Can anyone help with there ages....

[SpidersHuman]

hi I'm new to ducks an was wondering if anyone could approximately tell how old they are. I'm not sure there ages when I got them but I've had the mallard since May. 7th and the Pekin (large whitish one) and the 2 Indian Runners since May.12th.Thank you.

 

[SouthernPride]

4-5 weeks would be my guess.