rails error. who is calling postgres? who?

rails-log

$ bundle exec rails server
=> Booting WEBrick
=> Rails 3.2.13 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/Users/gill/.rvm/gems/ruby-1.9.2-p320/gems/bundler-1.1.4/lib/bundler/rubygems_integration.rb:147:in `block in replace_gem': Please install the postgresql adapter: `gem install activerecord-postgresql-adapter` (pg is not part of the bundle. Add it to Gemfile.) (LoadError)
  from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:7:in `<top (required)>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:50:in `resolve_hash_connection'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:27:in `spec'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:130:in `establish_connection'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/railtie.rb:82:in `block (2 levels) in <class:Railtie>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:26:in `block in on_load'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:25:in `each'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/lazy_load_hooks.rb:25:in `on_load'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activerecord-3.2.13/lib/active_record/railtie.rb:74:in `block in <class:Railtie>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `instance_exec'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `run'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/initializable.rb:55:in `block in run_initializers'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `each'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `run_initializers'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/application.rb:136:in `initialize!'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in `method_missing'
	from /workspace/vagrant/rails-dev-box/AMA/config/environment.rb:5:in `<top (required)>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
	from /workspace/vagrant/rails-dev-box/AMA/config.ru:3:in `block in <main>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
	from /workspace/vagrant/rails-dev-box/AMA/config.ru:in `new'
	from /workspace/vagrant/rails-dev-box/AMA/config.ru:in `<main>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/builder.rb:40:in `eval'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/builder.rb:40:in `parse_file'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/server.rb:200:in `app'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/commands/server.rb:46:in `app'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/server.rb:304:in `wrapped_app'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/rack-1.4.5/lib/rack/server.rb:254:in `start'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/commands/server.rb:70:in `start'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/commands.rb:55:in `block in <top (required)>'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/commands.rb:50:in `tap'
	from /Users/gill/.rvm/gems/ruby-1.9.2-p320@global/gems/railties-3.2.13/lib/rails/commands.rb:50:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'