Marabou stork – Leptoptilos crumenifer
The marabou stork is not the most
attractive bird and it would make a terrible dinner guest as carrion forms a
large part of its diet. Marabous will follow vultures to carcasses, allowing
them to do the difficult work of ripping open the skin, before plunging their
own huge bills into the flesh. As with vultures, the lack of facial feathers
prevents blood and gore from building up around the head. In addition to
scavenging, marabous are generally opportunistic, taking small vertebrates,
eggs and invertebrates. This generalism has facilitated an increase in the use
of rubbish dumps as sources of food in the burgeoning urban areas of Africa.
The marabou stork is a member of
the stork family, Ciconiidae, and order, Ciconiiformes. This is small order of
about 19 species which used to include ibises and spoonbills until their move
to the Pelecaniformes.
Australian pelican – Pelecanus conspicillatus
Speaking of the Pelecaniformes,
the Australian pelican is a handsome example of the eight species of pelican.
It is notable for having the longest beak of any living bird! It was also one
of the first species I spotted on my trip to Queensland. Unfortunately I did
not see it eat. The foraging ecology of pelicans is famous (or perhaps
infamous) for the utilisation of the huge gular pouch to catch fish. Whilst
small and large fish form the majority of the diet, pelicans will also eat
amphibians and crustaceans and some observations from Regent’s Park even show
them to eat pigeons! Pelicans can also use the skin of their pouches to
regulate their temperature, fluttering the skin to promote cooling in the same
way that elephants flap their ears.
The habitat of pelicans is
generally, and unsurprisingly, based particularly around wetlands (although I
have seen brown pelicans [Pelecanus
occidentalis] off the beaches of Miami and the Caribbean). There they join
a wider assemblage of pelecaniform species. The Pelecaniformes have evolved
various ways of plying the waterways for food with much emphasis on beak
morphology. The statuesque herons come in a range of sizes but most are expert
anglers. The ibises (or, more correctly, ibides) take a more relaxed view,
probing the substrate for invertebrates whilst the spoonbills sweep the water with
their huge utensils. Perhaps the oddest members of the order are the hamerkop (Scopus umbretta) and shoebill (Balaeniceps rex), two monotypic species
related to pelicans. The former is a small, hammer-headed wading bird which
build huge nests whilst the latter is a large, stork-like bird with an even
larger, whale shaped bill (hence the Latin 'king whale-head'). The shoebill also
has a dastardly stare which could strike fear into anyone.
Andean condor – Vultur gryphus
The Andean condor means playing
the superlative game again. I had thought that this condor had the second
largest wingspan of any living bird but apparently the two largest pelicans are
also bigger. Moreover, the splitting of the wandering albatross species complex
into many species throws a few more, longer winged species into the mix. The
Andean condor does, however, have the largest wing area of any living bird species
which is not surprising as the barn doors of the condor are far wider than the
tapered wings of the albatrosses.
As the name suggests, the Andean
condor hails from the Andes mountain range which forms the spine of South
America. Without a sternum, the condor is not designed for flapping, instead it
relies heavily on thermals to keep it aloft, keeping to high places and using
the topography of the land to soar about. Seeing these birds in their element
must surely be an amazing sight and its unsurprising that the ancient Native
Americans worshipped them as sun deities. Their legendary appearance lives on
in the coats of arms of no fewer than five South American countries.
Soaring around, looking for
carrion is what traditionally makes the Andean condor a vulture, one of the
seven species in the New World vulture family Cathartidae. In the second half
of the 20th century, some ornithologists began to realise that the
similarity between the Old and New World vultures might only be skin deep.
Morphological and karyotypic (number and shape of chromosomes) data were used
to support the grouping of New World vultures with the storks with the
apparent similarity with Old World vultures resulting from convergent evolution. Whilst this
convergence in morphology and ecology still stands, the evolutionary
relationships have been better resolved with the placement of New World
vultures as a sister clade to the rest of the birds of prey (excluding
falcons), either sharing the order Accipitriformes or being elevated to their
own order Cathartiformes.
Lammergeier – Gypaetus barbatus
The lammergeier (or bearded
vulture) is a true vulture in the sense of being a member of the Aegypiinae Old
World vultures however it is atypical in its appearance and ecology. It has
orangey-yellow head plumage to match its torso and the face is completed with a
stiff, black beard (barbatus = ‘bearded’). Although lammergeiers are scavengers,
their diet is unique for being based largely on bone marrow. Obviously bone
marrow can be pretty difficult to access. For smaller bones, lammergeiers can
crack the bone open but for bigger bones, they have a rather clever technique.
Lammergeiers have learnt to carry bones up to 150 m into the air, dropping
them from a height so that they fall and crack open on the ground. Adult birds
can carry bones weighing nearly as much as they do! Sometimes this method is
even extended to crack open tortoises. Bone cracking is a classic example of a
learned technique and immature birds can spend years honing their skills. Once
ingested the bones need industrial strength acid dissolve. As such,
lammergeiers have stomach acid at pH 1 which dissolves the calcium rich bone in
a day.
Lammergeiers cling to high
altitude regions across Southern Europe, Central Asia and Africa. The
mountainous habitat is a harsh environment but living off bones means that food
can often be found. Furthermore, when carcasses are all but stripped of flesh,
the marrow can live on, desiccated within the bones.
Great bustard – Otis tarda
The great bustard is generally
cited as the heaviest flying bird, weighing up to 18 kg. It is also, arguably,
the most sexually dimorphic bird species in terms of size as males can weigh up
to four times the weight of females. Great bustards have a patchy distribution
across the grassland and steppes of Iberia, Central Europe and Asia. They were
once part of the British countryside too but they were hunted to extinction by
the 1840s. Now the Great Bustard Project is working to establish a new breeding
population in the rolling fields of Wessex. Since 2004, birds reared from
Russian and then Spanish eggs have been introduced annually. Bustards bread for
the first time in nearly 200 years in 2009 and the population is slowly
growing.
In the UK, great bustards have
much in common with the common crane as both were almost absent from our
countryside and now programmes are tirelessly working to bring them back with
the Great Crane Project experiencing much success. Evidence of these two
species in our heritage is subtle but present. Most noticeably, bustards,
cranes and other species are found in the heraldic emblems of the past. Bustards
are found on the coats of arms of Wiltshire and Cambridgeshire. Peregrine
falcons are found on the arms of Surrey, Bagshot and the University of Lincoln
whilst Lincolnshire’s is capped by a lapwing. Northamptonshire even has a white
falcon that looks a bit like a gyrfalcon (unlikely that gyrs have ever visited
Northants). Finally, in Cornwall, red-billed choughs used to be a common sight,
flying on broad wings along the cliffs, and as such they grace the coat of arms
of Cornwall. Another word for chough is beckit and the 12th Century
Bishop Thomas Beckit had three choughs on his coat of arms, as did the seat of
his power, Canterbury. During the reign of the Tudors, Cardinal Thomas Wolsey
took the choughs of his namesake for his own crest and bestowed that crest on
his new college of Christchurch in Oxford.
Red-crowned crane – Grus japonensis
Cranes are members of the Gruidae family which sits in the Gruiformes order with the rails, crakes and gallinules. This relationship might seem surprising but when measuring both the rails and cranes I could see the similarity in bill morphology. Cranes are essentially rails on steroids.
The red-crowned crane is one of
the largest and (in my opinion) most beautiful of the 15 crane species. Cranes
are characterised by the long legs and necks which are stretched out in flight.
They have a generally omnivorous diet, although a degree of niche segregation
can occur when multiple crane species live in sympatry. China is the hotspot of
crane diversity, containing, at various points, eight species. Many are
migratory so may either only winter or breed in China. The red-crowned crane exhibits different migration strategies between the two disjunct populations.
In Japan, the cranes barely move at all, hopping just 150 km whilst the mainland race breeds in Northern China and Siberia then splits up and migrates around 1,500 km to Korea and Jiangsu, China.
The red-crowned crane is one of
the most endangered crane species. It is possible that the risk to cranes is
somehow linked to diet as it has been noted that the most common species are
largely herbivorous within the scale of omnivory whilst the red-crowned and
(rarer) whooping cranes feature more animals in their diet including invertebrates, fish, amphibians,
reptiles and birds. A carnivorous diet results in a degree of dispersal whilst
foraging as opposed to the gregarious nature of more herbivorous cranes.
Red-crowned cranes do, however, breed in groups, taking advantage of safety in numbers.
Cranes are typically monogamous, keeping the same partner for many years.
Couples maintain their bonds via the rhythmic, synchronised dancing as well as duetting with loud, trumpeting calls.
The red-crowned crane has
important symbolism for both the Chinese and the Japanese. In China, and
particularly Taoism, the crane symbolises longevity and immortality. In Japan, red-crowned
cranes were said to live for 1,000 years whilst they are also recognised for their loyalty
in monogamy and their strength in migration. I think they are impressive birds
and should rightly be respected and cherished.
