Killing for conservation - a challenging but necessary tool for endemic island species conservation

By Jennifer Appoo

Jennifer is a PhD student supervised by Prof. Sébastien Jaquemet from the University of La Réunion and Dr Nancy Bunbury from the Seychelles Islands Foundation. Jennifer has worked in island conservation and research, on Western Indian Ocean islands for the last six years.

Photo 1: The Reunion cuckoo-shrike, one of the rarest birds in the Mascarenes. © Jaime Martinez / SEOR.

I live on Reunion Island, an incredible island, subtropical, dizzyingly high, and atop a volcanic hotspot: one of the planet’s most active volcanoes, Piton de la Fournaise, is in the south of the island. Reunion is the tallest island in the Indian Ocean, peaking at 3070m. This great height has produced a large variety of habitats, from subtropical rainforest, and cloud forest, to heath and lowland coastal dry forest, creating a remarkable and stunning mosaic of ecosystems and dramatic landscape features, and, of course, high endemism.

Photo 2: Typical scenery of Reunion: rugged terrain and impressive escarpments, forested gorges and basins creating a visually striking landscape

Reunion has inevitably seen its fair share of extinctions and many remaining species are still threatened due to habitat loss and invasive alien species. Today, several species are clinging on to survival thanks to small-scale local conservation programmes. Despite being knee-deep into a PhD in marine ecology, I am a conservation biologist at heart and am always compelled to join endemic threatened species conservation efforts. Hence, I recently found myself volunteering on a rat control programme to protect the Reunion cuckoo-shrike Lalage newtoni.

This cuckoo-shrike (or “tuit tuit”) is a critically endangered endemic forest bird surviving in an area of only 12 km2. Rat control was started in 2004 by SEOR (Société d’Etudes Ornithologiques de La Réunion) a local ornithological organization, when the population had dropped to only six breeding pairs. With support from the LIFE BIODIV’OM project, in 2018, the programme started including volunteers to increase public sensitisation and coverage of the control area, and the cuckoo-shrike population is now up to 48 pairs thanks largely to these efforts. Rat control is done between May to September, during the non-breeding season and the programme has attracted people of all ages with more volunteers every year.

I packed an overnight bag and headed out early one Saturday morning to our meeting point at the base of the Roche Ecrite massif in the Reunion National Park and UNESCO World Heritage Site. From there, we hiked along a steep path away from the main trails, bringing us deep into the national park and into cuckoo-shrike habitat, at 1800 m. The forest was vibrant, filled with endemic bamboo, tree ferns and highland tamarind trees, and other birds such as the Mascarene paradise flycatcher, Reunion stonechat and Reunion white-eye.

Photo 3: The group on reaching the highland forest of Roche Ecrite National Park

Over 3 hours later, we reached the first stop where big aluminium containers were filled with rodenticide bait blocks. We off-loaded personal gear and filled each of our bags with 10 kg of rodenticide. We split into smaller groups and headed into the forest along pre-defined baiting lines.

Every 30 m we stopped at a bait station, recorded how much bait was left and refilled it. Then, using slingshots, we spread bait on each side of the line to increase the coverage. The forest was dense and we had to bush bash and clamber through the low vegetation. We kept our ears open for any sound of “tuit-tuit” and were eventually rewarded with a few sightings of the rare cuckoo-shrike.

Photo 4: Using slingshots to disperse bait blocks on each side of the line

Four hours and 32 baiting stations later, we reached the end of our line. Aching and tired, we headed to a small mountain lodge, about two hours walk away, where we would sleep. We spent the evening learning more about the cuckoo-shrike and of each other, bonding over a creole curry cooked over the fire. We went to sleep that night satisfied with our work but mostly relieved to be inside the lodge as the rain poured outside and temperatures dropped to below 5˚C. We had an early start and another 3 hours of baiting the next day.

Photo 5: Using the fire to prepare our creole curry and warm up!

My two days volunteering on this rat control programme were absolutely amazing: a relatively tough but very rewarding activity on so many levels. I took a break from the laptop and the lab, discovered the wild endemic forest of Reunion Island, met people who are passionate about saving their local wildlife, got the rare chance to see the critically endangered Reunion cuckoo-shrike and more importantly, assisted in their conservation efforts.

Rat control and eradication is part and parcel of the conservation of many endemic island species. Unpleasant and difficult though it can be, this work helps to counter the impact of these clever and adaptable omnivores, which pose one of the greatest threats to island species wherever they haven’t been eradicated. As such, I’ve worked in rat control in every conservation job I’ve had. In Seychelles, I helped control rats around nests of the Seychelles black parrot for the Seychelles Islands Foundation. I also assisted the Mauritian Wildlife Foundation with rat control on Ile aux Aigrettes in Mauritius, which hosts many endemic reptiles and birds. Here in Reunion, although the cuckoo-shrike population remains small it is clear that, without this rat control programme, they would no longer be around today.