Dragonflies In Sinai

1. Dragonflies In Sinai Tom Webborn, Heba Abdul-Aziz, James Gilbert and Salma Zalat

2. Introduction Dragonflies (Odonata: Anisoptera) • Abundant • Large and colourful • Variation • In morphology • In behaviour • In activity patterns

3. Activity < Thermoregulation < Morphology • Adaptation • for example, the cuticular window (prothorax) • Objective • Composition • Activity pattern • Height of flight

4. Materials and methods • Two species • Hemianax ephippiger (Vagrant Emperor)

5. Crocothemis erythraea (Red Darter) • Males red, females brown

6. Three sites • Rasis (alfalfa) • Wadi Bowaleia (achillea) • Wadi el Arbaein (fresh water)

7. Experimental methods • Observation every five minutes • The number of each species • Height of flight • Temperature measured every half hour • From the first dragonfly until the last, or until dusk

8. Results • Hemianax ephippiger (larger species) • Activity and height increase with temperature • Two peaks of activity: morning and afternoon • One peak at Bowaleia • Fly highest at midday • But height not related to temperature

9. Figure 1 (H. ephippiger at St Katherine days 1 & 2) Height of flight against temperature 2.5 2.0 1.5 HEIGHT 1.0 .5 0.0 20 22 24 26 28 30 32 34 TEMPERATURE Height increases with temperature (n=42, p~0)

10. Results • Hemianax ephippiger (larger species) • Activity and height increase with temperature • Two peaks of activity: morning and afternoon • One peak at Bowaleia • Fly highest at midday • But height not related to temperature • Probably following prey • Temperature-dependent (>>cuticular window) • Numbers disappeared abruptly > migration

11. Crocothemis erythraea (smaller species) • Numbers increase with temperature • But flight height doesn’t • Height and numbers remain roughly constant • Males displace females in the afternoon

12. Figure 16 (Femaleand Male C. erythraea at St Katherine days 4 & 5) Frequency against time 14 12 10 8 6 Mean FREQ Female 4 Male 2 0 8:00:00 9:59:59 11:59:59 13:59:59 15:59:59 17:59:59 8:59:59 10:59:59 12:59:59 14:59:59 16:59:59 TIME

13. Crocothemis erythraea (smaller species) • Numbers increase with temperature • But flight height doesn’t • Height and numbers remain roughly constant • Males displace females in the afternoon • At Bowaleia, activity follows the larger species by about 2 hours • Larger dragonflies may displace smaller ones

14. Figure 7 (H. ephippiger and C. erythraea at Wadi Gebel) Frequency against time 70 60 50 40 Mean FREQ 30 H.ephippiger 20 S.striolatum 10 0 l 10:59:59 13:29:59 14:59:59 16:29:59 17:59:59 18:29:59 10:29:59 11:59:59 12:29:59 13:59:59 15:29:59 15:59:59 16:59:59 17:29:59 11:29:59 12:59:59 14:29:59 9:29:59 9:59:59 TIME Wadi Gebal, day3

15. Crocothemis erythraea (smaller species) • Numbers increase with temperature • But flight height doesn’t • Height and numbers remain roughly constant • Males displace females in the afternoon • At Bowaleia, activity follows the larger species by about 2 hours • Larger dragonflies may displace smaller ones • Territorial dragonflies • Males may establish territories in the afternoon

16. Conclusion • Not enough data for a firm conclusion • But some interesting suggestions • Thermoregulation and behaviour • Daily patterns of behaviour • Competition between species • Tracking the migrant species