Unlocking dispersal mysteries of SA’s juvenile Secretarybirds

Posted 18 July 2019 by Dr Melissa Howes-Whitecross under Announcements & Notices • Journal: Ostrich: Journal of African Ornithology
Unlocking dispersal mysteries of SA’s juvenile Secretarybirds

A golden Secretarybird Sagittarius serpentarius sits atop the national emblem of South Africa with its wings spread wide below the shining sun. Given this prestigious location one would think that the observed declines in this iconic bird’s population of over 70% across southern Africa in the last three decades would have sparked more alarm in the public domain. 

To inform BirdLife South Africa’s conservation work on this species and their grassland habitats, Mr Ernst Retief commenced the fitment of ten small (38g), solar-powered tracking units that worked with the cellular network around South Africa to provide near-real-time location data of where the selected individuals were. 

Tracking devices were attached to the backs of eight-week-old Secretarybird chicks while they were still on their nests. This allowed the research team to monitor the development of these chicks as they began to fledge and explore the areas around their nests.

By understanding the amount of space-use needed by a young Secretarybird during its early development, BirdLife South Africa has been able to provide developers, including those from the renewable energy sector, with scientifically-based estimates for buffer zones around identified Secretarybird nests to prevent disturbance and fatalities of the young birds. 

Tracking the movements of these ten individuals has provided a wealth of information for the research team, unforutnately not all of it positive. Of the ten individuals tracked, three confirmed mortalities were identified liked to collisions with powerlines and fences which are two major threats to large terrestrial birds. Another individual was lost shortly after crossing into Lesotho, likely killed by people but no carcass was recovered so this is still speculation. Young raptors often face high mortality rates due to their inexperience and far ranging behaviour which often brings them into contact with landscapes that are unfamiliar to them such as the patchy grasslands of northern Pretoria where a young bird from southern Limpopo found itself after initially dispersing all the way to the Makgadigadi Pans in Botswana in just two weeks after leaving its nest. 

This study highlighted the vast distances which juvenile Secretarybirds are capable of travelling shortly after leaving their natal territories. A bird originally tagged in Calvinia, Northern Cape flew north-west during its dispersal covering a distance of over 1000 km in just 8 days. Another mammoth dispersal was made by a bird called Taemane who was fitted with a tracker in Warden, Free State and dispersed south-west to the coast of KwaZulu-Natal just south of Scotbourgh covering approximately 345 km in just over 2 weeks. 

Taemane incidentally went on to become the first ever bird to have been tracked from hatching to age of first breeding only two years and nine months when he was located a mere 35 km from his natal nest on a nest of his own with two small chicks. A finding like this gives us hope for the resilience of this large species which is clearly capable of breeding quickly under the right conditions, unlike many other large birds which can take up to nine years to reach breeding age such as the Southern Ground Hornbill. 

Conserving South Africa’s Secretarybirds is no easy feat with only 4% of tracking points being located within the protected area network. Through their biodiversity stewardship programmes across the eastern Free State, BirdLife South Africa is in the process of securing over 30 000 ha of high altitude, good quality grasslands for birds like the Secretarybird to continue thriving in our rapidly transforming landscapes across South Africa. 

The Secretarybird has been bestowed the title of 2019 Bird of the Year by BirdLife South Africa and the organisation is developing education materials and interactive lessons which are free to download from their website. A number of citizen science initiatives are also underway which you can find out more about on the website as well.

The research article, titled, Dispersal dynamics of juvenile Secretarybirds Sagittarius serpentarius in southern Africa.
THIS STUDY IS AVAILABLE TO READ AT NO COST UNTIL 31 AUGUST 2019 HERE: 

 

 

The proofs look great! Thank you so much. The efficiency of the journal now is really excellent. Easy to work with, and so thorough. I appreciate it.
- Regular SAJP Author on his first interaction with NISC
Since 1995, NISC has systematically built up competence and the necessary capacity in all aspects of publishing high-level research journals, with the professionalism needed to flourish in the increasingly competitive world of international research publications. No other publisher in South Africa commands the necessary technical skills, experience, competence, enthusiasm and resources to the same degree as NISC, in my view.
- Graham Baker, Editor of the South African Journal of Science (1973-2008)
The NISC partnership has benefited the Indo-Pacific Journal of Phenomenology by bringing sustainability, additional branding and marketing, a wider reach through its websites, and the added value of expertise in the very competitive world of publishing.
- Chris Stones, IPJP Editor-in-Chief since 2003
It has been an enriching experience working with such enthusiastic and professional people at NISC who have become more friends than business partners over the years.
- Stan Pillar, Editor of the African Journal of Marine Science (1996-2013)
Perhaps the most important change, in terms of bringing the Journal to a wider audience, has been its publishing in collaboration with the NISC (Pty) Ltd.
- Stan Pillar, Editor of the African Journal of Marine Science (1996-2013)