This document summarizes findings from citizen science data on secretarybird populations in South Africa. Analysis of data from the Southern African Bird Atlas Projects and Coordinated Avifaunal Roadcounts showed that secretarybird reporting rates have declined in most provinces, with the strongest declines in the Eastern Cape, Free State, and Northern Cape. The data also indicated that secretarybirds prefer natural habitats to transformed habitats, though they are still seen more often in transformed areas in the Western Cape due to habitat loss. Overall, the South African secretarybird population appears to be declining due to habitat loss and bush encroachment.

1. Secretarybirds
in South Africa:
what citizen science
can tell us
Sally Hofmeyr & Les Underhill
Animal Demography Unit
University of Cape Town
Craig Symes
University of the Witwatersrand
Dawie de Swardt
Sally Hofmeyr

2. Secretarybird (Sagittarius serpentarius)
• Eats insects, reptiles, mammals, birds, eggs
• Disturbs prey by stamping on ground; kills prey with bill
or by stamping on it
• Large territories: 50–60 km2 around nest
• Breeds in pairs in trees; usually seen in pairs, walking
around, hunting
• Mainly grassland and open savanna habitats
Beverly Joubert
• Vulnerable (2011 IUCN Red List),
declining throughout rest of Africa –
but how is it doing here in SA?

3. We used data from:
CAR project
(Coordinated Avifaunal
Roadcounts)
SABAP1 & SABAP2
(Southern African Bird
Atlas Projects 1 and 2)

4. Bird lists collected throughout
southern Africa, which is divided up
into grid cells based on latitude and longitude.
Comparing the two projects:
Southern African Bird Atlas
Projects (SABAP)
SABAP2:
• 2007 – ongoing
• Pentads (5 × 5)
• 5-day recording period
SABAP1:
• 1987 – 1992
• Quarter degree grid cells
(15 × 15)
• 30-day recording period

5. SABAP data analysis
• Compared reporting rates between SABAP1 and
SABAP2.
(Reporting rate = % of checklists for each grid cell that report the
species you’re looking at)
• Used a statistical method to test how likely the
differences are to be real
• Made a map with grid cells colour-coded
according to how sure we are that the difference
is real

6. SABAP data – changes in
Secretarybird reporting rates from
SABAP1 to SABAP2
22 May 2014
Johann du Preez
Red, orange, yellow =
DECLINES
Blue, green, green =
INCREASES
The darker the colour,
the more sure we are
that the change is
real, and reflects a
change in abundance.

7. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Kruger National Park
Northern Cape
Eastern Cape
Free State
Western Cape
North West
Gauteng
Mpumalanga
KwaZulu-Natal
Limpopo
SABAP data – counts of each type of grid cell in each
province and in Kruger National Park

8. The CAR project
• Counts of large terrestrial birds in agricultural habitats
• Fixed routes, mostly about 60 km long; strict protocol
• Two counts per year – summer and winter – same day
countrywide
• Project started in 1993, spread across south-eastern
half of SA
• We used the habitat data to look at Secretarybirds’
habitat selection and habitat use

9. 340 routes;
~ 19 000 km
CAR route map – a huge chunk
of the country is sampled!

10. -0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
S W S W S W S W S W S W S W
Eastern Cape Free State Gauteng KwaZulu-
Natal
Mpumalanga Northern
Cape
Western Cape
Transformed|Natural
CAR data – habitat selection
Dawie de Swardt
S = summer, W = winter
E Cape F State Gauteng KZN Mpum. N Cape W Cape
This shows that except in Northern Cape in winter, Secretarybirds
prefer natural habitats to transformed. “Transformed” includes
everything from cultivated land to cities and mines. “Natural”
includes natural veld that is used as grazing land, however, so it does
not necessarily mean “pristine”.

11. CAR data – habitat use
The majority of Secretarybirds were
seen in natural habitats, except in
W Cape, where more than half were
In transformed areas.
In W Cape, cultivation has converted fynbos shrublands
into open habitats, more suitable for Secretarybirds.
Despite this, these long-legged marching birds still
actually prefer natural W Cape habitats – it’s just that
there’s so little of those left now.
Helen and Dicky Badenhorst

12. • SA population seems to be declining overall
• Main causes in SA are probably habitat loss and bush
encroachment
Most importantly, we could not have known this without
the hugely valuable contributions of thousands of
citizen scientists!
Read the full paper:
Hofmeyr SD, Symes CT, Underhill LG (2014) Secretarybird Sagittarius serpentarius Population
Trends and Ecology: Insights from South African Citizen Science Data. PLoS ONE 9(5): e96772.
doi:10.1371/journal.pone.0096772
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0096772
To conclude
Nico Myburg Dawie de Swardt