 The red @-@ billed chough breeds from three years of age , and normally raises only one brood a year , although the age at first breeding is greater in large populations . A pair exhibits strong mate and site fidelity once a bond is established . The bulky nest is composed of roots and stems of heather , <unk> or other plants , and is lined with wool or hair ; in central Asia , the hair may be taken from live Himalayan tahr . The nest is constructed in a cave or similar fissure in a crag or cliff face . In soft sandstone , the birds themselves excavate holes nearly a metre deep . Old buildings may be used , and in Tibet working monasteries provide sites , as occasionally do modern buildings in Mongolian towns , including Ulaanbaatar . The red @-@ billed chough will utilise other artificial sites , such as quarries and <unk> for nesting where they are available . 
