Dusky Moorhen (Gallinula tenebrosa)
It is a fascinating species of bird. The Dusky Moorhen belongs to the rail family and is scientifically known as Gallinula Tenebrosa. This water bird is of medium size and has a blackish-grey body with different shades, along with a glowing reddish shield on its bill.
This dusky moorhen thrives in wetlands. It is found in India, Australia and New Guinea. This article will examine the physical characteristics and appearance of dusky moorhens.
Physical Characteristics of Dusky Moorhen
Appearance
The Dusky Moorhen, a medium-sized species of bird, is slightly smaller than the Purple Swamphen. It is a large bird, measuring between 34 and 40 cm. This makes it stand out in its habitats. The body of the bird is mostly dark grey or black, with brownish tinges on its uppish parts. This colouration is used to camouflage the bird in dense vegetation such as swamps and marshes.
The Dusky Moorhen’s red shield on the front and its yellow bill tip are two of its most striking features. These colours are not only a way to identify this bird but also help in social interaction and mate attraction. The legs of the Dusky Moorhen are a mixture of green-red and orange-yellow, among other characteristics.
Appearance of Juveniles and Chicks
The appearance of immature Dusky Moorhens is different from that of adults. They are usually duller in colour, with greyish-brown feathers on the head area ending in black beaks.
These colour patterns can help nestlings avoid predators by helping them blend into their surroundings. This is due to the camouflage qualities that nature has bestowed on these animals through evolution.
Nestlings are black, have red mandibles, and appear downy. They can easily be distinguished from adults, while they grow. Their feathering changes gradually, becoming similar to older birds.
Body and Plumage
The Dusky Moorhen’s compact, streamlined body allows it to move through dense swamp vegetation. The majority of their plumage is dark grey or black, with a slight reddish tint on the top.
This colour allows birds to blend in with their surroundings, protecting them from predators like cats and hawks that hunt only by sight. The belly feathers have a light grey wash, and there is an obvious white spot on the underside of the tail that is used to show alertness or dominance.
Head and facial features
The Dusky Moorhen’s head and body are both dark grey. Its red shield between the eyes on its frontal shield is a striking feature.
It can also be worn to display territory or for mating displays. This bird can eat almost anything because of its red bill and yellow tip.
Legs and feet
The legs of Dusky Moorhens are well-adapted to the wetlands where they live most often. The colours range from green-red to orange-yellow. They also have elongated toesids that make it easier to walk in mud and swim. This allows them to feed both on land and in water. The legs and feet can also be used for territorial defence, nest building, as well as nest construction.
Habitat and Distribution
Geographical Distribution
The dusky moorhen is found in India, Australia and New Guinea.
They are found in Australia from the eastern state of Victoria, down to Queensland and as far as Cooktown. Also, they are found in the extreme east of South Australia as well as the southwest corner of Western Australia.
New Zealand is home to a few vagrants and non-breeding birds. However, rare vagrants are also found there.
Habitat Preferences
Dusky moorhens are mainly found in wetland habitats. The birds thrive in freshwater marshes, swamps and lakes, as well as rivers, urban parks and ponds where water lilies, rushes, and reeds grow.
They are rarely seen outside of these wetland habitats, except for when they are foraging in nearby vegetation. They can also be seen around river banks, dams and urban parks. This makes them a familiar sight at places such as the Gold Coast Regional Botanic Gardens or the Brisbane Botanic Gardens.
The dusky Moorhen prefers heavily vegetated freshwater swamplands, including large lakes or reservoirs and city ponds. The dusky moorhen is often found in open water with vegetation and reeds. However, they can also be found near parks, pastures, or grassy areas close to water.
Feeding Techniques
The Dusky Moorhen feeds in a variety of ways. The first is to dip its head in the water and reach aquatic plants and creatures. One way is to tilt forward the top of the body to reach submerged vegetation.
Dusky Moorhens will use their beaks to lightly peck at grasses, seeds or other food materials when they are not near water. The opportunistic nature of the Dusky Moorhen is shown by its tendency to scavenge for bird droppings and carrion.
Food and Feeding Behavior
The dusky moorhen is an omnivorous species that consumes both animal and plant material. It has a varied diet that includes seeds, young shoots from shrubs and grasses as well as fruits, algae, snails and other invertebrates.
The dusky moorhen can take advantage of the many food sources in its environment because it has a diverse diet. The dusky moorhen also feeds on carrion, bread, and bird droppings from gulls and other ducks.
Foraging Behavior
Dusky Moorhens have many different foraging habits that allow them to take advantage of different sources of food. It uses its feet and legs to navigate in different landscapes. During the breeding season, the birds are often seen moving together in search of food.
Animal-Based Diet
The dusky moorhen also feeds on animals. This includes insects, small fish, snails and annelid worms.
In addition to getting the proteins it needs, the bird’s omnivorous diet also provides other nutrients. The chicks of birds that breed during this period are fed mostly annelid worms, snails, and plant matter.
Plant-Based Diet
Plant material is also a part of its diet. In its habitat, it consumes aquatic plants such as grasses and algae. These plants are important sources of energy and nutrients for birds.
The dusky moorhen feeds by either dipping its head in the water or reversing itself, similar to other duck species. It can reach submerged aquatic plants and algae by doing so.
Breeding and Feeding of Young
The breeding season for the Dusky Moorhen varies from region to region. In the south of Australia, breeding occurs between August and December, while in the north, it takes place from January to June. Birds gather in groups to breed and build nests using reeds or other wetland plants. Nests can be placed in reeds or on the surface of open water.
Feeding Chicks
In the first weeks following hatching, the diet of the chick is mainly composed of annelids worms and insects. As they grow older, plants are gradually added to the feed.
Adults feed the chicks, and one or two adults are responsible for bringing food back to their nests. The older juveniles can also feed the chicks, by approaching adults with food and showing yellow patches on white feathers.
Nesting and Incubation
In a nest that is shared by several females in the group, females will lay between six and ten eggs. The group members all take part in the incubation of the eggs and the feeding of the young. Incubation takes approximately 24 days, with fledging occurring at around 28 days.
The chicks are constantly cared for during the early stages of their life.
Incubation and egg-laying
These dusky birds have a unique reproduction strategy, wherein several females deposit eggs in one nest. The average clutch size for females is 5-18 eggs, which means that they have communal nests.
During the 24-day incubation period, all breeders are responsible for hatching. This ensures the eggs will have a good chance of survival, as they are well protected in case predators attack.
Breeding Seasons and Nesting
The breeding season for dusky moorhens varies depending on where they live. In the southern part of Australia, breeding usually occurs from August to January. However, in the northern parts, it happens between January and June. The birds can then take advantage of the best environmental conditions to raise their young.
During the breeding period, dusky moorhens form territorial breeding groups consisting of two to seven adults. These groups incubate the eggs and raise chicks. Nests are usually built near or over water using aquatic plants and reeds. The nests can be placed at water level, slightly above it or on floating platforms. Nests can be large and bulky, with an entrance ramp made of trampled grasses.
Chick Development & Parental Care
When chicks hatch from their eggs they are fluffy and black with a bright red bill. The breeding group takes turns feeding and protecting the chicks.
Around 28 days of age, the chicks are ready to leave the nest. However, they remain protected until they can be completely independent. This extended period when the parents feed their young is crucial for them as it gives them the skills to find food and move comfortably around.
Group Foraging
During the breeding season, groups of two to seven Dusky Moorhens are formed. They also protect their territories and take care of their young. Foraging in groups has many benefits, including the fact that multiple hands make it easier to find food and provide safety from predators.
Adults will usually feed chicks by mouthing the eggs to them. This is done in groups.
Vocalizations, Behavior and Behaviour
The dusky moorhen is an extremely vocal bird, and it produces a wide variety of sounds throughout its daily life. They can be divided into different categories:
Courtship Calls
Some of these vocalizations are deep, like ‘wheeoo-wheeoo-wheeoo’ or louder sounds such as ‘kook- kook – kook. Some of these consist of deep sounds like ‘wheeoo-wheeoo-wheeoo’ or others which are loud such as ‘kook- kook – kook’. They are essential in the selection of mates and marking territory.
Alarm Calls
When faced with a threat, dusky moorhens will shriek a series of cries that alert the flock. These cries are used as warning signals. The calls are high-pitched, and can be described as “kak kak kak” or a rough “krek krek krek”. These calls can increase in frequency and intensity depending on the danger level.
Distress Calls
A dusky moorhen may scream when it is in distress or injured. This can be heard by other birds and could scare away predators. These calls can be described as sharp, short-lived sounds, such as “eek”, or “eek-eek”.
This bird’s varied voice has been shown to play a key role in its social and reproductive behaviour, as well as its survival strategy.
Communication allows individuals to converse, plan their activities in groups and prepare for potential dangers. All these factors contribute to the adaptability and prosperity of species.
Contact Calls
Dusky moorhens use a variety of contact calls to communicate within their social group and ensure unity. Some of these calls are low grunting noises like “kuk kuk kuk”, or a more melodious voice such as “wheeoo”, or “wheep”. These sounds are often used when foraging, relaxing, or engaging in activities that involve other members of the tribe.
Begging Calls
The calls of juvenile dark birds are recognizable and they ask their parents for food. These sounds are high pitched and can be described as a continuous “cheep cheep cheep” (or “peep peep peep”) These vocalisations are what ensure that the young survive and thrive.
Conservation Status
According to the IUCN Red List, the dusky moorhen is classified as “Least Concern,” meaning that it is not in immediate danger of extinction.
IUCN estimates that the global population of dusky moorhens is between 100,000 and 1,000,000 individuals.
The population trend of the dusky moorhen is stable and does not show any significant decline. This can be attributed to its ability to adapt to and thrive in a variety of wetland environments like freshwater swamps, lakes and urban ponds.
Threats and Challenges
There are still some threats and challenges that it may face in the future, despite its current status as a ‘Least concern’ bird. The destruction of habitats as wetlands are used for agriculture, urbanization or water management is one of the biggest threats to the birds.
Nesting sites of the Dusky Moorhen are located in dense vegetation close to water, making them particularly vulnerable during periods when water levels fluctuate. Water regime changes, such as drying up or draining wetlands, can have a direct impact on the breeding success of this species and its population size.
Conservation Efforts
Even though there is no conservation priority list in place, monitoring and protection activities are ongoing across its entire distribution range. It is protected in Australia, where it is the most abundant species.
Conservation organizations and government agencies conserve habitats in wetlands that are vital to the survival of dusky moorhens. These initiatives are being implemented across the areas occupied by dusky moorhens, including water management, invasive controls and sustainable land use.
The conclusion of the article is:
The Dusky Moorhen has a unique morphology, multiple feeding strategies, and complex mating behaviours. These birds can be found in many parts of Asia and Australia, where they thrive in wetlands habitats and make a significant contribution to ecosystems.
The destruction of their habitat is one of today’s major challenges for animals, and conservation measures are needed to address this. We can save this creature and its environment by understanding it.
