The Israeli deer is in danger of extinction, and to save it, we need to find out what the best diet is for it. New Israeli research has found a way to discover what goes on deep in the deer's stomach – without touching it.
By Omer Kempler, Zavit – Science and Environment News Agency

With its smooth brown fur, noble antlers, and graceful leaps, the Israelite deer is one of the most impressive animals in our country. The deer live in most parts of the country, but their number, estimated at about 5,000 individuals, is dwindling. The decline of open areas and natural habitats have pushed deer more and more into the pine forests planted in Israel, which are not their natural habitat. A new study published in the journal 'Ecology and environment' Describes the diet of deer in Israel with the aim of knowing how to better care for them.
Check without killing
The deer in Israel are EndangeredAccording to the article, in recent years there has been some stabilization in the number of deer, but their number is still lower than in previous decades. Many problems such as hunting, trampling and predation regularly harm deer. Their proximity to cattle herds also puts them at risk because they may be infected with various diseases that cattle herds are vaccinated against. "There are a number of factors, but in the end it all boils down to habitat loss. We are losing Open spaces that can accommodate the deer"We cannot keep an animal in the wild without open spaces," explains Dr. Guy Dovrat of the Volcanic Institute, who coordinated and directed the research together with Dr. Uri Segev, Dr. Amir Arnon and Dr. Jan Landau, in collaboration with Yahel Porat and Shani Gleitman of the Israel Defense Forces.
Deer usually live in open, vast areas, more reminiscent of African savannahs than coniferous forests. In the past, there were many such vast areas in Israel, but due to intensive construction and road construction, they shrank, and the deer began to get used to living in planted forests. Forests in Israel were also not part of the landscape until the beginning of the last century. Most of them are forests planted in open areas that could be used by the deer. "We wanted to test whether the deer can rely on forest nutrition throughout the year," explains a spokeswoman. The researchers tested whether the vegetation in the forest, such as grasses and shrubs, was nutritionally sufficient for the deer. To test this, the researchers had to understand what the deer eat, and what nutritional values they receive when they live and eat in the forest. In the past, to study the diet of deer, they would kill them and examine their stomach contents. During the current study, deer droppings were collected, and with the help of a new method developed by the research team and based on advanced technologies, they were able to collect data on the deer's diet.
The droppings were collected from deer populations in forests in various regions of the country: Birya forest in the Upper Galilee, the Gilboa Forest, the Carmel Beach Forest and the Holy Forest in the Jerusalem Mountains. The dung was examined using a new method, and the data obtained was compared to that collected from soldiers who were run over and collected for research purposes. In other words, the researchers found a way to examine what the deer eat based solely on their dung, without harming them.
Another important tool used in the study is trail cameras. The cameras provided information about the deer that is very difficult to locate in the field. With their help, it is possible to learn about the behavior of wild animals, for example, their hours of activity and the courtship process. They allow for continuous monitoring, and over a period of time that is not possible with observation. Another great advantage is the use of cameras that sense motion, which are placed in front of wildlife activity sites, based on familiarity with the animals' behavior and not randomly placed in the field.

Territory of dung
"Deer don't migrate as long as they have enough food in their habitat," explains Dovrat. In addition, "they have fixed stations where they come to drop dung," he says. This allowed the researchers to monitor the populations over time and see what changes occur in their diet throughout the seasons.
The results of the study show that the forest provides the deer with everything they need throughout the year, that they have a varied menu, and that the nutritional values of the deer's diet are good: they have enough protein, calcium, fiber, and more. According to a spokesperson, the deer eat different types of plants, not just grass as is commonly thought. "Deer know how to carefully choose the types of plants they will eat. For example, they will prefer to eat fruits and seeds that have higher nutritional values, and they eat a lot of leaves from Mediterranean shrubs, not just herbaceous vegetation," he explains. The deer's wisdom is that it knows how to eat different things throughout the year, according to what its environment - in this case the forest - provides it. The assumption is that most deer stay in the forest, which provides them with protection and quiet from humans, as well as enough food to sustain themselves, but sometimes they go out to the edges of the forest and also eat agricultural products.
Do deer also eat more carbohydrates in the winter?
The researchers examined whether the density of trees in the forest affects the deer's diet during different seasons of the year. Some forests, such as the Kedousim Forest and the Ofer Forest on the Carmel Coast, are sparser in trees and therefore have more plant species in the understory – such as shrubs and grasses that grow between the trees, which are the deer's main food source. In forests that are sparse in trees, where there is a developed understory, food is more available to the deer. On the other hand, in forests that are dense in trees, where there is less understory, explains Dovrat, "you feel the deer's pressure at the end of the summer." In other words, by examining the deer's droppings, they found that the deer's diet at the end of the summer includes more fiber and less protein. In addition, the researchers found that in the summer the deer become more territorial – they return more to the same regular stations and mark their territory with their droppings. This territorial behavior ensures available food.
Deer are of particular importance in nature conservation because they are considered a "flagship species." That is, because of their popularity, they are used to raise public awareness of environmental problems and animal conservation. "In recent years, we have been investing a lot of effort in preserving and nurturing biodiversity by increasing the structural complexity of the forest and increasing the scenic diversity, while striving to maintain the continuity of the open space," explains Dr. Gilad Ostrovsky, KKL-JNF's chief forester. "All of this supports deer populations in the forests. Through monitoring and additional research, we will deepen our knowledge about deer and formulate it into the implementation of an appropriate interface," he says. Thanks to the research, we better understand what conditions deer need in the new spaces they have adopted. In the future, we will be able to try to cultivate the forests in a way that will allow the species to continue to live and thrive.
More of the topic in Hayadan: