Here at Suffolk Owl Sanctuary, you may have enjoyed seeing Jack and Rose, our pair of Hooded Vultures, who take part in our afternoon display. This species is listed as Critically Endangered and it is our aim to raise awareness about their plight. We hope in the future that any progeny produced will contribute towards international conservation efforts.
In early 2020, our Education Officer, Susan, visited Kartong Bird Observatory in The Gambia to carry out two weeks of bird ringing surveys in the area. The area is well known for birds, in particular the wintering ground of many common British migrants. There is also a stable population of Hooded Vultures, which the Observatory have been monitoring for a number of years. Here, she’s asked Roger Walsh, Vice Chairman of the Observatory to explain more about the work they do.
What is Kartong Bird Observatory and what work does it do?
First-winter Lanner Falcon captured near the disused quarries at Kartong. Photo credit Colin Cross
A migratory Eurasian Scops Owl being measured. Photo credit Susan Jones
The first bird ringing surveys at Kartong in The Gambia ran in October 2000. In 2009, Colin Cross moved out to live permanently in the village and the Kartong Bird Observatory (KBO) was subsequently formed in 2010. Since that starting point, there have been up to three survey expeditions each year aimed at gathering data about the importance of the area for wildlife, and for migrant birds in particular.
We carry out regular surveys of the birdlife, with a focus on recording the usage of different habitats by the migratory species that spend the winter months in West Africa. This survey effort involves mist netting of birds at different times of the year at a number of core study sites.
New birds that are captured are identified, ringed and measured while recaptured birds are recorded and measured. A subset of the species we capture is sampled for different research projects, including genetic sequencing, parasitology and isotopic analysis. Other survey work includes year-round recording of waders and seabirds using the littoral areas around the Kartong coastline, transects for core study species and observations of birds wearing coded colour rings.
KBO collaborates with university and conservation organisations on a number of research projects looking at different aspects of ecology and conservation of both migrant and resident birds.
What is a typical day like at KBO?
KBO research assistant Dembo Jatta putting a metal ring on an adult Shikra. Photo credit Oliver Fox
No one day is like any other at the Observatory. If an expedition is running, then team members generally get up at 0530 and head out to the designated ringing survey site for a 0600 start.
Some of the mist nets will be opened in silence while it is still dark to try to catch certain species like Owls and Nightingales. We are cautious about opening all the nets too early though as there are large numbers of bats in the area that come into roost and we prefer not to catch those!
The rest of the morning is spent regularly checking the nets and extracting any birds captured, returning them to the nearby base to be ringed, measured and photographed.
Generally by around 1030 it gets too hot for catching birds safely so we take the nets down and head back to our lodge for a rest.
The afternoons are an ideal time to look for birds marked with colour rings – especially gulls, terns and waders at roosting or feeding sites on the beach and estuaries. By early evening, when the temperature has dropped to a more manageable level, we can head back out to a new survey area and put up the mist nets ready for the following morning.
The variety of dry scrub, forest, freshwater wetlands, reedbeds and tidal estuarine areas means that each survey session turns up different sets of species and often a number of unexpected surprises.
Photo showing one of the local Observatory staff surveying the mangroves for waders. Photo credit Hugh Hanmer
Can you describe the work you do with Hooded Vultures?
Wing-tagged Hooded Vulture Yellow-BA using the drinking pool at the Observatory. Photo credit Colin Cross
Three Hooded Vultures leaving roost to forage on the beach. Photo credit Hugh Hanmer
Like the majority of vulture species across the world, Hooded Vulture populations are decreasing at a worrying rate with an estimated decline of 62% in global population over the last 50 years and the species is now considered to be critically endangered.
However, in the coastal parts of The Gambia, it appears that Hooded Vultures are locally abundant and have adapted to be urban scavengers making use of a wide variety of food sources, including road kill, abattoirs, rubbish dumps and fish waste.
Understanding the population structure of different geographical groups of Hooded Vultures is necessary to determine the level of genetic diversity. We have a study underway to sample the genetic diversity at three locations in The Gambia and provide a unique insight into the population level mixing of these vultures. The blood samples taken from the vultures we are able to capture, individually mark and release, will also inform work on blood parasites. Knowledge about blood parasite diversity can be important in understanding the spread of pathogens and the influence of parasitism and disease on population levels. This work is being currently carried out in collaboration with Dr Jenny Dunn at the University of Lincoln.
What species of owls and raptors have you caught in Kartong?
As well as our focus on Palaearctic migrant birds we have captured a wide range of birds of prey during our mist-netting and other surveys at KBO, including:
Adult Lizard Buzzard showing underwing pattern. Photo credit Oliver Fox
· Western Osprey
· African Harrier-Hawk
· Hooded Vulture
· White-backed Vulture
· Eurasian Griffon Vulture
Heavily-spotted underparts on this adult female Barn Owl of the affinis race from continental Africa. Photo credit Oliver Fox
· Lizard Buzzard
· Gabar Goshawk
· Red-chested Goshawk
· Shikra
· Ovambo Sparrowhawk
· Yellow-billed Kite
· Western Barn Owl
Grey morph of the migratory Eurasian Scops Owl which winters in West Africa but is rarely seen there. Photo credit Oliver Fox
· African Scops Owl
· Eurasian Scops Owl
· Northern White-faced Owl
· Pearl-spotted Owlet
· Grey Kestrel
· Red-necked Falcon
· African Hobby
· Lanner Falcon
How can people help support the work of KBO?
The Hobby-like Red-necked Falcon is resident in Kartong and is most active at dawn and dusk when it hunts over the wetlands and woodlands. Photo credit Oliver Fox
As an organisation employing seven Gambians, we rely entirely on the financial support from individuals and groups. All the bird ringers who join our activities fully finance their own trips to West Africa. Therefore, we remain very grateful for any donations that contribute to our running costs.
We are currently applying for funding to support further work on vultures and any contributions towards this are particularly welcomed.
As well as the conservation science work with birds and other wildlife, the KBO team works closely with the local community in Kartong and surrounding villages in a variety of ways. This includes supporting youth initiatives, funding for health centres and community education projects. As part of this, we provide some funding for a dentist to visit and carry out regular hygiene checks in the local schools. KBO is proud to support this and other community projects in Kartong.
To find out more about Kartong Bird Observatory, please visit:
http://kartongbirdobservatory.org/
