<I>

  <&>Wellington Corpus of Spoken New Zealand English Version One</&>
  <&>Copyright 1998 School of Linguistics & Applied Language Studies</&>
  <&>Victoria University of Wellington</&>

  <&>side one</&>
  <&>0:54</&>
  

  <WSC#MUL011:0005:AC>
      so first of all a brief history of past attempts at captive
      breeding <,>

  <WSC#MUL011:0010:AC>
      perhaps the <&>1:00</&> first attempt and certainly one of the
      best documented was that made by professor a b w thomas of the
      university college of auckland last century <,>

  <WSC#MUL011:0015:AC>
      he started by collecting twenty nine animals from kariwa island
      in eighteen eighty five for the express purpose of breeding in
      captivity <,>

  <WSC#MUL011:0020:AC>
      even then an ignorance of basic biology was one of the main
      reasons for failure

  <WSC#MUL011:0025:AC>
      in his first attempt he collected twenty nine animals and
      brought them into captivity and obtained no result after twelve
      months

  <WSC#MUL011:0030:AC>
      he decided to go back to the wild and investigate whether the
      animals were sexually dimorphic or not he'd been told that they
      weren't

  <WSC#MUL011:0035:AC>
      when he went back to the wild and he dissected animals he found
      that this was incorrect and in fact all the animals he'd
      collected were male <O>laughter</O>

  <WSC#MUL011:0040:AC>
      he persevered and collected twelve animals that he considered
      were female out of the <?>tuis</?> colony and three years later
      had still <.>ob</.> obtained virtually no success

  <WSC#MUL011:0045:AC>
      he did manage to <&>2:00</&> get one clutch of fertile eggs but
      those were dissected from a female that had just died so no
      naturally laid fertile eggs in his attempts

  <WSC#MUL011:0050:AC>
      he wrote in his paper and you can sense his frustration <reads>captivity
      would seem to interfere with their reproductive powers an effect
      which could hardly <.>an</.> be anticipated with animals of so
      sluggish a nature</reads> <O>laughter</O>

  <WSC#MUL011:0055:AC>
      following these heroic attempts there were <O>tut</O> <.>m</.>
      more attempts over the first er half of this century to breed
      tuatara in captivity but these attempts have been poorly
      documented

  <WSC#MUL011:0060:AC>
      one can speculate that they probably involved a fairly victorian
      approach

  <WSC#MUL011:0065:AC>
      this is the reptile house at london zoo last century where
      animals were literally passed placed in small glass fronted
      viewing cabinets er and the success of these attempts with
      tuatara being um abysmally <&>3:00</&> low <,,>

  <WSC#MUL011:0070:AC>
      since nineteen fifty two there are much better records available
      of the success of attempts at captive breeding and these data
      come from some results that tony and i collated from records
      available through the protected species unit of the department
      of conservation and also by circulating questionnaires to
      various zoos that we were told had tuatara in captivity

  <WSC#MUL011:0075:AC>
      to summarise over the last thirty eight years there've been at
      least ninety adults that have been collected for the purposes of
      display and or breeding in the zoo situations

  <WSC#MUL011:0080:AC>
      of these fifty two have been adults with one of each sex at
      least so theoretically situations where breeding could've
      occurred

  <WSC#MUL011:0085:AC>
      thirty four survived <,> and from these at least twenty six
      clutches of eggs have been laid but note that probably about a
      quarter were from females that were already carrying eggs when
      they were collected and these were eggs that were laid within
      the first year of collection

  <WSC#MUL011:0090:AC>
      forty three hatchlings have <&>4:00</&> been produced and thirty
      survive today but the oldest is seven years and as i mentioned
      earlier none has yet reached maturity <,>

  <WSC#MUL011:0095:AC>
      it might seem quite good that we have this many juveniles
      surviving or and this many <.>ha</.> hatched over this time but
      when one looks at the potential reproductive rate of of as
      female in the wild these results are actually rather poor

  <WSC#MUL011:0100:AC>
      the average clutch size on steven's island which is <.>incid</.>
      incidentally the population where all captive animals documented
      here come from the average clutch size is about ten eggs and
      females reproduce on average once every four years and the
      incubation success in nests is about forty four percent which
      means that over thirty eight years a single female should
      produce about forty two hatchlings about the total that
      reproduced from um fifty two pairs in captivity <,,><&>5</&>

  <WSC#MUL011:0105:AC>
      the table here summarises the <&>5:00</&> tuatara that are held
      in captivity in new zealand at present and there are very few
      overseas so these are essentially all of them

  <WSC#MUL011:0110:AC>
      there are about eight adults overseas and no juveniles

  <WSC#MUL011:0115:AC>
      as far as these go there are adult males adult females in this
      column and these are ones that are paired with at least one <.>oth</.>
      one other member of the opposite sex

  <WSC#MUL011:0120:AC>
      we can see that there's a number of zoos that have just a single
      male or a single female together in fact there are four of those
      <?>with</?> some of wellington zoo's animals are just a single
      pair housed together and then there are some others places
      notably otorohanga where there are several animals in large
      outdoor colonies in this case four males and four females
      together so a total of twenty seven adults in er situations
      where breeding could theoretically occur <,>

  <WSC#MUL011:0125:AC>
      from these about thirty eggs have been <&>6:00</&> hatched from
      the eggs that have been laid in captivity and there are also
      nine juveniles at these institutions that have been hatched from
      eggs collected from nests on steven's island <,,>

  <WSC#MUL011:0130:AC>
      there's also a large number of juveniles now in captivity as a
      result of the incubation experiments that mike thompson carried
      out at victoria university

  <WSC#MUL011:0135:AC>
      these generated a lot of hatchlings that were distributed
      throughout new zealand to these er people or institutions

  <WSC#MUL011:0140:AC>
      um thirty five still remain at victoria university and the a
      total of eighty two are er currently alive at the moment
      <,,><&>4</&>

  <WSC#MUL011:0145:AC>
      well if we look now at some possible reasons for poor breeding
      success there's a number of factors that can be identified and
      i'm going to go on to talk about these in more detail <,>

  <WSC#MUL011:0150:AC>
      firstly um high adult mortality lack of appropriate physical
      cues for reproduction lack of social interactions for instance
      males and females have often been in pairs with just one other
      member of the opposite sex <,,> er improper nutrition <unclear>word</unclear>
      <&>7:00</&> all these factors you can deem sufficiently
      inappropriate conditions for egg incubation simply <,> so i'll
      go on to talk about some of these factors <,,><&>4</&>

  <WSC#MUL011:0155:AC>
      first of all high adult mortality

  <WSC#MUL011:0160:AC>
      of the ninety adults that are known to have been collected and
      distributed to zoos over the last thirty eight years the results
      for those sent overseas make rather horrifying reading

  <WSC#MUL011:0165:AC>
      half of them have been er sent overseas and of these a third
      were dead within one year

  <WSC#MUL011:0170:AC>
      this is a very poor rate of survivorship for an animal that has
      a life span in the wild of at least seventy years <,,>

  <WSC#MUL011:0175:AC>
      er <.>th</.> <.>th</.> the rate of um the death rate's much
      lower for those that were distributed within new zealand and an
      analysis of the records that are available which are in many
      cases scant suggest that acute temperature stress is likely to
      have been a major factor in many deaths <,>

  <WSC#MUL011:0180:AC>
      tuatara are adapted to cool temperatures and die within a few
      <&>8:00</&> hours at temperatures in excess of thirty degrees
      celsius and these temperatures are relatively low compared with
      the temperatures that many overseas institutions maintain other
      reptiles <,> and this is likely to have been a major factor in
      these deaths

  <WSC#MUL011:0185:AC>
      nevertheless it is quite possible to maintain adults for a long
      time in captivity if conditions are right and within new zealand
      there are there's at least one animal that's been in captivity
      in excess of thirty years <,,><&>3</&> um <,,><&>3</&>

  <WSC#MUL011:0190:AC>
      this is moving on to another possible well variety of possible
      reasons that could explain poor reproductive success

  <WSC#MUL011:0195:AC>
      this is the enclosure at wellington zoo

  <WSC#MUL011:0200:AC>
      it's on public display

  <WSC#MUL011:0205:AC>
      it's a glass fronted tank where just one male and one female are
      present

  <WSC#MUL011:0210:AC>
      it's a small enclosure so er high density high area er small
      area per animal and just one of each sex and it's also an indoor
      <&>9:00</&> enclosure where temperature and <?>photo</?>
      <unclear>word</unclear> are almost constant year round
      <,,><&>3</&>

  <WSC#MUL011:0215:AC>
      now we know from wild tuatara that they are seasonal breeders
      and like most reptiles it's highly likely that fluctuations in
      temperature play an important role in triggering various
      reproductive <.>e</.> events

  <WSC#MUL011:0220:AC>
      this graph summarises changes in testosterone levels in male
      hormone in male tuatara on steven's island these are wild males
      that are reproducing

  <WSC#MUL011:0225:AC>
      testosterone is the male sex hormone and it stimulates sperm
      production and mating behaviour

  <WSC#MUL011:0230:AC>
      we find if we look from nineteen eighty six through to may
      nineteen eighty eight that there's clear annual pattern that
      there is a high around the time of spermiodusis which is when
      mature sperm are produced and at the time males are displaying
      the territorial and aggressive amongst each other and mating
      with females

  <WSC#MUL011:0235:AC>
      levels then fall low over winter and rise again in healthy males
      when it's when the late summer and <&>10:00</&> it's highly
      likely that er temperature is an important factor in triggering
      these changes <,,><&>4</&> and as far as social interactions are
      concerned during the breeding season the males become
      territorial they'll defend their territories from other males
      they'll engage in fights at the boundaries although these are
      rarely fatal <,,><&>4</&>

  <WSC#MUL011:0240:AC>
      to investigate whether <,> a <,> there might be abnormalities in
      testosterone cycles in captive males i carried out some sampling
      on animals that are held in captivity in new zealand zoos and
      compared those with data available from the studies on wild
      tuatara on steven's island

  <WSC#MUL011:0245:AC>
      er the open circles are the mean plus or minus one standard
      error for five to six wild animals over the following months and
      the captive animals where six to eight animals are in various
      enclosures throughout new zealand

  <WSC#MUL011:0250:AC>
      the sample over this <.>per</.> this <&>11:00</&> spring summer
      autumn period when levels were expected to rise and then fall

  <WSC#MUL011:0255:AC>
      we didn't continue beyond this point with captive animals
      because the zoos became rather upset that some of their tuatara
      were becoming very secretive and they didn't want the sampling
      to continue because their animals were no longer displaying very
      well um <,> so we just had the data for the seven months but the
      interesting result is that the captive animals do show <.>norm</.>
      what appear to be relatively normal levels of testosterone
      during summer

  <WSC#MUL011:0260:AC>
      they reach about the same maximum level and they fall again in
      autumn <,>

  <WSC#MUL011:0265:AC>
      there seems to be a displacement of about one month in their
      cycles so that they fall earlier and this is possibly related to
      differences in temperature er compared with that on steven's
      island

  <WSC#MUL011:0270:AC>
      i'm not sure of the exact reasons but that's one possible
      explanation <,,>

  <WSC#MUL011:0275:AC>
      in <&>12:00</&> separating the data for the males in captivity i
      separated here to those where there was just a single male by
      himself with one other female and those where there were at
      least two males in the enclosure with females and what we find
      interestingly <.>i</.> is that there's no difference between the
      cycles

  <WSC#MUL011:0280:AC>
      they're both showing high levels during the late summer period
      and then falling in the autumn as one would expect so at this
      point no evidence to suggest any er lack of um <.>th</.> the
      lack of interaction with other males is causing a depression in
      testosterone levels no <unclear>word</unclear> <?>there</?> <,>

  <WSC#MUL011:0285:AC>
      i also looked er analysed the <.>d</.> the same data in terms of
      whether the males were present or had a had an ovulating female
      in their enclosure or had no ovulating female in their enclosure

  <WSC#MUL011:0290:AC>
      females only ovulate once every four years on average in the
      wild and this is the time when they're sexually <&>13:00</&>
      receptive so it's conceivable that in the absence of a sexually
      receptive female the male cycle might be impaired but we don't
      see any evidence of this

  <WSC#MUL011:0295:AC>
      we find that the <unclear>word</unclear> levels are high in both
      groups at the same time and show a generally similar pattern
      <,,><&>3</&>

  <WSC#MUL011:0300:AC>
      i also looked at levels of sex hormones in females and here the
      situation becomes a little more complicated because as i
      mentioned females reproduce only <.>ev</.> every four years on
      average in the wild

  <WSC#MUL011:0305:AC>
      one can illustrate this reproductive cycle graphically in the
      following way

  <WSC#MUL011:0310:AC>
      you follow this through <.>thr</.> november in four years these
      ovals represent eggs in the oviducts that are about to be laid
      so the female nests here in the spring

  <WSC#MUL011:0315:AC>
      she then spends about three years <,> during which time the
      follicles in the ovary represented by these circles are
      incorporating yolk so this period <&>14:00</&> of <?>myophilogenesis</?>
      or yolk production extends over about three years

  <WSC#MUL011:0320:AC>
      she then mates when her ovaries are ready to ovulate <&>pronounced
      obulate</&> ovulate which means the eggs pass through the
      oviduct and get fertilised and then she carries the eggs in the
      oviduct and <.>sh</.> and the shell is laid down over about
      seven months before she nests again <,,><&>4</&>

  <WSC#MUL011:0325:AC>
      obviously in in my study it was important to discriminate <&>pronounced
      discrimulate</&> discriminate between females that were
      ovulating when we were sampling and those that weren't um <,>

  <WSC#MUL011:0330:AC>
      this is because the levels of sex hormones differ markedly
      depending on whether the female is is ovulating that year or not
      and this graph i've produced much the same figure along the top
      here er although it's just shown over three years because er in
      in these wild animals with sex hormone cycles we were unable to
      separate females in the later stages of yolk production into
      several years so what <&>15:00</&> i've shown here is the levels
      of <?>estrodiol</?> which is the sex hormone that stimulates
      yolk production and receptivity of mating <,> levels of
      progesterone <,> <unclear>word</unclear> which rises high at the
      time of ovulation and testosterone whose function is not
      entirely known but rises high at the time of mating and probably
      also associated with sexual receptivity possibly inhibits the
      <.>completi</.> er stimulates the completion of the yolking
      phase and may contribute to oviduct hypertrophy as well so the
      important thing to note here is that levels of all of these
      hormones are high if the female is ovulating at the beginning of
      the year but not so high if the female is not ovulating
      <&>15:48</&>
</I>
