136 SURAPON 0 UANGKHAE 20 BURMA 18 THAILAND 14 KAMPUCHEA SEA 10 GULF OF THAILAND 8 0!10 loo Km. 1...-1.-...J 6 98 10 Figure I. A, Sai Yok National Park in western Thailand. B, Study site at cave 30.
ECOLOGY AND BEHA VIOR OF KITII'S HOG-NOSED BAT 137 -...... '"-\ ' '... \ \. 8 o' '- --~ c 0 2 4 6 8 Km. - - -SAl YOK PARK BOUNDARY - KHWAE NOI RIVER (RIVER KHWAE) A BURMA"-. \.. Figure 2. Map showing: A, Sai Yok Nati onal Park ; B, Sai Yok cave: C, Wang Pra cave: D, Study site in dry evergreen fo rest at cave I.
ECOLOOY AND BEHAYIOR OF KITT!'S HOG-NOSED BAT 139 24 25 Figure 3. St udy s ite at cave 30. A.B.C.D = fl yways: CP =check-poi nt 125 m from cave entrance. Map redrawn from I : 50.000 sheet 4837 Ill. Amphoe Sai Yok. edi ti on 2- RTS D. Numbe red grid li nes are I km apart.
ECOLOGY AND BEHAYIOR OF KITTI'S HOG-NOSED BAT 141,...----,_ 2!50 ~ ~ ~ E E 20 o- r---...1 <J. 1!50 LL.. z Cl Q: - I-- 1001- r-- 9 0- ~ 1--- 1 1-=---1 u!... w 0:: :::> 1- <t Q: w 0.. :E w 1-40 3!5 30 25 20 15 90 :::0 ~--_...--_...- -... ['1'1... ----&..... _......... ~ - mox. RH'"' r --- --... eo ~ mox. T 70 rn ::z::: 60 c '.. --...--... -min. - RH ' ',..._ ~ 0 ' 50.. < -< 40 - ~ in.t ' ' -i J F M AP M JU JL AU s 0 N D 30 Figure 6. Above: Average monthly rainfa ll (Royal Irrigation Dept., Lum Sum station, Sai Yok, 197 1-1980). Below: Average maximum and minimum monthly temperature and relati ve humidity (Royal Meteorological Dept., Kanchanaburi Station, 197 1-1980).
... t EVENING ACTIVITY MORNING ACTIVITY IOj 'A :~. ;L ' [WINTER! ' ' f'~~l ' I Cl) ~ ID g, 0::: w ID ~ :::> z 5 10 20 30 40 50 60 50 40 30 20 10 5 IOj A: ' ::,~ :;:L_ I SUMMER I ' ~ ~~~~. I 5 10 20 30 40 50 60 50 40 30 20 10 5 IOj j;: ~~ING L [.:~:~.I ',~:~ /11 Vl c ~ ~ 0 c > z Cl ;.: :c > m 5 10 20 30 40 50 60 50 40 30 20 I 0 5 MINUTES AFTER SUNSET MINUTES BEFORE SUNRISE Figure 7. Schematic representation of distribution of activity of Craseonycteris in wi nter, summer and rainy season. Left, evening activity; right, morning activity.
Ta~le
ECOLOGY AND BEHA VIOR OF KITTI'S HOG-NOSED BAT 147 w 55 > ~ 5 (.) 0 1-4:5 (,!) ~ 40 z a:: :;) 3:5 1- w a:: 30 (f) 1-25 ~ m 20 IJ... 0 a:: I :!I w m :::!: 10 :;) z 5... 0.. I :!I 16 17 18 19 20 21 22 23 24 2:5 MORNING TEMPERATURE ( C) Figure 8. Scaner diagram of nu mber of bats in the feeding area in relation to morning air temperature (r=0.66, P<O.O I, n=28). + 's, winter; squares, summer; circles, ra in y season. w 70 1- :;) z ~ 60 (,!) z w :50 > w w J: 1- X 40 X z X X 0 x \x 0 a: 30 LIJ (l. >- 1- > i= (.) ~ 20 X X 30 40 50 60 70 80 90 EVENING RELATIVE HUMIDITY (%) X Figure 9. Scaner diagram of length of evening activity period (m in.) in relation to relative humidity in the evening. (r=0.045, P<O.OS, N=27). X's, winter; squares, summer; circles, rainy season.
148 SURAPON 0UANGKHAE - ltj t- :::> 50 z - ~ (!) z 40 z 0: x 0 :E 30 ltj :I: t- z 20 0 0 0: X w Q.. to X X >- ~ > ~ 0 60 70 eo 90 100 <{ MORNING RELATIVE HUMIDITY (%) Figure I 0. Scatter diagram of length of morning activity period (min.) in re lation to relative humidity in morning (r=-0.67, P<O.Ol, N=25). X's, winter; squares, summer; circles, rainy season. Light intensity Correlation coefficients between light intensity and activity of Craseonycteris are shown in Table 5. There was a significant correlation between light intensity and both the onset and finish of Craseonycteris activity in the evening for the rainy season only; for the summer, only the onset of activity was correlated. There was an overall correlation between light intensity and the finish of activity in the morning. In general, however, correlations with light intensity are weak; the bats tended to leave and return to the cave at fixed times regardless of sky conditions. Correlations between activity and sunrise and sunset are relatively strong (Table 6) especially over all seasons. Within seasons there is probably insufficient variability to yield strong correlations.
ECOLOGY AND BEHAVIOR OF KITTI'S HOG-NOSED BAT!53 6 TOTAL X= 25.6 ( N =58) 4 2 6 4 MAY 17 x= 26.4 (N = 18) MORN ING 2 (/) ti (l) u.. 6 4 2 0 6 a:: 4 w (l) ~ ::::::> z 2 MAY 18 x= 28.9 (N= 15) MORNING MAY 19 x= 23.3(N=I3) MORN ING 6 4 MAY 17 x= 22. 5 (N=7) EVENING 2 6 4 MAY 18 x=23.6 ( N=5l EVENING 2 16 18 20 22 24 26 28 30 32 34 36 38 40 FLIGHT SPEED (Km/h) Figure 11. Distribution of flight speed of Craseonycteris.
(BE~L,
156 SURAPON 0 UANGKHAE Figu re 13. Picture showing specia l organs for carrying young in female Crasen11ycteris (2 fin ger- li ke projec tions on lower abdomen). species of birds (BROWN, 1986; G ROOT, 1980; K REBS & D AV IES, 198 1 ). In C liff Swall ows (Hirundo pyrrhonora), it has been reported that birds unsuccessful in finding food fo ll ow the successful birds in order to reach the food sources (BROWN, 1986). Humidity and Temperature The evening acti vity period of Craseonycteris was longer in seasons with hi gh re lative humidity th an in the dry season butthere was no signi ficant corre lation w ithin seasons. The mo rning acti vity peri od, however, was longest in the season with lowest re lative humidity in the foraging area. There are two possible reasons to explain the positi ve effect of re lative humidity on bat activity in the evening and the inverse re lation in the morning. One mig ht be that in sects are more abundant during times of hi gh re lati ve humidity, if the temperature is appropri ate. Temperature in the morning in the cold season may reduce insect acti vity even tho ugh humidity is very hi gh. R OMOSER ( 1984) mentio ned th at extreme ly hi g h or lo w relati ve humidity causes feeding, reproducti on and development of insects to decrease. Vari ati on of relati ve humidity from day to day within each season might have onl y small effects on in sect abundance, but large scale vari ation from season to season might
19~2.