Matrix Model of the Steller’s Sea Eagle Population: Improvements and New Data
Romanov M.S., Masterov V.B.
Institute of Mathematical Problems of Biology, Russian Academy of Sciences, Institutskaya str., 4, Pushchino, 142290, Russia
Lomonosov Moscow State University. Moscow, 119991, Russia
Abstract. This work continues and develops our study of the Steller’s sea eagle population with help of Leslie matrix model, which results were published here in 2008. During the past 6 years the model was improved and supplemented by new series of observations. The changes affected estimations of survival of adults and immature (1–5 yrs old) birds. Earlier survival of these age classes was equated with the survival of adults in captive population of closely related species — the Bald eagle. The new estimations of survival are based on the Weibull’s model of ageing, which coefficients were assessed via allometric equation, relating survival and body mass. In addition, by 2014, new field data were collected in Sakhalin that for a total gave us 10 years of observations. Also, one of the authors collected a series of 7 years of observations of Steller’s sea eagles in Lower Amur region. Modeling of the Sakhalin population on the new material confirmed previous result about its’ decline, which rate is estimated as 1.6% per year. This estimation is even more pessimistic than the former (0.86% per year). Results for the Amur land population also suggest its’ decline at a rate of 1% per year.
Key words: Steller’s sea eagle, Haliaeetus pelagicus, matrix population model, Leslie model, stochastic model, Sakhalin, Lower Amur region, Russia.