The following two texts are dedicated to notable physical abilities of Short-toed Eagles and, like the previous one of Bernard Joubert, are going to be included in the next issue of La Plume du Circaète (Fr):
Returning to the important topic of correct identification of differently aged Short-toed Eagles in the nature, Gábor Papp has tried to briefly describe the main characters of juvenile, 2, 3 and 4 cy eagles, and also visual differences between adult males and females. His description are illustrated with the corresponding images. Here is two versions of the text, Hungarian and English ones:
• Gábor PAPP, 2015 – A kígyászölyv kor és ivarhatározása – segédlet a terepi megfigyelések minőségének javításához [Ageing and sexing of the Short-toed Eagle – an aid to improve the quality of field observations in Hungary] // short-toed-eagle.net – (Hu), (En).
The images of an eagle killing a snake is quite widely distributed and can be found in various works of art in different countries, with different cultural traditions, rather geographically distant from each other. Some considerations to this matter are given by Bernard Joubert in his short essay for the next issue of the La Plume du Circaète bulletin which is prepared for release in the near future:
How different reproduction of different pairs can be? Some adult Short-toed Eagles occupy the same sites from year to year. They had yet been identified in 2011 by photos taken since 2006 and according to previous and new observations. The birds had got indexes A11, B11 etc. although, in spoken communication we give them more harmonious names: for example, K11 is Barry, B11 is Ospry, and so on. Then later pictures of the individuals repeatedly got into the annual photo galleries. The natural identifying details are general plumage patterns, shapes of heads, wings, beaks and general silhouettes in flight from certain angles as well as signs of moulting. The number of the examined images should be enough to select the details and to collate them. Thus, now it is possible to compare the mean reproduction – – of pairs of individuals identified from year to year for certain, definitely without replacements of mates and without clear differences in objective conditions for breeding.
• K. PISMENNYI, 2015 – Data on breeding of Short-toed Eagle in Northern Ukraine – , XLS file with formulas – ; Replacement of the biggest 14 flight feathers – ; Some short notes on Short-toed Eagles in Northern Ukraine in 2014 // short-toed-eagle.net (En).
Monitoring of 9 different pairs of Short-toed Eagles has been conducted during 10 years in Northern Ukraine (Kiev Region /map/, Mizhrichynskyi Park /map/ of Chernihiv Region, southern part of Sumy Polissya /map/). Some calculations and results of the monitoring are represented in tabular forms:
Average breeding success amounts to 0.60 juvenile / territorial pair and is quite close to this index for France: 0.57. The last result is based on observations of 2835 (!) breeding cases which have been managed to make by French national Circaetus gallicus network for 11 years (Bernard Joubert, personal communication). Also some other conclusions can be made: old pines (Pinus sylvestris) are prefered by Short-toed Eagles for nesting in Northern Ukraine; the eagles more often change their nests than they successfully breed; nest height is highly variable; the eagles’ choice of a nest depends on their previous breeding success; after an unsuccessful season the nest is changed with high probability, after successful one the following choice of a nest is unpredictable.
During 10 years of observations in Central Northern Ukraine (Kiev Region /map/, Mizhrichynskyi Park /map/) a lot of photos of several the same Short-toed Eagles have been taken. Some of them can be viewed in the galleries (just an example). Since Short-toed Eaglers’ the biggest flight feathers are often seen from a great distance they are easily recognizable in photos. Especially it concerns 4th-10th primaries of both wings. Accumulation of data allowed to determine inter-moulting periods of certain feathers:
First of all, the results might be of interest as additional information for recognizing individuals in the nature from year to year, together with individually typical plumage colouration and silhouettes in flight at certain angles in certain poses. Regular photographing of Short-toed Eagles at their breeding sites and foraging grounds allows to distinguish them with high probability without special marking, without stressing and often even without disturbing the birds at all.