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84 The mere plesence of a Dale is not sufiicient. Female geen anoles hous€d with a c?strated male, who is Dot sexually active, show a Pattem of ovaria.o go*tl that is not drfferedt from that of females that are housed in all-female goups or as isolates (Gews, 1C74b). On the other han4 if females are exposed to castrated males that have received anilrogel replacement therapy (which reinstates sexual activity), the pattem of ova;atr response i5 similar to that of females housed with intact, sexually active males. This'behavioral facilitation of reproduction is due specifically to the courtship display of th€ nale (Crews et al., 1974). Inde€d, the more fr€quently the mal€ displays, which in tlis species consists of bobbing movements associated with extensions of tho dewlap, the more rapid the rate of ovarian growth (Crews, 1974a). Talen together, these stuahe suggesthat failure in a captivo br€eding frogram requires asse*sment of the behavior and level of activity of males in the breeding population It is important to keep in liind that sP€cific behaviors catr also iDhibit reproduction. Female green anoles eq)osed to mal€-male aggression, rattrer than to male courtship, n€v€r i tiate ovarian lrowth, even iI ihey are exposed to a stimulatory environmental regilren (Cr€ws, lnaa)Oigure 2). iadeed this aggressive beLavior, which is not dilected to*ards the fenale but rathcr to other males, is so potent a stimr. us that reproductive females rill cease all further reproductive activity ard any yolking fotticle(s) that are Fesent will undergo atresi& obviously, a c-aptive breeding prograrn should be dcsigned to minimize agonihc interactions among males. It also is impofiant to Dnderstand that this behavioral modulation of r€production operates in a redprocal matrner. That is, not only does male behavior inlluence female ovarian growth, bul so does fernali behavior inlluence mal€ reproductive activity. This can be seen in male grecn anoles (Crews and Garrick, 1980). Using the same conditions as in ttre above experiments, males hous€d ir all-male groups or in isotation show a diminished pattern of testicular activity compared to males housed with intact femal€s. r00 Clem i do ph o rus in o ln d I u 5 ?c< ISOL FEMALE CAST CAST+A C, an i doq h o ru s un ip o, e n 5 t50 OVEXT INTACT OVEX+ SLANK PROG F'ge3. Bosrnn|| idlirdbtr ofrcptlduci@ i! s@oduillic ud p.r6.!.e@li.3Fd6 ol sLiet|n (oaid4pr@) liz.r&, s!Mi. tL Fealsrolirdividu.L @t .iogrLd Loun uldd difd.lr dil @inja AOL - lohio4 PEMALE ' ED.L .r'sFr.rc; CaS! - ..i&.rcd D.lc cag.dq C.AST + ,{ ! &dros.'-tuGd srncd Dqlc -e -"tai O!€x + BLINX - 6i@- h!t.n @id@i:rd ..adaIc; INIACT - inlet .:g@.I.i OVES + PROC - pro&di.ro'c.r.atod Miar@izd ..scD.t (Ird o.ua 1933).
85 2. Behavioral facilitation of reproductio! has been documenled also is teiid liz3rals such as lhe wupl3ns (Cnemidophorus spp.). As ir the green anole, h the litde strip€d whipta;l (C inomatus), th. presence, a[d more specificallt th€ leproductive statuE of the male is an important feature of the feaaale's housing environrnent. Females housed as isolates or housed with castrate4 se)olaly i.nactive Dales, fail to ovulate (Cre*s et al., 1986xFigure 3). ODly those feEales expos€d to htact scxually active males undergo complete o\ariar growth aad lay eggs. It is not known what aspect of the male is importalt for facilitatiDg th€ stimulatory etrects of the environment, altlough the behavior of the animals suggest tlat chemicaf signals ale likely to be importa.nt. 3. The tunda&edal importarce of complementary behavioral interactions (e.&, nounting alxd receptive behaviors) is seen parlicularly clea y i.n studies with the partbenogenetic whiptail, C enlidophotus unipa.ens. ID this species there are no male individuals ard reproduction is via obligate parthenogenesis. Rather, tle species coasists e irely of females and sperm are not required for ovarian development. Intereslingl, these partherogeos exhibit both male-like and fenale-like behaviors duri.ng spccific stages of the reproductiv€ cycle (Crews, 1989; Crews and litzgerald, 1980). The,se behaviors are seeD bot! ia the laboratory as wel as in nature (Crews and Young, 191). Experinents iDdicate that altlough nale individuals are Dot essedial for ovariar glowth id the parthenogeA participation itr pseudos€xua.l interactioDs geatly facilitates tho nte of ovalialr growth (Crews et al., 1986) (Figure 3) as wel as the total number of eggs producEd during a breeding season (Crews ard Moorg 1991; Crelr$ €t al., 1983). The specific stimuli respoDsible for tffs facilitation is not kno\n!, but lhe question is amenable to experime ation. 4. In the gekkonid lizard, the leopard gecko (n , kphoris ma.ularius), lenales will only lay eggs if sexually active males are present (Figure 4). Fbtler, tle fertility of the ruale is i$porta . That i5, females housed with sexuatly actrve but vasectohized Eales will lay eggq but the eggs often lack a shell coati.ng (J. J. Bull unpublished data). This suggests t-hat not only is the b€havior of the male important, but tlat at least id some species th€re must exist semory receptors withh the f€nale's reproductive tract that are activated by sp€rm deposition. Sp€cialized sperm storage ducts occur id many .eptiles. This may b€ why i! mary reptiles the female c-atr continue to lay fertile eggs for years in captivity in tte absence of males. These data aiso suggest [hat wbjle it is advisable in a captii€ breealitrg prograD to establish that each male is depositing sperm during math& a fortile male is not an absolute requirement so long as the females mate successfully at least ocrisionally. = 60 5ao o Ezo 0 gw 4. &hvid.r f:dlir.li@ olE!rodudic i! r[c l6p:rdg..ro @,i!td@it @rqiBt. Nub.. ofiudividut c!@dc3 ouaid. paorfiEqr *iiL !@bd *nni! rcp..&!r. !!. nuh.. ol
Page 1 and 2:
CROCODILES Proc€€dings of the l
Page 3:
FOREWORD The two volumes of this PR
Page 6 and 7:
Elsey, R M, McNease, L & Joanen, T:
Page 9 and 10:
CFAZ CIIAIRMAN'S OPENING COMMENTS F
Page 11 and 12:
PRESENTATION FROM THE MINISTER OF E
Page 13 and 14:
Fitting Curves to crocodilian Aqe-s
Page 15 and 16:
7 a.set of uniforrn random nunbers.
Page 17 and 18:
2. VON BERTAI"ANFFY MODEL FOR GROWT
Page 19 and 20:
11 The -following four tables give
Page 21 and 22:
UNIFoRU sarnpling MEDfUM sahpl ing
Page 23 and 24:
15 Sectior IV: Actual Croc Data, l,
Page 25 and 26:
1'l (ii) Linear regressron. same ra
Page 27 and 28:
1,9 rejecting nufl hypotheses that
Page 29 and 30:
21 Brisbin, I.L., Jr., c.c. White,
Page 31 and 32:
Iength lthich corresponds to the ni
Page 33 and 34:
25 Because of lack of funds Eo carr
Page 35 and 36:
27 Despite the fact that during a p
Page 37 and 38:
29 FIGURE N9 2 BLACK CAIIIAN POPULA
Page 39 and 40: I'Effect of diets conplenented vith
Page 41 and 42: 3i Two of the 6 x 2 m. tanks four e
Page 43 and 44: : .i ; -3, E .-1 t FFdF !_9 + + + +
Page 45 and 46: 10 Table IV : fl aernathological Re
Page 47 and 48: 4l 4.- CONCLUSIoNS 1) The most favo
Page 49 and 50: 43 THE INVOLVEMENT OF RURAL COMMUNI
Page 51 and 52: 45 the rainy season and, in conhast
Page 53 and 54: 47 difficulties and the isolation o
Page 55 and 56: 49 Eacb time that one of the villag
Page 57 and 58: 51 CONCLUSION Naturally, these rcsu
Page 59 and 60: 53 LONG-TERM POPUT-A.TION S'ruDIES
Page 61 and 62: 55 'Ile study reporled here was des
Page 63 and 64: 5'7 made of transmilteFequjpped ndm
Page 65 and 66: 59 wilhin the reservoir was lypific
Page 67 and 68: 6l However the use of such winter d
Page 69 and 70: 6.1 surface to breathe (Kellogg 192
Page 71 and 72: 65 ACKNOWLEDGMENTS This work was su
Page 73 and 74: Murphy, T. M., P. M. Wilkinson, J-
Page 75 and 76: 69 t 3 ^ 3 :9s 3P o ;x !B 'rr.l9 3e
Page 77 and 78: 7l FoDd B + i Poud C I Pltllr. l. U
Page 79 and 80: 73 9 October 1991 L t' I L t' 26 Ma
Page 81 and 82: 75 80 -r- 1987-88 + 1991-92 t -40 .
Page 83 and 84: 77 GROWTH RAIE OF CAIMAN (Caiman cr
Page 85 and 86: 79 Values of the life lable paramet
Page 87 and 88: 81 REFERENCES Craig. G.C., D. Si.C.
Page 89: 83 CUMATIC F{w L Stirldi .6.aiDS EF
Page 93 and 94: 87 TeEperature, hy&ic coaditionq aa
Page 95 and 96: 89 The sexual behaviors of irdividu
Page 97 and 98: 9l 2o I E F conuor o.r r.0 r0.0 a0.
Page 99 and 100: 93 Referetrces Ber!, H.A. (1990). T
Page 101 and 102: 95 GROWTH RATES AND BODY CONDITION
Page 103 and 104: 97 LIPID AND FATTY ACID COMPOSMONAL
Page 105 and 106: 99 be removed sustalnably, provided
Page 107 and 108: 101 necessary as the endurance of t
Page 109 and 110: 103 Table 2. The ratio of first sig
Page 111 and 112: 105 3) Movement and dispersal The r
Page 113 and 114: 107 Disease Trend$ on Crocodite Far
Page 115 and 116: 109 Fuigol and other dermar,?ir - d
Page 117 and 118: 111 THE FEEDINC ECOLOGY OF TWO NILE
Page 119 and 120: 113 areas outside the National park
Page 121 and 122: 115 been done for a tlpical populat
Page 123 and 124: 117 ACKNOWLU)GEMENTS This study was
Page 125 and 126: 119 THE STATUS AN'D DISTRIBUTION OF
Page 127 and 128: Figure l: Crocodile Survey - Tanzan
Page 129 and 130: 123 :rD ES e € a 69 PE e 3 Er t !
Page 131 and 132: 125 Ruaha River (Figure 2) The Ruah
Page 133 and 134: 127 lake Mtera (Figure 4) This is a
Page 135 and 136: t29 with 6shermenand subsistence f'
Page 137 and 138: lil Kilimmjaro/Tanga Region Pa gani
Page 139 and 140: 133 The numbers of crccodiles durin
Page 141 and 142:
135 REFERENCES Chabreck, R.H. 1966.
Page 143 and 144:
l -37' 3.1.4 lagal Trad.e Local tra
Page 145 and 146:
l.l9 In order to gecure credibility
Page 147 and 148:
l4l 'rould apply to 6kins of good h
Page 149 and 150:
143 This infdrrDation cduld be supp
Page 151 and 152:
l.l-s ].nternational reEplfnstbitit
Page 153 and 154:
t4'/ illegal sttjns in their pr,r,d
Page 155 and 156:
149 CROCODILE SKIN INDUSTRY IN ETII
Page 157 and 158:
l5l Table 2. Ouotas for Ethiopian c
Page 159 and 160:
153 depriving EWCO of incentive for
Page 161 and 162:
155 A PRELII{] NARY ASStsSS!.IENT O
Page 163 and 164:
15',7 Origin l Payert lltosk Breedi
Page 165 and 166:
159 dropped, producing 23 and l9 eg
Page 167 and 168:
l6l This figure ts even lorrer than
Page 169 and 170:
163 =z 3F \riciNoraj {
Page 171 and 172:
165 References EArr,ER, R.D. ( 1976
Page 173 and 174:
t6'1 IPPIIDIX tt BtoBtE cI0@(DILX n
Page 175 and 176:
l()t/ Backqround l,lelano5uchus nio
Page 177:
t7l The numbers of black cainan c'b
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