Southern Ground-Hornbill conservation
Southern Ground-Hornbills Bucorvus leadbeateri are globally Vulnerable, and have been up-listed to Endangered in South Africa. They have experienced a two-thirds reduction in their national range, and presumably population size, in the past 100 years. Since 2000, they have been studied at the Fitz, investigating their habitat use, reproductive success as well as natal and breeding dispersal, largely to inform activities of the Mabula Ground-Hornbill Project (MGHP) and the national Ground-Hornbill Action Group, who are our partners in implementing the national Species Recovery Plan. The main study area is the Associated Private Nature Reserves (APNR), covering some 180 000 ha adjacent to the central Kruger National Park, that supports about 30 ground-hornbill groups. We have reproductive histories spanning a decade for more than 20 groups. Breeding success increases with group size and the amount of open habitat within 3 km of the nest site.
PhD student Kate Carstens completed her field research during 2016 and will submit her thesis on the effectiveness of artificial nests as a conservation tool in early 2017. Kate has expanded the data from the long-term study monitoring breeding biology and her thesis will provide valuable insights into the impact that the installation of artificial nests has had on groups in the APNR.
As a unique cooperative breeding species, Southern Ground-Hornbills offer a significant opportunity to investigate behavioural aspects of their life history and thus Dr Rita Covas, Research Associate at the Fitz, has started a new phase focussing on the social structure and cooperative behaviour of the APNR groups. Several aspects of their life history such as high longevity, low fecundity, large body size and large territory size, a social system comprising both family members and immigrants, and their phylogenetic position make them an interesting species in which to study the factors promoting sociality and cooperation and the associated conflicts. Furthermore, the long-term data available allows investigation of how social factors interact with environmental factors to determine population trends. This is interesting in itself and is highly relevant in this species, given the substantial population decline that the species has experienced.
Activities in 2016
- The new behavioural component of the research was initiated at the start of the 2016/17 breeding season.
- Kyle Middleton and Carrie Hickman were appointed as field assistants to help with the start of the behavioural research and to continue the monitoring of breeding activity and foraging habits of the groups in the APNR.
- Field assistant Maxime Loubon, received training on how to record bird vocalisations with an acoustics specialist working on the Sociable Weaver project at Benfontein. Maxime will also train Kyle Middleton.
- Camera traps were placed close to nest entrances, starting with a single camera-trap in 2016, but 2-3 cameras could be used rotating among nests, if the system works. The cameras take short videos of ca 30 seconds of the birds when they enter the nest to feed.
- Increased efforts were made to identify individuals by non-invasive techniques such as the use of photographs of their face to obtain distinctive individual features of their bill or cask shape, red throat pouch, ‘side-burns’, etc.
- Vocalisation recording has been started to determine whether calls have group and individual bird ‘signatures’.
- The collection of genetic samples from known individuals is continuing through non-invasive methods, such as from moulted feathers, fresh faeces, and by swabbing eggs. Genetic finger printing will allow us to determine parameters such as investment in cooperative behaviour and associations between individuals.
- Blair Zoghby’s second MSc thesis paper on the roost site selection by Southern Ground-Hornbills was published in Ostrich during 2016.
- Kate Carstens published an article in the Klaserie Chronicle, which is distributed to the greater Hoedspruit community and surrounding private nature reserves.
- The 2015/16 breeding season saw 11 active nests with six chicks successfully fledged, and four second-hatch chicks were harvested for the reintroduction programme. One week before fledging, we colour-ringed, measured and took blood samples from the nestlings.
- The 2015/16 season also saw a confirmed case where the first egg failed to hatch for unknown reasons, resulting in the chance for the second chick to hatch and thrive.
- Since 2010, the APNR has contributed 33 second-hatched chicks for the species action group, of which 13 are intended for reintroduction releases.
- Ongoing repairs to and replacement of artificial nest boxes ensure that ground-hornbills can continue to thrive in an area which has a limited number of natural nest cavities.
- Two new artificial nests installed during 2015 were used by hornbills during the 2015/16 breeding season.
Impact of the project
This project has contributed to the basic science for the national SGH Species Action Plan and to the SGH Reintroduction Plan, and has substantial applied components assisting with the implementation of these plans. Rob Little and Kate Carstens represent the Fitz on the national SGH Action Group while Rob is also Vice Chairman of the MGHP management board.
Associated Private Nature Reserves; Dow Southern Africa (Pty) Ltd; The Foundation for Science and Technology FCT, Portugal; Senelala Estates.
Prof. Peter Ryan (FIAO, UCT)
Dr Rita Covas (FIAO, UCT and CIBIO, U.Porto)
Dr Rob Little (FIAO, UCT)
Student: Kate Carstens (PhD, UCT)
Research Assistants: Cassie Carstens, Carrie Hickman, Maxime Loubon, Kyle-Mark Middleton.