Information

Why African species are larger in size compared to other parts of world?

Why African species are larger in size compared to other parts of world?



We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Why are African species larger in size compared to other parts of world?

Best Example: African elephants are very famous for Giant ears.

So many African Animals listed in Guinness World of Records. (Source)


When it comes to mammals this cannot really be evaluated without taking the Megafaunal mass extinction into account. This mainly refers to the extinction of large mammals from the Pleistocene Megafauna, which affected different parts of the world differently. More species were extinct in the Americas, Australia and northern Eurasia, and fewer species in Africa and southern Asia. One of the reasons for the differential extinction is thought to be the shorter evolutionary history together with humans in the areas that were more affected (since over-hunting is though to be one of the main explanations, see e.g Sandom er al. 2014).

If you only look at currently extant animals, you ignore the Wooly mammoth, the Woolly rhinoceros, Ground sloths and many other large species inhabiting higher latitudes, and this will give a very biased picture when searching for evolutionary reasons for the differences in body size between continents.


The organisms listed in the question (elephant and the snail) are found in warm tropical regions (Africa is not completely hot continent 1). The organisms dwelling in tropical region shows adaptation for loosing excess heat by having longer extremities. This is known as Allen's rule 2.

This explains larger ear of African elephants.

In case of snail, probably it has to be vast resources which are available in tropics. The large amount of resources would cause a larger population to exist, resulting into more competition. The larger size of snail must be conferring increased fitness to snail.



Giant African Land Snail

The Giant African Land Snail is one of the largest terrestrial gastropods. They have a light to dark brown shells with vertical stripes of a darker shade of brown on them.

They have an average lifespan of about 5-7 years. When they have enough food, and the weather is satisfactory, they tend to live much longer. Some of them have been known to live up to 10 years.

The “Achatina fulica” is one of the most invasive species in the world and the United States Department of Agriculture consider it as one of the most damaging species for the agriculture and crops in the country. It is known to eat at least 500 different species of plants.

This species is on the list of the 100 most harmful invasive alien species in the world, but Achatina fulica does not seem to surrender. This snail that stands out for its large size has easily adapted to life in regions outside its natural habitat and is considered one of the biggest land snails.

Class: Gastropoda
Family: Achatinidae
Genus: Achatina


Why African species are larger in size compared to other parts of world? - Biology

How much do we really know about African lions? What is their current conservation status? Why are these lions significant? Once we know about these lions, how can we help them?

General facts about the African Lion…

Lions are the “King of the Jungle” — they dominate their environment as strong and brave creatures. Male lions are larger than their female counterparts. A male lion weighs in the range of 330 to 500 pounds, and has an average lifespan of 10 to 14 years. The African lion’s diet consists of animals such as zebra, giraffe, buffalo and rhino. According to Defenders of Wildlife, there are fewer than 21,000 African lions remaining on the entire African continent today. Lions are now only found in the south Sahara desert, and southern and eastern Africa.

Their current conservation status…

The African lion’s current conservation and protection status is ‘vulnerable’ under CITES. According to the Scientific American blog, they will be near extinction by the year 2050 — which is not too far in the future, when we stop and think about it. In March 2011, Born Free USA (among others) petitioned the U.S. Fish and Wildlife Service to reclassify the African lion as “endangered” under the U.S. Endangered Species Act. With the tragic trophy hunting of Cecil the lion in Zimbabwe in July 2015, the hope is this will be considered more seriously.

African Lion’s role in the ecosystem…

Population Control

Lions play a key role in the food chain by helping to control the herbivore population. If the herbivore population is not regulated, the increase of competition among them would cause some to go extinct and thus reduce biodiversity. The lions have a reputation of being the ‘chief’ predator of their habitat as they are known to even kill large herbivores such as elephants and giraffes.

Disease Control

Lions prey mainly on herd animals. Nature comes to play as lions take down the weakest of the herd. This keeps the herd population resilient and healthy. If lions did not exist, there would be a symbiotic relationship between parasites and herd animals. This way, parasites could increase and spread throughout the herd, resulting in fewer healthy animals.

Smaller Carnivores: Olive Baboons

Where predators like lions do not exist, smaller carnivores tend to increase. Smaller carnivores such as olive baboons will reproduce more and cause complications for farmers by destroying their crops and livestock, and spreading diseases.

Current news about the African Lion…

Human-Wildlife Conflict

As the human population increases, the lion’s habitat is more and more threatened. As humans encroach on what was once the lion’s territory, human-wildlife conflicts increase. When farmers’ livestock push out antelopes, lions begin killing cattle. In turn farmers will poison lions. However, some have found solutions to stop the killing with something as simple as lights. [Update January 2019: Marnus is working on an amazing project… saving the lions and their home]

Trophy Hunting

Dentist Walter James Palmer recently made news for killing “Cecil the Lion” in Zimbabwe, Africa. Palmer not only killed the lion, but skinned, beheaded, and left him on the outskirts of the national park. The hunters who did it tried to remove and destroy Cecil’s collar to cover their tracks. The media, celebrities and activist groups such as PETA reacted by sending hate emails and letters to Palmer for killing a well-known, protected lion loved by the locals. He allegedly paid someone USD$55,000 to kill and mutilate “Cecil the Lion” and is now faced with poaching charges. Because of men like Palmer, African lions are closer to extinction than we expected. The moral of the story is that locals, activists, and conservation groups need to be more cautious of their protected lions from big trophy hunters like Palmer.

How you can help to protect African Lions…

There are different ways to help protect these majestic creatures:

First, one can inform others about the conservation status of the African lion.

Second, help organizations by signing petitions for gaining approval of the U.S law that would make it against the law to sell lions or their parts across states and international borders.

Third, one can look for organizations — either national or global — that specialize in conserving lions.

Fourth, learn how to appreciate African lions and their habitats.

Contributed by Nikela Volunteer Monserrat Gomez


Introduction

Carnivora is a remarkable order for comparative studies of neuroanatomy because of the wide range of brain and body size of its members, from the smallest, mouse-sized least weasel to the 5-ton Southern elephant seal, overlapping with most other mammalian clades. Carnivoran brains are highly convoluted, although less so than cetartiodactyl and primate brains of similar mass (Pillay and Manger, 2007 Manger et al., 2010). Carnivorans are also highly diverse: they can be social or solitary animals carnivorous, omnivorous, or even frugivorous domestic (such as cats and dogs) or wild.

Carnivory comes with costs and benefits that are likely to impose a delicate balance on the relationship between brain and body. Although meat eating (and therefore hunting) is not universal among carnivorans, hunting is a feature of this clade that might impose a larger cognitive demand on the brain than its counterpart: being preyed upon, since prey species tend to find safety in numbers. It is thus tempting to predict that cognitive demand has imposed positive pressure on carnivorans for larger numbers of neurons compared to their prey species, mostly artiodactyls, of similar or even larger body and brain size. However, this possible advantage conferred by larger numbers of neurons, particularly in the cerebral cortex, would have to be balanced by the metabolic cost of having more neurons. Daily sleep requirement and dietary content are key elements here. While artiodactyls afford large bodies through a large time investment in feeding on plant leaves of low caloric content (Du Toit and Yetman, 2005), an investment made possible by brains that can do with as few as 3 h of sleep per day (Zepelin and Rechtschaffen, 1974), carnivorans typically are inactive, possibly asleep, over 12 h per day (Zepelin and Rechtschaffen, 1974). Moreover, carnivorous species have highly variable feeding success (Gorman et al., 1998), and hunting comes at a particularly high metabolic cost for the largest predator species (Carbone et al., 2007), factors which are likely to be a liability for a tissue such as brain that has a consistently high metabolic requirement, and is one of the most expensive tissues of the body (Aschoff et al., 1971). Considering that the cerebral cortex is the most expensive structure within the brain (Karbowski, 2007), and that the energetic cost of the brain is proportional to its number of neurons (Herculano-Houzel, 2011), it is conceivable that large meat-eating carnivorans are particularly subject to energetic constraints that might limit their numbers of brain neurons, especially in the cerebral cortex. Such a limitation would be expected to appear in the form of a trade-off between body mass and number of brain neurons, as seen in large non-human primates (Fonseca-Azevedo and Herculano-Houzel, 2012).

Carnivorans are divided into two main suborders, Caniformia and Feliformia, both of which include species that were domesticated, which has been suggested to alter the relationship between brain and body size (Kruska, 2007). In phylogenetic terms, carnivorans are closely related to artiodactyls (Bininda-Emonds et al., 2007), animals that the large meat-eating carnivorans prey upon. We have previously found that artiodactyls share with marsupials, afrotherians, glires, and eulipotyphlans the scaling relationship between number of cortical neurons and decreasing average neuronal density in the cerebral cortex (which reflects larger average neuronal cell sizes Mota and Herculano-Houzel, 2014), such that the mass of the cerebral cortex scales faster than the cortex gains neurons across species (reviewed in Herculano-Houzel, 2016). Primates, on the other hand, have larger neuronal densities in the cerebral cortex than non-primates of similar cortical mass (Herculano-Houzel, 2016), and therefore larger numbers of neurons in similarly sized structures, which we have proposed to convey a cognitive advantage to primates (Herculano-Houzel, 2012). The relationship between body mass and number of brain neurons is highly variable in a clade-specific manner, but it is unlikely to contribute to cognitive capabilities across species (Herculano-Houzel, 2017). In contrast, all mammalian species examined so far share the same relationship between the mass of major brain structures and the numbers of non-neuronal cells that compose them (Herculano-Houzel, 2014 Dos Santos et al., 2017), which indicates that a single scaling rule has governed the addition of non-neuronal cells to brain tissue for at least 166 million years (Murphy et al., 2001, 2004 Bininda-Emonds et al., 2007).

Here we determine the cellular composition of the brain of eight carnivoran species (ferret, banded mongoose, raccoon, domestic cat, domestic dog, striped hyena, lion, and brown bear) to investigate several possibilities: (1) that all carnivoran brains and substructures follow the same non-neuronal scaling rules that apply to all other therians examined so far, with similar non-neuronal cell densities (2) that different neuronal scaling rules apply to carnivoran brains compared to other non-primate brains, in particular such that carnivoran brains have more neurons than artiodactyl brains of similar mass (3) that domesticated species diverge from wild species in their neuronal composition and relationship to body mass and (4) that carnivoran brains exhibit evidence of an energetic trade-off between body mass and number of brain neurons, especially in the cerebral cortex.


Your Penis Is Huge

Photo illustration by Lisa Larson-Walker. Photos by Shutterstock

Excerpted from God’s Doodle: The Life and Times of the Penis by Tom Hickman, out now from Soft Skull Press.

Intellectually, a man knows that the size of his penis shouldn’t be specifically relevant in a relationship, to him or to a woman. His common sense tells him that it will certainly not be the major or controlling factor in a woman’s response to him. And yet … he can’t help believing that it is.

The most frequent question on all Internet Q-and-A sex sites continues to be, “Is size important?” A downloadable chart of four outline drawings (“low average” to “extraordinarily large”) can be found on the net, which a man can print out and use as a template against which to judge himself. Even the most balanced of men is capable of half-believing he is under-endowed. Many American men, according to the Kinsey Institute, believe the average erection is 10 inches—this despite (or because of) frequently accessing Internet pornography in which participants have shaved off their pubic hair to increase visibility and many have used a vascular device to pump up temporarily. But there should be solace for the average man in knowing that he is statistically within touching distance, as it were, of some 90 percent of all his fellows.

When the Kinsey Institute reviewed its founder’s data 30 years after it was published, in the light of subsequent findings, it showed that 1 in 100 men reaches beyond the 5- to 7-inch erectile median to 8 that 7 in 1,000 men go beyond 8 and only 1 in 1,000 touches 9. But Durex and the Definitive Penis Internet surveys, while stressing that their core findings are consistent with Kinsey, have cautiously proposed that there are more very big penises—between 4 and 7 in every 100 men reaching 8 inches, between 30 and 40 in every 1,000 reaching 9, and between 10 and 30 in 1,000 reaching beyond. And where the institute’s data showed that erections above 9 inches are so rare (a word, incidentally, that Kinsey himself always used rather than “big”) as to be statistically immeasurable, both surveys have suggested that 1 in 100 men posts double figures. In the round, the institute found that 18 in 1,000 men have an erection over the median Durex and the Definitive Penis propose this figure to be between four and eight times greater. Could Kinsey have been so wrong?

The problem for researchers has been that they have had to rely on participants providing their own measurements. The bulk of Kinsey’s data came from self-measurements (marked off on the edge of returned postcards) all the data in the Durex and the Definitive Penis survey undertakings were collected in this way—the DPS giving the average erection as 6.3 inches, with Durex giving it as 6.4. Are penises, then, like people, getting bigger? If men’s ears have pricked up at this point, the answer is no: The depersonalised and anonymous nature of the Internet almost certainly explains the apparent increase. Not that Durex and the DPS have not taken safeguards against humorists and delusionists. Durex eliminates extreme replies: lengths under 75 mm (3 inches), “the size of a large chilli”, and those over 250 mm (a touch under 10 inches), “the size of a large cucumber,” The Definitive Penis Survey has disregarded the blatantly fraudulent (“17-year-old lawyers and those claiming American Zulu warrior ancestry”) and eliminates the bottom 1 percent and the top 2 percent of replies additionally the website has asked participants to provide an electronically transmitted photo which includes a tape measure.

Averaging the averages of Kinsey from over half a century ago, his institute’s from 25 years ago, and the Durex and Definitive Penis surveys from the last year of the millennium (only three-tenths of an inch apart, top to bottom, after all) we arrive at 6.25 inches, with a circumference of just under 5 inches being pretty consistent in all surveys and that surely seemed as definitive as you can get, except that in 2001 Lifestyle Condoms (on the same mission as Durex) carried out the only large-scale study not to rely on self-measurements—and turned the penis issue on its head. After getting 300 volunteers to submit their aroused manhood to the attention of two tape-wielding nurses under the constant supervision of a doctor, Lifestyle reported the average erection to be 5.8 inches—about one-half an inch less than the above averaged averages. It’s worth noting that five years earlier two small-scale studies (one in Germany, one in Brazil) had pharmacologically induced erections in volunteers and both had averaged out at 5.7 inches. Even more startlingly, the same year the Journal of Urology had published the findings of a study in which 80 normal men of various ethnicities had also been pharmacologically aroused (the object in this case was ultimately to help in counselling others considering penile augmentation)—and arrived at an average of 5.08, almost three-quarters of an inch less than Lifestyle’s.

The medical profession continues to measure penises between 2007 and 2010 at least 15 different studies were published, all of them hands-on. What now seems to be the focus of attention is the likelihood that men who know or think they are below average are unlikely to volunteer to be sized up, or allow themselves to be, meaning that averages could be lower than those recorded (allusion to which hypothesis might, in some circumstances, stand a small-penised man in good stead). What is incontrovertible is that where men and their penises are concerned there are lies, damned lies, and self-measurements.

Objectively, even big human penises are small, other than in comparison with other human penises but virtually all human penises are big in comparison with those of the other 192 primate species. Flaccid, the penis of the gorilla and the orangutan, both with much bigger bodies, is virtually invisible erect, it reaches 1.5 inches or less the chimpanzee, man’s closest relative (sharing 98 percent of his DNA) achieves an erection twice that of the other two apes but still only one-half the average human one. Why, comparatively, man’s penis is so disproportionately large is a question that engages a clutch of disciplines including archaeology, anthropology, and zoology, as well as the evolutionary, psychological, and sociological branches of biology. Collectively they remain at a loss to provide what is known as “ultimate causal explanation.”

The consensual “ological” view is that when man’s hominoid ancestors came down from the trees 4 million years ago, their penises were of a size with the apes—“vanishingly small,” according to archaeologist Timothy Taylor in The Prehistory of Sex. Then, however, when upright walking swivelled the sexual focus from rear to front of both sexes, a focus that was intensified by the loss of the majority of bodily hair other than in the genital area, the penis began the process of “runaway selection.”

Feminists incline to the view that it happened because females wanted it that way that when femina became erecta, the angle of the vagina swung forward and down, moving deeper into the body, obliging the penis, as Rosalind Miles put it in The Women’s History of the World, to follow the same principle as the giraffe’s neck: “it grew in order to get to something it could not otherwise reach.” On the other hand, the big penis may have evolved because that’s what possessors wanted—a greater attractant to potential mates and a more visible means of warning off rivals. A big penis also increased the male’s chance of inseminating a female who was having sex with other males, by getting closer to the cervix. There are objections to such theories—not least that other primate males have continued to propagate their species with considerably less at their disposal. As to the theory that the penis grew to assist humankind’s imaginative variety of sexual positions, orangutans and chimpanzees, particularly the pygmy chimpanzee or bonobo (a separate species, found in the Congo, which has a more upright gait and a more “human” skeleton), are equally imaginative in their coupling—and they can do it swinging from trees while man only talks about doing it swinging from chandeliers.


What is a Gene Pool and Why is it Important?

Apart from a healthy habitat, the survival of a species depends on the genetic diversity among its members. BiologyWise defines the concept of a 'gene pool', and gives its examples to shed more light on this concept.

Apart from a healthy habitat, the survival of a species depends on the genetic diversity among its members. BiologyWise defines the concept of a ‘gene pool’, and gives its examples to shed more light on this concept.

Did You Know?

As far as humans are concerned, women have contributed more DNA to the gene pool than men, because women have outnumbered men throughout our history.

Would you like to write for us? Well, we're looking for good writers who want to spread the word. Get in touch with us and we'll talk.

A species is a way of describing organisms of the same kind who can breed among themselves. Therefore, dogs, humans, and horses belong to different species. However, all individuals of a species do not occur in a single region they live as groups in different geographical areas. These groups are called populations. Thus, every species is made up of a number of populations. For example, a group of deer living in a forest forms one population, while a group of the same species living on a wildlife reserve forms another.

The bodies of plants, animals, insects, and several other organisms are made of small units called cells. Each cell contains hereditary information passed down from parents to their offspring in the form of genes. Animals that reproduce sexually have two sets of every gene, called alleles one from each parent. For example, a gene that produces eye color can have two alleles – one produces brown color while the other imparts blue color. The characteristics produced by a gene depends on which allele of that gene is active in an individual. Let us now understand the concept of a gene pool.

What is a Gene Pool?

The combination of all the genes present in a given population is called the gene pool of that population. It represents the complete genetic diversity found within a population or species.

What are its Characteristics?

♦ The concept of a gene pool is only used for sexually-reproducing organisms (because asexual reproduction produces clones).

♦ It includes all the variants or alleles of every gene.

♦ It includes all the genes present in the population.

♦ In most cases, the population includes individuals of the same species only.

♦ A gene pool includes even those genes whose effects are not visible in an individual.

Why is it Important?

Would you like to write for us? Well, we're looking for good writers who want to spread the word. Get in touch with us and we'll talk.

Since a gene pool represents the total number of genes found within a population, those populations with larger gene pools tend to have more genes, and hence, more genetic diversity. Each gene has a specific purpose, such as giving the plant/animal a particular characteristic, resistance to a disease, tolerance to harsh climate, and so on. Therefore, a population with a larger genetic diversity will be better prepared to deal with disease outbreaks or extreme environmental changes, because they will, most likely, have those genes that protect them from such adverse changes.

On the other hand, populations with a lesser number of genes in their gene pool will be susceptible to such problems, which may cause them to become endangered or even perish altogether, i.e., become extinct. Therefore, populations with a large gene pool will have more chances of survival, while those with small gene pools are in danger of acquiring genetic diseases, deformities, and infertility.

How Does a Gene Pool Change?

1. By Mutations
Mutations are changes in the genes of an individual. These variations may be as minute as a change of a single nucleotide (an organic molecule) in the DNA, to changes in entire sets of chromosomes. Depending on whether the mutation is passed down to offspring, it may be permanent or temporary. They are beneficial to the population if they add valuable genes, but some may cause diseases.

2. By Natural Selection
Natural selection is one of the most important factors affecting a gene pool. Individuals from a population which carry beneficial genes are more likely to survive and produce offspring, than those that don’t. Therefore, the next generation will, most probably, carry genes from such individuals, which may even become fixed, i.e., occur in every individual.

3. By Genetic Drift
Sometimes, the type of genes in a population changes due to random events (such as the death of a few individuals), and not always because the change is beneficial. This is called ‘genetic drift’, and affects a smaller population more than a larger one, because, in the former, such genes are likely to occur in every individual.

Examples

❒ About 60,000 to 70,000 years ago, our early ancestors migrated out of Africa into Europe and the Middle East. Since the climate here was colder, genetic modifications produced lighter skin to help them absorb more ultraviolet light. Ultimately, these changes became a part of their gene pool, helping them evolve.

❒ The potato originated in the western part of South America, from where it spread to Europe and Ireland, where it eventually became a staple food for the population. Since all potatoes grown in Ireland descended from a small number of plants, the small gene pool made the entire crop susceptible to blight (a fungal plant disease). Potato crops all over the country were ruined in the mid-19th century, causing a million deaths due to starvation.

❒ A number of animal species, such as mountain lions in the Americas, and leopards in South Africa, are threatened by human activities. Their habitat has been divided into fragments, surrounded by towns and farmlands. This results in interbreeding among smaller populations, and the small gene pool makes them susceptible to diseases.

As can be seen, a gene pool represents the future of a species. This is the reason why wilderness areas should be protected – they contain the gene pools of a number of crops and domestic animals, which ensures our own survival.

Related Posts

The following article presents some points that are related to the subject of DNA studies, and which specifically describe the importance of DNA.

Meiosis is a phase in sexually reproductive organisms, wherein cell-division takes place. It is of great importance, because it creates genetic diversity in the population.

Meiosis is a phase in sexually reproductive organisms, wherein cell-division takes place. It is of great importance, because it creates genetic diversity in the population.


Raven

Our editors will review what you’ve submitted and determine whether to revise the article.

Raven, any of approximately 10 species of heavy-billed dark birds, larger than crows. Closely related, both ravens and crows are species of the genus Corvus. The raven has a heavier bill and shaggier plumage than the crow, especially around the throat. The raven’s lustrous feathers also have a blue or purplish iridescence.

The common raven (C. corax) is the largest of the perching birds: it reaches a length of up to 66 cm (26 inches) and has a wingspan of more than 1.3 metres (4 feet). (Some magpies and the lyrebird exceed the raven in length, but their bodies are smaller.) In the white-necked raven (C. cryptoleucus) of western North America, the bases of the neck feathers are white. Other species of ravens—some with white or brown markings—occur in Africa, southern Asia, Australia, and North America.

Formerly abundant throughout the Northern Hemisphere, the raven is now restricted to the wilder, undisturbed parts of its range. It is among the hardiest of birds, inhabiting the northern tundra and boreal forests as well as barren mountains and desert. It is keen-sighted and notably wary. Long before it was immortalized in Edgar Allan Poe’s poem “ The Raven,” the common raven was a near-universal symbol of dark prophecy—of death, pestilence, and disease—though its cleverness and fearless habits also won it a degree of admiration, as evidenced in its noble heraldic roles in the mythology of some peoples.


About Pest Samurai

I’m Thomas Matthews, the guy behind Pest Samurai. I owned one and worked in several Pest Control service companies. I have become obsessed with pest control. I’m here with my team writing about best pest control practices. To find out more about me and my team visit about Pest Samurai page.


Affiliate Disclosure
As an Amazon Associate, this site earns from qualifying purchases. We may also earn small commissions on purchases from other retail websites.


Gorilla

Gorillas are gentle giants and display many human-like behaviors and emotions, such as laughter and sadness. In fact, gorillas share 98.3% of their genetic code with humans, making them our closest cousins after chimpanzees and bonobos. The largest of the great apes, gorillas are stocky animals with broad chests and shoulders, large, human-like hands, and small eyes set into hairless faces. The two gorilla species live in equatorial Africa, separated by about 560 miles of Congo Basin forest. Each has a lowland and upland subspecies. Gorillas live in family groups of usually five to 10, but sometimes two to more than 50, led by a dominant adult male—or silverback—who holds his position for years. The bond between the silverback and his females forms the basis of gorilla social life. Females become sexually mature around seven or eight years old but don’t begin to breed until a couple of years later. Males mature at an even greater age. Once a female begins to breed, she'll likely give birth to only one baby every four to six years and only three or four over her entire lifetime. This low rate of reproduction makes it difficult for gorillas to recover from population declines. Both gorilla species have been decreasing in numbers for decades, and a 2010 United Nations report suggests that they may disappear from large parts of the Congo Basin by the mid-2020s.

Conservation efforts by WWF, other organizations, and governments are making a difference for gorillas. New protected areas are being designated for some gorilla populations, and the population of mountain gorillas has continued to increase in recent years, leading to its downlisting from Critically Endangered to Endangered in November 2018.

The first rule of gorilla tracking? Listen well

Twenty years ago, a gorilla habitation program provided the Ba’Aka living near the Dzanga Sanga Park with a new opportunity. And by 2020, Dzanga-Sangha employed more than 50 Ba’Aka as gorilla trackers.


Why African species are larger in size compared to other parts of world? - Biology

AFRICAN PENGUIN > Spheniscus demersus
FAMILY: Sphenisciformes

DESCRIPTION: This penguin grows to be about 26.5 to 27.5 inches tall and weighs between 4.4 and 11 pounds. It has a black stripe and a pattern of unique black spots on its chest, as well as pink glands above its eyes that become pinker as the penguin gets hotter. Males are larger than females and have larger beaks.

HABITAT: African penguins are usually found within 40 kilometers of the shore, coming onshore to a variety of coastal habitats to breed, molt, and rest.

RANGE: This penguin breeds on the African mainland from Hollams Bird Island, Namibia to Bird Island, Algoa Bay, South Africa. The species formerly bred at many additional sites but has been extirpated from much of its range. Range Map

MIGRATION: Juvenile African penguins tend to disperse along the coastline to the west and north. Birds regularly reach southern Angola and vagrants have been found off Gabon, Congo, and Mozambique.

BREEDING: Breeding takes place from May through August on rocky ground with little or no vegetation. These penguins excavate nest-burrows wherever possible, with guano being the preferred nesting substrate.

LIFE CYCLE: This penguin's average lifespan in the wild is 20 years.

FEEDING: African penguins feed on pelagic schooling fish, particularly sardine and anchovy.

THREATS: Global-warming-induced shifts in the marine and atmospheric environment are destructive to the African penguin's habitat and comprise a major threat to the bird. Global warming also intensifies the other severe threats the species faces, including guano and egg collection at breeding colonies, oil pollution, and commercial fishing.

POPULATION TREND: African penguin populations have been reduced by approximately 90 percent since the beginning of the 20th century. In 1910, there were probably approximately 1.4 million adult birds in one population alone at Dassen Island, which had been reduced to about 145,000 birds by the mid-1950s. The worldwide population was estimated at 179,000 birds in the late 1990s and is still declining.