Bird in Vietnam with Reddish-Brown Vent

The birds in Vietnam with reddish-brown vent could be:

1/ Eurasian hobby 
(Cắt Trung Quốc, Falco subbuteo) or just hobby

Vietnam Travel Guide

Travel Inspirations

Cai Rang Floating Market in Can Tho Vietnam, adventure travel in Vietnam
Vietnam Adventure Travel
Mui Ne Fishing Village in Phan Thiet, beach holidays in Vietnam Vietnam
Vietnam Beach Vacations
Sail boat on Halong Bay, luxury cruises in Vietnam
Vietnam Cruise Travel
Ky Quan San Mountain (Bach Moc Luong Tu), family tours in Vietnam
Vietnam Family Holidays
Turquoise blue sea in Nha Trang, luxury travel in Vietnam
Vietnam Luxury Travel
Pongour Waterfall for romantic escape holidays in Vietnam
Romantic Escapes
Hue Royal Tombs for photography tours in Vietnam
Vietnam Photo Tours
Cat Tien National Park for eco tours, wildlife tours, birding tours in Vietnam
Vietnam Eco & Wildlife
Dien Bien Phu for Vietnam historical tours, Vietnam military history tours
Vietnam Historical Tours
Vietnam Birds & Bird-Watching
Vietnam Birding & Bird Watching

Vietnam Travel Tips

Bac Kan Hotels 1
Bai Tu Long Bay Boats 3
Binh Thuan Hotels 1
Cam Ranh Hotels 3
Can Tho Hotels 5
Con Dao Islands Hotels 2
Da Lat Hotels 6
Da Nang Hotels 22
Dien Bien Hotels 1
Ha Giang Hotels 2
Halong Bay Boats 25
Halong Hotels 3
Hanoi Hotels 14
Ho Tram Beach Hotels 1
Hoa Binh Hotels 3
Hoi An Hotels 15
Hue Hotels 5
Khanh Hoa Hotels 2
Lan Ha Bay Boats 11
Lang Son Hotels 1
Moc Chau Hotels 1
Mui Ne Beach Hotels 2
Nghe An Hotels 1
Nha Trang Hotels 16
Ninh Binh Hotels 5
Phu Quoc Island Hotels 14
Phu Tho Hotels 1
Quang Binh Hotels 4
Quang Ninh Hotels 2
Quy Nhon Hotels 3
Saigon Ho Chi Minh City Hotels 10
Sapa Hotels 17
Son La Hotels 1
Thanh Hoa Hotels 1
Tien Giang Hotels 2
Vung Tau Hotels 1