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Thailand: Elephants Aid in Spreading Fruit Seeds

Based on the diets and habits of mammals, scientists found that elephants are the best allies for the Thai Annonaceae tree to spread its seeds.

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Many Elephants Die Due To Trains, Trucks. Pixabay
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Massive fruit trees in the Thailand evergreen forest need Elephants to help spread their seeds, according to a new study.

Based on the diets and habits of mammals, scientists found that elephants are the best allies for the Thai Annonaceae tree to spread its seeds.

In the diverse environment of Khao Yai National Park, there is a complex set of relationships between the plants and animals. Not every species of fruiting tree is an attractive meal to all herbivores. A team of researchers, led by Kim McConkey from the University of Nottingham, set out to study one particular tree, the Platymitra macrocarpa from the family of custard apple trees.

The p. macrocarpa produces 3-to-5-inch fruit that are ripe from May through August. McConkey tracked how often animals visited the trees and ate the fruit, including elephants, bears, monkeys, gibbons and Sambar deer. They measured the animals’ fruit consumption as well as the ensuing seed dispersal and seed viability.

Researchers found the seeds in the dung of some species while others like the Sambar deer regurgitated the large seeds. When asked about tracking animal poop, McConkey admitted, “I’ve got two boys so they just love what I do.”

As expected, the Asian elephants were the major seed dispersers for the p. macrocarpa. Elephants aren’t often seen in the area of the trees McConkey studied, but as she told VOA, “I thought if I’m going to see them feed on any fruit, it’s going to be this one.” Her hunch was borne out in the data, with elephants consuming only 3 percent of the fruit but producing 37 percent of the viable seedlings.

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The p. macrocarpa produces 3-to-5-inch fruit that are ripe from May through August. VOA

These findings regarding the Asian elephants point to the important role they play in the ecosystem. Jedediah Brodie, chair of conservation in the Wildlife Biology Program at the University of Montana, told VOA that “overhunting in the tropics often drives large animals locally extinct but leaves smaller species like rodents. And this study shows that those smaller animals just are not able to replicate the ecological role of the larger species.”

When looking at the performance of other species, the researchers were surprised by how effective Sambar deer were at dispersing seeds. “Sambar deer generally have quite a bad rap in these forests,” McConkey said. “People think they’re seed predators, but it turns out they actually do disperse a lot of seeds.” While the Sambar deer weren’t quite as effective seed dispersers as gibbons (21 percent), they still produced a respectable 17 percent.

Bruchid beetles were the primary challenge to producing viable seedlings. The beetles, which are known to infest all kinds of seeds and beans, spoiled most of the seeds left exposed on the forest floor. Unlike the regurgitated seeds of the sambar deer, the seeds went through the elephants’ digestive system and were covered by excrement. The seeds were protected from beetles and provided with an effective, natural fertilizer and were able to survive and grow into seedlings.

It is easy to think of animals adapting to their environment through evolution and behavioral change, but we rarely consider the same relationship in the opposite direction. The massive Platymitra macrocarpa has perhaps evolved to provide fruit that appeals to more than one frugivore.

Also Read-Breaking the Law? Sri Lanka Cracks Down on Owners of Elephants taken from Wild

As McConkey told VOA, “The husk of the fruit — it’s like the outer covering of the fruit — has become very thick, and it’s that outer covering that deer eat. But if you open up the fruit, each seed is covered by this juicy, soft pulp, and it’s that that the monkeys and gibbons like.” She thinks that this might be a case where the tree evolved to appeal to multiple animal species to increase the chance of spreading viable seeds.

Despite the variety of animals eating the seeds, elephants are still the tree’s best chance of producing viable seedlings. When asked what might happen if elephants were to disappear from the region, Brodie responded, “That’s the million-dollar question.” (VOA)

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USA And Other Countries Pledge To Eradicate Illegal Wildlife Trade

The real test is how quickly they will act on those words.

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illegal wildlife trade
Thai Navy officers and forestry officials display seized dead tigers, leopards and pangolins in That Phanom district of Nakhon Phanom province, northeastern Thailand. VOA

The United States and dozens of other countries have pledged to work together to tackle the illegal wildlife trade and treat it as a “serious and organized crime” following a two-day conference in London that ended Friday.

Trade in endangered wildlife, such as elephant tusks, rhino horns and tiger bones, is worth an estimated $17 billion a year and is pushing hundreds of species to the brink of extinction.

Speaking to heads of state from across the world, Britain’s Prince William, a passionate conservationist, said he recognized that law enforcement resources are already stretched in many countries.

illegal wildlife trade
Britain’s Prince William gestures as he makes speech at the Illegal Wildlife Trade Conference in London. VOA

“But I am asking you to see the connections, to acknowledge that the steps you take to tackle illegal wildlife crime could make it easier to halt the shipments of guns and drugs passing through your borders,” the prince told delegates.

Worldwide, the illegal wildlife trade is booming.

Illegal ivory trade activity has more than doubled since 2007, while over 1,300 rhino were killed in 2015. Asian tigers have seen a 95 percent decline in population, as their body parts are in demand for Chinese medicines and wine. In the last year, more than 100 wildlife rangers have died trying to tackle poachers.

U.S. Attorney General Jeff Sessions told the conference the U.S. will give $90 million to programs that fight illegal wildlife traffickers.

illegal wildlife trade
Seized wild birds are seen inside a cage at a news conference by police officers following a bust on illegal wildlife trade, in Kunming, Yunnan province, China. VOA

“Their criminal acts harm communities, degrade institutions, destabilize our environment and funnel billions of dollars to those who perpetuate evil in the world. These criminals must be and they can be stopped,” Sessions said.

It is not only big mammals at risk.

For example, a critically endangered water frog from the remote Lake Titicaca in Peru has seen its numbers plummet in recent years, as thousands have been trapped and taken to make a juice that some believe has medicinal properties, despite no scientific evidence.

Delegates at the conference applauded progress made, including China’s decision at the beginning of this year to close its domestic ivory market, hailed as a major step in safeguarding the world elephant population.

Aron White of the Britain-based Environmental Investigation Agency says other animals need similar protection.

“This market was both stimulating demand for ivory and also enabling illegal ivory to be laundered through this legal trade,” White told VOA. “But that same issue still exists for big cats. You know, there’s a trade in leopard bone products [for example], large-scale commercial trade.”

Campaigners say existing United Nations Conventions on transnational organized crime offer firepower for tackling the illegal wildlife trade, but they are not being used effectively.

In the closing declaration, conference attendees pledged to work together to tackle the illegal wildlife trade and recognize it as a serious and organized crime.

Also Read: Salman Khan Sentenced to Five Years In Poaching Case, Others Acquitted

The real test is how quickly they will act on those words. (VOA)