Presented during the 17h Annual Sahelo-Saharan Interest Group Meeting organized by the NGO Sahara Conservation Fund in Senegal, from 4 to 6 May 2017. The Sahara Conservation Fund (SCF) gathers every year about a hundred people who are interested in the field of Sahelo-Saharan species conservation.

1. 17th Annual Sahelo-Saharan Interest Group Meeting
2 days of talks on biodiversity conservation in the Sahara and in the Sahel
Assessing the impact of overgrazing on the habitat structure and food
availability of the African Houbara Bustard
Yves HINGRAT, Research Manager – Reneco for Wildlife Preservation
Thomas MARTIN, Researcher – Reneco for Wildlife Preservation
May 4 – 6, 2017

2. Assessing the impact of overgrazing on the habitat
structure and food availability of the African
Houbara Bustard
Tom Martin & Yves Hingrat
Reneco for Wildlife Preservation

3. Overgrazing can have a devastating effect on
arid ecosystems!
Moderately grazed steppe in Uzbekistan Extremely over-grazed steppe in Eastern
Morocco
Ecosystem-scale impacts of overgrazing are generally well-studied, but little research exists
on its impact on specific threatened species within the Sahelo-Saharan zone.

4. The African houbara (Chlamydotis undulata)
Considered vulnerable by the IUCN (2017)
Main threats considered to be hunting and habitat destruction and
degradation.
However, this last point remains
unproved empirically!
We set out to test this in the context
of our Eastern Morocco study area.

5. Study site locations

6. Large fenced areas allowing for a clear “grazed” and “ungrazed”
comparisons
Missour - 2.915 km2 area exclosed for 21 years
Enjil - 10.604 km2 area exclosed for 13 years

7. Examining impacts of overgrazing on houbara in the context of habitat structure
variability and food resource availability
- Two variables known to be linked to the demographics of the Houbara.
- Habitat structure examined using point intercept method.
- Five 40x40m sample plots inside each exclosed area, and five 40x40m sample
plots outside – these plots surveyed every spring between 2008-2016.
- A series of 20m transects in each sample plot.
- All species encountered on transects also identified for food resources analyses.

8. - Arthropod trapping conducted exclusively at Missour in two years (2002 & 2012)
- 16 pitfall traps established inside and 16 pitfall traps outside the fenced area (± 700m)
- Checked weekly.
- Post-trapping sampling focuses on Tenebrionidae beetles and ants
(based on Bourass 2012).
- All identified to a species level via collaborations with specialists.
- Number of individuals and dry mass of each sampling category noted.

9. Analysis focussed on:
- Vegetation density
- Invertebrate abundance
- Invertebrate and plant diversity
- Invertebrate and plant community structure

10. Results – density and abundance
- With one exception, vegetation density always higher at ‘inside’ fence sites
(all Mann-Whitney P = <0.05)
- No difference in Tenebrionidae abundance in either year or any season
(all Mann-Whitney P = <0.05)
- No difference in overall ant abundance in either year (both Mann-Whitney
P = <0.05). However it was consistently higher in spring (both Mann-Whitney P = <0.05)
and in one year (2012) in Autumn.

11. Results – Plant diversity
- Rarefaction curves and non-parametric richness estimators suggest plant species diversity
actually increases outside fenced areas (except in the unusual climatic conditions experienced
in Missour in 2016)

12. Results – Arthropod diversity
- Rarefaction curves and non-parametric richness estimators suggest Tenebrionidae and ant
diversity does not change substantially between ‘inside’ and ‘outside’ sites (except
Tenebrionidae in 2012).
Tenebrionidae
Ants
2002 2012

13. Results – Community dissimilarity
Community structure always changed significantly between “inside and “outside”
sites (all Mantel test P = <0.05).
Community dissimilarity analyses indicates that some plant and arthropod groups are
more abundant in overgrazed study sites (eg. Lycium intricatum and Cataglyphis ruba.)
Other plant and arthropod groups are more abundant in ungrazed study sites
(eg. Salsola sp., Messor foreli, and Blaps sp.)

14. Discussion and conclusions
Results suggest that overgrazing in Eastern Morocco does not have a
catastrophic impact on Houbara habitat suitability, but we cannot say it has no impact.
Overgrazing significantly influences vegetation density, but Houbara is not a species
inhabiting densely vegetated grasslands!
Arthropod food availability aggregated annually does not vary, but ants are less
abundant at key times of the year (e.g. spring) and certain important species are less
abundant in overgrazed areas.
Results also cannot yet be related to other demographic parameters (breeding, display etc).
More research necessary to determine full impacts of habitat degradation on Houbara.

15. Next stage – initiating long-term habitat survey
protocols across a spatially extensive area
- Permanent study squares set up throughout Morocco (and UAE, Uzbekistan and Kazakhstan).
- 5x5 km2 squares spanning a variety of habitats, altitudes, disturbance levels etc.
- Habitat structure, botanical, and invertebrate abundance/mass surveys at each.
- Supported by remotely-sensed weather and vegetation cover indices.
- Long-term surveys to take into account seasonal variability.
- Can be directly correlated with houbara demographic data.

16. This next survey will allow the exploration of many
more in-depth research questions
Knowledge of carrying capacities.
Better knowledge of key species threats (habitat degradation vs hunting vs climate change)
Knowledge of key conservation areas
Predicting new areas of good Houbara habitat
More on this in the near future!

17. THANK YOU FOR
Listening!