enzh-TWfrderues
  • Slide number 0
    African lion (Pan­thera leo)
  • Slide number 1
    Chee­tah (Aci­nonyx juba­tus)
  • Slide number 2
    Clouded leop­ard (Neo­fe­lis neb­u­losa) | more info
  • Slide number 3
    Euro­pean wild­cat (Felis sil­vestris)
  • Slide number 4
    Jaguar (Pan­thera onca)
  • Slide number 5
    Jaguarundi (Her­pail­u­rus yagouaroundi)
  • Slide number 6
    Puma, Moun­tain lion, Cougar (Puma con­color)
  • Slide number 7
    Ocelot (Leop­ar­dus pardalis)
  • Slide number 8
    Pal­las’ cat, Manul (Oto­colobus manul)
  • Slide number 9
    Sand cat (Felis mar­garita)
  • Slide number 10
    Ser­val (Lep­tail­u­rus ser­val)
  • Slide number 11
    Snow leop­ard (Pan­thera uncia) | more info
  • Slide number 12
    South Chines tiger (Pan­thera tigris ssp. amoyen­sis)

201408Mar10:31

Here’s what might hap­pen to local ecosys­tems if all the rhi­nos disappear

Infor­ma­tion
pub­lished 08 March 2014 | mod­i­fied 08 March 2014
Archived

African land­scapes may become very dif­fer­ent places if rhi­nos aren’t there to diver­sify plant life and cre­ate prime graz­ing spots for other animals.

White rhinoSome large ani­mals influ­ence their sur­round­ings more than oth­ers. Ele­phants are known as ecosys­tem engi­neers for their ten­dency to push over trees and stomp shrubby areas in the savan­nah into sub­mis­sion. This keeps forests at bay, which oth­er­wise would over­take open grass­lands. Wolves, on the other hand, are apex preda­tors. They keep other species like deer in check, pre­vent­ing her­bi­vore pop­u­la­tions from get­ting out of hand and eat­ing all the plants into obliv­ion. Both ele­phants and wolves are key­stone species, or ones that have a rel­a­tively large impact on their envi­ron­ment in rela­tion to their actual pop­u­la­tion numbers.

African rhi­nos, it turns out, also seem to be a key­stone species. Accord­ing to a study pub­lished online on 12 Feb­ru­ary by Scan­di­na­vian and South African researchers in the Jour­nal of Ecol­ogy, rhi­nos main­tain the diverse African grass­lands on which count­less other species depend.

Sur­pris­ingly, prior to this study no one had looked closely rhi­nos’ roles in shap­ing the ecosys­tem. Most researchers focused on ele­phants instead. Sus­pect­ing that these large ani­mals influ­ence their envi­ron­ment, the authors took a close look at rhi­nos in Kruger National Park in South Africa.

Rhi­noc­eros and baby at Lon­dolozi in Kruger National Park, South Africa:

(Source: Jef­frey Sun­ner YouTube channel)

Today, around 10,500 white rhino live in the park, but that was not always the case. In 1896, rhi­nos went extinct there due to overzeal­ous tro­phy hunt­ing. In the 1960s, con­ser­va­tion­ists began rein­tro­duc­ing the ani­mals back into the park. The pop­u­la­tion rebounded over the decades, although the rhi­nos haven’t dis­trib­uted them­selves around the 7,500-square mile area equally. As a result, Kruger acts as a sort of “well-​documented nat­ural exper­i­ment,” the researchers write, show­ing what hap­pens when an ani­mal is excluded from and then put back into an environment.

The authors first exam­ined a 30-​year aer­ial sur­vey record (begin­ning in 1980) of where the rhi­nos did and did not live around Kruger. This record also showed how rhino dis­tri­b­u­tions var­ied over time as they slowly expanded into new areas. So, by study­ing these sur­veys, the researchers could iden­tify and com­pare places where rhi­nos had inhab­ited the longest or the shortest.

After pin­point­ing high– and low-​density sites, the authors went into the field and recorded the plant species found along 40 sec­tions of the park, totalling just under 20 miles. They built a sta­tis­ti­cal model to analyse the results and con­trolled for fac­tors such as soil con­tent and the pres­ence of other large graz­ers, includ­ing impala, warthog and wildebeest.

The places where the fewest rhi­nos lived, they found, had 60 to 80 per­cent less short grass cover than places where rhi­nos fre­quently hung out. “Short grass” is a catch-​all met­ric com­monly used to approx­i­mate plant diver­sity in grassy areas in Africa, refer­ring to a num­ber of munch­able species. Rhino-​inhabited areas also had about 20 times more graz­ing lawns, or patches where spe­cific grass species grow that are prime eat­ing for not only rhi­nos but also smaller graz­ing ani­mals such as zebra, gazelle and antelope.

Based on these find­ings, the authors think that the rhi­nos are prob­a­bly play­ing a role in con­trol­ling the make-​up of the park’s grass­lands. Rhi­nos, like other graz­ing species, selec­tively browse on cer­tain grass species, which leaves room for oth­ers that oth­er­wise could not com­pete to move in and pro­motes a diverse mosaic of edi­ble plants. As a sci­ence writer for the Uni­ver­sity of Wash­ing­ton put it, “Think of them less as lawn­mow­ers and more as…selective lawnmowers.”

Rhi­nos have only been around the park for a rel­a­tively short amount of time, so future stud­ies will have to con­firm whether their pres­ence leads to even more sub­stan­tial ecosys­tem changes. Exam­in­ing other places in Africa will also help con­firm whether or not rhi­nos have the same influ­ence wher­ever they go.

Rhi­nos are one of the few mega­her­bi­vores — plant-​eaters that weigh more than 2,000 pounds — that still live in the world. Most oth­ers have long gone extinct, many of which were vic­tims to human hunt­ing and expan­sion. Rhi­nos’ con­tin­ued exis­tence, how­ever, is ques­tion­able. Poach­ers killed nearly 1,000 rhi­nos in South Africa alone last year — an almost 50 per­cent increase from 2012 — so as things now stand, rhi­nos may very likely go the way of so many other species before them.

If the rhi­nos do dis­ap­pear from Africa, the authors warn, the savan­nah will likely become a dis­tinctly dif­fer­ent place — in addi­tion to an emp­tier one.



(Source: Smith­son­ian Mag­a­zine, 27.02.2014)


UN Biodiversity decade
WWF Stop Wildlife Crime
Amur leopard conservation
End Ivory-funded Terrorism
Support Rewilding Europe
Snow Leopard Trust

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
Fol­low me on: