In Greece golden ealge mostly feeds on tortoises in summer time and differents kind of prey in winter period.

http://www.parquesnaturales.gva.es/documents/79584147/165139391/Censo+y+conservaci%C3%B3n+de+%C3%A1guila+perdicera+y+%C3%A1guila+real+en+la+CV-2018/82d157e6-7be4-4548-a1aa-437126a1ed22
https://www.researchgate.net/publication/307865472_Preliminary_age_and_spatial_structure_analysis_of_a_threatened_golden_eagle_Aquila_chrysaetos_population_in_Thraki_NE_Greece_English_translation_from_original_poster_in_Greek

Bonelli's Eagle (Hieraaetus fasciatus) is a medium sized eagle (65-72 cm), with a wingspan of 150-180 cm, living in Europe only near the Mediterranean. Its world distribution extends from NW Africa and the Iberian peninsula east to N Indochina and S China.

Bonelli's Eagles occur in mountainous areas of low and medium height (up to 1,500 m), rarely higher. They are mainly found in warm rocky mountainous regions with extended scrub (maquis, phrygana), and less frequently in woodland, but also in bare slopes with no vegetation. They use most of the habitats for hunting, besides closed woodland and desert, and they breed in steep rocks and rarely in trees.

Every pair builds several nests (1-6), close to each other (even on the same rock), which are used consecutively. The nests become larger and larger each year, up to 1,80 m in height and 2 m in diameter.

Breeding birds are sedentary, while juvenile and immature, at least in SW Europe, scatter to low altitude regions with high food density, where there are no adult birds.

It feeds on medium sized mammals, mainly rabbits and partridges, but also on hares, squirrels, rodents, doves, corvids, gulls and reptiles, caught on the ground but also on air.

Bonelli's Eagle is not a globally threatened species (IUCN), while BirdLife Internationalclassifies it as a European threatened species (Tucker and Heath 1994). 

It is a rare species, with an irregular distribution in the Mediterranean. Its European population, estimated at fewer than 1,000 pairs, has seriously declined. Especially for the period 1980-90, there is a 25% reduction of its numbers in Spain, where 75% of the European population is found.

The most serious threats for the Bonelli's Eagles in Europe are hunting, collision of juvenile and immatures on electric wires, the expansion of human presence as well as food reduction.

The most significant threat, however, is the change of land use and the abandonment of traditional agricultural exploitations, that has overthrown the equilibrium of the Mediterranean landscape ("habitat mosaic") either by natural reforestation, or through new agricultural practices. The result is the shrinkage of biodiversity and, consequently, suitable prey for Bonelli's Eagles.
 Food habits: The main preys of the Bonelli’s Eagle are medium size mammals (in particular European rabbits Oryctolagus cuniculus and hares Lepus sp.) and birds, like partridges (Alectoris rufa), pigeons (Wood pigeon Columba palumbus, Feral pigeon C. livia domestica), crows (Corvidae: Jackdaw Corvus monedula, Hooded crow Corvus corone, Jay Garrulus glandarius, Magpie Pica pica), sometimes gulls and herons, rats, squirrels, less often reptils.

The raptor is quite adaptable in diet, being the spectrum of preys variable among different part of the range, according to local prey availability. Ontiveros (2016) reports the following diet composition: rabbits (28%), pigeons (24%), partridges (15,3%), other mammals (7%), crows (7%), reptils (6,4%). In Catalonia, a study on food pellets revealed a diet consisting of European rabbit (27%), Columbidae (32.5%) and Red partridges (11.7%) (Resano, 2011). In Greece the rabbit represent 40.8 % of rests in food pellets, whereas birds account for 32.4% (Kastritis 2011). In Cyprus, partridges account for 30-33% as proportion of preys in food pellets, rats 29-33% Columbidae 14-26%, Corvidae 2-7%, with food spectrum ranging according to breeding stage (Iezekiel et al., 2011). Changes in diet due to seasonal prey availability are also reported, showing birds prevailing (80%) from August to April, and mammals from May to July, as rabbits become more abundant (Cramp & Simmons 1980). The diet of juveniles in dispersal appears richer in rabbit than that of breeding adults (Moleón et al., 2009).

The preys are searched by patrolling and taken on ground after stoop from perches or soaring position; birds are often catched in flight with ambushes from cover of trees as they take-off. Frequently the raptor hunts in pair. The frequency of catching rabbits is more affected by prey accessibility (due to a lower vegetation coverage) than prey abundance (Ontiveros et al., 2005).

In the Mediterranean region, Bonelli’s eagles coexist simpatrically with Golden eagles (Aquila chrysaetos). Although the two eagles can nest quite closely without apparent hostility, interspecific competition is reported, sometimes by means of mutual exclusion from their respective territories (Thiollay 1968, Cheylan 1973 in Cramp & Simmons 1980). Competition for food and occupation of territories previously inhabited by Bonelli’s eagle (impeding recolonization) have been proposed as the main competition mechanisms (López-López, 2011). However the presence of neighbour Golden eagle breeding pairs is considered as negligible for productivity, being this parameter negatively affected only in areas with high density of Golden or Bonelli’s eagles, or in breeding pairs composed by pre-adult Bonelli’s eagles (Carrete et al. 2006).

During hatching, Bonelli’s eagle males frequently show aggressive behaviour and pursuits against intruding Golden eagles, as well as Griffon vultures or Booted eagles, although most other diurnal raptors are tolerated; likewise, Bonelli’s eagles intruders in golden eagles territories can be attacked, with possible fatal consequences.

Pairs are highly territorial and defend their territories from neighbour pairs by visual displays consisting of typical undulating flights, with sequences of aerial plunges and rises. Direct attacks to conspecific birds are mainly launched by males during the breeding period. Immatures are often tolerated by adults, even in August-September, possibly being young birds of the previous breeding season. Territories are variable in size reflecting differences in quality, the majority extending 50-130 km2, with normal activity radius of 5-6 km around the eyrie during the breeding period (Thiollay 1968 in Cramp & Simmons 1980). Recent studies on Bonelli’s eagles tagged with GPS devices revealed very little overlap between home-ranges of different neighbour pairs, and a higher quality in smaller home-ranges (Rosario et al. 2011).

Pair density is variable among different areas. In Spain, the average distance between neighbour pairs is 11.9 km, ranging between 8.2 km (highest density in the Penibétic Cordilleras) and 33.7 km (Ebro basin, Arroyo)

The main known threats for this species in our country are hunting, habitat destruction (quarries, house building etc), disturbance in nesting sites (growth of tourism), road opening which makes habitats more accessible for poachers and probably food shortage in certain places. Moreover, in many areas Bonelli's Eagle is - unduly - considered to be a threat for newborn lambs .

Moreover, studies of its ecology should be conducted and the features of the islands’ population must be investigated. With the obtained knowledge, we will be able to proceed to careful management and protection per area as well as to inform residents and hunters in the areas where it occurs.

 

●      the ecological niche of two characteristic animals;

Weasel (Mustela nivalis) and Fox (Vulpes vulpes )

●      two organisms that share the same food (niche partitioning) and the way that they manage it;
Golden eagle and Bonelli eagle.