Ostrich, bee humming bird
On the matter of biodiversity: the biggest versus the smallest bird species. The photo on the right shows the silhouette of a male ostrich. In the display case in the foreground are some vulnerable hummingbirds. The smallest, 1.8 cm long, is not visible in the photo.
Struthio camelus, Linnaeus, 1758
The biggest bird (you already saw it, of course), is the ostrich. The male weighs up to 150 kg and the female up to 100 kg. The biggest bird also has the biggest egg: 1.7 kg. [Extinct elephant birds of Madagascar and the giant moa of New Zealand did lay larger eggs].
The eggs have a very, very hard shell.
Is this to the advantage of the chick inside? Of course, it is; it has to be
able to carry the weight of the father. Nevertheless, it is also at the
disadvantage of the chicks.
When is that the case?
Hover over me for the answer.
When they are hatching
Ostriches do not bury their heads in the sand. However, at the approach of trouble, ostriches will lie down and press their necks to the ground. This, from a distance, gives the appearance that they have buried their heads in the sand.
REPRODUCTION:
In the mating season, the male chooses a defended area or territory. It selects a suitable place for the nest. It makes a simple pit by scratching with its legs, 30 to 60 centimetres deep, and 3 metres wide. It tries to attract a female by means of a very special show. Sitting on the ground it raises one wing while lowering the other. At the same time it moves the tail up and down. This is irresistible for the females.
You know where that leads: that's where eggs come from. While the female is laying the eggs, the male seduces other females, so in the end up to five of these females go into the nest, lay the eggs and leave. Once there are about twenty eggs in the nest, the pair starts sitting on them. The male at night, the female during the day.
When things get out of hand, the number of eggs in the nest could exceed up to more than seventy. Do all those eggs hatch? No, usually no more than twenty chicks hatch. The pair's female positions her own eggs in the centre. That way their possibilities of hatching are enhanched. Despite the constant watch of the male and female, less than 10 per cent of the eggs will hatch. Incubation takes about six weeks, hatching all the eggs over a period of three to five days. Soon the hatchlings leave the nest and by the third day they are on their way. When two families meet, what happens? The adults go into a fight and the winner takes all the chicks. It is not unsual to meet a couple with more than a hundred chicks of all sizes, or even more. Can the parents take good care of all of them? Of course not. Only about 12% of these young survive to adulthood that is 0.9 survivors per nest.
Paradisaea apoda (Linnaeus, 1758)
At the photo to the left you see the legs of a male ostrich, and the body of a female. Also an egg is partly visible. But the greater-bird-of-paradise steals the show. Carl Linnaeus named the species Paradisaea apoda, or "legless bird-of-paradise", because the skins were traded for the sake of of the beautiful feathers. So the legs and wings were cut off by the indigenous New Guinean people before shipping; some people were convinced that these birds came from paradise and were kept aloft by their plumes, so they did not need wings. Furthermore they should never come to the earth, or sit down, until death, so they did not need legs either.
Mellisuga helenae (Lembeye, 1850)
Bee hummingbirds are the smallest birds in the world. They spend more time of their lives flying than most other species. Adult males are about 5.5 cm long and weigh about 2 g. Adult females are about 6 cm long and weigh about 2.5 g. Their wingspan is about 3.2 cm. How big would be the nest they make? And imagine how big their eggs would be. Hummingbirds can fly in two ways: like other birds. Which direction are they on then? Then they go forward as any other bird. However, they are also capable of flapping their wings in a figure-8-like pattern. They do this an average of 50 times per second. You cannot follow their wings with your eyes, but you can hear them.
What sound do they make??
When they do this, they hover like a helicopter. They can turn, move backward or forward, even fly upside down. They can fly forward with the beak into a flower.
What do they suck up from the flowers?
They take nectar from brightly coloured, scented small flowers of trees, shrubs, and epiphytes. They have to visit up to 1,500 flowers on an average day, in order to get enough nectar. So they spend most of the daytime feeding. They have to eat half their total body mass and drink 8 times their total body mass in water each day [to support their extremely high metabolism.]
The hummingbird has the largest heart in proportion to its body. Their hearts pump about 1,200 times per minute in flight and 200 beats per minute at rest. Their daytime body temperature fluctuates around 41°C. (Over 40)
At night, they are not feeding. Why is that? Most flowers are closed and the darkness is not very helpful either. [To conserve energy,] their bodies go into a state of torpor. (Temporary hibernation). The body heat escapes and the body temperature drops down to 19 °C. The heartbeat also drops down, to 80 beats a minute. Their muscles stiffen and they cling to a branch and sit almost lifeless; what would happen when you touch the branch they are sitting on? Even a very small breeze is enough to swing them downwards. Then they remain hanging upside down until the next morning.
Is it possible for them to live in Holland?
Why can’t they?
They cannot live here, for instance in January. They have to live in a country where are many flowers blossoming every day of the year. In this case, it is Cuba.
