Here are my pencil, penned and final version of the vampire hummingbird.
Initially I thought about creating a vampire robin instead of a vampire hummingbird but after doing some research about the vampire finch (which is a real bird) and hummingbirds I decided that a vampire humming bird was more appropriate. However I looked at various birds in order to create an image that I liked. There are some many different kinds of hummingbirds that I felt it was important to look at a lot of them. Here are the images and information I gathered when thinking about my vampire hummingbird.
Hummingbirds are New World birds that constitute the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm (3–5 in) range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird.
They are known as hummingbirds because of the humming sound created by their beating wings which flap at high frequencies audible to humans. They hover in mid-air at rapid wing flapping rates, typically around 50 times per second,[1] but possibly as high as 200 times per second, allowing them also to fly at speeds exceeding 15 m/s (54 km/h; 34 mph),[2] backwards or upside down.[3][4]
Hummingbirds have the highest metabolism of any homeothermic animal.[5] To conserve energy when food is scarce, they have the ability to go into a hibernation-like state (torpor) where their metabolic rate is slowed to 1/15th of its normal rate.[6] The smallest species of hummingbird weighs less than a penny.
Hummingbirds drink nectar, a sweet liquid inside certain flowers. Like bees, they are able to assess the amount of sugar in the nectar they eat; they normally reject flower types that produce nectar that is less than 10% sugar and prefer those whose sugar content is higher. Nectar is a mixture ofglucose, fructose, and sucrose, and is a poor source of nutrients, so hummingbirds meet their needs for protein, amino acids, vitamins, minerals, etc. by preying on insects and spiders.[7]
Hummingbird bill shapes vary dramatically, as an adaptation for specialized feeding. Some species, such as hermits (Phaethornis spp) have bills that are long allowing them to probe deep into flowers that have a long corolla. Thornbills have short, sharp bills adapted for feeding from flowers with short corollas and piercing the bases of longer ones. The Sicklebills' extremely decurved bills are adapted to extracting nectar from the curved corollas of flowers in the family Gesneriaceae. The bill of the Fiery-tailed Awlbill has an upturned tip, as in the Avocets. The male Tooth-billed Hummingbird has barracuda-like spikes at the tip of its long, straight bill.
The two halves of a hummingbird's bill have a pronounced overlap, with the lower half (mandible) fitting tightly inside the upper half (maxilla). When hummingbirds feed on nectar, the bill is usually opened only slightly, allowing the tongue to dart out and into the interior of flowers.
Hummingbirds drink with their tongue by rapidly lapping nectar. While it had been believed that capillary action was what drew nectar onto the tongue, high-speed photography has revealed that a hummingbird's tongue’s tubes open down their sides, and close around nectar, trapping it.[8] Hummingbirds do not spend all day flying, as the energy cost would be prohibitive; the majority of their activity consists simply of sitting or perching. Hummingbirds eat many small meals and consume approximately half their weight in pure sugar (or twice their weight, if drinking nectar that is 25% sugar) each day.[9] Hummingbirds digest their food rapidly due to their small size and high metabolism; a mean retention time (MRT) of less than an hour has been reported.[10] Hummingbirds spend an average of 10–15% of their time feeding and 75–80% sitting and digesting.
Because they starve so easily, hummingbirds are highly attuned to food sources. Some species, including many found in North America, are territorial and will try to guard food sources (such as a feeder) against other hummingbirds, attempting to ensure a future food supply for itself.
Co-evolution with ornithophilous flowers[edit]
Hummingbirds are specialized nectarivores[11] and are tied to the ornithophilous flowers they feed upon. Some species, especially those with unusual bill shapes such as the Sword-billed Hummingbird and the sicklebills, are co-evolved with a small number of flower species.
Many plants pollinated by hummingbirds produce flowers in shades of red, orange, and bright pink, though the birds will take nectar from flowers of many colors. Hummingbirds can see wavelengths into the near-ultraviolet, but their flowers do not reflect these wavelengths as many insect-pollinated flowers do. This narrow color spectrum may render hummingbird-pollinated flowers relatively inconspicuous to most insects, thereby reducing nectar robbing.[12][13] Hummingbird-pollinated flowers also produce relatively weak nectar (averaging 25% sugars w/w) containing high concentrations of sucrose, whereas insect-pollinated flowers typically produce more concentrated nectars dominated by fructose and glucose.[14]
Aerodynamics of flight[edit]
Hummingbird flight has been studied intensively from an aerodynamic perspective using wind tunnels and high-speed video cameras.
Two studies of Rufous or Anna's Hummingbirds in a wind tunnel used particle image velocimetrytechniques to investigate the lift generated on the bird's upstroke and downstroke.[16][17] The authors concluded that the birds produced 75% of their weight support during the downstroke and 25% during the upstroke. Many earlier studies had assumed that lift was generated equally during the two phases of the wingbeat cycle, as is the case of insects of a similar size. This finding shows that hummingbird hovering is similar to, but distinct from, that of hovering insects such as the hawk moths. Further studies using electromyography in hovering Rufous hummingbirds showed thatmuscle strain in the pectoralis major (principal downstroke muscle) was the lowest yet recorded in a flying bird, and the primary upstroke muscle (supracoracoideus) is proportionately larger than in other bird species.[18]
The Giant Hummingbird's wings beat is as low as 12 beats per second, the wings of medium-sized hummingbirds beat about 20 to 30 beats per second and the smallest can reach 100 beats per second during courtship displays.
A slow motion video has shown how the hummingbirds deal with rain when they are flying. To remove the water from their heads, they shake their heads and body, similar to a dog shaking to shed water.[19] Further, when raindrops collectively may weigh as much as 38% of the bird's body weight, hummingbirds shift their bodies and tails horizontally, beat their wings faster, and reduce their wings' angle of motion when flying in a heavy rain.[20]
Metabolism[edit]
With the exception of insects, hummingbirds while in flight have the highest metabolism of all animals, a necessity in order to support the rapid beating of their wings. Their heart rate can reach as high as 1,260 beats per minute, a rate once measured in a Blue-throated Hummingbird.[21] They also consume more than their own weight in nectar each day, and to do so they must visit hundreds of flowers daily. Hummingbirds are continuously hours away from starving to death and are able to store just enough energy to survive overnight.[22]
Hummingbirds are capable of slowing down their metabolism at night or at any other time food is not readily available. They enter ahibernation-like state known as torpor. During torpor, the heart rate and rate of breathing are both slowed dramatically (the heart rate to roughly 50 to 180 beats per minute), reducing the need for food. Hummingbirds are rare among vertebrates in their ability to rapidly make use of ingested sugars to fuel energetically expensive hovering flight, powering up to 100% of their metabolic needs with the sugars they drink, (in comparison, humans athletes max out at around 30%). A recent study[23] from the University of Toronto Scarborough has shown that hummingbirds can use newly ingested sugars to fuel hovering flight within minutes of consumption and can fuel as much as 100% of their intense hovering metabolism with either glucose or fructose. These data suggest that hummingbirds are able to oxidize fructose in flight muscle tissues at rates high enough to satisfy their extreme metabolic demands. By relying on newly ingested sugars to fuel flight hummingbirds can reserve their limited fat stores to see them through the overnight fasting period or to power migratory flights.
The dynamic range of metabolic rates in hummingbirds[24] requires a corresponding dynamic range in kidney function.[25] The glomerulusis a cluster of capillaries in the nephrons of the kidney that removes certain substances from the blood, like a filtration mechanism. The rate at which blood is processed is called the glomerular filtration rate (GFR). Most often these fluids are reabsorbed by the kidneys. During torpor, to prevent dehydration, the GFR slows, preserving necessities for the body such as glucose, water and salts. GFR also slows when a bird is undergoing water deprivation. The interruption of GFR is a survival and physiological mechanism unique to hummingbirds.[25]
Studies of hummingbirds' metabolisms are highly relevant to the question of how a migrating Ruby-throated Hummingbird can cross 800 km (500 mi) of the Gulf of Mexico on a nonstop flight. This hummingbird, like other birds preparing to migrate, stores up fat to serve as fuel, thereby augmenting its weight by as much as 100 percent and hence increasing the bird's potential flying time.[26]
Lifespan[edit]
Hummingbirds have long lifespans for organisms with such rapid metabolisms. Though many die during their first year of life, especially in the vulnerable period between hatching and leaving the nest (fledging), those that survive may live a decade or more. Among the better-known North American species, the average lifespan is probably 3 to 5 years. By comparison, the smaller shrews, among the smallest of all mammals, seldom live more than 2 years.[27] The longest recorded lifespan in the wild is that of a female Broad-tailed Hummingbird that was banded (ringed) as an adult at least one year old, then recaptured 11 years later, making her at least 12 years old. Other longevity records for banded hummingbirds include an estimated minimum age of 10 years 1 month for a female Black-chinned similar in size to Broad-tailed, and at least 11 years 2 months for a much larger Buff-bellied Hummingbird.[28]
I also watched this documentary which is where I probably learned the most. I made notes in one of my sketchbooks.
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