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Posts tagged ‘intraspecific’


Bernard Joubert’s article on communication of ST Eagles

Dec 10, 2017 / Comment

Photos taken by Bernard Joubert: Short-toed Eagles' communication posturesThe following paper by Bernard Joubert on Short-toed Snake Eagle communication abilities was recently published:

• Bernard JOUBERT, 2017 – Circaète Jean-le-Blanc : des "mots" pour le dire [Short-toed Eagle: "words" to tell] // Rapaces de France, n° 19: pp. 54-55. – Short-toed Eagle. file (Fr) {rough translation}.

The summary

Short-toed Snake Eagles have the rich social language, various tools which help them to express their intentions and relation to behaviour of other representatives of their species. The main problem of studying their behavioural language is defined by difficulties of correct interpretations. Besides various vocal signals, these eagles reveal a rich body language vocabulary, thanks to the extraordinary plasticity of their plumage, which is used for hovering in different airflows while hunting. Simplistically, 3 types of signals are identified: those related to movements, postures and holding of plumage.

Examples of the gestural communication are: aggressive demonstratively slow and strong wing-beats, so-called «vulture» flights, territorial «festoon» display flights.

Communicating through postures includes: an aggressive «albatross» posture, a posture of «angel» which is used for marking a chosen nest for the partner.

Communicating through appearance changes at close contacts comprises states of occipital feathers and pupil size, which can express both tension and relaxation of birds.

This brief review is nothing more than an invitation to observe and puzzle out those various and subtle means of ST Eagles’ communication.

 

Life of Short-toed Eagles in photos by Bernard Joubert

Feb 19, 2017 / Comment

JOUBERT B. 2010-2016. Haute-LoireThese amazing pictures and text were published in the latest La Plume du Circaète. Few of them were included in the previous galleries of Bernard Joubert on our site. Then, several new photos taken in March 2016 have been added and described by the author. Many thanks to him for sharing the pictures and especially for detailed comments on them, also to Ferenc and Gábor Papp for their kind help in the translation!

Moments of life

During these 20 years, while we have been following the Short-toed Eagles, we could obtain numerous pictures taken in ideal conditions, some of which we later published, however, I never played with the thought seriously that I should take advantage of it since photography is very laborious and has little use in conservation.

Nevertheless, in 2010, I decided that I would give it a try at a nest site where I could do it without any disturbance. In January, I built a hide, which I dug in the ground about twenty metres from the nest. I made a frame of beech and covered it with smaller pine branches. This nest site seemed to attract this particular pair, they visited it during last autumn several times.

I made myself comfortable in the hide in the first days of March, not knowing how remarkable moments and wonderful events of the everyday life I would experience soon.

I used a quite mediocre Nikon camera with 110 mm equivalent focus length*, but still I could record their whole breeding cycle except incubation without being noticed by them.

I would like to share a few pictures…

Bernard Joubert

* – also, photos taken with Panasonic Lumix FZ1000 are included.

 

Short-toed Eagles in Northern Ukraine. Photos of 2016

Jan 31, 2017 / Comment

PISMENNYI K. 2016. Northern UkraineHere is the next annual gallery of pictures taken in Kiev, Chernihiv and Sumy Regions of Northern Ukraine in 2016. Short-toed Eagles of local pairs monitored during more than 10 years are captured in them. All the birds are indicated in captions by a letter and a year of the first representation in photo galleries on our site, starting with A11 – the old, very striped and dark-spotted, rather small but aggressive female living in the Mizhrichynskyi Nature Park /map/.

 

Migrations & wintering of STE, works of Ugo Mellone et al.

Sep 29, 2016 / Comment

An adult short-toed eagle reaching the Spanish coast of the Strait of Gibraltar during springThe following post is dedicated to migrations of Short-toed Eagles of the Apennine Peninsula; Ugo Mellone summarizes research and observational data on the topic obtained at the moment:

• Ugo MELLONE, 2016 – Resolving the puzzle of Short-toed Eagle migration // www.bou.org.uk (En).

The previously described article is currently available to download:

• Ugo MELLONE, Giuseppe LUCIA, Egidio MALLÌA, Vicente URIOS, 2016 – Individual variation in orientation promotes a 3000-km latitudinal change in wintering grounds in a long-distance migratory raptor // Ibis. Accepted Author Manuscript. doi:10.1111/ibi.12401 – Short-toed Eagle. file (En).

 

Fresh article on migration & wintering of Short-toed Eagle

Jul 30, 2016 / 1 Comment

The following article has recently been accepted for publishing online. The abstract and description are available for free at the moment:

Ugo MELLONE, Giuseppe LUCIA, Egidio MALLÌA, Vicente URIOS, 2016 – Individual variation in orientation promotes a 3000-km latitudinal change in wintering grounds in a long-distance migratory raptor // Ibis. Accepted Author Manuscript. doi:10.1111/ibi.12401 (En).

 

Video and pictures of STEs in Northern Ukraine in 2015

Feb 7, 2016 / Comment

This video is a compilation of various short parts of the filmingPISMENNYI K. 2015. Northern Ukraine done in Northern Ukraine during the last year’s season from spring to fall. The shown moments of Short-toed Eagles’ life are provided with explanatory subtitles. The second part of the annual photo gallery contains descriptions of behaviour and habits of local STEs as well. Please see them under each presented picture.

 

La Plume du Circaète n° 11 is out

Mar 12, 2015 / Comment
La Plume du Circaète on the LPO website

The long-awaited next issue of the bulletin La Plume du Circaète has come out – Short-toed Eagle. file (Fr) {rough translation} at long last!

The list of contents (Fr):

Suivi et conservation 2 »

Parc national des Cévennes: protection et nidification 2; Suivi dans les Alpes 4; Le circaète dans l’Aude 5; 12 ans de suivi en Isère 6; Exigences écologiques 7; Oiseaux et lignes éléctriques 11

Etude des comportements 12 »

Gestion des conflits 12; Que font-ils au nid ? 13

International 14 »

Reproduction en Israël 14; Feeding ecology 15

Yves BOUDOINT () 16 »