Migratory birds of the maltese islands
Rachel Balzan 5 Diamond
Introduction In this project I will be writing about variations and selection with reference to a small selection of migratory birds of the Maltese islands. I chose to study birds as part of my e-Twinning project with Spain, Greece, Italy and Poland “Across Europe With Migratory Birds�. In this project I will relate our work to the work done by Charles Darwin in the Voyage of the Beagle. The voyage began on 27 December 1831. It lasted almost five years. Darwin spent most of that time on land investigating geology and making natural history collections, while the Beagle surveyed and charted coasts. He kept careful notes of his observations and theoretical speculations, and at intervals during the voyage his specimens were sent to Cambridge together with letters including a copy of his journal for his family. He had some expertise in geology, beetle collecting and dissecting marine invertebrates, but in all other areas was a novice and ably collected specimens for expert appraisal. Despite suffering badly from seasickness, Darwin wrote copious notes while on board the ship. The avifauna of Malta includes a total of 384 species, of which 167 are rare or accidental. Malta has a limited range of breeding birds with only 21 regular breeders and about 17 occasional breeders. However, it lies on a major migration route and many more species pass through during spring and autumn.
Variations in Maltese birds
Loons Order: Gaviiformes Family: Gaviidae Loons, known as Divers in Europe, are group of aquatic birds found in many parts of North America and northern Europe. They are the size of a large duck or small goose, which they somewhat resembles in shape when swimming, but they completely unrelated to these waterfowl. There are 5 species worldwide and 1 species which occurs in Malta .
The Red-throated Loon or Red-throated Diver is a migratory aquatic bird. It breeds primarily in Arctic regions, and winters in northern coastal waters. The Red-throated Loon is the smallest and lightest of the world's loons. In winter, it is a nondescript bird, greyish above fading to white below. During the breeding season, it acquires the distinctive reddish throat patch which is the basis for its common name. Fish form the bulk of its diet, though amphibians, invertebrates and plant material are sometimes eaten as well. The Red-throated Loon has a large global population and a significant global range, though some populations are declining. Oil spills, habitat degradation, pollution and fishing nets are among the major threats this species faces.
Gannets Order: Pelecaniformes Family: Sulidae This group comprise medium-to-large coastal sea-birds that plungedive for fish. There are about 10 species worldwide and 1 species which occurs in Malta.
The Northern Gannet is a seabird and is the largest member of the gannet family, Sulidae. Gannet pairs may remain together over several seasons. They are migratory and most winter at sea, heading further south in the Atlantic.
Pelicans Order: Pelecaniformes Family: Pelecanidae Pelicans are large water birds with a distinctive pouch under the beak. As with other members of the order Pelecaniformes, they have webbed feet with four toes. There are about 8 species worldwide and 1 species which occurs in Malta.
The Great White Pelican is a huge bird. It is well adapted for aquatic life.
Flamingos Order: Phoenicopteriformes Family: Phoenicopteridae Flamingos are gregarious wading birds, usually 3 to 5 feet (1.5 m) high, found in both the Western and Eastern Hemispheres. They are more numerous in the latter. Flamingos filter-feed on shellfish and algae. Their oddly-shaped beaks are specially adapted to separate mud and silt from the food they consume, and are uniquely used upside-down. There are about 6 species worldwide and 1 species which occurs in Malta.
The Greater Flamingo is the most widespread species of the flamingo family. Some populations are short distance migrants, and sightings north of the breeding range are relatively frequent; however, given the species' popularity in captivity, whether or not these are truly wild individuals is a matter of some debate. The Greater Flamingo is the state bird of Gujarat, India.
Osprey
Order: Falconiformes Family: Pandionidae The Pandionidae family contains only one species, the Osprey. The Osprey is a medium large raptor which is a specialist fish-eater with a worldwide distribution.
The Osprey tolerates a wide variety of habitats, nesting in any location near a body of water providing an adequate food supply. It is found on all continents except Antarctica although in South America it occurs only as a non-breeding migrant. The Osprey's diet consists almost exclusively of fish.
Thick-knees Order: Charadriiformes Family: Burhinidae The thick-knees are a group of largely tropical waders in the family Burhinidae. They are found worldwide within the tropical zone, with some species also breeding in temperate Europe and Australia. They are medium to large waders with strong black or yellow black bills, large yellow eyes and cryptic plumage. Despite being classed as waders, most species have a preference for arid or semi-arid habitats. There are about 9 species worldwide and 1 species which occurs in Malta.
This species prefers dry open habitats with some bare ground. Food consists of insects and other small invertebrates. It will also take small reptiles and rodents. It lays 2-3 eggs in a narrow scrape in the ground.
Colours Bird
Colours
Loons
In winter - greyish above fading to white below. During the breeding season, it acquires the distinctive reddish throat patch.
Gannets
Their plumage is white with black wing tips. The head and neck are brushed in a delicate yellow.
Pelicans
Pure white, a bare pink facial patch around the eye and pinkish legs.
Flamingos
White body with pink and pink legs.
Osprey
Brown on the upperparts and predominantly greyish on the head and underparts, with a black eye patch and wings.
Thick-knees
Strong yellow and black beak, large yellow eyes and cryptic plumage. The bird is striking in flight, with black and white wing markings.
Brown and black birds have an advantage because they can hide behind trees. Their colour is good for camoflauge. A white bird has a problem because it is easily seen.
Size of bird Bird
Size
Loons
53cm - 69cm
Gannets
81cm – 110cm
Pelicans
140cm - 180 cm
Flamingos
110cm – 150 cm
Osprey
60 cm
Thick-knees
38cm - 46cm
From the table we see that there are many different sizes of birds. They range from 38cm to 180cm. The smaller birds can fly with ease and build small nests. They can look for small food in different places like soil, bark of trees, holes, between rubble walls etc. The larger birds seek food in larger places. They also need larger or more abundant food. They are heavier to fly although they fly with ease and migrate to distant countries.
Size of leg Bird
Size of leg
Loons
Short
Gannets
Short
Pelicans
Short
Flamingos
Tall
Osprey
Short
Thick-knees
Tall
There are more birds that have short legs. A bird with long legs can walk more comfortable on land.
Size of leg
Short
Tall
Type of feathers Bird
Type of feather
Loons
Fine soft down feathers
Gannets
Lightening feathers
Pelicans
Dark, flight feathers
Flamingos
Black, flight feathers
Osprey
Finger-like feathers
Thick-knees
Black and white flight feathers
Structure of beak Bird
Structure
Loons
Long, narrow and pointed
Gannets
Long, narrow and pointed
Pelicans
Long and wide
Flamingos
Long and wide
Osprey
Small and pointed
Thick-knees
Long, narrow and pointed
There are a lot of birds with long beaks. This is an advantage for them because they can catch their prey more easily. It’s easy to reach for food in holes. Short beak is comfortable to feed on seeds.
Conclusion In this project I did some research about six migratory birds of Malta. I wanted to point out the different variations in only 5 characteristics. Different variations allow for different exploitations of different habitats, acquisition of different foods, different forms of shelter and defence from predators and different movements. The better adapted species will be better during competition for food, shelter, mate, etc and therefore they will be able to survive more. Variation exists within all populations of organisms. This occurs partly because random mutations cause changes in the genome of an individual organism, and these mutations can be passed to offspring. Throughout the individuals’ lives, their genomes interact with their environments to cause variations in traits. Individuals with certain variants of the trait may survive and reproduce more than individuals with other variants. Therefore the population evolves. Factors that affect reproductive success are also important, an issue that Charles Darwin developed in his ideas on sexual selection, for example. Natural selection acts on the phenotype, or the observable characteristics of an organism, but the genetic (heritable) basis of any phenotype that gives a reproductive advantage will become more common in a population. Over time, this process can result in populations that specialize for particular ecological niches and may eventually result in the emergence of new species