Hamster rescue: Ukrainian scientist champions rewilding to preserve endangered species

Most people first come across a hamster in childhood — in a pet store, at a friend's house, or when their parents bring a cage with a small furry ball home. These encounters form stereotypes, leading us to mistakenly believe that hamsters are tame and friendly pets. Former and current hamster owners often joke that these rodents' main goal is to find the most inaccessible corner in the house and die there.

Of course, this is untrue. In this article, we debunk myths about hamsters, explain why they need to be saved, and, most importantly, describe how they are returned to the wild.

Hamsters are wild animals. They feed on seeds from steppe plants and dig deep burrows with many "chambers" where they spend the winter. They live independently — one hamster per burrow — and have a terrible temper, often fighting over territory or mates. Yet, they live in colonies.

Hamsters once inhabited the steppes and forest steppes across Europe, including most of Ukraine. Today, this species has almost disappeared in the wild. In 2009, hamsters were red-listed, but even after that, their numbers continued to decline. 

This problem is continent-wide, as hamster habitats are being plowed for agricultural land, where farmers use poison to control rodent populations. Hamsters need protection, and people in Ukraine are working to remedy this issue.

Mykhailo Rusin, a research associate at the Kyiv Zoo, oversees the hamster department at the Rare Species Recovery Center. Last year, the International Fund for Animal Welfare (IFAW) supported his work so Rusin could create the Hamster Rescue Center. In the spring, Rubryka reported on the leading work areas of both centers. Now, we have seen firsthand how the rewilding of wild hamsters happens.

Mykhailo finds people who don't like having hamsters around, catches them in live traps, and releases them in safer locations. This time, we observed the joint work of the Hamster Rescue Center and the Free Wings Bird Rehabilitation Center. Viktor Shelvinskyi, a Ukrainian ornithologist and Free Wings founder caught European hamsters in several villages near the western city of Yavoriv, Lviv, region, and later set them free with Mykhailo Rusin.

Viktor caught five European hamsters, the largest of all hamsters, weighing more than 700 grams, using live traps — special cages that do not harm the animals.

It might seem the most challenging part of catching hamsters is over, but the rewilding requires a few more critical steps.

Setting up his field laboratory, Mykhailo begins the inventory: each hamster needs to be weighed, sexed, and assessed for overall health. These data and information about parasites and the hamster's age are recorded in the field journal. It's also essential to take a DNA sample:

"We need the data to determine the level of relatedness and interbreeding of hamsters in different regions. Then, we'll add them to the DNA map," says Mykhailo. "According to our data, which we published jointly with Polish colleagues from Białystok University, Ukraine is likely the center of origin for many European genetic lines of hamsters. Between glacial periods, it was here that conditions were most favorable for hamsters, and from here, they spread across Europe."

The research is complete at this stage, and the rodents are ready to be released into the wild.

The next day, we looked for a suitable place for the hamsters. The location needs to meet several criteria: the area should be away from populated places and have enough unplowed land with diverse vegetation. It's better if the location has fields nearby where people practice traditional farming, meaning small patches of land with various plants instead of hectares of monoculture, as is often the case in Ukraine with sunflowers or rapeseed.

"Small plots are less treated with chemicals, and there is more diverse food for the hamster here," says Rusin.

We searched for a new home for the hamsters on the outskirts of the Northern Podillia National Nature Park in the western Lviv region. The task was very challenging because most of the park's territory has not been taken from private owners, so there are hardly any unplowed patches between the remote villages, and if you find them, they are too small. 

However, after three unsuccessful attempts, we found a place — a few hundred square meters of meadow vegetation next to an abandoned homestead where villagers no longer live but left behind thin strips of gardens sown with oats, millet, and corn. Such food diversity will be an excellent base for feeding the five hamsters.

You're mistaken if you think rewilding hamsters is a simple task of just opening the cage and releasing the rodent into the wild. First, scientists create proto-burrows, using a drill to make a meter-long burrow and fill it with food.

"te a safe home for the hamster. Underground, it is protected from predators and has enough food for the beginning," Mykhailo comments.

Next, quick steps follow: the hamster is released directly from the transport cage into this proto-burrow and covered with a heavy slab.

"The slab is needed so that the hamster doesn't run away in fear and become easy prey for predators. Hamsters dig very quickly and actively, so very soon, [the released hamster] will dig an exit to the surface," says Rusin.

The process may seem easy, but settling just five hamsters took several hours of coordinated teamwork. Now, the hamsters are in a safe place with a good supply of diverse food. The five rewilded hamsters included a female so the red-listed European hamsters may build a new colony in their new picturesque home next year.