Silovanje planete

Silovanje planete

Tokom poslednjih 10.000 godina, ljudske aktivnosti su dovele do velikih promena u svetskim ekosistemima. irenje naselja i stvaranje polja za gajenje useva ili napasanje stoke, krenje uma, te isuivanje movara i vlanih stanita, redukovali su stanita gotovo svih vrsta biljaka i ivotinja. Sistematski lov ivotinja radi hrane, krzna i drugih proizvoda (i, u mnogim sluajevima, sporta), drastino je redukovao brojnost mnogih vrsta, a neke doveo do izumiranja. ...

Golub selac

Moda najstraniji primer masovnog pokolja nije bio onaj bizona, ve golubova selaca to je pria u koju je gotovo nemogue poverovati. Prvi evropski doseljenici u Severnu Ameriku esto su komentarisali ogroman broj plavih i dugorepih, brzih i gracioznih golubova. Jedan od prvih doseljenika u Virdiniji opisao je:Zimi je vie divljih golubova nego to se to moe zamisliti, ja sam viao neprekinuta jata u vazduhu koja su prolazila po tri ili etiri sata, toliko gusta da su nam zasenila nebo.Slini izvetaji potiu i od Holanana sa Menhetna iz 1625, iz Salema u Masausetsu iz 1631. i od nekih od prvih istraivaa Luizijane iz 1698. godine. Jo 1854, jedan stanovnik okruga Vejn u dravi Njujork napisao je:Ima dana i dana kada ih je vazduh prepun, teko da bi se koji prekid pojavio u jatu koje prolee po pola dana. Jata su se protezala koliko oko see, red iznad reda.

U Saginou u Miigenu, 8. aprila 1873, zabeleen je neprekidan prelet golubova selaca od 7.30 ujutru do 4.00 po podne. Drugi izvetaji opisuju jata iroka jednu milju kako u rano prolee nadleu posmatraa etiri ili pet sati neprekidno, tokom seobe sa juga u gnezdilina podruja Nove Engleske, Njujorka, Ohaja i junog podruja Velikih jezera. Jata su bila toliko gusta da bi jedan hitac oborio 30 ili 40 ptica, a mnoge su ubijane tako to su niskoletea jata sa uzvisina gaana motkama. I njihove gnezdiline kolonije su bile podjednako enormne neke su pokrivale podruja veliine 8x20 km, sa i po 90 gnezda u istoj kronji. Teina gusto naikanih ptica lomila je grane, a ponekada obarala i stabla.Broj golubova selaca u Severnoj Americi u vreme dolaska Evropljana nije poznat, ali se procene kreu oko pet milijardi, ili jedne treine svih ptica tog regiona u to vreme. Ukupan broj svih ptica u dananjim SAD procenjuje se na oko pet milijardi.

Jedan razlog zato su golubovi selci bili toliko brojni jeste odsustvo grabljivaca, sa izuzetkom jastrebova i drugih ptica grabljivica. Sa druge strane, ptice su bile iznenaujue osetljive na ljudske delatnosti. enka bi polagala samo jedno jaje godinje, pa se gubici nisu mogli lako nadomestiti. Gradili su krhka gnezda, a navika kolonijalnog gneenja i seobe u divovskim jatima izlagala ih je riziku od napada. Ptice su se hranile hrastovim irom, te plodovima bukve i kestena, a kada su prvi doseljenici iskrili ume, redukovali su povrine stanita i koliine dostupne hrane. Samo po sebi, to bi samo redukovalo broj ptica. Pravu krizu izazvao je lov. Indijanci su ih lovili velikim mreama, a ve 1630-ih, i Evropljani su radili isto. Ptii su smatrani poslasticom, a odrasli su lovljeni zbog perja i mesa. Tokom prva dva veka evropskog naseljavanja, brojnost im je donekle opala, ali je sredinom XIX veka i dalje iznosila vie milijardi. Do tog vremena su razmere lova bile ograniene.

Milijarde golubova selaca su dovedene do izumiranja za 50 godina. Pokolj je zapoeo komercijalnim lovom irokih razmera radi snabdevanja rastuih gradova na istoku jeftinim mesom. Taj razvoj dogaaja bio je omoguen gradnjom eleznike pruge koja je poetkom 1850-ih spojila podruje Velikih jezera i Njujork. Oko 1855, oko 300.000 ptica godinje isporuivano je u Njujork. To je jo uvek bio mali obim ubijanja, u poreenju sa onim to e uslediti 1860-ih i 1870-ih. O obimu operacija svedoe nam gotovo neverovatne, ali paljivo unete cifre u trgovakim knjigama. Lov je bio deo legalne i visokoprofitabilne trgovine. U samo jednom danu (23.7.1860), iz Grand Rapidsa u Miigenu poslato je 235.200 ptica na istok. U jednoj godini (1874), miigenski okrug Okeana je tritima na istoku poslao 1.000.000 ptica. Dve godine kasnije, taj broj e porasti na 400.000 nedeljno na vrhuncu sezone, i 1.600.000 godinje. Godine 1869, okrug Van Bjuren u Miigenu isporuio je 7.500.000 ptica. Do kraja 1870-ih, broj golubova selaca je znatno opao, ali je 1880. Miigen ipak poslao 527.000 ptica na istok. Do kraja 1880-ih velika jata, koja su do skora bila obina pojava, potpuno su nestala, a opaanja golubova selaca postala vredna panje. Poslednje poznate ptice su u veini istonih drava uginule tokom 1890-ih.U prirodi je vrsta izumrla oko 1900, kada su u Ohaju uginule poslednje poznate ptice, dok je poslednji primerak vrste, iji se broj izraavao milijardama, uginuo u zatoenitvu 1914. godine.

neke od zivotinja izumrlih u poslednjih 40 godina

Golden Toad (1989)

The golden toad is not the only species to disappear in the past 40 years, but it might just be the brightest. This fluorescent amphibian was found in the high-altitude ridges of Costa Rica, but thanks to pollution, global warming and fungal skin infections, the species became extinct in 1989.Read on to find out about 10 other incredible species we've lost in the last several decades.

Zanzibar Leopard (1996)

One of several subspecies of leopard, the Zanzibar leopard made its home on the Zanzibar archipelago of Tanzania. It's still unclear whether this large cat is technically extinct there are occasional unconfirmed sightings.Cause of extinction:Locals believed the leopards were kept by witches, and aggressively hunted them. The animals were seen as evil predators that must be exterminated and even thegovernmentwas in on the campaign. In the mid-'90s there was a short-lived conservation effort but it was deemed too little, too late.Po'ouli (2004)

A native of Maui, Hawaii, the Po'ouli, or Black-faced Honeycreeper, was only discovered in the 1970s. The birds inhabited the southwestern slope of Haleakala volcano. But the population declined rapidly, and by 1997 there were only three known Po'ouli left. Efforts to mate the remaining birds failed and the species was formally declared extinct seven years later.Cause of extinction:Habitat loss, along with disease, predators and a decline in its food source native tree snails are all seen as reasons for the bird's demise.

Madeiran Large White (2007)

The stunning Madeiran Large White butterfly was found in the valleys of the Laurisilva forests on Portugals Madeira Islands. The butterfly's closest relative, the Large White, is common across Europe, Africa and Asia.Cause of extinction:Loss of habitat due to construction as well as pollution from agricultural fertilizers are two major causes of the species' decline.Tecopa Pupfish (1982)

The Tecopa pupfish, a native of the hot springs of the Mojave Desert, has the distinction of being the first animal declared extinct under the provisions of the Endangered Species Act of 1973. The pupfish's decline was precipitated when its natural habitat was encroached upon by developers.Cause of extinction:Destruction of natural habitat.Pyrenean Ibex (2000)

The last Pyrenean ibex died in 2000. However, acloned ibex, created from skin samples taken from the last Pyrenean ibex, was birthed in 2009. It died shortly after birth from lung complications.Cause of extinction:Hunting of the ibex had caused the animal's numbers to seriously dwindle and conservationists blame the Spanish governmentfor failing to act in time to save it.West African Black Rhinoceros (2006)

The majestic West African black rhino was declared extinct in 2006, after conservationists failed to find any in their last remaining habitat in Cameroon. The West African black rhino was one of four subspecies of rhinoceros.Cause of extinction:Poachers hunted the rhino for its horn, which is believed by some in Yemen and China to possess aphrodisiacal powers.Javan Tiger (1979)

Similar in appearance to the Sumatran tiger, the Javan tiger was native to the Indonesian island of Java. In the 1800s they were so common they were considered pests by island natives, but as the island was developed their population dwindled. By the 1950s, only 20 tigers remained.Cause of extinction:Loss of habitat and agricultural development led to severe population decline. Conservation efforts in the 1940s and '50s were unsuccessful due to a lack of adequate land and planning.Spix's Macaw (2004)

Spix's Macaw, also called the Little Blue Macaw, was known for its beautiful blue feathers. While some still exist in captivity, these tiny blue birds are extinct in the wild.Cause of extinction:Habitat destruction and illegal trapping and trade contributed to the macaw's dwindling numbers.Round Island Burrowing Boa (1975)

Native to Round Island, a tiny island off the coast of Mauritius, the Round Island Burrowing Boa preferred to live on the topsoil layers of volcanic slopes. It was once found on several other islands around Mauritius, but its population had dwindled by the 1940s, and it could only be found on Round Island after 1949. It was last seen in 1975.Cause of extinction:The introduction of non-native species of rabbits and goats to the island destroyed vegetation and upset the boas habitat.Dutch Alcon Blue Butterfly (1979)

This Dutch butterfly a subspecies of the Alcon Blue was found mainly in the grasslands of The Netherlands. While closely related species (pictured here) still exist in parts of Europe and Asia, the last Dutch Alcon Blue was seen in the wild in 1979.Cause of extinction:Increases in farming and building had a negative impact on the Alcon Blue's habitat and caused it to lose its main food source.