This email came to our Auckland branch today - any help in answering would be greatly appreciated:
I'm an Auckland University Masters student currently studying a lake out near Bethells Beach, Lake Kawaupaku. There is a resident shag colony out there, which i have roughly identified as pied shags. I was just wondering if anyone at Forest and Birds knows a lot about shags, or could point me in the direction of some good information. As far as i can gather the colony at Bethells has only been present for the last 10 to 15 years. However the name of the lake (Kawaupaku = little shag) would suggest that shags were present there in the past. Would you happen to know a reason for their decline? I realise that a bounty was put on shags heads for some time, but i've also had it suggested to me that DDT may have played a role in the lowering of their numbers also, but i havnt been able to find any good literature to back this up yet.
Also, i was wondering whether shags chicks tend to stay with the colony after they become adults, or move away (obviously this affects how fast the colony grows in size).
Any information you could give me would be greatly appreciated.
Thanks
Stacey