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
Oryx reintroduction to Chad
Tim WACHER, Conservation Biologist - Zoological Society of London
May 4 – 6, 2017

2. ORYX – RE-INTRODUCTION TO CHAD
Tim Wacher
Zoological Society of London

3. POST-RELEASE MONITORING II
• What is post release survivorship?
• Habitat use, coping with conditions?
• Interactions with other wildlife - livestock
• Calf production and survival?
• Causes of mortality?

4. ORGANISATION OF THE
OBSERVATIONS
• Group 1 – 21 Oryx 8 Males 13 Females
Released 14 Aug. 2016
• Group 2 – 14 Oryx 6 Males : 8 Females
Released 21 Jan. 2017
• Group 3 – 37 Oryx 14 Males : 23 Females
Not released: + 7 CALVES TO DATE
81 oryx in Chad April 2017 (including calves)

5. THE MONITORING TEAM
Abe (Bobby) Zaid
Habib Ali
Krazidi Abeye
© Tim Wacher
© Tim Wacher
© Tim Wacher

6. POST-RELEASE SURVIVAL
• Group 1
– 262 days….. 100%
• Group 2
– 102 days…..100%
[Group 3 – all 37 alive in prelease 03/05/2017]

7. HABITAT CONDITIONS
Group 1 - August 2016
21 Aug. 2017
© Tim Wacher

8. HABITAT CONDITIONS
September 2016
07 Sep. 2016© Tim Wacher

9. 25 Feb. 2017
GROUP 1 – END OF FEBRUARY
(No rain or free water since September – Excellent body condition)
HABITAT CONDITIONS
February 2017
© Tim Wacher

10. END OF MARCH 2017
Some oryx losing body condition
Adult male B34M :
On the day he returned
spontaneously
to the feeding station –
(compare to next slide)
B34M walked directly to the
release site after 7 months living
independently in the Group 1
herd >30 km away
30 Mar. 2017© Tim Wacher

11. 03 Apr. 2017
ADULT MALE B34M
4 DAYS AFTER RETURN TO FEEDING STATION
Compare body condition to previous slide…
© Tim Wacher

12. GROUP 1 – ORYX NOT USING FEED
STATION AT ALL
12 Apr. 2017
© Tim Wacher

13. DRY SEASON IMMOBILITY ALERTS
3 ORYX IN THIS GROUP TRIGGERED IMMOBILITY ALERTS AROUND THE TIME
THIS LATE AFTERNOON PICTURE WAS TAKEN –
ALMOST ALL MOVEMENT NOCTURNAL AT THIS SEASON
© Tim Wacher

14. 6mm Rain – 15-16 April 2017
Rainfall and cloud cover brought temporary relief from high temperatures and aridity
and created water pools for a few days over a wide area in mid-April
(Meteorological data from oryx camp automatic weather station)
© Tim Wacher
© Tim Wacher

15. AFTER RAIN – ACTIVE MIDDAY
19 Apr. 2017
© Tim Wacher

16. AFTER RAIN – ACTIVE MIDDAY
22 Apr. 2017
© Tim Wacher

17. OTHER WILDLIFE AND LIVESTOCK
APRIL 2017 TRANSECT SURVEY
Mahamat Hatcha Coordinateur du Reserve et l’Equipe DCFAP
© Tim Wacher

18. HABITAT USE
LINE TRANSECT SURVEY Feb. 2017
February Group 1 oryx (red points) – burnt areas (grey) and livestock relative density
contours
15,865 dorcas (cv 14.35%)
52,550 Tropical Livestock Units (cv 29%)

19. B36F – CALVING BEHAVIOUR
27 Jan. 2017
The first female to give birth on the project, was B36F on 21 September 2016
She isolated from Group 1 on the day she gave birth: considered typical oryx behaviour.
She has not re-joined a herd since, becoming widely separated from the only herd available
© Tim Wacher

20. GROUP 1 B36-01 Born 23/Sep/2016
16 Apr. 2017© Tim Wacher

21. B23F – CALVING BEHAVIOUR
B23F also separated from Group 1 to give birth : the male who joined her
from group 1 in a consort pair shortly afterwards was B38M,
not the socially dominant male of Group 1, B40M.

22. B23F – CALVING DETAILS
0
5
10
15
20
25
Group size
Female
Group 1 Male
Calf
B23F’s calf was reported to be very small and was no longer seen after 10 days.
The dam moved widely with group size and composition more variable
A sign of emerging more flexible social structures

23. B31F – CALVING BEHAVIOUR
B31F also separated to give birth and consorted with 2 different males post-partum;
Neither was the dominant male of Group 1 with whom she had associated since arrival in Chad.
Detecting this distinctive spatial and social indicator of calving from satellite location data is
proving difficult and planned automatic alerts based on it have not yet been developed.
© Tim Wacher

24. GROUP 2 – 2 CALVES
B02F gave birth at the feeding station, at very high risk from jackals attracted there:
© Tim Wacher

25. GROUP 2 – 2 CALVES
Jackals are present in numbers all night long every night at the feeding station water trough

26. GROUP 2 – FIRST CALF
B02-01 was killed by jackals 250m from the feeding station within 24 hours :
© Tim Wacher

27. GROUP 2 – SECOND CALF
R30-01 and all calves born at the feeding station subsequently
have been herded back to the pre-release pens successfully
© Tim Wacher

28. 12 calves born (to 27.04.2017)
• Wild born wet season release Survival
3 calves – 1 mortality
(lost calf small, born mid dry season, abandoned?) 60%
• Wild born – dry season release
2 calves – 2 mortalities
(1 killed by jackal / 0%
1 abandoned after moving back into pen system)
• Pre-release pen birth
7 calves 100%

29. NEXT RELEASE – AUG 2017
Manage calving in relation to dry season post-release behaviour
© Tim Wacher

30. MALE CONFLICT IN PRE-RELEASE PENS STRONGLY
ESCALATED WITH ONSET OF CALFING
© Tim Wacher

31. SUMMARY
• RELEASE ORYX SURVIVAL OVER FIRST 8 MONTHS – 100%
• DISPERSAL MODERATE AND GROUP 1 HERD COHERENT
• FIDELITY TO / AWARENESS OF RELEASE SITE PROVEN AFTER 7 MONTHS
• CALVING IN THE WILD SUCCESSFUL ALTHOUGH LOW POPULATION SIZE
HAS CONTRIBUTED TO 2 of 3 BREEDING FEMALES LOSING CONTACT WITH
HERDS FOLLOWING TYPICAL ISOLATION BEHAVIOR AT BIRTH
• MAINTENANCE OF THE FEEDING STATION AT THE RELEASE SITE HAS
CREATED A CONCENTRATION OF JACKALS REQUIRING LOCAL
MANAGEMENT OF BREEDING FEMALE ORYX
• MID-DRY SEASON SOME ORYX ARE HOLDING BODY CONDITION BETTER
THAN OTHERS - A SHORT RAIN STORM IN EARLY APRIL STIMULATED AN
IMMEDIATE CHANGE IN BEHAVIOR AND RAPID RESPONSE IN BODY
CONDITION FOR MANY
• CONCLUSIONS PREMATURE UNTIL FIRST FULL CALENDAR YEAR
COMPLETED