White-tailed Eagle Ingar found dead in Femanagh, Ireland
Ingar was almost four years old and was released as part of the Irish reintroduction programme. The cause of death is unknown, but according to the Golden Eagle Trust, illegal poisoning has been the greatest mortality factor in Ireland. http://www.goldeneagletrust.org/index.p ... Itemid=294
Naumann, Natural history of the birds of central Europe, 1899. Public domain
In most raptor species the female is the considerably larger bird – but why? “Many hypotheses have been proposed to account for the origin and maintenance of reversed size dimorphism (RSD, females being larger than males) in hawks, falcons and owls, but no consensus has been reached.” Find more information in the research article by Oliver Krüger, Bielefeld University: The evolution of reversed sexual size dimorphism in hawks, falcons and owls: a comparative study. PDF available here: Publication list Krüger, see #41 http://www.uni-bielefeld.de/biologie/vh ... tions.html
Re: Talk about
Posted: March 10th, 2015, 7:50 pm
The Genius of Birds - Embryonic development ... It's absolutely incredible!
Danish Eagle-TV: Here´s the egg-thief. Many thanks for the hint to b.h-p.
- Video available at DOF, Danish Ornithological Society -
There is a short but interesting article on egg robbers in the New Scientist, 14 March 1985, p 19. It says that the pine marten “remembers where it has robbed nests and returns to them the following season. A record of successful raids on nests, spanning more than 13 years, shows that a clutch is more likely to be lost to a pine marten if the hole (here referring to the nest of Tengmalm´s owls) has been robbed in the previous season. (…) However, if a pine marten is removed from its range it takes less than two seasons for another individual to establish itself and find the nesting sites.”
Could this be one of the reasons why White-tailed Eagles build several nests in their territory? Would make sense, since “owls recognized a nest site that had been vacant for a season as ´safe´again – the pine marten had either died or had forgotten the existence of that nest.”
Sea eagles nesting in Orkney after 142 year absence
“The two birds, which have been regular visitors to the island of Hoy over the past two years, have now built an eyrie among crags on the island. It is not clear where the pair have come from, but it is possible they may have travelled across the North Sea from Scandinavia.” Sources: The Orcadian/BBC Read more: http://www.bbc.com/news/uk-scotland-nor ... d-32181462