Ilimin abinci na gaggafa mai zinariya

The golden eagle (Aquila chrysaetos) is one of the most powerful predators in the avian world. One author described it as "the pre-eminent diurnal predator of medium-sized birds and mammals in open country throughout the Northern Hemisphere". Golden eagles usually hunt during daylight hours, but were recorded hunting from one hour before sunrise to one hour after sunset during the breeding season in southwestern Idaho. The hunting success rate of golden eagles was calculated in Idaho, showing that, out of 115 hunting attempts, 20% were successful in procuring prey. A fully-grown golden eagle requires about  of food per day. In the life of most eagles, there are cycles of feast and famine, and eagles have been known to go without food for up to a week. Following these periods without food, they will then gorge on up to  at one sitting. The powerful talons of the golden eagle ensure that few preys can escape them once contact is made. The talons of this species exert approximately  of pressure, around 15 times more pressure than is exerted by the human hand, although some claim that the largest individual females may reach a pressure of . It has been claimed that the golden eagle can lift more than its own body weight in flight. However, other sources claim that a hare, marmot or deer calf weighing  is a struggle for even a large female to carry and that prey much over  would require favorably high wind conditions.

Hanyar farauta ta gaba ita ce "jirgi na kewayawa tare da gajeren hari", wanda ake la'akari da hanyar farauta da aka fi amfani da ita ga gaggafa na zinariya. Wannan ya kunshi jirgin sama mai ƙarancin matakin sau da yawa a 5 zuwa 15   kawai sama da ƙasa don haka ba sa karya layin sama lokacin da aka lura da su daga ƙasa kuma za su iya rungumar yanayin ƙasa a ƙasa. Wannan hanyar tana da amfani don farautar mulkin mallaka (sau da yawa burrowing) ganima kamar Squirrels na ƙasa, leporids masu yawa ko tsuntsaye da aka samu a cikin taro, kamar kiwo ko ma tsuntsayen teku. A bayyane yake cewa an zaɓi abin da aka kama a cikin wani nau'i na seconds kafin yajin aikin. Idan yunkurin farko ya gaza, gaggafa na iya tashi a kusa kuma yayi ƙoƙari ya sake kwantar da ganima.

Golden eagles are opportunists and virtually any animal of a reasonable size may be predated. Well over 400 species of vertebrate have been recorded as prey. Prey selection is largely determined by the local availability and abundance of prey species. They normally prefer wild, native prey but can easily adapt to domesticated and/or exotic animals, most often when the prey returns to a feral state. This is most apparent on islands that have very few (or no) native land mammals, such as Corsica in France, Santa Rosa and Santa Cruz Islands in California and many of the Inner and Outer Hebrides of Scotland. Most analysis of dietary habits of raptors results from examining the prey remains around an active eyrie at the end of the breeding season (September or October), based on pellets, skeletons and skins found. This method is not comprehensive for prey analysis, as particularly small prey may leave no trace and it cannot take into account the prey selected by wintering adults and highly nomadic juvenile eagles (both of which are believed to include a higher level of carrion and large prey items). However, since eye-witness accounts of hunting and close monitoring of prey brought to the nest are both rare and likely to disturb the eagles, this is the best known method of studying the eagle's prey. Studies have revealed that the average golden eagle nest contains 3.57 species of prey, although there is considerable variation in the dietary breadth across the range, ranging from an average of 11.2 species in the French Pyrenees to a mere 1.4 in Alaska. In general, the dietary breadth is greater in Eurasia than it is in North America, where eagles frequently only need to hunt two or three species throughout the nesting cycle. This is a moderate dietary breadth by the standards of the genus Aquila, and not remarkable when compared to some other raptors. Overall prey weight has ranged from  to at least , although most prey taken are around half the weight of the preying eagle, with a typical prey weight range of  but mostly in the lower half of that range. Studies have shown an estimated mean prey weight of  for golden eagles across their range. Only 15.8% of prey weighs over . At a nest studied in Mongolia, prey items were found to be heavier than those known elsewhere in the range, with an estimated mean weight of around . The average estimated weight of prey taken by most other Aquila species is generally much lower but the wedge-tailed eagle seemingly takes prey of a similar weight (both in average and range of prey weights) while the Verreaux's eagle average prey weight is higher, probably over .

 Leporids 
19 daga cikin binciken 45 a cikin Palearctic sun lissafa leporids a matsayin dangin da aka fi Mali da ganima ga gaggafa na zinariya. Muhimman nau'o'in ganima sun haɗa da Hare na dutse (Lepus timidus) (a cikin Highlands na Scotland da Alps na Faransa), rabbit na Turai (Oryctolagus cuniculus) (a kan Highlands, Sicily, Dutsen Apennine, Switzerland, Spain, Massif na Tsakiya na Faransa da Alps Faransanci, a cikin shafuka biyu da aka ambata, rabbit shine nau'in da aka gabatar da mutane), Brown hare (Lepus prey) (Lepus europaeus) (a Switzerland, Dutsen Alpine)  wasu abubuwan da Cape Nijar)  Nejandan (Lepy)  Nejandan ne  Nejandan da aka sani da Capeus) [4] Nejiran (Lepus) [4] masu tasheya) [4] Nejarus) [4] A cikin Japan (Lepus da Cape Nejiran) [4] Nejerun (Lepus), [4] Nejarin Nejarin ne [4] Nejar) [4] Neijaniya (Lepus [4] Nejaran (Lepus suna da JapanAdamain, M.S. & Klem, D. 1999. Handbook of the Birds of Armenia. Armenia Corporation, . Hare tolai (Lepus tolai) wani abu ne na biyu a Mongolia, wanda ya kai kusan kashi 21% na ganima. Rabin Turai ya bayyana a matsayin na biyu a Hungary, inda ya kunshi 14.3%.

Squirrels na ƙasa gabaɗaya dabbobi ne na zamantakewa kuma wasu nau'o'in ma suna rayuwa a cikin yankuna masu haɗin kai. Dukkanin squirrels na ƙasa suna zaune a cikin burrows, wanda a cikin nau'o'in kamar karnuka na filayen na iya zama cikakke. "Flight na kewayawa tare da gajeren hari" shine ainihin hanyar farauta da gaggafa ta zinariya ke amfani da ita a kan squirrels na ƙasa. Squirrels na ƙasa yawanci suna cin abinci a cikin nesa mai gudu na ɗaya daga cikin ƙofofin burinsu, don haka yana da mahimmanci ga gaggafa ta zinariya ta sami abin mamaki. Eagles ba za su shiga burrows ba, ba kamar wasu dabbobi masu cin nama da ke cin squirrels na ƙasa ba. Lokacin da suke farautar squirrels na ƙasa, gaggafa na zinariya suna da alama suna zaɓar wanda aka azabtar a cikin 'yan seconds na ƙarshe kafin su kai farmaki. Yawancin squirrels na ƙasa da gaggafa suka yi niyya ƙananan ne, tare da dukan ƙungiyar Spermophilus da wasu karnuka masu nauyin ƙasa da   . Marmots sun fi kamawa tun lokacin da yawancin jinsuna ke da nauyin akalla 1.5 zuwa 3.5   a cikin bazara kuma kusan sau biyu wannan ta hanyar faduwa, wanda shine kusan mafi girman nauyin da za'a iya ɗauka ga gaggafa mai tashi don ɗauka. Kodayake suna iya yin niyya da yawa na yara a cikin gida, a wasu lokuta suna iya raba wani babban marmot bayan kashewa don haka suna iya ɗaukar shi zuwa gida. A cikin Alps, an yi imanin cewa yana da fa'ida ga gaggafa su yi gida a ƙarƙashin makiyaya waɗanda ke karɓar bakuncin ganimarsu ta Alpine marmot don su iya tashi ƙasa, hanya mai sauƙi ta tashi yayin ɗaukar nauyi mai nauyi fiye da tashi sama.

 Gwargwadon 

 Manazarta