Long-tailed Cormorant at Lake Victoria

Species Profile

Microcarbo africanus — the Long-tailed Cormorant

The Long-tailed Cormorant is, despite its name, a distinctly compact bird — around 55 centimetres from bill tip to tail, with a wingspan of roughly 80 centimetres and a body weight of about 700 grams. It is the smaller of the two cormorant species commonly encountered at Lake Victoria, dwarfed by its larger relative the Greater Cormorant which can reach 100 centimetres and weigh up to 2.5 kilograms. The "long-tailed" part of the name refers to the relatively long, graduated tail compared with other small cormorants in its genus, though this feature is most apparent in flight.

Adults in breeding plumage are a deep, glossy blackish-green above, with a matt black underside and a distinctive bright red eye. A short crest appears briefly on the forehead at the start of the breeding season. Non-breeding birds and juveniles are browner, with a pale throat and breast that can cause confusion with immature African Darters — though the Darter is considerably larger and has a noticeably longer, kinked neck. The Long-tailed Cormorant's bill is slender and strongly hooked at the tip, perfectly adapted for gripping slippery fish.

Like all cormorants, Microcarbo africanus lacks the waterproofing oils that ducks and other waterbirds secrete onto their feathers. This makes the bird more hydrodynamic when swimming underwater, but means it must spend considerable time drying its wings after diving. The characteristic spread-wing posture is one of the most recognisable sights along Lake Victoria's papyrus-fringed shores — birds perched on exposed branches or reed stems with wings held open, like small dark angels facing the sun.

Nakiwogo Bay: A Cormorant Hotspot

Nakiwogo Bay, on the northern shore of Lake Victoria near Entebbe, holds the highest recorded Long-tailed Cormorant count in the Uganda waterbird survey network. The 1,016 individuals recorded here represent a concentration that reflects the bay's exceptional combination of productive fishing grounds and suitable roosting and nesting habitat. The bay is shallow enough for the cormorants to exploit efficiently, while the fringing papyrus and mature trees provide nesting platforms safe from most ground predators.

The bay also hosts 4,593 waterbird individuals across 41 species — a remarkable diversity for a single site. Grey-headed Gulls (1,230) lead the count, followed by Long-tailed Cormorants, with the rest of the waterbird community making up the balance. This community structure — dominated by two abundant species against a backdrop of diverse lower-abundance species — is typical of productive tropical lake shorelines where a few species exploit the most abundant food sources while many others occupy narrower ecological niches.

During eight visits to the Nakiwogo and Entebbe area, the Long-tailed Cormorant was encountered on every trip, often in groups of ten to thirty birds moving between roosting and feeding areas in the early morning. The species is most active at dawn and dusk, when fish are closer to the surface and light conditions favour ambush predation. Through the middle of the day, birds tend to roost communally, packed tightly on favourite branches or papyrus clumps, wings periodically spread to dry.

Ecology: Diving Behaviour and Prey

Long-tailed Cormorants are pursuit divers — they locate prey from the surface, then dive and swim underwater using their feet as paddles, pursuing fish through the water column. Dives are typically shallow, lasting 10–30 seconds, and the birds forage in water depths of 0.5 to 3 metres — the productive zone in Lake Victoria's nearshore habitats where sunlight penetrates and aquatic vegetation supports dense prey fish populations.

At Lake Victoria, the cormorant's diet includes juvenile Nile Perch (Lates niloticus), haplochromine cichlids — the lake's endemic fish community — and dagaa (Rastrineobola argentea), the small sardine-like fish that forms the basis of the lake's industrial fishery. This last species is of particular ecological and economic importance: dagaa shoals in enormous concentrations at night, attracted to lights from fishing boats, and forms the critical prey base not just for cormorants but for a wide range of waterbirds, including the Grey-headed Gull, African Fish Eagle and pelicans.

A single Long-tailed Cormorant may consume 100–200 grams of fish per day — modest individually, but significant in aggregate at a site like Nakiwogo Bay where over a thousand birds are present. The species is therefore a meaningful component of the bay's fish consumption, and its abundance is a reasonable proxy for the overall productivity of the nearshore fish community. A site that can sustain 1,016 Long-tailed Cormorants is a site with substantial fish resources.

Breeding and Nesting at Lake Victoria

Long-tailed Cormorants are colonial breeders, nesting in groups ranging from a handful of pairs to several hundred at favoured sites. Nests are platforms of sticks and reed stems built in trees or on papyrus over water, typically 1–4 metres above the waterline. The species can breed at any time of year in East Africa, though activity often peaks towards the end of the dry season when water levels are lowest and fish are most concentrated in the remaining shallows.

Clutch size is typically 2–4 pale blue-green eggs, with both parents sharing incubation over about 23 days. Chicks are initially naked and helpless, fed by regurgitation from both parents. They become mobile within the nest after 2–3 weeks and fledge at around 7–8 weeks. Juvenile birds remain in family groups and near the natal colony for several months, gradually becoming independent as their diving skills improve.

Nest disturbance is one of the primary threats to breeding success. Human activity near nesting colonies — fishing boats, tourist boats operated too close, or the presence of terrestrial predators at accessible nest sites — can cause entire colonies to abandon clutches or chicks. This sensitivity to disturbance makes the management of lake access around known nesting sites an important conservation consideration.