Back to slow ringing

Observations:

Ringing:

I'm starting to sense something of a pattern with the good ringing days immediately being followed up by pretty bad days. As yesterday was among the best days of the season, it must thus come as no surprise that today was pretty boring by comparison, with not even 20 birds being caught. This probably owes in great part to the fact that a constant light and foggy precipitation throughout the morning and day had reduced visibility to less than five kilometers, and (in my experience) birds tend to be less active during such conditions. 

Robins (Erithacus rubecula) still make out bulk of the captures, today with 8 individuals out of the total 18, but as they in general are very nice birds to work with, I have no complaints about that. With so many birds of one species being caught, it's fun to compare and contrast especially variable traits among individuals, such as, in robins, the size and colour of the light dots at the tips of the primary coverts. Now, most Robins have juvenile-type greater coverts rather large, whitish-buff tips on them, while most of the time, the adult-type coverts lack any such spots. However, there are many exceptions to this rule, with the juvenile feathers of some Robins lacking the spots entirely, and some adult feathers having (usually smaller and darker coloured) spots. A less extreme example of the last type of exception is shown in the picture below:

Wing of a 1k Robin, with the red line showing the moult limit between the juvenile-type outer greater coverts with big light spots on the tips, and the adult-type inner greater coverts, with small, more dark-buffish tips. Foto: Alba M. Holmberg.

Because of these complications, it is always important to, in addition to any change in the spotting of the greater coverts, also establish that there is a difference of base colours between the two generations of feathers before declaring a moult limit to be present (in Robins). 

Today's captures:

At the station: Strummer, Alba, Johan, Emil?