The knob-billed duck (Sarkidiornis melanotos), or comb duck, is an unusual, pan-tropical duck, found in tropical wetlands in sub-Saharan Africa, Madagascar and south Asia from Pakistan to Laos and extreme southern China. It also occurs in continental South America south to the Paraguay River region in eastern Paraguay, southeastern Brazil and the extreme northeast of Argentina, and as a vagrant on Trinidad.

It is the only known species of the genus Sarkidiornis. The supposed extinct "Mauritian comb duck" is based on misidentified remains of the Mauritian shelduck (Alopochen mauritianus); this was realized as early as 1897, but the mistaken identity can still occasionally be found in recent sources.
Comb Duck
Date Location Count
2020-11-05 11:11Etosha NP--Namutoni Camp4
2020-11-29 09:17Liuwa Plain NP1
2020-11-20 22:03Santawani Lodge
2020-11-25 10:20Naretoi4
2020-11-19 06:53Roodekopjes Dam Nature Reserve4
2020-11-19 13:00Marlborough Vlei Sewage Works1
2020-11-11 13:20Rietvlei Nature Reserve2
2020-11-10 14:41Tarangire NP--Entrance Gate2
2020-11-12 07:34Tarangire NP--Lemiyon Circuit Grasslands11
2020-11-10 06:45Lewa Wildlife Conservancy4
2020-11-28 15:30Ngala Private Game Reserve
2020-11-27 07:00Kruger NP--Transport Dam
2020-11-24 08:08Kruger NP--Lake Panic
2020-11-22 10:00Mpempe Pan2
2020-11-20 06:17Parc de Tsarasaotra (Lac Alarobia)3
2020-12-03 17:16Dhinchada Lake5
2020-11-26Bedi Port Rd8
2020-11-29 08:26Lakhota Lake5
2020-11-16 15:30Vibhapar10
2020-12-04 07:00Khijadiya Bird Sanctuary3
2020-11-21 07:50Sachana Beach1
2020-11-14 12:32Balachadi Beach2
2020-11-07 18:28Garida Dam3
2020-11-17 07:36Bhaskarpara Narmada Canal Area6
2020-11-29 08:36Nalsarovar Bird Sanctuary3
2020-11-28 15:36Kumbharwada wetland5
2020-11-13 07:25Victoria Park2
2020-11-27 07:17Lakhanka Dam3
2020-11-29 17:42Lake on New Port - Airport Rd2
2020-11-09 09:15Kanjari Deer Sanctuary2
2020-12-01 07:00Thol Bird Sanctuary
2020-11-30 16:57Rancharda Lake25
2020-11-22 12:57Gobarapura Reservoir20
2020-11-08 16:43Limbasi-Vastana Rd3
2020-11-14 06:30Narmada Canal, Karai4
2020-11-14 15:09Sant Sarovar4
2020-11-29 15:50Pariej Lake4
2020-11-11 17:00Kailana Lake11
2020-11-29 16:48Tena Lake50
2020-12-03 07:30Gogte saltpans vasai1
2020-11-27 16:55Vasundhara Park Society2
2020-11-16 09:02Timbi Lake2
2020-11-23Vadhavana Lake, Dabhoi50
2020-11-15 08:00Ottu Lake, Sirsa, IN/HR2
2020-11-22 08:00Dera Bhiana Sahib2
2020-11-20 15:50Sonvad Reservoir, Dhule1
2020-11-22 08:01Mattewara Forest1
2020-11-21 06:35Lake Chandlai, Jaipur3
2020-11-28 07:00Barkhera1
2020-11-17 10:50Kishanpura (Machal) Wetland, Indore6
2020-11-22 07:30Babaji Ki Paal--Kanota Dam3
2020-12-03 07:30Sirpur Tank8
2020-12-01 10:35Sirpur Lake1
2020-11-20 07:00Bilavali lake40
2020-12-04 08:24Buranakhedi Wetland3
2020-12-04 10:28Baroda Daulat Village Pond15
2020-11-22 07:00Baroda daulat7
2020-11-22 07:41Hatnur Dam (IBA)8
2020-11-25 10:57MoteMajra Lake25
2020-11-16 11:00Kheda Jhanjhrola HR/IN5
2020-11-29 10:00Madothi jahjjar HR/IN
2020-11-08 07:07Budhera WTP, Gurgaon2
2020-11-22 07:55Basai Wetland2
2020-12-02 12:00Hauz Khas--Lake3
2020-11-29 08:00Kheoni Wildlife Sanctuary2
2020-12-04 09:59Ankasamudra Bird Sanctuary1
2020-11-17 15:15Okhla Bird Sanctuary
2020-11-09 12:14Kot Bayana50
2020-11-14 08:25kumbhari lake, Akola3
2020-12-02 07:57Bharatpur--Keoladeo Ghana NP2
2020-11-28 07:30Bharatpur--Keoladeo Ghana NP--Sapan Mori3
2020-11-16 16:15Asan Conservation Reserve2
2020-12-02 14:15Dhanauri Wetlands -- Dhanauri Kalan East20
2020-11-29 13:37Dhanauri Wetlands6
2020-11-06 07:37Yamuna River Bed at General ganj, Mathura1
2020-11-17 10:46Vrindavan2
2020-11-08 07:50Jodhpur Jhal Bird Sanctuary4
2020-12-01 16:11Soor Sarovar Bird Sanctuary8
2020-12-03 11:00Haiderpur Wetlands -- Muzaffarnagar Zone25
2020-11-30 08:00Haiderpur Wetlands -- Madhya Ganga Canal Trail3
2020-11-29 09:00Haiderpur Wetlands and Ganga Barrage1
2020-11-11 10:00Haiderpur Wetlands -- Bijnor Zone3
2020-11-07 08:23Hastinapur Wildlife Sanctuary8
2020-11-28 12:14Sheikha Jheel (IBA IN-UP-21)
2020-11-22 07:00Chhatri Lake--Backwaters, Amravati4
2020-11-29 07:15Patna Pakshi Vihar (Pundhir Bird sanctuary) Etah23
2020-12-01 06:30Kekatpur Lake2
2020-11-29 07:16Dodda Tumakuru Kere3
2020-12-01 07:00Manjeera Wildlife Sanctuary6
2020-11-29 15:40Gangaikondan Kulam7
2020-11-11 06:00Vijayanarayanam Tank8
2020-12-01 08:00Kovilpapakudi Tank1
2020-11-29 08:00Ghodazari Lake3
2020-11-23 15:05Periya Kanmai4
2020-11-28 13:57Barbanda Pond and Surroundings4
2020-11-28 06:56Baruipur Marshes2
2020-11-28 12:00Kulia Jhill1