Like other humming birds they mainly feed on nectar and smaller insects.
They feed mainly from flowers where they obtain nectar. The bird uses its slender bill to enable it collect nectar from flowers. The bill further enables it to feed from certain type of flowers which may be in an inaccessible area. The feeding mechanism is called trap lining method. This method enables this humming bird to move over few flowers in a long distance. After getting to a food source, they use their long tongues to suck nectar as their tails move up to maintain balance. They lick the nectar at high speeds of up to thirteen times per second. Its long wings enable it to move between the flowers thus allowing it to eat more food. Humming bird feeders also provide the hermits with sugar water or form fountains from which the birds will feed from. Male usually establish territories from which they can feed from and defend them using intimidate displays and aerial flights.
Apart from eating nectar they also eat insects through a process called hawking. Hawking is a mechanism whereby the bird catches the insect by flying then diving to grab them out of the air. The body of the great billed hermit is small therefore they need a lot of calories. It is adapted to this in the sense that it digests its food very fast (Conservapedia).
Their feeding habits are different from other humming birds in that they visit plants that are along a route covering areas of up to 1 km while other species usually have a feeding territory which is constantly maintained.
This species is non-migratory in nature thus stays within a certain range. They live in humid and transitional forests, shrubs, bamboo thickets and pre montane habitats. Exist in areas of sea level up to an altitude of about 2400m.
It is part of the Phaethornithinae subfamily and is majorly found in the South American parts. They can be found in Peru, Ecuador, eastern Colombia, east to west of Brazil and south of Bolivia. Other populations can be found in French Guiana and Surinam. The subspecies of the great billed hermit usually occupy different ranges.
The Phaethornis malaris bolivianus is found in Bolivia, western Brazil and southeastern Peru. The Phaethornis malaris insolitus is found in south Venezuela, northern Brazil and Eastern Colombia. The Phaethornis malaris malaris is found in north central Brazil, Surinam and French Guiana. The Phaethornis malaris ochraceiventris is found in western Brazil and Northeastern Peru. The Phaethornis margarettae is found in coastal eastern Brazil with concentrations in the forest. In addition to that, Phaethornis malaris moorei is found in northern Peru, eastern Ecuador and Eastern Colombia (Sibylle).
The species occur in three groups. One is found from southern Colombia, Venezuela to central Bolivia and north-western Brazil. The second population is found along the coast of south east Brazil specifically from Bahia to Espirito Santo. The third group in French Guyana to Suriname and northern Brazil.
The great billed hermit humming bird is classified under certain taxonomical units. The Phylum is Chordate, subphylum is Vertebrata, Class is Aves and Order is Apodiformes. The Family is Phaethornithinae and Genus is Phaethornis. The Genus is divided into subspecies which are spread across their habitats in South America. The subspecies are: bolivianus, malaris malaris, malaris margarettae, malaris ochraceiventris and malaris insolitus (Gill, Frank and Minturn).
The Hermit male species usually come together at display grounds during the breeding season. In order to attract a female species, the males usually sing and wig their tails and then the female chooses the best dancer and singer. After copulation the male usually separates with the female where then it can mate with other females. The females also mate with other males.
The female usually builds the next alone. The nest is cone shaped and is covered with moss for camouflaging purposes and is woven from plant fibers, feathers and animal hair then stuck together with webs or other sticky material. It then uses spider webs to hold the nest in position 1-2 m above the ground. The nest is adaptable in that it is elastic so that it expands as the chicks grow (Sibylle).
It then lays eggs with a clutch consisting of about 1-3 eggs with an incubation period of between 14-16 days. The mother does the work of raising the chicks which fledge 21-24 days after hatching. One brood is raised per season. The hatched chicks are usually blind and immobile. The young feed on partially digested food which the mother pushes down their throats. The food mostly consist of insects as nectar lacks the proper protein content for their growth. The long bill ensures that the mother pushes the food directly into their stomachs. Great billed hermits tend to feed more on insects during the breeding period with a nesting female capturing up to two thousand insects in a day.
Triorchidism refers to a condition in which a male has three testicles. Research established that this condition does exist in this bird species though it is rare. The testis of the great billed hermit consists of two parts. The left testis is the unique one as it is divided into two spherical testes and connected by one ductus deferens. The right testis is smaller compared to the left one and is dominated by the left which tends to occupy a larger space. The research was conducted in Rio Chipaota Valley in Peru and the objective was to study bird physiology (Witt and Bautista).
Predators are a major challenge to great billed hermits as they reduce their population. Squirrels, chipmunks and road runners tend to eat hermits eggs as well as eating baby humming birds. Other predators include dragonflies, snakes and lizards.
Poor weather poses a threat to humming birds. Great billed hermit humming birds that inhabit mild snow areas are at high risks of facing over-wintering. This can result in their deaths due to heavy freezing. The tropical areas where they live are occasioned by high rainfall amounts. At times this heavy rains especially over the Mexican gulf causes them to drown. Sudden storms also can cause destruction of great billed hermits’ nests and food sources.
Existence of invasive plants. These plants are usually used to improve the ornamental value of landscapes. However they pose a challenge to food sources. A huge number of invasive plants can result in outgrowth thus leading to the depletion of native nectar producing plants. These plants tend to be insufficient in nectar thus a negative impact on feeding sources of great billed hermits (Mayntz).
The other threat is bad feeders. Uncleansed hummingbird feeders pose a risk to great billed hermits. They may contain harmful toxic materials which can affect the hermit’s biological system. Poorly maintained feeders can contain bee and wasp nests which attack the birds leading to their deaths. Lack of proper nutritious nectar is also another killer substance that can be found in poorly maintained feeders.
The overall major challenge is loss of their natural habitat due to alteration of the ecosystem by human activities such as deforestation.
These bird species occupy an extremely large area thus cannot be classified as threatened by biologists. Though their numbers are decreasing, they can only be classified as least concern. A number of conservation measures though can help improve their numbers.
Green billed hermits hummingbirds are protected under CITES with individual countries protecting them under specific laws. Other conservation programs to counter these threats are: reforestation, promotion of sustainable agriculture, wildlife monitoring, environmental education for communities living around green billed hermit’s habitats and constant patrols to ensure the safety of the hermits.