Joint studies by Israeli and Jordanian scientists reveal that it is human behavior that influences the differences between animal species on the two sides of the border.
In a series of joint studies, Israeli and Jordanian researchers have found that rodent, reptile and ant lion species behave differently on either side of the Israel-Jordan border.
For animals, the border between Jordan and Israel is nothing more than an invisible line, but the scientists, from the University of Haifa and Jordan, discovered that each species shows different characteristics on either side.
Israeli gerbils, for instance, are more cautious than their Jordanian counterparts, while there are more ant lions to be found on the Israeli side of the border than in Jordan, and more reptile species in Jordan, than in Israel.
“The boundary is indeed a virtual marking that appears on the map and is not capable of keeping these species from crossing the border between Israel and Jordan; but the line does stop humans from crossing it and thereby contains their different impact on nature,” explains Israeli researcher Dr. Uri Shanas, of Haifa’s Department of Environmental and Evolutionary Biology.
Identical climate, different farming techniques
The series of studies examined a variety of reptile, mammal, beetle, spider and ant lion species on either side of the border in the Arava desert region.
The Israeli team set out to discover whether the border, despite the fact that the species are unaware of it, could affect differences between them and their numbers on either side, even though they share identical climate conditions.
The first study inspected the reptile population and revealed that the number of reptiles is similar on both sides, but the variety of species in the sandy areas of Jordan is significantly higher than the variety found in the sands of Israel.
A second study revealed that Israeli gerbils are more cautious than their Jordanian cousins, while a third study showed that the funnel-digging ant lion population in Israel is unmistakably larger than it is in Jordan.
According to the researchers, the differences between Israel and Jordan are primarily in the higher level of agriculture and the higher number of agricultural farms in Israel as opposed to Jordan’s agriculture, which is primarily based on nomadic shepherding and traditional farming.
Beware the red fox
The agricultural fields on the Israeli side of the border not only create a gulf between habitats and thereby cause an increase in the number of species in the region, but they also hail one of the most problematic of intruders in the world – the red fox – which hunts gerbils.
On the Jordanian side, the red fox is far less common, so that Jordanian gerbils can allow themselves to be more carefree.
The higher reproductive rate of ant lions on Israel’s side is also related to the presence of another animal, the Dorcas gazelle. This gazelle serves as a sort of “environmental engineer” as it breaks the earth’s dry surface and enables ant lions to dig their funnels.
In Israel, the Dorcas gazelle is a protected animal. In Jordan, it is permitted to hunt the animal, compromising the presence of the Jordanian ant lions’ soil engineers.
“The current studies clearly display the influence that man has on nature – for better and for worse,” says Shanas. “Over the past years, advanced agricultural technology has been transferred from Israel to Jordan; and we must strengthen our understanding of the influences that modern agriculture has on nature, so that we can assist in preserving the large variety of species in the Arava region.”