Nest box selection in the Eurasian kestrel (Falco Tinnunculus) in the Trysil region in Norway
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- Master's theses (INA) 
Nest box selection in the Eurasian kestrel (Falco tinnunculus) in Southern Norway was estimated from fieldwork in Trysil Municipality in 2007 and by use of additional field data from 2005 and 2006. Used versus not used nest boxes was used as response variables and tested against multiple explanatory variables. Time of hatching also was used as response variable in 2007, where early arrivals were hypothesized to select the best nest boxes or the best habitats. Microhabitat analyses within a 0.1 ha quadrate around the nest boxes and macrohabitat analyses outside this quadrate gave "general preference" over time, "year effect" preference and "early arrival" preference. Kestrels generally selected nest boxes in open, flat habitats such as bogs and falling areas where there were not too many competing pairs nearby. Differences in vole numbers between years resulted in year effect when voles were scarce. Kestrels selected nest boxes in close proximity to developed areas in 2005 when voles were scarce, probably because of higher density of alternative prey, such as birds, lizards and insects. Neither nest box size nor construction was important for nest box selection, but kestrels seemed to prefer boxes where the entrance hole was not too big. Some degree of cover around the nest box tree, measured as number of trees around the nest box, also seemed to matter. In addition, south facing nest boxes were selected earlier than others. I recommend using time of hatching in addition to nest box use as response variable in further studies on nest box selection by kestrels.