Vērotāj, varbūt tad, kad būs kas būtisks, jo pagaidām neko konkrētu nevaram tik un tā pateikt...
No Hankokas foruma šādi pētijumu rezultāti par baltgalvas ērgļu mazuļu izdzīvošanas izredzēm pirmajā gadā, bet interesanti, vai tas arī uz zivjērgļiem varētu būt attiecināms?
https://www.facebook.com/berrycollegeeagles
Claudia Perkins
Regarding the question of eaglet survival, I found the following quite informative and very encouraging (it's from the Hornby Eagle Group website) :
Q. Is it true that 50% of bald eagle fledglings will not survive their first year?
A. This may not be the case; some scientists say that earlier estimates were speculative. As radio telemetry study data increase, it appears that first-year survival is better in some areas than in others, with urban eaglets not faring quite as well as those from rural areas.
Findings from some of these studies (all of which had good sample size):
•Chesapeake Bay: 100% survived from 8 weeks of age to nest departure at 10–12 weeks of age; 100% survived their first year
• Texas: 97% survived to nest departure
• Florida: 93% survived to nest departure; a minimum of 63% survived their first year
•California: 77% survived the first year
•Montana: 91% survived their first year
• Yellowstone National Park: 87% survived their first year
• Maine: minimum of 73% survived their first year
Survival chances improve with each succeeding year.