Know your islands
There are 11 species of herons represented in the Cayman Islands, including six breeding residents. These waterbirds are easy to distinguish by their stabbing bills and their neck folded back into their shoulders in flight.
The following information was sourced from Birds of the Cayman Islands, written by Patricia Bradley and the accompanying photographs were taken by Frank Roulstone.
The Tricolored Heron or Grey gauldin
Tricoloured herons are found throughout the Cayman Islands and are often seen in the local mangroves and breed in the mangrove at the edge of North Sound, Grand Cayman, along with the Snowy Egrets. The Tricolored heron is a bird of all wetland habitats.
Tricolored herons are medium-sized birds with the long legs and neck characteristic of herons and egrets. Legs are yellow in the non-breeding season and pink in the breeding season.
In flight and at rest this beautiful bird holds its neck at a curve, similar to an ‘S’. It has a long, pointed bill that, in the non-breeding season, is yellow with a black tip. In the breeding season, bright blue replaces yellow on the bill.
Its underside and neck is white, a characteristic that is unique to this particular species, but makes them very difficult to find because they blend into the vegetation in their habitat.
The young are mostly chestnut on the neck, back and wings. Female Tricolored herons lay approximately three to four bluish eggs per clutch, with one clutch per year.
Tricolored herons are migratory birds. You may see large groups of this bird with other herons in the early morning while feeding, otherwise they are usually solitary.
This heron flies for short distances with its neck outstretched like an ibis, giving a complaining croaking call. The majority of its diet is fish, but it also eats amphibians and spiders.
The Tricolored heron also eats insects, including mosquitoes. They are also a biological indicator which will help determine if other species in the habitat are healthy or are in danger due to environmental conditions.
The Green Heron
Green herons have a range throughout the Cayman Islands, and frequent both salt and fresh water, showing great flexibility in habitat choice.
Favoured habitats are mangrove-lined shores and estuaries, but it is also found along the Ironshore and MRCU canals on Grand Cayman
Green herons are small with short legs, compared to other herons. Adults have a glossy dark steely blue crown and back, wings that are dark petrol blue with pale edging to feathers.
The bill is dark with a long, sharp point and the legs and feet vary from olive to bright orange in breeding season.
Coloration of immature herons is different. They are smaller and paler, the chestnut is also replaced by brown streaks on the neck. Its back and crown are striped light and dark brown. Green herons breed once yearly which generally begins anytime from March through July. It nests on or near the ground in mangroves and around grassy ponds with an average clutch of three.
Green herons have an elaborate set of calls and body postures that they use for communicating with other green herons. Examples are their elaborate courtship displays, warning calls when a predator is detected, and territorial displays. It has a loud raucous call when it is alarmed.
The most common feeding technique is to stand in a crouched position, horizontal to the water surface, with neck and head retracted. They stand still for long periods of time (except for a flickering tail). Their heavy bill enables them to capture large prey.
Green herons are carnivorous, mainly eating fish and invertebrates including dragonflies and other vertebrates including lizards, frogs and snakes. Green herons are important predators of fish and invertebrates in the aquatic ecosystems where they live.
You can support native and migratory birds by keeping a natural yard. Plant a variety of native trees (Wild Fig attracts many species) and shrubs. They offer both food and protection for birds. Please control introduced animals – rats, cats and dogs! You could also get involved with the Wildlife Rescue Unit and help care for injured birds and other wildlife. Please contact [email protected] or 949-0121.
Last week’s answer: The name of the fish distinguished by filaments trailing from dorsal and anal fins, with a blunt forehead often swimming in open water off the North Wall is the beautiful and elusive African Pompano.
Trivia question: What is the composition of the Ironshore?
Look for the answer in next week’s feature!