Many thanks to Luca Baghino for sharing this fresh article dedicated to ongoing studies of Short-toed Eagle migration from regions of Europe:
• 
Nicolantonio AGOSTINI, Luca BAGHINO, Wouter M. G. VANSTEELANT & Michele PANUCCIO, 2016 – Age-related timing of Short-toed Snake Eagle Circaetus gallicus migration along detoured and direct flyways // Bird Study, DOI: 10.1080 / 00063657.2016.1264362. – 
(En).
The paper is available on the ResearchGate and Medraptors websites.
Currently, you can find online full texts of these two articles published in scientific journals in 2004 and 2005. The papers have already been mentioned on our site before:
• Paola SACCHI, Dominga SOGLIA, Sandra MAIONE, Giuseppe MENEGUZ, Massimo CAMPORA, Roberto RASERO, 2004 – A non-invasive test for sex identification in Short-toed Eagle (Circaetus gallicus) // Molecular & Cellular Probes, 18 (3): pp. 193-196. – (En).
• Massimo CAMPORA, Guido CATTANEO, 2005 – Ageing and sexing Short-toed Eagles // British Birds, 98: pp. 370-376. – (En).
A website of the Ukrainian Birds of Prey Research Centre (Український центр досліджень хижих птахів) exists since 2008. Posts dedicated to Short-toed Eagle have also been published on it. They contain texts, tables and photos. The main of them are represented below:
• К. Письменный, 2014 – Спостереження за змієїдами біля їхніх гніздових ділянок [Observations of Short-toed Eagles at their breeding sites] (Uk).
• К. Письменный, 2013 – Некоторые результаты десятилетнего мониторинга змееяда на севере Украины [Some results of ten years monitoring of Short-toed Eagle in the North of Ukraine] (Ru) {related post}.
• С. Прокопенко, М. Бескаравайный, 2013 – Встречи змееядов в Крыму зимой 2013 года [Records of Short-toed Eagles in Crimea in winter 2013] (Ru) {related post}.
• К. Письменный, 2010 – Спутниковое слежение за миграциями змееяда [Satellite tracking of the Short-toed Eagle migration] (Ru)(En).
• С. Домашевский, М. Дравецки, М. Легоцки, М. Олекшак, 2010 – Результаты украинско-словацкой экспедиции на севере Украины [Results of Ukrainian-Slovac expedition to the north of Ukraine] (Ru)(En) {related post}.
• К. Письменный, С. Домашевский, Р. Ватрасевич, 2010 – Практика установки защиты от куниц на гнездовых деревьях хищных птиц [The practice of installing protection against martens for nesting trees of birds of prey] (Ru)(En).
• 2011 – Создание онлайн-определителя возраста и пола змееяда [Creation of online handbook for aging and sexing of Short-toed Eagle] (Ru) {related post}.
• 2010 – Опыт спасения гнезда змееяда [The experience of saving Short-toed Eagle’s nest] (Ru).
Rough translations from the original languages are available on the UBPRC website; please, use the special button in the top menu.
Dear Circaetus gallicus lovers and researchers! Let us, please, invite you to contribute your photos (info@short-toed-eagle.net) of the Eagles of age and sex known for certain. These photos will be inserted into the special gallery which has been created on initiative of Francesco Petretti. We aim to make something like an online handbook to help to describe differences between sexes and ages of Short-toed Eagle and finally to make their field identification easier. Each contributed photo should be supplied with information, examples of which can already be seen below each inserted image.
Photos of different aged Short-toed Eagle chicks are made by Jean-Pierre Malafosse and are published now by courtesy of the author.
They can be helpful to researchers for estimated determination of the chicks’ age.
Visit please Javier Blasco-Zumeta’s site to find some information on identification of birds in nature. This information sheet – (En) on two pages with demonstrative photos (moult and age-specific changes) – could be helpful in the field together with article of Guido Premuda and Andrea Corso about the plumage characters. Also we have the fullsized illustrations to view the plumage more particularly.