1 Introduction  
2 Bird monitoring surveys data  
2.1 TOV-E and BBS data  
2.2 Exploratory Analysis  
2.3 Explanatory variables  
3 Modeling and inference approach  
3.1 Models  
3.2 Inference and computational approach  
3.3 Assumptions and possible extensions  
3.4 Model assessment  
4 Simulation studies  
5 Results  
5.1 Simulation Studies  
5.2 Results of the case study on total abundance of birds in mid-Scandinavia  
6 Discussion and conclusions