**Abstract**

The Amazon basin is the largest tropical rainforest in the world covering almost 40 per cent of the South American continent. For centuries, its vastness and inaccessibility have been protecting this area. The general belief is that the Amazonia region has unparalleled biodiversity which means that one in five of all bird species known in the globe lives in the Amazon Jungle. The author is testing this claim against the known occurrence of the world owl species. There are fewer owl species in Amazonia than expected namely 34 (against 54 expected). Two possible reasons are that our knowledge of the Amazon region species is still incomplete as may be indicated that new owl species have been found recently. The other reason could be that the rainforest is not after all the most wanted biotope for many of the owl species which often depend on the prey available in the bottom tier of the forest which is flooded during the wet season. Whatever the reason is, more detailed research is needed on all species of the Amazon region as there must be many new owls and other animal species out there waiting to be discovered. We have no idea how many of those new species have been or will be lost due to the rainforest destruction before they can be discovered. Therefore, it is necessary to stop deforestation in the Amazonia, be it due to forest logging, uncontrolled fires (often deliberately set) agriculture expansion or industrial development. Deforestation is not the only reason that the Amazon basin is changing. The rainforest suffers also from the global climate change when the higher temperatures reduce the rainfall in the tropical Atlantic region, causing drought and increasing the fire susceptibility of the rainforest. Luckily the owls are not so sensitive to surrounding forest cover as many other tropical forest-dependent bird species, like the large-bodied avian frugivores. Impacts of forest fragmentation on owls will need additional research.

**Keywords:** Amazonia, conservation, owl species, number of wildlife species, climate change

#### **1. Introduction**

The history of geology tells us that at one time Amazon River flowed westward when it was still inside the Gondwana continent and part of the proto-Congo River system [1]. Later the African and South American continents separated and the Atlantic Ocean widened enough to provide a moist and warm climate to the Amazon region. The rainforest formed during the Eocene era between 56 and 34 million years ago [2]. The Andes have formed 15 million years ago and some 5 million years later the Amazon River began to flow eastward [1].

Now the Amazon River is the largest of the world's rivers in terms of water volume discharged into the sea, carrying more than five times the volume of the Congo River

or twelve times that of the Mississippi River [1]. The Amazon River basin covers almost 40 per cent of the South American continent and the main river is some 4080 miles long, second only to the River Nile in length [3]. The Amazon river and its 1100 tributaries have a drainage area covering 2.7 million square miles belonging to nine nations: (the percentage share of each nation is shown in brackets) Bolivia (7.7%), Brazil (58.4%), Colombia (7.1%), Ecuador (1%), French Guiana (1.4%), Guyana (3.1%), Peru (12.8%), Surinam (2.5%) and Venezuela (6.1%) [4]. Even in this book, the percentages vary as the perceived extent of the Amazon depends on the definition. Often people as well include areas outside the basin and that biogeographic Amazon ranges 3–3.2 million sq. mi, of which just over 80 per cent is forested [1]. Whatever definition is used the Amazon basin has the world's largest rainforest, bigger than the next two largest rainforests – in the Congo River basin and Indonesia – combined. The moist broadleaf forest comprises an estimated 390 billion individual trees representing some 16,000 species [5]. Billions of trees pump daily huge quantities of water vapour into the atmosphere. A large part of this water rains down locally, but part of this moisture is carried in the air to other areas including the agricultural heartland of South America. It has been estimated that two-thirds of Brazil's national product comes from the areas that receive Amazon rainforest generated rainfall [1].

It was for a long time a general belief that the Amazon rainforest has been always only sparsely populated by the humans due to the poor soils. Recent archaeological findings, however, suggest that the Amazon was earlier densely populated and that up to 5 million people were living in the region in 1500 AD. However, by 1900, the population had fallen to one million and by the early 1980s, it was estimated to be less than 200,000. Indigenous civilizations were devastated by the spread of new diseases like smallpox and typhus after the arrival of the first Europeans, in 1542 and after [6]. The UK broadcaster BBC 4 presented evidence that the Amazon rainforest has been shaped by humans for at least 11,000 years through activities like forest gardening and'terra preta' indigenous soil management, instead of being only a pristine wilderness [7]. In recent decades the human population has accelerated and incoming people have introduced mechanised agriculture and integrated the region into the global economy. Large quantities of the Amazon-produced commodities like cattle beef and leather, timber, soy, oil and gas, and minerals are sold to China, Europe, Russia and the U.S. [1].


**5**

*Average 22.*

**Table 2.**

*[25–33].*

*Diversity of the Owl Species in the Amazon Region DOI: http://dx.doi.org/10.5772/intechopen.94977*

and not just in Amazonia.

**2. Material and methods**

statements hold for the world owls.

The wet forests in Amazon have consistently higher species diversity than any comparable forests in Africa and Asia [8]. The Amazonia Region is home to a large collection of living plants (40,000 or more) and animal species in the world. However,

The largest discrepancies seem to be in the numbers of mammals and amphibians whilst the number of birds and reptiles is relatively uniform. It is possible that the highest numbers represent the number of South American species in its entirety

It has been said that one in ten known species in the world occurs in the Amazon region and one in five of all bird species are found in the Amazon rainforest [11]. The author knows best "Owls of the World" [12] and compares here how these

The history of owls in the Amazon region is far less known than that of human history. Fossil records of the Amazon owls are very few if any [13] so we do not know what kind of owls lived in the region before the present species. Even today, Amazonian owl species are not well known, and few studies have focused on the species from the region (see [14–24]. In the nine countries sharing the Amazon basin the number of owl species

However, it is important to note that only part of the above-listed owl species lives in the Amazon basin of that country. In the following, the scientific names are in the same form as in the "Owls of the World" [34] to avoid the complicated taxonomic discussions. In Bolivia, the tropical lowland evergreen forests are found in all the Amazonian ecoregions of the country. They represent the habitat with the second highest diversity of owls, with the following species: *Tyto furcata*, *Mecascops choliba*, *M. watsonii*, *M. hoyi*, *M. guatemalae*, *Pulsatrix perspicillata*, *Bubo virginianus*, *Strix chacoensis*, *S. virgata*, *Glaucidium brasilianum* and *Aegolius harrisii* [25]. In Brazil, there are five owl species, which occur exclusively in this biome: *Megascops watsonii*, *M. usta*, *M. roraimae*, *Glaucidium hardyi* and *Lophostrix cristata* [26]. From Colombian 28 owl species 10 are found in the Amazon area of the country. This corresponds well with the fact that in the Amazon region Colombia represents 30% of the national territory. Amazon species include *Tyto furcata*, *Megascops choliba*, *M.* 

**Country Number of owl species Source of information**

Bolivia 25 [24] Brazil 23 [25] Colombia 28 [26] Ecuador 28 [27] French Guiana 13 [28] Guyana 16 [29] Peru 30 [30] Suriname 15 [31] Venezuela 22 [32]

*A total number of owl species listed in the 9 countries sharing the Amazon basin. Sources of information* 

is on average 22 species ranging from 13 to 30 per country (**Table 2**).

**Table 1** above shows considerable discrepancies in the stated species diversity.

#### **Table 1.**

*Biodiversity of Amazonia plant and wildlife [1, 2, 9, 10].*

*Diversity of the Owl Species in the Amazon Region DOI: http://dx.doi.org/10.5772/intechopen.94977*

*Ecosystem and Biodiversity of Amazonia*

sold to China, Europe, Russia and the U.S. [1].

**Butler/Mongabay [1]**

Plant species 40,000 At least

Invertebrates Na 96,660

*Biodiversity of Amazonia plant and wildlife [1, 2, 9, 10].*

**Wikipedia [2]**

40,000

– 128,843 Brazil alone

Mammals 430+ 427 427 More than 1400 Birds 1300 1294 1300 1500 Fishes 3000 2200 ca. 3000 2200 Reptiles 400+ 378 378 Na Amphibians 1000+ 428 Over 400 More than 1000

Insects Na 2.5 million Na 90% of all animal

**WWF [9]**

ca. 100,000

40,000 Na

**Ascent of the Amazon [10]**

Na

species are insects

**Number of plants/and animal group species**

or twelve times that of the Mississippi River [1]. The Amazon River basin covers almost 40 per cent of the South American continent and the main river is some 4080 miles long, second only to the River Nile in length [3]. The Amazon river and its 1100 tributaries have a drainage area covering 2.7 million square miles belonging to nine nations: (the percentage share of each nation is shown in brackets) Bolivia (7.7%), Brazil (58.4%), Colombia (7.1%), Ecuador (1%), French Guiana (1.4%), Guyana (3.1%), Peru (12.8%), Surinam (2.5%) and Venezuela (6.1%) [4]. Even in this book, the percentages vary as the perceived extent of the Amazon depends on the definition. Often people as well include areas outside the basin and that biogeographic Amazon ranges 3–3.2 million sq. mi, of which just over 80 per cent is forested [1]. Whatever definition is used the Amazon basin has the world's largest rainforest, bigger than the next two largest rainforests – in the Congo River basin and Indonesia – combined. The moist broadleaf forest comprises an estimated 390 billion individual trees representing some 16,000 species [5]. Billions of trees pump daily huge quantities of water vapour into the atmosphere. A large part of this water rains down locally, but part of this moisture is carried in the air to other areas including the agricultural heartland of South America. It has been estimated that two-thirds of Brazil's national product comes from the areas that receive Amazon rainforest generated rainfall [1]. It was for a long time a general belief that the Amazon rainforest has been always only sparsely populated by the humans due to the poor soils. Recent archaeological findings, however, suggest that the Amazon was earlier densely populated and that up to 5 million people were living in the region in 1500 AD. However, by 1900, the population had fallen to one million and by the early 1980s, it was estimated to be less than 200,000. Indigenous civilizations were devastated by the spread of new diseases like smallpox and typhus after the arrival of the first Europeans, in 1542 and after [6]. The UK broadcaster BBC 4 presented evidence that the Amazon rainforest has been shaped by humans for at least 11,000 years through activities like forest gardening and'terra preta' indigenous soil management, instead of being only a pristine wilderness [7]. In recent decades the human population has accelerated and incoming people have introduced mechanised agriculture and integrated the region into the global economy. Large quantities of the Amazon-produced commodities like cattle beef and leather, timber, soy, oil and gas, and minerals are

**4**

**Table 1.**

*Na = Not available.*

The wet forests in Amazon have consistently higher species diversity than any comparable forests in Africa and Asia [8]. The Amazonia Region is home to a large collection of living plants (40,000 or more) and animal species in the world. However, **Table 1** above shows considerable discrepancies in the stated species diversity.

The largest discrepancies seem to be in the numbers of mammals and amphibians whilst the number of birds and reptiles is relatively uniform. It is possible that the highest numbers represent the number of South American species in its entirety and not just in Amazonia.

It has been said that one in ten known species in the world occurs in the Amazon region and one in five of all bird species are found in the Amazon rainforest [11]. The author knows best "Owls of the World" [12] and compares here how these statements hold for the world owls.

## **2. Material and methods**

The history of owls in the Amazon region is far less known than that of human history. Fossil records of the Amazon owls are very few if any [13] so we do not know what kind of owls lived in the region before the present species. Even today, Amazonian owl species are not well known, and few studies have focused on the species from the region (see [14–24]. In the nine countries sharing the Amazon basin the number of owl species is on average 22 species ranging from 13 to 30 per country (**Table 2**).

However, it is important to note that only part of the above-listed owl species lives in the Amazon basin of that country. In the following, the scientific names are in the same form as in the "Owls of the World" [34] to avoid the complicated taxonomic discussions. In Bolivia, the tropical lowland evergreen forests are found in all the Amazonian ecoregions of the country. They represent the habitat with the second highest diversity of owls, with the following species: *Tyto furcata*, *Mecascops choliba*, *M. watsonii*, *M. hoyi*, *M. guatemalae*, *Pulsatrix perspicillata*, *Bubo virginianus*, *Strix chacoensis*, *S. virgata*, *Glaucidium brasilianum* and *Aegolius harrisii* [25]. In Brazil, there are five owl species, which occur exclusively in this biome: *Megascops watsonii*, *M. usta*, *M. roraimae*, *Glaucidium hardyi* and *Lophostrix cristata* [26]. From Colombian 28 owl species 10 are found in the Amazon area of the country. This corresponds well with the fact that in the Amazon region Colombia represents 30% of the national territory. Amazon species include *Tyto furcata*, *Megascops choliba*, *M.* 


#### **Table 2.**

*A total number of owl species listed in the 9 countries sharing the Amazon basin. Sources of information [25–33].*

*watsonii*, *Lophostrix cristata*, *Pulsatrix perspicillata*, *Pulsatrix melanota*, *Strix virgata*, *Strix huhula*, *Glaucidium brasilianum*, and *Athene cunicularia* [27]. In Ecuador, the rather homogenous forests of the Amazon lowlands are home to nine species mostly distributed throughout the entire region including *Tyto furcata*, *Megascops choliba*, *M. watsonii*, *Lophostrix cristata*, *Pulsatrix perspicillata*, *Strix virgata*, *Strix huhula*, *Glaucidium brasilianum*, and *Asio clamator* [28].

Unfortunately, there is no available specific study on owls in Guyana, Peru and Venezuela. Also in the French Guiana and Surinam the total of 13 and 15 owl species sounds very small and it is equally not well defined which owls live in the Amazon basin of the country.

The occurrence of different owl species in the comparison of this chapter is based entirely on the latest known distribution maps [12, 13] and no new field research was undertaken in the region. Therefore, especially in the Andean region, it was not so easy to decide which "Pacific side" owls may or may not belong to the Amazonian fauna. As all these owl distribution maps are still in a state of flux so one can expect that the total numbers may hold up very well as any mistakes have most likely been made in both directions.
