Category Archives: Birds

Striated Caracara (Phalcoboenus australis)

Striated-caracaras-squabbling-over-food-on-beach

  • Name: Striated caracara
  • Latin: Phalcoboenus australis
  • Classification: Bird
  • Origin: Falkland Islands
  • Lifespan: 25 years
  • AKA: Johnny rook, Falkland caracara

Taxonomy

  • Kingdom: Animalia (Animals)
  • Phylum: Chordata (Vertebrates)
  • Class: Aves (Birds)
  • Order: Falconiformes (Falcons and caracaras)
  • Family: Falconidae (Falcons, kestrels and falconets)
  • Genus: Phalcoboenus (Andes, Patagonia and Falkland Islands)
  • Species: Phalcoboenus australis (Striated caracara)

Appearance

  • Height: 53-65cm (20.8-25.5 inches)
  • Weight:2-2.3kg (2.6-5lb)
  • Wingspan: 116-125cm (45.6-49.2 inches)

The striated caracara is a dark bird with the plumage ranging from deep brown to almost black. It has its characteristic white streaking on the nape of the neck running down the breast and along the upper back. The underwings are reddish-brown with white tips on the primary feathers and a white band at the end of the tail. The caracara has a blueish bill with bare yellow skin around the eyes and the base of the beak. There is no major sexual dimorphism between species.

Juveniles of the species have browner plumage than the adults. The have a tawny patch on the upper back in place of the distinctive white streaking and tail band. Youngsters acquire their full adult plumage at approximately five years of age.

Adult
Adult
Juvenile
Juvenile

Relatives

Below are all other members of the genus Phalcoboenus

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  • Carunculated caracara (Phalcoboenus carunculatus) -LEAST CONCERN-
  • Mountain caracara (Phalcoboenus megalopterus) -LEAST CONCERN-
  • White-throated caracara (Phalcoboenus albpgularis) -LEAST CONCERN-

Habitat & Distribution

The striated caracara is rare throughout much of its range however, is common on some of the smaller islands in the West Falklands. They exist on isolated coasts and islands off extreme South Argentina and Chile. These birds are also found on islands where populations of seal and / or seabirds are present, including the south and east coasts of Isla Grande on Tierra del Fuego, Isla de los Estados, Navarino, Cape Horn and the Falkland Islands. They occupy open lowland areas, mainly across rocky coastlines but may also inhabit higher elevations on low coastal mountains.

phalcoboenus_australisDiet

The striated caracara is an opportunistic bird and primarily a scavenger. The majority of its diet is made up of carrion, offal and food scraps and will occasionally take insects and earthworms dug from the ground with its talons. They will also prey upon weak and injured animals including young seabirds and newborn lambs. The striated caracara has also been observed to dig seabirds nesting in their burrows during the day and then hunt for them on wing throughout the night. They will also eat the eggs and chicks of larger seabirds such as albatrosses and feed on the carcasses of dead fur seals and penguins.

These birds have also been observed moving rocks and raiding dustbins in order to access food sources and will scavenge the internal organs of butchered animals. Their tendency to attack newborn lambs and injured sheep have led to the development of a resentful relationship with local livestock owners.

Striated-caracara-feeding-on-musselsBehaviour

The striated caracara shows a level of tameness and curiosity unlike that of other raptors. They show little fear of humans and will often examine tourists by tugging at shoelaces and trouser legs or stealing hats and cameras. Their curious behaviour is more like that of a corvid and it is thought that this ‘pathological curiosity’ helps the birds to develop novel ways of finding food. They fearlessly examine everything in their environment and are able to take advantage of a wide diversity of food sources.

Striated caracaras are highly social and juveniles with exhibit ‘gang’ behaviour similar to that of corvids in order to compete with the more aggressive adults. Adults are also territorial and will advertise their presence with loud calls. They are a non-migratory species but will move seasonally up into coastal mountains.

http://www.discoverwildlife.com/gallery/raptor-returns-falkland-islands
http://www.discoverwildlife.com/gallery/raptor-returns-falkland-islands

Reproduction

The breeding season of the striated caracara occurs in austral summer, from December to late February. The male and female will display to each other, such as the ‘head throwing’ display. The nest is built either on the ground or on cliff ledges and is constructed of twigs and vegetation and lined with grass and wool. These birds are loosely colonial, with neighboring pairs often nesting less than 10 meters from each other when nest sites are scarce.

The female will lay a clutch of approximately four eggs, which are incubated for around 32 days. The hatching of the chicks is timed to coincide with the hatching of young seabirds, in order to secure a constant food supply for the caracaras offspring. The nest is defended by both adults, who will chase intruders away. The chicks fledge after approximately three months, who then form large juvenile groups.

Striated-caracara-at-nest-with-chicks-in-rock-overhangAdaptations

  1. The striated caracara shows a level of curiosity unlike that of other raptors. It is thought this behaviour is to help them take advantage of a wide range of food sources and find novel ways of reaching others.
  2. These birds have a set of sharp talons, common to all birds of prey. These claws aid the striated caracara in reaching food sources such as muscles, eggs, carcasses and earthworms.
  3. Like other raptors, the striated caracara has exceptional eyesight, which is eight times better than that of a human. This aids them in spotting potential items of food in the distance.
  4. After fledging, the juveniles form large groups. This increases their chances of surviving their first few winters, the times when juvenile mortality is high, and offers them better defense against aggressive adults.

Threats

Due to their curiosity and lack of fear towards humans, the striated caracara became a pest to sheep farmers by targeting newborn lambs and weak ewes. In 1908, they became designated officially as a pest species and a bounty was put on their heads on the Falkland Islands. Farmers were paid for every beak they handed in, and in just 17 years, the striated caracara was eliminated from East and West Falkland. In the 1920’s however, Government Naturalist, James E. Hamilton, objected to the killing of the birds and bounties were stopped in 1930. They did not receive protection however, until 1964.

The current population size is limited to approximately 1,000-2,499 mature individuals, which equates to 1,500-3,749 individuals altogether. A survey conducted in 2006 also found that the population was stable at around 500 pairs. At present, the striated caracara is not considered to be facing any serious threats.

Conservation

  • IUCN Status: Near Threatened

The striated caracara is officially protected by Falklands Islands (Malvinas) Law which makes it illegal to kill this bird without written permission from the government. They are also listed under CITES Appendix II, which classifies the striated caracara as ‘not necessarily threatened with extinction, but trade must be controlled in order to avoid utilization incompatible with their survival’.

Research and data collecting is also due to or already being carried out on the striated caracara including monitoring of the breeding population (which includes ringing to monitor juvenile mortality rate), ecology, dispersal, population dynamics and survival and to assess the damage to livestock caused by striated caracaras and evaluate the impact on sheep farming.

Since 1972, New Islands in West Falkland has been protected and managed as a private nature reserve which has allowed the striated caracara to re-colonize the island and now represents the largest single-island breeding population throughout their range.

Fun Facts

  • Male: Tercle, tierce
  • Female: Tiercelet
  • Young: Chick, eyass
  • Group: Cast, flock
  • Also known as ‘flying devil’, Johnny rook’ and ‘winged pirate’.
  • They are considered to be one of the most intelligent birds of prey.
  • They have been observed hunting in groups of up to 50 individuals.
  • They have been known to steal mainly red objects. It is thought because the birds mistake them for meat.

References

Arkive (2015) Striated Caracara (Phalcoboenus australis) [Online] Available at: http://www.arkive.org/striated-caracara/phalcoboenus-australis/image-G36841.html [Accessed: 30 October 2015]

Beauty of Birds (2015) Striated Caracara (Phalcoboenus australis) [Online] Available at: http://beautyofbirds.com/striatedcaracaras.html [Accessed: 31 October 2015]

Bird Land (2014) 20th June 2014 Species Spotlight – Striated Caracara [Online] Available at: http://www.birdland.co.uk/20th-june-2014-species-spotlight-striated-caracara/ [Accessed: 6 November 2015]

Bird Life (2015) Striated Caracara Phalcoboenus australis [Online] Available at: http://www.birdlife.org/datazone/speciesfactsheet.php?id=3568 [Accessed: 31 October 2015]

IUCN Red List (2015) Phalcoboenus australis [Online] Available at: http://www.iucnredlist.org/details/22696247/0 [Accessed: 6 November 2015]

Boise State University (2015) Autilio, Anna – Striate Caracara (Phalcoboenus australis) [Online] Available at: http://raptorresearchcenter.boisestate.edu/autilio-anna/ [Accessed: 6 November 2015]

Oiseaux Birds (2015) Striated Caracara – Phalcoboenus australis [Online] Available at: http://www.oiseaux-birds.com/card-striated-caracara.html [Accessed: 6 November 2015]

Wikipedia (2015) Striated Caracara [Online] Available at: https://en.wikipedia.org/wiki/Striated_caracara [Accessed: 30 October 2015]

Barn Owl (Tyto alba)

Male-barn-owl-perched

  • Name: Barn owl
  • Latin: Tyto alba
  • Classification: Bird
  • Origin: Almost global
  • Lifespan: 2-5 years
  • AKA: Common barn owl, screech owl, white owl

Taxonomy

  • Kingdom: Animalia (Animals)
  • Phylum: Chordata (Vertebrates)
  • Class: Aves (Birds)
  • Order: Strigiformes (Owls)
  • Family: Tytonidae (Barn owls)
  • Genus: Tyto (Barn owls)
  • Species: Tyto alba (Common barn owl)

Appearance

  • Height: 25-40cm (9.8-15.7in)
  • Wingspan: Up to 110cm (43.3in)
  • Weight: F=570g (1.2lbs) M=470g (1lb)

The barn owl is a medium sized bird with a heart shaped facial disk whose coloring can vary greatly among subspecies. In the UK, the barn owl has pure white underparts with buff back and wings. However, the plumage can vary from pale brown to grey on its back and from white to reddish buff on its underparts. The bill can also vary from pale to dark and the talons from pink to pinkish-grey.

Males in general, tend to have fewer spots on the underside and are paler in colour than females. Males are also smaller than females and roughly 10% lighter. The nestlings are covered with white down with their facial disk becoming apparent soon after hatching.

Colouration differation between individuals of the same species.
Colouration differation between individuals of the same species.

Relatives

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  • Australian masked owl (Tyto novaehollandiae) -LEAST CONCERN-
  • Western screech owl (Megascops kennicottii) -LEAST CONCERN-
  • Great horned owl (Bubo virginianus) -LEAST CONCERN-
  • Brown wood owl (Strix leptogrammica) -LEAST CONCERN-

Habitat & Distribution

The barn owl is the most widely distributed land bird in all the world, found on every continent except Antarctica. This species occurs throughout the majority of Britain and Europe, as well as Asia, African and much of North America (was introduced to Hawaii in 1958) and covers the entirety of Australia.

The barn owl was introduced to the Seychelles islands in 1949 to control rats on coconut plantations and now occurs as a problematic alien species on most of the islands, which prey on native animals such as fairy terns and the Seychelles sunbird. This situation is critical on the Aride Island (which is rodent free) where the owls will prey upon nesting seabird colonies. Pellet evidence collected from barn owls on this island have found remains of the brown noddy, which has since vanished from the island.

Barn owl populations can be found in rough grassland with good rodent populations and suitable roosting sites, such as field edges, watercourse edges and grass strips which run alongside woodland. Strips sown with Yorkshire fog and cocksfoot are good habitat for voles, which makes it ideal hunting ground for these owls.

Map of distribution of the barn owl
Map of distribution of the barn owl

Diet

The diet of barn owls in Britain and Ireland is made up primarily of rodents (90% of total diet) which includes short tailed voles, wood mice and common shrews. These birds are mainly nocturnal but have been known to hunt during dawn and dusk when they have young to feed and during the daytime at winter. Prey is usually swallowed whole and any parts the owl is unable to digest (such as teeth, bones and fur) is regurgitated as a pellet. These pellets are extremely useful to conservationists and researchers in understanding the diet and distribution of the barn owls.

Recent studies suggest that a single barn own requires 20-25km of field edges with suitable roosting sites to be able to hunt enough food for itself and any offspring. Strips sown with grasses such as Yorkshire fog and cocksfoot create a deep litter layer which is perfect for voles. Barn owls will normally hunt from exposed perches or during low flight and have the ability to find prey using sound alone due to their exceptional hearing.

The Shropshire Barn Owl Group has been collecting and analyzing barn owl pellets in the Shropshire area since 2002 and have documented 1,458 distinct prey items from 522 pellets collected from 69 sites. These studies have found that the field vole is the primary item of food for these birds making up 71% of the total diet. The following are wood mouse (12%), common shrew (9%) and bank vole (5%). The group also found pygmy shrew, house mouse, brown rat and birds, however, these account for less than 1% of the total items consumed.

Behaviour

Barn owls are nocturnal and can most commonly be seen flying at night or dusk over open fields with slow and silent wingbeat and a looping flight. They have excellent low light vision and can locate prey by sight in darkness, however, their ability to locate prey by sound alone is unequalled and is the best of any animal that has ever been tested. When threatened, the barn owl will spread its wings and move its head back and forth and will occasionally fall onto its back and strike at the threat with its talons.

Reproduction

Barn owls typically reproduce once a year (although two broods within a year have been documented) and will do so at any time of year depending on prey availability. Individuals will begin breeding at a year old and are most commonly monogamous (but there have been reports of polygyny). Courtship will begin with males making advertising calls and then chasing a female in flight, during which both will screech. The male will then display a ‘moth flight’, which consists of a male hovering in front of a perched female with his talons dangling beneath him for several seconds. The pair will then seek a nest site together (favoring old barns, nest boxes and tree hollows) and will copulate every few minutes. During copulation, the male will mount the female, grasp her neck and balance with outstretched wings.

Pairs will reuse old nests (some nests have been used repeatedly by different pairs for decades) rather than build a new one, and the female will line it with shredded pellets. Typically, 4-7 white eggs are laid at 2-3 day intervals with incubation lasting around 30 days. The chicks then hatch at 2-3 day intervals. The youngest of which may die if food is short as the mother will favor the elder chicks. 75% of chicks die within their first year with survivors living for another 1-2 years.

The female will leave the nest only briefly during brooding, living off food brought to her by the male. All brooding is carried out by the female and only she will feed the chicks on food brought to them by the male. During the first few weeks after hatching, the female will eat the chick’s feaces in order to keep the nest clean and to avoid altering predators to their nest location. Fledging will occur 50-55 days after hatching and will return to the nest to roost for 7-8 weeks after and will become completely independent 3-5 weeks after.

Barn owl feeding chicks
Barn owl feeding chicks

Adaptations

  1. Barn owls have very low wing loading, meaning they have large wings supporting a light body. This enables the bird to fly slowly without stalling and to hover.
  2. The heart-shaped facial disk of the barn owl directs sound towards the inner ear. The ears are positioned asymmetrically on either side of the head which means sounds are heard differently in each ear. This enables barn owls to locate prey using sound alone.
  3. The eyes are twice as light sensitive has humans and their low-light vision is highly movement sensitive. This means that anything that moves is instantly notices, helping the already keen hunting ability.
  4. The feathers are covered in thin hair-like structures which traps air on the surface, helping to avoid stalling while travelling at low air speeds. Also, the 10th primary has a row of tiny hooks which silences the sound of air hitting the wings edge – giving the barn owl silent flight.

Threats

Since the mid-19th century, barn owls have been in decline in Britain, originally due to persecution (during this time, it was widely believed that barn owls brought bad weather) and have suffered a decline of 70% since the 1930’s. This decline has continued into modern day due to a mix of factors including agricultural intensification, bad winters, road traffic accidents, pesticides and a loss of hunting and roosting sites.

2013 was the worst breeding season for barn owls in 30 years due to continuous bad weather since 2009 with only an average of 2 chicks per successful clutch. In Devon, of the 73 sites that were monitored, only 12% had nests down from 51% previously. 2012 saw the heaviest June rainfall since records began in 1910 and 2013 had the worst March snowfall in more than 30 years. This continuous bad weather hinders the breeding success of barn owls by killing of prey species (such as voles and mice) and waterlogging their feathers, making them unable to fly. The British Trust of Ornithology (BTO) recorded a 280% increase in reports of dead individuals during this year.

Loss of habitat affects barn owls as much as it affects any species. Suitable roosting, breeding and hunting sites are declining due to intensive farming methods and agricultural expansion. Newer and more intensive farming procedures results in less suitable land for the owls prey species which in turn, hinders breeding success. Old barns and hollow trees are also disappearing due to decay and general ‘tidying up’ of the countryside resulting in less suitable roosting and breeding sites.

Other threats to barn owls include sudden exposure to bright lights (such as car headlights) which can cause temporary visual impairment which more often than not leads to road traffic accidents. Barn owls also fall prey to natural predators including buzzards, eagle owls and goshawks, while mammalian carnivores (weasels and stoats) will occasionally take chicks and eggs.

Conservation

  • IUCN Status: Least Concern
  • Population Trend: Stable (since 2002)

The barn owl is protected under schedules 1 and 9 of the Wildlife and Countryside Act 1981, which makes it illegal to kill, injure or take a wild barn owl or to remove or damage their eggs. They are also classed as a species of conservation concern by the UK Biodiversity Action Plan (although they are not a priority species) and are classed as medium conservation concern by the Birds of Conservation Concern Amber List. The Hawk and Owl Trust also run a project called the Barn Owl Conservation Network (BOCN) which promotes suitable habitat creation and the erection of nest boxes.

Fun Facts

  • Male: Male owl
  • Female: Female owl
  • Young: Chick, owlet
  • Group: Flock, parliament, brood, diss, nest, looming, wisdom
  • In Spanish, male owls are called buho and females, lechuza.
  • Barn owls never hoot, instead they screech.
  • They weigh about as much as a grapefruit.
  • Old names for the barn owl include demon owl, death owl, ghost owl, hobgoblin and old hushwing.
  • They used to be killed and nailed to barn doors to protect against thunder and lightning.
  • In the 20th century, owl window were built into stone barns to encourage barn owls to nest, as they would eat rodents and prevent crops from being eaten.

References

All About Birds (2015) Barn Owl [Online] Available at: http://www.allaboutbirds.org/guide/Barn_Owl/lifehistory [Accessed: 3 September 2015]

Arkive (2015) Barn Owl (Tyto alba) [Online] Available at: http://www.arkive.org/barn-owl/tyto-alba/ [Accessed: 5 September 2015]

Barn Owl Centre (2015) Barn Own Diet [Online] Available at: http://www.barnowl.co.uk/page21.asp [Accessed: 22 July 2015]

Batchinski and Harris (2002) Tyto alba – Barn Owl [Online] Available at: http://animaldiversity.org/accounts/Tyto_alba/#reproduction [Accessed: 4 September 2015]

BBC (2014) Barn Owl [Online] Available at: http://www.bbc.co.uk/nature/life/Barn_Owl [Accessed: 19 June 2015]

Davies, C (2013) Britain’s Barn Owls Under Threat Due to Extreme Weather [Online] Available at: http://www.theguardian.com/environment/2013/aug/01/barn-owls-threat-extreme-weather [Accessed: 5 September 2015]

IUCN (2002) Tyto alba [Online] Available at: http://www.iucnredlist.org/details/22688504/0 [Accessed: 6 September 2015]

Nature Works (2015) Barn Owl – Tyto alba [Online] Available at: http://www.nhptv.org/natureworks/barnowl.htm [Accessed: 3 September 2015]

RSPB (2015) Barn Owl [Online] Available at: http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/birdguide/name/b/barnowl/ [Accessed: 19 June 2015]

Shropshire Barn Owl Group (SBOG) (2015) The diet of the barn owl in Shropshire [Online] Available at: http://shropshirebarnowlgroup.org.uk/diet-of-the-barn-owl-in-shropshire.php [Accessed: 22 July 2015]

The Barn Owl Trust (2015) Barn Owl Adaptations [Online] Available at: http://www.barnowltrust.org.uk/barn-owl-facts/barn-owl-adaptations/ [Accessed: 4 September 2015]

The Barn Owl Trust (2002) Barn Owls on Site: A Guide for Developers and Planners [pdf] Available at: http://www.lbp.org.uk/downloads/Publications/PlanningGuidance/NE_barnowls.pdf [Accessed: 6 September 2015]

The Owl Pages (2015) Owls: Species: All [Online] Available at: http://www.owlpages.com/owls.php?genus=all [Accessed: 19 June 2015]

Wikipedia (2015) Barn Owl [Online] Available at: https://en.wikipedia.org/wiki/Barn_owl [Accessed: 19 June 2015]

Williams, G (2011) 100 Alien Invaders. UK, Brandt Travel Guides. USA, The Globe Prequot Press.

Bar-Headed Goose (Anser indicus)

Bar-headed-goose-standing

  • Name: Bar-headed Goose
  • Latin: Anser indicus
  • Classification: Bird
  • Origin: Asia
  • Lifespan: Up to 25 years

Taxonomy

Kingdom: Animalia (Animals)
Phylum: Chordata (Vertebrates)
Class: Aves (Birds)
Order: Anseriformes (Waterfowl)
Family: Anatidae (Ducks, geese and swans)
Genus: Anser (Geese)
Species: Anser indicus (Bar-headed Goose)

Apperance

Length: 71-76cm (28-30in)
Weight: 1.87-3.2kg (41.-7.1lbs)
Wingspan: 140-160cm (55-63in)

The bar-headed goose is characterised by the two bars of brownish-black feathers around the back of its neck. It has a light grey body and white spots on its face and neck. The bill and legs are a strong orange colour and possess webbed feet and broad wings. There is no sexual dimorphism between the male and female of this species.

Relatives

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  • Barnacle goose (Branta leucopsis) -LEAST CONCERN-
  • Canada goose (Branta canadensis) -LEAST CONCERN-
  • Egyptian goose (Alopochen aegyptiacus) -LEAST CONCERN-
  • Pink-footed goose (Anser brachyrhynchus) -LEAST CONCERN-

Habitat & Distribution

The bar-headed goose lives near high altitude lakes and winters on salt and fresh water marshes. They graze in grasslands and wetlands. Most of their time is spent near or on alpine lakes.

The bar-headed goose is mainly situated in central Asia but winters to India and Burma. Their migration takes them high over the Himalayan Mountains. European populations are generally escaped captive birds.

Map of distribution of the bar-headed goose
Map of distribution of the bar-headed goose

Diet

The diet of the bar-headed goose is mainly grass, barley and rice. They will also eat paddy and corn which can cause a lot of damage to farms and gardens. Occasionally they will feed on crustaceans and invertebrates and whilst on the coats they will eat sea weeds.

The young goslings grow fast on a diet of midges during the warm summer months.

Behaviour

The bar-headed goose has one of the most amazing migrations of any animals. They migrate north from India to the Tibetan plateau to breed which takes them high over the Himalayan Mountains. They are the world’s highest flying birds and have been tracked (using GPS or satellite logging technology) flying higher than 6,540 meters (21,460ft). Their migration is taken in stages. They fly non-stop for seven hours over the Himalayas.

Reproduction

The bar-headed goose nests around lakes in dense colonies and at altitudes of up to 16,000 feet. A clutch of 4-8 eggs are laid in a shallow nest lined with the mothers down feathers. The bar-headed goose can breed at 2-3 years of age and will double clutch if the first eggs are removed. Incubation of the eggs lasts around 28-30 days and the young will fledge at 50 days. Both parents care for the goslings.

These geese will remain at the breeding grounds from late Marsh to mid-April and will leave the nesting area in late August.

Adult geese with young
Adult geese with young

Adaptations

  1. The bar-headed goose has a higher wing area for its weight than other geese. This helps it to glide at high altitudes.
  2. These geese can breathe more deeply and efficiently under low oxygen conditions. The haemoglobin of their blood can carry a lot more oxygen than other geese.
  3. Bird lungs have a counter exchange system which extracts O2 much more efficiently than mammals. The lungs in a bar-headed goose are much larger than in other waterfowl.
  4. In hypoxic conditions, the bar-headed goose can hyperventilate 7.2 times faster than their rate at sea level and suffer no ill effects.

Threats

The bar-headed goose was an early sufferer of HPAI (Highly Pathogenic Avian Influenza) and some cases are still reported today. They have many predators including crows, foxes, sea eagles and gulls and their eggs are regularly stolen by ravens. They are also hunted by humans for food, feathers and eggs.

Conservation

IUCN Status: Least Concern

More than 5,000 bar-headed geese regularly visit the Gharana Wetland Conservation Reserve in Jammu during their migration. They are also radio tracked using GPS satellite tags to map their migration routes. These are extremely lightweight and do not hinder the geese’s movements.

Fun Facts

Male: Cob
Female: Pen
Young: Gosling
Group: Gaggle, Flock

-These are the highest flying birds in the world, reaching heights of up to 20,000 feet.
-Their constant flight generates body heat which is retained in their down feathers. This keeps the goose warm while flying in the freezing temperatures of the sky.
-They are able to migrate more than 1,000 miles in a single day.
-They can fly at speeds of up to 50mph without wind to assist them.

African Fish Eagle (Haliaeetus vocifer)

African-fish-eagle-in-flight-over-lake-fishing(http://www.arkive.org/african-fish-eagle/haliaeetus-vocifer/)

  • Name: African fish eagle
  • Latin: Haliaeetus vocifer
  • Classification: Bird
  • Origin: Africa
  • Lifespan: 25-30 years
  • AKA: Fish eagle, river eagle

Taxonomy

  • Kingdom: Animalia (Animals)
  • Phylum: Chordata (Vertebrates)
  • Class: Aves (Birds)
  • Order: Falconiformes (Diurnal birds of prey)
  • Family: Accipitridae (Hooked Billed)
  • Genus: Haliaeetus (Sea eagles)
  • Species: Haliaeetus vocifer (African fish eagle)

Appearance

  • Height: 73cm (28.7 inches)
  • Wingspan: 2m (6ft)
  • Weight: 2-2.7kg (4.4-5.9lbs)

The adults have a very distinctive appearance and have a mostly brown body. They have large, powerful black wings and their head, breast and tail are snow white. Their featherless face is bright yellow. Their eyes are dark in colour and their hooked bill is yellow with a black tip. The feet have rough soles and sharp talons, used for catching and holding onto wriggling fish.

The juveniles are brown in colour and tend to have paler eyes than the adults. The females are generally smaller than the males.

Relatives

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  • Tawny eagle (Aquila rapax) -LEAST CONCERN-
  • Black hawk eagle (Spizaetus tyrannus) -LEAST CONCERN-
  • Harpy eagle (Harpia harpyja) -NEAR THREATENED-

Habitat & Distribution

These eagles can be found in large numbers around the lakes of South Africa where there is an abundant food supply. A pair may require less than a square mile of water to have enough food, however, if living near a river, they may need up to 15 miles.

The African fish eagle is widespread throughout southern Africa and is particularly common in and around the Rift Valley Lakes.

Map of distribution of the African fish eagle
Map of distribution of the African fish eagle

Diet

Live fish make up about 90% of this birds diet. The rest is made up of other animals including water birds and their young, amphibians and carrion. The birds taken include ibis, storks, herons, spoonbills and the lesser flamingo.

These birds hunt by scanning the water from up in the trees. Once they spot a fish, they swoop down from their perch and snatch it from the water with their talons. The fish is then taken back to the perch to be eaten, or dragged to shore if it is too heavy to carry.

Behaviour

The African fish eagles tend to live in pairs close to streams and lakes. They are active and agile and can perform bold ariel displays, sometimes diving entirely into the water to catch their prey. They can remain on their perch for up to 85-90% of the day.

They are opportunistic feeders and will steal prey from other birds. They are also highly territorial all year round and can be extremely aggressive. They will either chase intruders away or attack from behind.

Reproduction

The breeding season of the African fish eagle is in the dry season, when the water level is low. They are monogamous, meaning they mate for life, and make 2 or more nests which they frequently re-use. They can measure 2m (6 feet) across and 1.2m (4 feet) deep.

The female lays 1-3 eggs which are white with red speckles. The incubation is mainly done by the female but the male will take over while the female hunts. The eggs take around 42-45 days to incubate. The first chick to hatch will often kill its younger siblings. This is known as siblicide and is a behaviour seen in many birds of prey.

Fledging takes 70-75 days and the young can feed itself after 8 weeks. They young birds will leave the nest and establish their own territories after 10 weeks of birth.

chick
African fish eagle parent feeding chick.

Adaptations

  1. The African fish eagle has a hooked beak which helps it to tear flesh from its prey and pull the strong muscles from its bones.
  2. This bird of prey also has powerful talons which it uses to grip onto the slippery and wriggling fish it eats.
  3. The African fish eagles are aggressive birds and will attack each other if they stray into others territory. It has adapted to have feathered legs in order to protect them from the sharp beak of its opponents.
  4. Like all birds of prey, the African fish eagle has excellent eyesight. It uses this sense of sight to spot fish and other prey from its treetop perch.

Threats

Over fishing is a big threat to this bird as well at the increasing size of the local human populations. Large numbers of people move into the African fish eagle’s territory and fish their food supply dry. The birds then have no option than to leave to other areas to feed.

The biggest threat to these birds however, is pesticides. They enter the water system as run off or ground water from the crops on land and contaminate the water system. This kills huge numbers of fish as well as infecting the birds themselves. These pesticides cause reproductive failure in these animals and thin their eggs shells, making them more receptive to breakages.

Conservation

IUCN Status: Least Concern

This animal is listed as ‘Least Concern’ by the ICUN and there are 300,000 individuals. There are no conservation efforts for the African fish eagle.

Fun Facts

Male: Gigallos
Female: Eagless
Young: Eaglet
Group: Flock

-The young chicks often partake in siblicide. This is where the first chick to hatch will destroy the other eggs, in order to have its parent’s undivided attention.
-African fish eagles are monogamous, meaning they mate for life.

Greater Flamingo (Phoenicopterus roseus)

Greater flamingo coming in to land

(http://www.arkive.org/greater-flamingo/phoenicopterus-roseus/image-G50087.html)

  • Name: Greater flamingo
  • Latin: Phoenicopterus roseus
  • Classification: Bird
  • Origin: Africa, South America
  • Lifespan: Up to 40 years

Taxonomy

  • Kingdom: Animalia (animals)
  • Phylum: Chordata (vertebrates)
  • Class: Aves (birds)
  • Order: Phoenicopteriformes (‘purple’ ‘wing’)
  • Family: Pheonicopteridae (flamingo)
  • Genus: Phoenicopterus (flamingo)
  • Species: Phoenicopterus roseus (greater flamingo)

Apperance

  • Height: 110-150cm (43-60in)
  • Weight: 2-4kg (4.4-8.8lbs)
  • Wingspan: 95-100cm (37-39in)

The greater flamingo is the tallest species of flamingo with legs longer than its body (measuring 80-125cm (31.5-49in)). The ankle is located about halfway up the leg and the knee is so close to the body it isn’t externally visible. The males are slightly larger than the females.

This bird has a characteristic long, curved neck and a black tipped bill with a distinctive downward bend. The plumage colour varies from pale pink to crimson and its colouration is derived from carotenoids pigments found in their diet of shrimp and other crustaceans. The newly hatched young are grey or white and take one-two years to obtain adult colouration.

Relatives

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  • Caribbean flamingo (Pheonicopterus ruber) -LEAST CONCERN-
  • Andean flamingo (Phoenicoparrus andinus) -VULNERABLE-
  • James’ flamingo (Phoenicoparrus jamesi) -NEAR THREATENED-
  • Lesser flamingo (Phoeniconaias minor) -NEAR THREATENED-

Habitat & Distribution

The greater flamingo has the most widespread distribution of all flamingo species. They can be found in Northwest India, Africa, the western Mediterranean and the Middle East. Large flocks of these birds can found in large alkaline or saline lakes or estuarine lagoons lacking vegetation. They also inhabit mangrove swamps, tidal flats and sandy islands.

(http://www.theanimalfiles.com/birds/flamingos/greater_flamingo.html)

Diet

Greater flamingo are filter feeders and sucks water through its bills to filter out food such as small shrimp, seeds, algae, molluscs, insects and microscopic organisms. It first stirs up the mud by stomping its feet and then fully submerges its head upside down in the water to begin the filtering process (a flamingo can keep its head underwater for up to 20 seconds). They then pump their tongue up and down 5-6 times a second to push water back out of its bill, leaving any traces of food remaining. Greater flamingos will also swim out to deeper water and upend like a duck to reach food.

The flamingo’s food contains carotenoid pigments which are broken down in the liver and deposited into the feathers, skin and egg yolk. This is what gives the bird its pink plumage.

Behaviour

Greater flamingos are very social birds; colonies of tens of thousands of birds are common. They are also very vocal and have a number of different calls. When flying they are often mistaken for geese because of the honking noises they make and chicks can make calls while still inside its egg. Flamingos will often move from place to place during the night to areas of fresh food supplies.

These birds are active throughout day and night and daily activities include preening, feeding, resting and bathing. Greater flamingos are capable of swimming and bathe in shallow water, often submerging the whole body. These flamingos spend about 15-30% of the day preening their feathers, distributing oil from a gland near the base of the tail for waterproofing.

Reproduction

Greater flamingos will begin to breed at about six years of age and have no set breeding season, although rainfall and food supply seem to have an effect on when breeding and nest building occur in the year. Flamingos will carry out synchronous nesting so chicks will hatch at roughly the same time.

These flamingos are usually monogamous and form strong pair bonds but have been occasionally observed to mate with more than one partner. During courtship, individuals will perform ritualised stretching and preening and will call to each other frequently. Groups of males will also run with their bills pointed upwards and necks stretched out as part of their displays. The female will initiate copulation by leading the male away from the group and then invite him to mount by lowering her head and spreading her wings.

Flamingos will begin to build their nest mounds about six weeks before the egg is laid. These mounds are made from mud, stones, straw and feathers and can stand up to 30cm (12in) tall. A shallow well is made in the top for the egg to sit. These mounds provide protection from extreme heat and flooding.

One chalky white egg is laid and is incubated by both parents for 27-31 days. When the chicks first hatch, they are fed a white substance from the upper digestive track of the parent, known as ‘crop milk’. When they are old enough to walk, the chicks gather together in crèches which is watched over by a few adults.

Female greater flamingo feeding young under wing

(http://www.arkive.org/greater-flamingo/phoenicopterus-roseus/image-G52013.html)

Adaptations

  • Greater flamingos can cope with high levels of salinity and often the only fresh water they have access to come from boiling geysers. These flamingos are capable of drinking boiling water. They also have a gland located in their nostrils for expelling excess salt.
  • Greater flamingos will frequently stand on one leg and curl the other under their body as a method of thermoregulation.
  • When resting, flamingos will face the wind to stop cold air penetrating their feathers. They can often be seen swaying in the wind.
  • When flying, a flock can reach speeds of up to 50-60kph (31-37mph) and will travel 500-600km (311-373m) each night between habitats.

Threats

The greater flamingo is vulnerable to changes and disturbance to its limited number of breeding sites and breeding success is often reduced due to lowering water levels, which can increase salinity in an area and affect food levels. Thick soda deposits can also smother chicks.

Climate change can also have a serious impact on breeding sites of flamingos in the future due to rainfall and changing sea levels. Other threats to these birds include pollution, disease, lead poisoning and habitat loss from harbour and industrial development or drainage of wetlands for agricultural use.

In Egypt, large numbers of flamingos are shot or captures for sale in local markets and in Algeria, egg collection is still a big problem. The greater flamingo has few natural predators although eggs and chicks are preyed upon by other birds including the marabou stork.

Conservation

  • IUCN Status: Least Concern

The greater flamingo breeds well in captivity and populations are currently maintained in various locations around the world. It has also been recommended that the conservation of this species depends on the protection of both its breeding and wintering sites.

In 1978, the Flamingo Specialist Group (FSG) was established to carry out research and conservation activities on this species. In France and Spain, colonies of flamingos are managed to increase suitable nesting sites and in Abu Dhabi (United Arab Emirates), populations are monitored by a satellite tracking programme and lead polluted sand is also removed from inhabited areas.

Fun Facts

  • Male: Cock
  • Female: Hen
  • Young: Chick
  • Group: Colony, Flamboyance, Flurry, Regiment, Stand
  • ‘Flamingo’ is derived from the Latin word ‘flamenco’ which means ‘fire’ and refers to the colour of the birds feathers.
  • Genetically, flamingos are most closely related to grebes.
  • The greater flamingo is the largest of the six species of flamingo.
  • In the USA, there are more plastic lawn flamingos than real ones.

References

Herring Gull (Larus argentatus)

Herring gull (Larus argentatus argenteus)

(http://www.arkive.org/herring-gull/larus-argentatus/)

  • Name: Herring gull
  • Latin: Larus argentatus
  • Classification: Bird
  • Origin: Northern hemisphere
  • Lifespan: Up to 30 years

Taxonomy

  • Kingdom: Animalia (animals)
  • Phylum: Chordata (vertebrates)
  • Class: Aves (birds)
  • Order: Charadriiformes (waders, gulls and auks)
  • Family: Laridae (gulls)
  • Genus: Larus (gulls)
  • Species: Larus argentatus (herring gull)

Apperance

  • Length: Males – 60-67cm (24-26in) Females – 55-62cm (22-24in)
  • Weight: Males – 1,050-1,525g (2.3-3.36lb) Females – 710-1,100g (1.6-2.4lb)
  • Wingspan: 125-155cm (49-61in)

The adults have a grey back and upper wings with a white head and under parts. The wingtips are black with white spots (known as ‘mirrors’). They have a yellow bill with a red spot underneath. They have bare yellow skin around the pale eyes and the legs are usually pink but can become yellowish. The males and females have identical plumage so are not incredibly sexually dimorphic, although the males tend to be slightly larger than the females.

The juvenile and 1st winter birds are mainly brown with dark streaks and have a dark bill and eyes. The 2nd winter birds lose some of their dark features and have a whiter head and under part with less dark streaking. The 3rd winter birds have plumage similar to adults but still retain some of their juvenile features such as brown feathers in the wings and dark markings on the bill.

Immature herring gull resting on ice during its first winter
First winter

(http://www.arkive.org/herring-gull/larus-argentatus/image-A22842.html)

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  • Swallow-tailed gull (Creagrus furcatos) -LEAST CONCERN-
  • Ivory gull (Pagophila eburnea) -NEAR THREATENED-
  • Laughing gull (Leucophaeus atricilla) -LEAST CONCERN-
  • Silver gull (Chroicocephalus novaehollandiae) -LEAST CONCERN- 

Habitat & Distribution

Herring gulls tend to live and breed in coastal areas and is commonly seen perching on cliffs overlooking the sea to decrease the risk of predation by terrestrial mammals. Their habitat requirements seem to include shelter from the prevailing winds, a food source and protection from predators. These birds can also be found in seaside towns, nesting on the rooftops and eating the refuse.

These birds are commonly seen throughout the northern hemisphere as their range starches across countries such as Russia, Alaska and northern Canada. The herring gull can be found further south although they tend to breed in the northernmost areas of their range.

Map showing the distribution of the Herring gull taxa

(http://www.bbc.co.uk/nature/life/Herring_Gull)

Diet

Herring gulls are omnivorous, opportunistic predators with their diet consisting of marine invertebrates, fish, small birds, eggs, carcasses and human refuse (the refuse will often make up as much as half of the birds diet). When foraging at sea, they will follow whales, fishing boats and groups of fish and squid to find food and will then form a scattered group when feeding. Herring gulls will often dive for food but struggle to go further than 1-2m deep due to their natural buoyancy. These birds will also eat nuts, fruits, grains and roots.

Herring gulls have proven themselves to be intelligent feeders as they have been observed dropping shellfish from great heights in an effort to break the shell open and will also use bread as bait to lure in and capture small fish. Also, herring gulls can often be seen drumming their feet against the ground in a comical manner for long periods of time. This causes vibrations to ripple through the soil which drives earthworms to the surface. These vibrations are thought to mimic those produced by digging moles which causes this escape behaviour in the worms.

Herring gulls are also fully capable of drinking seawater although they seem to prefer fresh water when presented with the choice. They have specialized glands above the eyes which removes excess salt from the body. This salt is then excreted as a solution through the nostrils.

Behaviour

Flocks of herring gulls have a very loose hierarchy which seems to be based on size and physical strength. Adult males are generally dominant over females and juveniles, although the females can become dominant when choosing nesting sites. Communication of this species is highly developed and very complex which includes the use of body language as well as vocal calls.

Unlike other flocking birds, herring gulls do not partake in social grooming and tend to keep physical contact between individuals to a minimum. They tend to maintain safe distances from each other and scrapping can occur if they get too close, although serious injuries usually do not occur.

Reproduction

During courtship, the female will intrude on the male’s territory and approach him in a submissive posture and making begging calls. If the male approves of her, he will respond with an upright posture and mewing calls. Then the two will dance, making head swaying movements for each other. After all this, the male will then regurgitate food and if accepted by the female, the two will copulate.

2-4 eggs are laid in a clutch although the average is three. They are laid in nests on the ground or on cliff edges which are defended fiercely by both parents. The eggs themselves are olive coloured adorned with dark blotches and are incubated for 28-30 days.

When the chicks emerge, their natural instincts tell them to peck the red spot on the adults beak to indicate hunger, which will cause the mother or father to regurgitate food. The young can fly after 35-40 days and fledge at 6 weeks. The parents will continue to feed the chicks up to 12 weeks to 6 months of age.

Herring gull chick and egg hatching

(http://www.arkive.org/herring-gull/larus-argentatus/image-A22774.html)

Adaptations

  • The herring gull has striking white plumage. This is to signal to others where food is found on the open ocean. This enables an individual to see exactly where food is and also aids the survival of large numbers of these birds.
  • The herring gull has large webbed feet which allows it to manoeuvre effectively while sitting on the sea surface.
  • The herring gulls have natural buoyancy which stops them from sinking into the sea. However, because of this, herring gulls can’t dive very deep, only up to 1-2m.
  • A herring gull chick is led by instinct to peck the red spot on an adults beak when it is hungry. This encouraged the adult to regurgitate food, which aids in the survival of the chicks.

Threats

These birds are threatened by coastal oil pollution and oil spills which can poison individuals and render many incapable of flight. Herring gulls are also susceptible to avian influenza (bird flu) and are hunted in Denmark. Breeding colonies of these gulls are predated upon by great black-backed gulls, harriers, corvids, herons, racoons and foxes.

Conservation

  • IUCN Status: Least Concern

The herring gull is protected under the Conservation of Wildlife (Jersey) Law 2000 which makes it illegal to intentionally injure or kill any gull or to take, damage or destroy an active nest or its contents. Jersey also requires anybody to have an official licence to cull gulls.

In Britain, they are protected by many conservation groups including EC Birds Directive, Birds of Conservation Concern 3, Birds of Conservation Concern in Ireland 2 and it is also listed as a UK BAP species.

Fun Facts

  • Male: Cock
  • Female: Hen
  • Young: Chick
  • Group: Flock, Colony
  • The herring gull is named so because of an original belief that herrings were its favourite food.
  • The long, territorial call of the herring gull is also known as the laughing call.

References

Adelie Penguin (Pygoscelis adeliae)

Adélie penguin walking

(http://www.arkive.org/adelie-penguin/pygoscelis-adeliae/)

  • Name: Adelie penguin
  • Latin: Pygoscelis adeliae
  • Classification: Bird
  • Origin: Antarctica
  • Lifespan: 10-15 years

Taxonomy

  • Kingdom: Animalia (animals)
  • Phylum: Chordata (vertebrates)
  • Class: Aves (birds)
  • Order: Sphenisiformes (penguins)
  • Family: Sphenisidae (penguins)
  • Genus: Pygoscelis (brush-tailed penguins (rump legged))
  • Species: Pygoscelis adeliae (adelie penguin)

Apperance

  • Height: 46-75cm (18-30 inches)
  • Weight: 3.6-6kg (7.9-13lb)

Adelie penguins are mainly black. They have a black head with a white eye ring and their back is covered in blue-tipped black feathers. Their chest is white, their feet are grey-pink and their bill is red.
The chicks have sooty-blackish heads and their bodies are covered in grey down-feathers. After 10 days of hatching, they develop thicker ‘woolly’ dark grey down.

Relatives

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  • Chinstrap penguin (Pygoscelis antartica) -LEAST CONCERN-
  • Emperor penguin (Aptenodytes forsteri) -NEAR THREATENED-
  • Little blue penguin (Eudyptula minor) -LEAST CONCERN-
  • Southern rock-hopper penguin (Eudyptes chrysocome) -VULNERABLE-

Habitat & Distribution

Adelie penguins live mainly in rockeries on the Antarctic coastline, in colonies of up to 300,000 birds. They spend their winters offshore in the seas surrounding the Antarctic pack ice.

(http://seaworld.org/en/animal-info/animal-infobooks/penguin/appendix/)

Diet

Adelie penguins feed mainly on Antarctic krill, ice krill, Antarctic silverfish and glacial squid, although their diet can vary depending on geographical location. Penguins in general can go through a lot of fish; a colony of 5 million Adelie penguins is capable of eating nearly 8 million kg (17.6 million lb) of krill and small fish in a single day.

Adelie penguins feed mainly at sea and rely on their excellent vision to help them catch their prey (it is unknown how these penguins are able to catch fish in murky waters or at night). They catch their prey with their bill and swallow it whole while swimming. They also have spiny tongues and powerful jaws to grip onto slippery prey.

Behaviour

Adelie penguins are highly social animals as they forage and nest in huge groups which sometimes contain thousands of birds. They are constantly interacting with each other, with body language and eye movements being the most common form of communication.

Although they are not territorial, it is not uncommon for adults to bicker and squabble over nesting sites and have also been known to steal rocks from the nests of their neighbours.

Like all penguins, Adelie’s are excellent swimmers and are able to swim at speeds of up to 45 miles per hour, enabling them to jump straight from the water and onto land. They hunt in large groups as it is thought to reduce the risk of being eaten by predators. The predators of the Adelie penguin include leopard seals, skua gulls and killer whales.

Reproduction

Adelie penguins reach sexual maturity at about 2-3 years old and their breeding season is in the Antarctic summer months of November-December. This is when they return to the breeding grounds from the surrounding sea.

Once a penguin has selected their mate for life, the female will lay two eggs a couple of days apart in a nest built from rocks. Both the male and female will incubate the eggs, taking turns while the other hunts for food, sometimes taking up to 10 days. This will continue for about 2 months.

The chicks have what is called an egg-tooth (a small bump on the top of their beak) which helps them to break free of their egg. Once hatched, the parents will continue to alternate turns of taking care of the chicks, while the other hunts food and brings it back for both the partner and the young.

After about a month, the chicks will congregate in large groups known as crèches and are able to fend for themselves at sea at 2-3 months. The chicks are fully fledged after 90 days.

Adaptations

  • This penguin expels heat through their feet after swimming as they do not sweat. When they are not exercising, the feet turn white as less blood flows to them, helping to conserve heat in the body.
  • The wings have adapted to have no flight feathers and have changed shape for use as flippers to help propel the penguin through the water.
  • The Adelie penguin has a longer tail than other penguins which it uses for steering through the water. They also use it to prop themselves up when sitting on their heels and have their toes buried in their feathers. There is also a gland near the tail which secretes oil which keeps its feathers waterproof.
  • The tongue has backwards facing spines which grip its prey and guide it down its throat. The penguin uses these spines in place of teeth.

Threats

The biggest threats to the Adelie penguins are its predators. They have no land based predators as such because of the uncompromising conditions of their habitats. However, they are widely hunted and eaten by leopard seals and killer whales. The young are also targeted by skua gulls.

The lives of Adelie penguins are also threatened by global warming. The increasing temperature of the earth is melting the ice on which these and other penguins live. Over commercial fishing of krill and fish also affects Adelie penguins, as they need to eat a lot of these foods every day in order to stay alive. If there isn’t enough, thousands of these birds will simply cease to exist.

Conservation

  • IUCN Status: Least Concern

Adelie penguins are abundant in number and therefore do not need many conservation efforts on them. However, there are some groups and organisations that exist to help these penguins stay in such large numbers, such as the International Penguin Conservation Work Group (IPCWG) and the Polar Conservation Organisation (PCO). Some are also kept in zoos and wildlife parks, and take part in breeding programmes.

Fun Facts

  • Male: Cock
  • Female: Hen
  • Young: Chick
  • Group: Colony
  • Adult Adelie penguins have been observed stealing rocks from their neighbours nests.
  • They are the smallest species of penguin found in the Antarctic.
  • They were named in 1840 by French explorer Jules Dumont d’Urville after his wife, Adelie.
  • A colony can be made of up to 100 to 250,000 pairs of birds.