Editing Wildlife (section)

==Loss and extinction==
{{See also|Biodiversity loss}}
[[File:World map of prehistoric human migrations.jpg|thumb|350px|Map of early [[human migrations]], according to [[Mitochondrial DNA|mitochondrial]] [[population genetics]]. Numbers are [[millennia]] before the present.|alt=World map of prehistoric human migrations]]
This subsection focuses on [[human impact on the environment|anthropogenic]] forms of wildlife destruction. The loss of animals from ecological communities is also known as ''[[defaunation]].''<ref name="def ant">{{cite journal|last1= Dirzo|first1= Rodolfo|first2= Hillary S.|last2= Young|first3= Mauro|last3= Galetti|first4= Gerardo|last4= Ceballos|first5= Nick J. B.|last5=Isaac|first6= Ben|last6= Collen|title= Defaunation in the Anthropocene|journal= [[Science (journal)|Science]]|date= 2014|doi= 10.1126/science.1251817|pmid= 25061202|volume= 345|issue= 6195|pages= 401–406|url= http://www.uv.mx/personal/tcarmona/files/2010/08/Science-2014-Dirzo-401-6-2.pdf|url-status= live|archive-url= https://web.archive.org/web/20170511160501/https://www.uv.mx/personal/tcarmona/files/2010/08/Science-2014-Dirzo-401-6-2.pdf|archive-date= 2017-05-11|bibcode= 2014Sci...345..401D|s2cid= 206555761}}</ref>

[[Exploitation of natural resources|Exploitation]] of wild populations has been a characteristic of modern man since our exodus from Africa 130,000 – 70,000 years ago. The rate of extinctions of entire species of plants and animals across the planet has been so high in the last few hundred years that it is widely believed that a sixth great extinction event ("the [[Holocene Mass Extinction]]") is currently ongoing.<ref>{{Cite book |last=Kolbert |first=Elizabeth |author-link=Elizabeth Kolbert |title=The Sixth Extinction: An Unnatural History |title-link=The Sixth Extinction: An Unnatural History |year=2014 |publisher=[[Henry Holt and Company]] |location=New York City |isbn=978-0805092998}}</ref><ref>{{cite journal | last1 =  Ceballos | first1 = Gerardo| last2 =  Ehrlich| first2 = Paul R.| last3 = Barnosky| first3= Anthony D. | last4 = García | first4 = Andrés| last5 =  Pringle | first5 = Robert M.| last6 =  Palmer| first6 =Todd M. |  year = 2015 | title = Accelerated modern human–induced species losses: Entering the sixth mass extinction |  journal = [[Science Advances]] | volume = 1 | issue = 5 | page = e1400253 |doi = 10.1126/sciadv.1400253| pmid = 26601195| pmc = 4640606| bibcode = 2015SciA....1E0253C}}</ref><ref>{{cite journal|vauthors=Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF|title=World Scientists' Warning to Humanity: A Second Notice|journal=[[BioScience]]|volume=67|issue=12|pages=1026–1028|date=13 November 2017|doi=10.1093/biosci/bix125|quote=Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century.|doi-access=free|hdl=11336/71342|hdl-access=free}}</ref><ref>{{cite journal|last1= Cowie|first1=Robert H.|last2=Bouchet|first2=Philippe|last3=Fontaine|first3=Benoît|date=2022|title=The Sixth Mass Extinction: fact, fiction or speculation?|journal=Biological Reviews|volume=97|issue=2|pages=640–663|doi=10.1111/brv.12816|pmid=35014169|pmc=9786292 |s2cid=245889833|doi-access=free}}</ref> The 2019 ''[[Global Assessment Report on Biodiversity and Ecosystem Services]]'', published by the [[United Nations]]' [[Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services]], says that roughly one million species of plants and animals face extinction within decades as the result of human actions.<ref>{{cite news |vauthors=Vidal J |date=March 15, 2019 |title=The Rapid Decline Of The Natural World Is A Crisis Even Bigger Than Climate Change |url=https://www.huffpost.com/entry/nature-destruction-climate-change-world-biodiversity_n_5c49e78ce4b06ba6d3bb2d44 |work=[[The Huffington Post]] |access-date=November 8, 2021 |archive-date=October 3, 2019 |archive-url=https://web.archive.org/web/20191003084130/https://www.huffpost.com/entry/nature-destruction-climate-change-world-biodiversity_n_5c49e78ce4b06ba6d3bb2d44 |url-status=live }}</ref><ref name="Stokstad">{{cite journal |last1=Stokstad |first1=Erik |title=Landmark analysis documents the alarming global decline of nature |journal=Science |date=6 May 2019 |doi=10.1126/science.aax9287 |s2cid=166478506}}</ref> Subsequent studies have discovered that the destruction of wildlife is "significantly more alarming" than previously believed, with some 48% of 70,000 monitored animal species experiencing population declines as the result of human industrialization.<ref>{{cite news |author=<!--not stated--> |date=May 23, 2023 |title=Biodiversity: Almost half of animals in decline, research shows |url=https://www.bbc.com/news/uk-northern-ireland-65681648 |work=BBC |location= |access-date=July 12, 2023 |archive-date=July 17, 2023 |archive-url=https://web.archive.org/web/20230717222234/https://www.bbc.com/news/uk-northern-ireland-65681648 |url-status=live }}</ref><ref>{{cite journal |last1=Finn|first1=Catherine|last2=Grattarola|first2=Florencia |last3=Pincheira-Donoso|first3=Daniel |date=2023 |title=More losers than winners: investigating Anthropocene defaunation through the diversity of population trends|url= |journal=Biological Reviews|volume= 98|issue= 5|pages= 1732–1748|doi=10.1111/brv.12974|pmid=37189305 |s2cid=258717720 |access-date=|doi-access=free}}</ref> According to a 2023 study published in ''[[PNAS]]'', "immediate political, economic, and social efforts of an unprecedented scale are essential if we are to prevent these extinctions and their societal impacts."<ref>{{cite news|last=Greenfield|first=Patrick|date=September 19, 2023|title='Mutilating the tree of life': Wildlife loss accelerating, scientists warn|url=https://www.theguardian.com/environment/2023/sep/19/mutilating-the-tree-of-life-wildlife-loss-accelerating-scientists-warn|work=The Guardian|location=|access-date=September 26, 2023|archive-date=September 25, 2023|archive-url=https://web.archive.org/web/20230925213112/https://www.theguardian.com/environment/2023/sep/19/mutilating-the-tree-of-life-wildlife-loss-accelerating-scientists-warn|url-status=live}}</ref><ref>{{cite journal |last1= Ceballos|first1=Gerardo|last2=Ehrlich|first2=Paul R.|date=2023 |title=Mutilation of the tree of life via mass extinction of animal genera|url= |journal=[[Proceedings of the National Academy of Sciences of the United States of America]]|volume=120 |issue=39 |pages=e2306987120|doi=10.1073/pnas.2306987120|access-date=|doi-access=free|pmid=37722053 |pmc=10523489|bibcode=2023PNAS..12006987C }}</ref>

The four most general reasons that lead to destruction of wildlife include overkill, [[habitat destruction]] and [[habitat fragmentation|fragmentation]], impact of introduced species and chains of extinction.<ref>Diamond, J. M. (1989). Overview of recent extinctions. Conservation for the Twenty-first Century. D. Western and M. Pearl, New York, Oxford University Press: 37-41.</ref>

===Overkill===
Overkill happens whenever hunting occurs at rates greater than the reproductive capacity of the population is being exploited. The effects of this are often noticed much more dramatically in slow-growing populations such as many larger species of fish. Initially when a portion of a wild population is hunted, an increased availability of resources (food, etc.) is experienced increasing growth and reproduction as [[Density dependence|density dependent]] inhibition is lowered. Hunting, fishing and so on, have lowered the competition between members of a population. However, if this hunting continues at rate greater than the rate at which new members of the population can reach breeding age and produce more young, the population will begin to [[resource depletion|decrease in numbers]].<ref>{{cite web|url=http://www.conservationandwildlife.com/critical-species/|title=Critical Species|publisher=Conservation and Wildlife|access-date=14 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20120519025342/http://www.conservationandwildlife.com/critical-species/|archive-date=19 May 2012}}</ref>

Populations that are confined to islands, whether literal islands or just areas of habitat that are effectively an "island" for the species concerned, have also been observed to be at greater risk of dramatic population rise of deaths declines following [[Unsustainable fishing methods|unsustainable hunting]].

===Habitat destruction and fragmentation===
{{main|Habitat destruction|Habitat fragmentation}}

[[File:Amazonie deforestation.jpg|thumb|300px|[[Deforestation]] and increased road-building in the [[Amazon Rainforest]] are a significant concern because of increased human encroachment upon wild areas, increased resource extraction and further threats to [[biodiversity]].|alt=Amazon Rainforest deforestation]]
The habitat of any given species is considered its preferred area or [[Territory (animal)|territory]]. Many processes associated with human habitation of an area cause loss of this area and decrease the carrying capacity of the land for that species. In many cases these changes in land use cause a patchy break-up of the wild landscape. Agricultural land frequently displays this type of extremely fragmented, or relictual habitat. Farms sprawl across the landscape with patches of uncleared woodland or forest dotted in-between occasional paddocks.

Examples of habitat destruction include grazing of bushland by farmed animals, changes to natural fire regimes, forest clearing for timber production and wetland draining for city expansion. This is particularly challenging since wild animals cannot drink tap water, which means they cannot autonomously survive in those habitats where there is no [[surface water]] access.

===Impact of introduced species===
{{main|Introduced species}}

{{see also|Invasive species}} Mice, cats, rabbits, dandelions and [[poison ivy]] are all examples of species that have become invasive threats to wild species in various parts of the world. Frequently species that are uncommon in their home range become out-of-control invasions in distant but similar climates. The reasons for this have not always been clear and [[Charles Darwin]] felt it was unlikely that exotic species would ever be able to grow abundantly in a place in which they had not evolved. The reality is that the vast majority of species exposed to a new habitat do not reproduce successfully. Occasionally, however, some populations do take hold and after a period of acclimation can increase in numbers significantly, having destructive effects on many elements of the native environment of which they have become part.

===Chains of extinction===
This final group is one of secondary effects. All wild populations of living things have many complex intertwining links with other living things around them. Large [[herbivorous]] animals such as the hippopotamus have populations of [[insectivorous]] birds that feed off the many parasitic insects that grow on the hippo. Should the hippo die out, so too will these groups of birds, leading to further destruction as other species dependent on the birds are affected. Also referred to as a [[domino effect]], this series of [[chain reaction]]s is by far the most destructive process that can occur in any [[Biocoenosis|ecological community]].

Another example is the [[black drongo]]s and the [[cattle egret]]s found in India. These birds feed on insects on the back of cattle, which helps to keep them disease-free. Destroying the nesting habitats of these birds would cause a decrease in the cattle population because of the spread of insect-borne diseases.