Working as we do with highly threatened species and habitats, we have to be able to respond rapidly and effectively. We assess the current state of the species and the threats facing it. We then evaluate the options available to address the declines, whether these are in situ habitat management actions or ex situ measures such as conservation breeding programmes. In most cases we will balance a combination of responses with measures to evaluate the effectiveness of these approaches. Although we focus on species as our flagships for conservation we also undertake a number of habitat based actions that have wide-ranging effects for many species and human communities.
In situ responses
In situ measures are actions that we employ within the native habitat of a species. In most cases they will start with a component of monitoring or assessment to better understand the situation and threats (see Science section for details). Then we identify the key responses needed to manage threats and protect a species remaining habitat. At the level of the habitat the primary threats facing species are habitat destruction, over-exploitation or invasive species.
In a number of locations the work Durrell has undertaken has led to the protection of sites under national legislation or international treaties. In most cases the underlying goals were to restore key species within their native ranges and this required the generation of knowledge, the management of threats and the protection of populations. As a result the importance of these particular sites for their broader biodiversity becomes more apparent and measures can be established with national and regional governments to manage the areas in the longer term. In this way, the Centre Hills region of Montserrat, the Black River Gorges of Mauritius and the dry forests in the Menabe region of Madagascar have all become protected thanks to the work of Durrell and its partners.
In each of our field programme regions, Durrell provides technical and logistical support to protected areas authorities to manage and protect key sites and build the necessary capacity to address threats.
More broadly Durrell supports the adoption and implementation of international treaties and we were instrumental in the adoption of the Ramsar Covention for wetlands of international importance in Madagascar and our work led to Lac Alaotra being declared a Ramsar site in 2003 and Lac Bedo in 2006 and the Nosivolo watershed in 2010.
In Assam our project to restore the native pygmy hog works closely with the protected areas authorities to manage habitat and control the threats from grassland burning, train reserve wardens to monitor wildlife and support local communities to reduce the need to encroach on the sensitive grassland habitats. This project has seen the successful reintroduction of pygmy hogs back to the Assamese grasslands.
Invasive Species control
Invasive species are one of the leading causes of species decline worldwide. They also affect island species the most. We can chart the major waves of human settlement around the world through the species they carried with them either intentionally as livestock or pets, or unintentionally, for example with species such as black rats. This is not only a historical problem, the great rise in global transportation of goods and people has dramatically increased the movement of these species, for example in the ballast tanks of cargo liners or in shipments of fruit and vegetables.
In all cases preventing the arrival is the key as removing them is extremely difficult, expensive and time consuming. Durrell is actively engaged in the management and removal of invasive species in all its field programmes with examples including the Galapagos islands with rats and the Philornis fly, St Lucia with introduced green iguanas, Madagascar with water lilies and Mauritius with rats, musk shrews and non-native bird species.
Unfortunately in many cases the movement of invasive species is inevitable and it is something that requires continuous management. Working in small and unique islands, the management and control of invasive or introduced species is a priority for Durrell. Our staff work closely with local partners to design and implement control and bio-security programmes and have to remain ever vigilant to the first signs that an invasive species once removed may have returned.
Ex situ Measures
Whereas habitat protection provides the most viable long term option to save species and habitats, we focus on some of the most threatened species that are on the edge of extinction. These species have often dwindled to very few numbers and are vulnerable to random environmental events such as storms or droughts that could remove the remaining individuals. Therefore sometimes we have to act quickly to either establish breeding programmes to ensure the species persists should it be removed in the wild, or to start generating animals that can be re-introduced into their habitat. These programmes are always conducted with the participation of host country partners and authorities and in conjunction with measures to protect remaining habitat in the wild.
Traditionally conservation breeding programmes either in Jersey or in project regions around the world have been a core strength of Durrell’s approach. We developed notable breeding successes with species such as the aye-aye and black lion tamarin and established field-based breeding programmes for pygmy hog in India and ploughshare tortoises in Madagascar.
Animal management staff in Jersey develop husbandry skills either with the target species themselves or with closely related model species. These skills are used to support the conservation of the highly threatened species in the wild, the welfare of animals in captivity or to train conservationists from other institutions.
Increasingly breeding programmes directly linked to conservation efforts are based in the species country of origin. Thus Durrell maintains breeding centres in India and Madagascar and provides training to staff from around the world.
Translocations and release
In many cases we focus on species whose numbers have declined to critical levels. While we address the threats that have caused this decline, it is not often possible to expect the population to bounce back without intervention. Therefore through collaborative planning processes we identify the most appropriate responses, from captive breeding programmes where individuals are brought into captivity and their offspring are released into the wild, to the temporary holding of animals below a certain age (called headstarting), to the movement of animals from neighbouring populations (called translocation). We then monitor the effects of such actions on both source and introduced populations closely.