of ground squirrels (e.g. Ammospermophilus, Spermophilus, Notocitellus, Ictidomys, Urocitellus), emit alarm calls in the presence of predators to warn their kin. These calls show high intra- and inter-species variation. The alarm calls of many species have potential to encode information about caller identity, and possibly enable the ground squirrels to recognize unreliable callers or to estimate the degree of risk. The alarm calls can be used to determine species or subspecies, and can also help resolve some taxonomic complexities. and Irena Schneiderová.
The article summarises results of our research on inter- and intra-species variability in alarm calls (emitted in the presence of predator) of the European Ground Squirrel (Spermophilus citellus) and closely related species (Taurus Ground Squirrel - S. taurensis, Anatolian Ground Squirrel - S. xanthoprymnus). Alarm calls of all three species mostly consist of two different elements; individuals producing alarm calls with only one of them were, however, also recorded. Although their alarm calls share the same basic structure, the three species can be clearly distinguished. Significant inter-individual differences allow identification of particular callers in a colony. and Irena Schneiderová, Richard Policht.
Na výstava Německé kresby, měšťan a jeho svět 1720-1820 vystaven akvarel Karla Postla U adršpašského vodopádu z roku 1801 z majetku Národní galerie v Berlíně