Estimation of fat reserves of Robins (Erithacus rubecula) migrating through the southern coast of the Baltic Sea in spring
Grzegorz Zaniewicz , Włodzimierz Meissner , Agnieszka Ożarowska
AbstractFat is the main source of energy during bird migration, and the visual fat scoring is widelyused in the studies on, e.g., stopover ecology of migratory species. Yet, visual fat scoringcan lead to wrong conclusion due to potentially different pattern of fat distribution in spe-cies that differ in size or even individuals being during active migration and those at stop-overs. To overcome limitations of this method, we developed the predictive equation forestimating fat reserves in spring-migrating Robins - one of the most numerous migratoryspecies in Europe. The equation allows estimating the amount of fat reserves based onbody mass of birds, which was the best predictor of fat mass accumulated by Robins. Thepredictive value of the equation was reasonable with the coefficient of determinationequal to 0.56 and the standard error of estimationSEE= 0.36. This equation was tested onthe sample of adult and immature Robins captured during spring migration. The studiedspecies is a typical short/medium distance migrant employing short step migration, whichdoes not require large fat reserves. The mean estimated fat mass in spring-migrating Rob-ins varied from 0.7g in individuals with the lowest fat reserves (fat score 0) to almost two-fold higher amount, i.e., 1.38 g, in birds with the high fat score (fat score 4). In the fattestRobins, fat composed about 8% of their total body mass.
|Journal series||Ornis Fennica, ISSN 0030-5685, (A 25 pkt)|
|Publication size in sheets||0.5|
|License||Journal (articles only); published final; ; with publication|
|Score||= 25.0, 30-09-2019, ArticleFromJournal|
|Publication indicators||= 1; : 2017 = 0.686; : 2017 = 1.39 (2) - 2017=1.272 (5)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.