Most head-slaps are proiluced by males although females account for a srralI percerltage of a]l disptays seen. The displays performed by females tend to be much less intense than those of na1es. Often a female performs only a jaw,clap with no accompanying body posturing, tail swlsh or vocafization. Alligators select specific areas from which to iaw claD. Tlrrs site selection often occurs as mLrcl as fifteen ;inutes_before the display is actualfy perforned. Dispfay sites are usuafly very near the shore or other physi-cal objects (such as energent togs in the water), often in secluded portions of the 1ake, and are often under overhanging vegetation. A head-s1ap alisplay apparently causes other animals to bead-slap. Often a display is followed by t,ro or three other head_stap displays within the next fifteen to twenty mlnutes and then no displays ale heard fo! thirty to forty-five minutes. The fleqEncy of heaal slaps varies throughout the day. Head-slaps are frequent (ca- 4.5/hr) in early morning, less frequent during the morning basking perlod, nost intense during the afternoon hours (6/hr) and then drop off through the evening basking perioals anat alusk- I have only bri.efly described the most conspicuous acts in the repertoire of alligator social behavior. Alligator social communication is fa! more complex than can be indicated in this paper. Subtle cues, sucb as shifts ln movenent patterns in relation to other alfigators, or sfight changes in body posture, have not been discussed- The intricate processes of social communrcation of the afligator are stifl poorly kno\{n and require furtber study. Literature Citeal Garrick, L.D., and l-ang, J.W. 1977. Sociat signafs anat behavior of adult alligators and crocodiles. Am. zoo1. tjt 225-239 - Garrick, 1--D., tang, J.W., anat Herzoq, H.A-, Jr. 1978. Social signals of aduft American alligators. Bu]1- Am- Mus. Nat. Hist. 160{3): 153-192. Herzog, fl.A., Jr- !974- The vocal communication system anal related behaviors of the American altigator (At I i qai or rLississippiensis) and other crocodilians. MS thesis, Univ. Tennessee. Knoxville, 83 pp. Kellogg, R- 1929. The habits and econonic importance of alligarors- Tech. Bul1. U.S.D.A., Ns 147- McIlbenny, E.A. 1935- The Alligator,s !ife History. Chrislopher Publ. House, Boston, 117 pp. Reese, A.M. 1907. The breeding habits of the Florida alligator. Smithsonlan Misc. Col1. ouart. Issue 3: 381_387. Reese, A.M. 1915. The Alligator anal its Al]ies. putnamrs, New York, 358pp - 271 STATUS, CONSERVATIONAND UTII,IZATION OF THE NILE CROCODILE IN ZIMBABWE D. K. BIAKE Natal Parks Board Pieternaritzburg, South Africa E!3!!q CURRENT: There is only one species of crocodile in zir.babwe - That is the Nile crocodile {crocodvlus niloticus laurenti). While the fortunes of the Nile crocodile population in ZiFibabxre have fluctuated over the last century they can currently be classified in terns of the luCN definitions as being "out of alanger". This is a result of sound crocodile conservation anal utilization policies implemented over the Iast twenty years by the Department of National Parls and wildlife Management. HISToRICAI: Prior to the advent of the European into the country, crocoaliles were seldom killed because they haal no comnercial or food value to Lhe local people. The early European hunters with their more sophisticated weapons shot the odd crocodile more to placate the local chiefs than for the trophy- with the opening up of more remote areas and a growing human population. the conflict between crocodiles and hunans increased. This resulted in a reduction of crocodile populations except in the more remote areas of the country mainly limited to stretches of t}re majo! rivers, which 1ay outsiale suitable agricultural areas- The construction of farge alams even within these areas has alloweal reestabfishnent of odd populations- Today crocoaliles are distributed throughout the country, but nainl-y below 1.500 metres in altitude. They have established themselves in most alams contructed below this altitude and even in some above thatr the Ngesi anal Sebakwe being classic exanples in which marginat populations exist- Being miglatorY animafs, during the rainy season they quickfy re-settle the upper stretches of the rivers and move down-stream once the rains abate. PoPULATION: The uide Clistribution of crocodiles through the country make an accurate estimate of the population i.Iilpractible. the major populations occur along the zancezi river and Lake Kariba as well as in the Sabi,/Dundi river systems of the south- east Lowveld. Irl a subnission to IUCN in 1982 the population of crocodiles in zinbabwe was estimated as being in the region of 40/50.OOO crocodiles, Of these 34.000 were estinrated to occur in the zanbezi systems. This was based on aerial surveys and niqht counts conducted alonq the shoreline of l,ake Kariba, Taylor q! g! (1982). Counts during 1983 over longer strelches of Lhe shorefine indicateal lower alensities than previousfy obtained. 212 For the lake itself the poputation has been estimated at ?,6 crocodiles per kilometel of shore-fine resulting in a reviseal figure of 13.000 crocodiles. Counts along the Zimbezi river between the Rukometjie and Chewore rivers have qiven estimates of between 20-40 crocoaliles per kitometer of river. Taking the lower figure of 20 crocodiles per kilometer and the tengti of the river from Karlba dam to Kanyeftba as 195 km.. this ;ive an estimateal population of 3.900 crocodiles- Usinq the fioire of 7.6 crocodiles per kilonetre for the river upsiream fr;m Kariba gives a population of 1.200. This gives a population for the Zanibezi river (includinq Kariba) of minimum of 18.OOO crocodiles. The rest of the country can be divialed into the rivers north of the watershed and those south of the watersheat. In the northern watershed there are 10 main rivers flowinq lnEo the Zambezi system. These each have a rinimunr of 2OOk.ilo;erers of suitable habitat. Taklng a nominal population of 2 crocodiles per kilometer, we have 10 x 200 x 2 = 4.000 crocoaliles - In the lowveld there are 7 main rivers. ilorkina on the same formula lre arrive at 2.800 crocodiles Thus we have population minimum of 25.000 for the countrv. This flgure is probably much higher as no allovance has been made for population in many alams such as Kyle, McIlwaine, Dan"/enda1e, Ngezi. etc. The known population population for Ngezi dam alone is some 70 crocodi les - ]t can safely be assumed therefore that the revised clocoalife population for Zihbablre is in the region of 35.000 crocodifes. Crocodile popUlations in Zirnbablre have shown an upward trend since the early 1960's, especrally in those areas in which the crocodile is protected. Recent intensive surveys on Lake Karrtra have shown a marked increase over the last four years. The same situation exists in the lower Zambezi and is supported by counts made in 1971 and L9al/A2 (unpublished Departamental recoias) - observations by Departamentat staff have indicated increased populations in the upper zambezi as weft as the Sambi,/Lundi river system of the south eastern lowve1d. Conservation Unti] 196l crocoaliles coulal be hunted \.rithout licence and there was no restriction on skin sales. The world demand ilr the l95O,s for crocodife skin led to even the more remote poputation of crocodiles being decimated. The Wlldlife Conservation Act (1961) classified the crocodj-le as a game animal with the result that it coufd only be hunted under licence. 273 Skins coulal no longer be sold unless they weie taken unaler a cr:oppiprg pernit. Probably as a result of-these measures anil aided by the renoteness and inaccessibifriy of sore stretches of the major rivers the Nile crocodile was not exterminated. In the mid-1960's the Department of wlldlife conservation aflowed the utilization of the growing crocoallle populations alol]g the Zambezi River including Lake Kafiba. In 1975 the promulgation of the Parks and wild Life Act (19?5) passed responsibility for aI1 animals to the fand holder. In order to safeguard the crocoalile populations along the zamlcezi river systen, afl crocoaliles afong the river (including Lake Kariba) were by Government Notice 969 of 1975, placed under the protection of the Director of National Parks and Wild Life Management for five years. This notice was replaceal by Statutory fnstrurnent ?19 in 1980 thus affording protection for a further five years. At a meeting in June 1984 between the Departnent of I,Iational Palks and wild Life Management and the Crocodife Talmers Association of zimbabwe it was agreed that crocodiles throughout zimbabwe should be placed untler the protection of the Director of Nationaf Parks anal Wild Life Management. sihce the inception of crocodile Farming the Department has formulateil a strong policy on the Conservation anal lvlanagement of crocodiles in zitnlcabwe since 1982- utili zation Utilization can be divialed into three main categories: SPORTHUNTING: under sport hunting a total of 12 crocoalifes per annum are allocated to five safari operators along tbe shores of Lake Kariba. These crocodiles are only taken by bgB fide Safari Hunters and the quota is not always taken up. A quota for local hunters of 3 crocodiles per annutn on a section of the Zaribezi River below Kariba was allosred up to 1983- This nas stopped in 1984 as it was apparent that the crocodiles were not being hunted as trophies but rnerely as "Par't of the Bag". on private land a nuniber of Safari Operators allott the hunting of crocodifes - whife exact numbers are not known, a total of five trophies were exporteal in 1983. The proposal to place all clocodiles 1n the country unaler the protection of the Director woulal mean that these crocodi.les would have to be hunted unaler perm].E.