Not very. He was on the railing on the boardwalk right in front of me, the birds at this place are not shy of people. They land on the railings and sometimes stay put when you approach them. Maybe 10-15 feet max. Sometimes with some lenses I have to back up when they do this!! The 100-400 is much better for close encounters than the Tamron or the 400 5.6 due to the better MFD.
Wakodahatchee Wetlands? If you care to say.