Hydrography

Ucreo River

The Ucero river is an inland river that crosses part of the province of Soria, running approximately 27 km from its source in the municipality of Ucero, which gives it its name, to its mouth in the Duero river, in the municipality of El Burgo de Osma.

The riverbed has its source at the spring of "La Galiana", also known as "Fuente Galiana", a few metres from the Cañón del río Lobos. The river's principal tributaries are the Abión and Sequillo rivers, which in turn constitute one of the most significant tributaries of the Duero. Furthermore, it is regarded as one of the most prevalent rivers in the province of Soria.

Although the Ucero riverbed has a limited surface flow, with periods of drought in certain stretches, especially during the summer season, it is mainly composed of groundwater.

The dominant vegetation in this area includes species such as holm oak (Quercus ilex), black pine (Pinus nigra) and Portuguese oak (Quercus faginea). As well as juniper (Juniperus communis) or shrub vegetation such as lavender (Lavandula sp.), sage (Salvia sp.), rosemary (Salvia rosmarinus), thyme (Thymus sp.), savory (Satureja sp.), lavender (Lavandula stoechas), bearberry (Arctostaphylos uva-ursi) or gorse (Genista scorpius).

And on the river bank we can find poplars (Populus spp.), willows (Salix spp.), ash trees (Fraxinus spp.), elms (Ulmus spp.) and walnut trees (Juglans regia).

With regard to the fauna, there are several species of birds of prey such as the golden eagle (Aquila chrysaetos), short-toed snake eagle (Circaetus gallicus), booted eagle (Hieraaetus pennatus), Bonelli's eagle (Aquila fasciata), griffon vulture (Gyps fulvus), peregrine falcon (Falco peregrinus), Northern Goshawk (Accipiter gentilis), kestrel (Falco sparverius), eagle owl (Bubo bubo), long-eared owl (Asio otus), western barn owl (Tyto alba), tawny owl (Strix aluco), scops owl (Otus scops) and little owl (Athene noctua). And other birds such as: grey heron (Ardea cinerea), red-billed chough (Pyrrhocorax pyrrhocorax), dipper (Cinclus cinclus) or kingfisher (Alcedo atthis).

Mammals include roe deer (Capreolus capreolus), wild boar (Sus scrofa), hares (Lepus), foxes (Vulpes vulpes), martens (Martes foina), weasels (Mustela nivalis) and badgers (Meles meles).

The Ucero river is regarded as one of the most prolific trout fishing locations in the province, with two fishing preserves, the Coto de Ucero and the Coto de Sotos, both located in the municipality of El Burgo de Osma.