海东青（学名：Falco rusticolus），又名矛隼、海青、鹘鹰，是隼属猛禽中最大的一种，分布在北极以及北美洲、亚洲的广大地区，在中国原产于黑龙江、吉林等地。 海东青身小而健，其飞极高，是狩猎中的重要帮手，能袭天鹅、搏鸡兔。海东青可分为秋黄、波黄、三年龙、玉爪，其中纯白色的玉爪最为珍贵；天鹅以珠蚌为食，食蚌后将珠藏于嗉囊，一说女真人训练海东青捕捉天鹅取珠。金代世传有捺钵制度，是指在春水围场中围猎天鹅，泰和七年（1207年），“募民种佃清河等处地，以其租分为诸春水处饵鹅鸭之食”。金章宗曾亲纵海东青擒鹅。所以女真很看重这种猎鹰。辽主天祚帝好打猎，每年冬天便逼迫女真族发甲马数百至五国城界猎取，“捕海东青于女真之城，取细犬于萌骨子之疆”，引起女真反抗，最终亡国。洪武四年，有外邦呈海东青珍禽，朱元璋命群臣献诗，宋濂有「自古戒禽荒」语，唐肃亦呈一绝句，有「词臣不敢志归谏，却忆当年魏郑公」语，上不怿而起。。郎世宁亦画有两幅「白海青」图。

The gyrfalcon (Falco rusticolus) (/ˈdʒɜːrfɔːlkən/ or /ˈdʒɜːrfælkən/), also spelled gerfalcon, is a bird of prey, the largest of the falcon species. The abbreviation gyr is also seen in the literature. It breeds on Arctic coasts and tundra, and the islands of northern North America, Europe, and Asia. It is mainly a resident there also, but some gyrfalcons disperse more widely after the breeding season, or in winter. Individual vagrancy can take birds for long distances. Its plumage varies with location, with birds being coloured from all-white to dark brown. These colour variations are called morphs. Like other falcons it shows sexual dimorphism, with the female much larger than the male. For centuries the gyrfalcon has been a precious hunting bird, highly valued among the Vikings. Typical prey includes the ptarmigan and water-fowl which it may take in flight. It has also been observed feeding on fish and mammals.