Researcher: Sara Tromp
The black mongoose (Galerella nigrata) was first described over 75 years ago and there has been much controversy surrounding its species status. At times it has been considered a subspecies of the slender mongoose and a subspecies of the Cape grey mongoose. However, unique characteristics of the black mongoose distinguishing it from both the slender and the Cape grey mongooses were noticed when analysing cranial measurements and pelage colour. On the basis of these morphological characteristics it was once again tentatively given species status in 1993.
Very little is known about this intriguing species, which is thought to be Namibia’s largest endemic carnivore. With these factors in mind, the Shadow Hunter Research Project was established in 2004. This project aims to build a sound database of behavioural, ecological, environmental and taxonomic knowledge on this species in order to accurately assess its conservation status and to make appropriate management recommendations for this species and the unique habitat in which it lives.
To monitor such an elusive animal, the project needs some sophisticated equipment, and the Trust’s contribution has gone towards the GPS telemetry part of the project. Over the next year 20 adult mongooses will be collared, tracked, and monitored, adding to the knowledge of population in the main study area.
Confirm the species status of the black mongoose
Amongst much controversy, a number of small African mongoose species from the genus Herpestes that weigh less than 1kg are often assigned to a separate genus or subgenus Galerella. The exact number of species in the Galerella group is uncertain, but the Cape grey mongoose (G. pulverulenta) and the slender mongoose (G. sanguinea) are two commonly recognised species. The black mongoose (G. nigrata) has also tentatively been given species status based on morphological characteristics.
Molecular techniques and the use of DNA are now being used to confirm the taxonomic positions of all these species – an important method as it distinguishes similarities present due to shared ancestry as opposed to convergence. Thus, an assessment of the phylogenetic status of all the suggested Galerella species would be of great benefit.
Investigate the habitat of the black mongoose and compare it with other species living in similar habitats
Endemic to Namibia, the black mongoose is a habitat specialist living in isolated granite inselbergs across north-western Namibia. Each of these inselbergs can be considered an ‘island’ of suitable habitat surrounded by a sea of sparse, uninhabitable landscape. For this reason it is highly probable that there is significant genetic differentiation occurring between separate populations of the black mongoose.
Studying the processes that may be responsible for the present distributions of the black mongoose (phylogeography) will provide an opportunity to investigate the micro-evolutionary processes involved in shaping the patterns of diversity in this fragmented habitat, a habitat with an unusually high biodiversity and high levels of endemism.
Describe the social behaviour and mating system of the black mongoose and relate this to the levels of social behaviours in mongooses (Herpestidae)
Mongooses display considerable diversity in ecology and behaviour, ranging from solitary to extremely social. Many studies have focused on the evolution of cooperative breeding in group-living mongoose species such as the banded mongoose, dwarf mongoose and meerkat. However, with few exceptions, solitary species are relatively poorly studied, not least because of their shy and often nocturnal behaviour. There are few recorded cases where species exhibit transitional behaviours and of these, none have been studied in great detail. Anecdotal evidence suggests that the black mongoose displays intermediate levels of sociality (sub-social): not being entirely social yet having more frequent social interactions than expected for a solitary species. A closer look at the social system of the black mongoose using both behavioural observations and genetic analysis will give valuable insight into steps towards the adoption of sociality in mongooses.
Use the knowledge to make appropriate management recommendations for the black mongoose and its unique environment
Very little is known about the black mongoose and the unique habitat in which it lives. The project aims to apply the knowledge gained in this study to conservation schemes for the region, elevating both national and international awareness of this area.
Provide training for Namibian students
Namibian students have been welcomed into this project so that they can gain valuable experience in a working field project. Over time the project has supported polytechnic students, work experience students and master’s students.
Annual Report 2011
After some final adjustments, all data has been analysed and papers are being submitted on the species status of the black mongoose. This is an important event for the Shadow Hunter Research Project – the long-term debate is over and it can now be officially recognised as Namibia’s largest endemic carnivore. It is hoped that the information we have gathered during the course of the Shadow Hunter Research Project will be valuable in terms of establishing targeted conservation practices and management of Namibia’s granite inselbergs through collaboration with local communities.
During this past year, the project has therefore focused on data management, analysis and publication. All molecular work was completed by July and I had the privilege of presenting some results at the international Conservation Biology meeting in Edmonton, Canada (6-9th July). This presentation was received very well and scientists from across the globe were very encouraging. All data analysis was complete by August and three publications are in the final stages before submission to journals with more to follow. The final project results and outcomes will be presented to relevant Namibian communities in July 2011 following international review.
April 2010 Report
After a long debate, the black mongoose can now be officially recognised as Namibia’s largest endemic carnivore.
Over the past three years an enormous amount of viable data and genetic samples from black mongoose have been collected. The next step is to analyse the genetic samples and write up scientific reports and articles for publication.
One of these will discuss the movement of the black mongoose across the landscape. Interesting data with regards to genetic exchange between populations has been collected. There is now a focus on genetic data from the agamas and mice as well, which will create an understanding of the evolutionary history of this fragmented ecosystem as a whole, relating it back to past large-scale climatic events.
With the scat project nicely wrapped up by Dietlinde at the end of last year, the study turned its attention towards a new branch of the project, focusing on the genetic exchange between populations of other fauna endemic to the same habitat as the black mongoose.
From last year’s study it is known that black mongoose populations are well-linked despite high levels of habitat fragmentation across the landscape. This finding was unexpected and incredibly interesting – to achieve this the mongooses have to travel vast distances between rocky outcrops. Thus the same question is being asked at an ecosystem level.