Mineral and energy contributions of egg of elected species

(1)

S. Afr. J. Antarct. Res .. Vol 8 .. 1978 75

Mineral and energy contributions of egg of elected species of seabirds to the Marion Island terrestrial ecosystem

.R. iccrfried, A.J. William , A. •. Burger and A. Berruti Percy Fitz. Pa tric k ln ' tilute of African rnith ol gy

ni v r it r Cape own, Rond eb c h 7700.

Tlte p11per repurts the re.mlt.1 of preli111i11ary wor/.. l(J de1ermilw 1/ie a11w1111ts of' energy a11d sclec1ed 111i11eral c/e111e111s comnined in 1he ei:g deposired by the a1111ual breeding pop11/a1io11s of selatl.!cl specie.\ o/'seabirds al Marion Island. These· pup11/a1ion.1 togeth<'r campl'ise mort> 1hw1 1.5 111illio11 hird~. mu/ ,here lire indications !hat 1hey co111ri{11//l' . ig11ijica11//y ^/0hiogrochemital

;wocesse.l' al Marion ls/c111d. The sp('fies are: l..i11g pe11,,!lll11. p1enod Les patagonicus: J.f('ll/oo pe11g11i11 . .Pyg . c Ii· papua:

111arnro11i pe11g11i11. ::udypte chrysolophw: rocJ..hoppa p<•11- g11i11. • chrysocome; wm1cleri11g albatross, Diomedea exul,tns;

,rrcy-hea led alhutross. D. hry ·ostoma: su111y alba11·uss.

Phoeb tria fu ca: lhd11-11w111/"d .1ooty alluar,,ss. P. palpebrntn:

1wr1/w,·11 Kia111 rwtrd, acr nc tc halli: w111/w1·11 Kiani f1<'/l'(^{1/ .}

M. gignntcu : i/1/fll'l'ia! cun111l'm11, Phal11crocora al bi enter:

sub· 1111,rcli<' t.110. atharacta ant,Hctica; a11d t.clp g11/f, Lams dominicanu~. Tow/ ""1111al 11.i:K pmd11ctifl11 (/ J 15 689 rggs). i11 1em1. of jrl'sl, /1io111as , i.l' alu1111 205 1. deposi1,•d mainly d11ri111< 011('111ber-Jm111ary. Aho111 JO~ /.;.J u/ e1wrgy is co111"i11etl in rhe 101al n11111/wr of' egg·. /11/or11w1itm i., {!ire11 1111 the m·erng,• co11n•111rmio11.~ o/ 111icro (C11. r. Z11. ·t1. \!11) mu/

111acm ( 'a. J\t/g. P, K, Na, N) minaaf ele1111'1//.1 ho1111d 11/1 i11 the ('g)!.I'.

Introduction

Omith logical sludies wen; carried out on arion lsla11d (46 4 · •• 37 -I • • l. in the southern I ntlian Ocean. a~ part of the 1973-197 rn gramme f cicntilic re carcl1 pon ored by the S uth frican cicmific Commiucc r r nwrctic Research. The primar. purpose of the 01'nithologic:il work is

LO determine the role ol' marine bird\ in th transfer

or

nutricnb from the open ·ca to the terre trial eco-,y·tem on ari n l~IJnd ( icgfried, 197 ).

The rm.: ent r,aper repl n~ the n.: ul~ 01· prclimim11·y

~tudie of the am unt,; of energy and. elected mineral elemenl't contained in the cg-' dep )~itcd b} the annual breeJini.:

populati< 11s of :elected pecics 01· eabirds on Mnrion lsl.'.111d.

'he e p pulation l gether c mprise m re than 1.5 millitln bird . and there urc indication that they c ntribute ignili- cantly tn biogeochcmical procc e on ation Island ( rcg·

fried. 1978). The species arc: king penguin. /lp1e11or(1·1e.1· patag1111i uc genlo penguin. P_,,K111n•/is pap11a: macar )11i penguin. Emfrptl'.1 c/1r_1:wf11p/111,: ro ·J..hopr,er penguin. /:..

lrrys11co111,,,; \ a ndcri ng a Iba t ro. s. Diomt·tlea , .. rnlw1.I': g:rc - headed ,tlbatrn s. D. c/11y.m.,11111w: so Hy albalrO~:... /¹/weh,•1ri11 /11sca: lh!hL-manth.:d . ty albatr ,s. I'. palpehmw: n ,nhcrn giam rctrel. Ma rmwc1e.,· Im/Ii: southern giant petrel. \/.

xigm,1<•11.1; imperial ,;ub- nwrctic ·kua, Lei rus do mi II i cm 1111.

o rmu ra 11 t, Plwfacrocora.r a/hi ,·eult•r; nllwmcta a11tarc1im: and kelp gu II,

Thi~ li~t reprc ·ms llf the 16 diurnall~ -acti e .. urf.tt:1,;- nes,i11g species fourtd on ariun Island, the utl\er_ being th ntar tic l rn, term, 1·i11C1ta the ergudcn tern,

rirgulil. and the I s~cr heathbill. hio11i, 111i11or. he l-,recding populauon of both te , · amou111 to fewer Lhan

·o

pair (Berl'llti & Harri~. 1976; illi.-tms el u!. 1979). The breeding popul,llion of the le·ser ·hcathbill ompri·e· 9 0 pairs (\ illiam. t>t al. 1979). but the e binb Lake \'Cf_ liule fo d direct) from th marine environmelll (Burger. 197 ). The balance of the known breeding avifouna on M:1rion I land on~ ist. of 10 p cic of ~mall petrel. (Procellariidae and .Pelet·an ididae) which ne. t undergr und and are mainl nocturnally acli c (Williams e1 al. 1979); they were not include I in the r ~carch programme durtng 197 -1978.

Methods and Material

ensu~es of the populations

or

^se^lêctedâvian ^pecie~âtÎ^he

Prince !ward i~l,rnds were made during January 1974- June 1975 (Williams el 1/. 197") and again during ;.\pril

1976- a 1977 (William. t'I al. 1979). All bre ding bird· were counted by ob·er\'er, who covered tl1e c:oa tal lowland and part. of the interior

or

Marion 1:-land on root. ddition- all . all larg ol nic of penguin.· were ph I graphed from a liclico1 ter. c1·ial photogrnph. were of gr·eat value in checking count· mude on the ground of colomes of penguin,, and in ccn u ing colonie of bird. in i olated and extreme!

rugg d parts of the islaml. The distribution or the brc ding populalion of cuch species , us plollcd on a I km' grid-map of the island ( Fig. I). I IOI ever, the cen~u~ data arc not ah,ays a uratc. ince estimate, rather than head count., of the numbers oi" birdi; were mad in some ca ·cs. unher commentary t,n the limit.1Lion.

or

the c:cn u. es

o r

some

or

the breeding population is included in ppendix I. Through ut thi, paper the term ·breedin • population· refer. to the curr nt annual breeding population. that is, the population breedi11g in :in} one year during 1974-1977. in e several ~pccies, such

~ thc !..in~ penguin. wandering albalros:. unu probabl) th~

other alhatro·~ s JS well, breed 0111 in altcrn~te )'ears if su;;;1:cs~ru1. l11for111atio11 on Lime of egg laying. clutch ~ize, egg monalit. and lo-s. and ulhcr a p ct

r

rcproducti perfmnancc, ,,ere g,uhered b clo'cly monitoring a range of

ub-p 1plilation.~

or

ind.ii idual ·peci s ( illiam · el al. 197 . However. the monitoring or egg mortality \ as not always fully repre entati'vc nor llmplete. and in ·uch cu.es we hav1:

relied ¹¹¹ uppl •mentary infom1ation taken fr m . ur ·c~

whicl1 arc identilicu where appropriate in Appendi, I. A111011g the I} :pecies 1.:011. ider..:d here, u11ly the king and gentoo penguin,;, imperial ormorant uh- ntar ti <ikua and k Ip gull are capable or laying replacement lutd1 ;;.

Fresh. clean egg .. takc11 \ ithin 48 hours of l11yi11g. were deep-frozen \ ithin four h 1urs after removal from the licld.

·ontamination and Jo· of albumen \1as a,oidcd b tightl.

wr..ipping a ·h egg scparatdy in a pol thylcnc bag. In the labOl'at 1ry. each egg wa~ wasl1ed in .listillcd wHler bef re being ~cparated whilst till ~emi-fro1 'n into ·hell and m m-

(2)

76

brane , albume11 and yolk. Th omponent part. of each egg were weighed while till wet. and were then ven-dried at 60 until n.stant ma wa achie ed. itrogen and. protein analy c of dried _ olk and albumen were arried UL u i.ng the Kjcldahl procedure ( r dLinski er al. 197 ). nergy value were determined for yolk and albumen separate! . using a allenkamp ballistic bomb calorimeter. The l'ollowing mineral elemental concentrations of egg content· and shell were dctermined by means fa arian Techtron A;\-6 at mic ab'orpli n pectrophotomcter. using acetylene fu,J and flame pectro p (Pringle e, al. 196 ), and after treating the organi material as described by Watling Watling ( 1975):

copper, m ngane ·e, zi11 , adm.ium, sodiL1m, p tas ium.

magne ium, and strontium. T tal calcitLrn wa · determined by DTA titratfon using ri hrome Black T indicator (Vogel, 1939). The component part of eggs were analysed for total pho,ph ru by the stann u. chloride procedure (Tar, et al.

1971 . II average concentrati ns of mineral element nl an average of three arnples, and each. ample con i ted f a compo il f al lea ·t three egg~ f r each specie , with the exception of the light-mantled soot albatross, for which only one egg wa analy ed.

S. Afr. T. Antarkt. Nav., Deel 8. 1978

Result

Br eding population and egg production

1or than 99 per cent f the combined breeding populations ( I 246 bird. ) f I he 13 pecie included here ne tin , J km-wiclt: strip of land al ng the coastline. oncentrati11g in the north-eastern sector

or

Marion I land (Table I).

The t pography and geology ol' this ide of! he i land provide opp rtun1t1e for the formali n f extra-large ol nies of breeding nguin Williams. 1978). The four penguin pecie.

t albalro s a11d rhe imperial cormorant n l almo·t ex It i el with.in I km

r

the c · tline. M 't f the king and ma or ni penguin are c nc ntrared in a fe er large colonic , wherea th rockhopper penguins tend to be dispersed along Lhe ntire c astline. Nesting albatrosses, giant

petrel.. skm1s and ⁰ull all penetrate farther inland than the penguin.. mong the I pe ie co,rid red here. only the light-mantled ooty albatr n l farther than km inland fr m 1he oasl fig. I •

The k.ing and the macar ni p nguin' r pe tivcl account ror 2 and 59 per cent of the wtal number or individual and 52 nnd 42 per cent

or

the total fresh biomass (9 910 t), of the

2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25

A B C D E F G H

J

I(

L M N 0 p Q R

0 1 2 3 4 5 .

Kilometres

ig. 1. Breeding distributi n of ea bird ( pccie Ii tcd in Tabl I) n 1ari n T land. Light-mantled o!y alba!r c n tin the quadrat indicated by a . alhatro e , giant p,:trcl . sub- ntar ·ti kua and kelp gull in 1hc quadrat marked b an , and penguins. alba1ro. sc:. giant pe1rel , i ^11pcrialcormornn . uh- nrnr 1ic ua and kelp gulls in the oliul} haded area.

he limil of the coa tal J)l:tteau (150 m above wa le el) i marked b ¹¹broken line.

(3)

S. Afr. J. Antarct. Res., Vol. 8., 1978

13 avian breeding populations con idered here. It should be noted that th_i biomass is concentrated in the island' coastal lowland which covers about I 00 km°.

Annual production of eggs by the king and macaroni -penguins together constitutes 85 per cent by number and 90 per cent by mass (dry weight) of the total egg product ion of the 13 species (Table 2). Total annual egg production, in terms of fresh biomass, amounts to about 205 t. which is 2 per cent of the total fresh biomass of the breeding bird . About 94 per cent of the annual egg production. (61,83 t dry weight of fresh eggs) i deposited during Nove111ber- January, in the austral summer Table 3). About 86 per cent of the total annual egg production is deposited. in a combined area of 90 ha. Tlfr; area encornpa ses the major nesting colonies of the king and macaroTli penguins. -lse- where around the island. however, egg production is pread relatively evenly. lf the contributions of the king pengllins and the two largest colonies (L ::!4 and Q 22, Appendix I) of the macaroni pengu irr are ignored, then a total of I l ,47 t (dry weight) of eggs is deposited annually in a 3 km-~ ide area embracing the coastal lowland of Marion lslarrd. This may be converted to an inpllt of 1,15 kg (dr weight eggs) ha-• yr ', as uming an even spread of eggs over the island' 100 km" coastal. lowland. Less than 0,01 per cent of Lhe total egg production is: deposited fartl1er inland than 3 km from the sea.

Energy and mineral contributions of eggs

More than 10' kJ of energy is contained in the total num bcr (I 315 689) of eggs considered here (Table 2 and Appe11dix 2). YoU11g bi.rds hatch from about 43 per cent of the lot,d number of eggs: the balance is made up of failed (inl'ertilc, etc.) and/or lost eggs (Table 2). Potentially. l11cse failed eggs are available as an increment to the f1ow of e11crgy and cycling of mineral. in the ecosystem of the island, as are also the energy (a negligible amourrt) and minerals bound up in the shell of all eggs laid on the island. Combining the mass of the hells of all egg laid, and the mas of the contents of those eg~ which do not give rise to hatched young, resuJts in a. sum of 42.20 t (dry weight) for the total annual increment of egg material (Table -).

Information on the average concentrations of micro Cu, Sr Zn. Cd. n) and macro (Ca, Mg, P, K, a, N) mineral elements bound up in eggs i given in Appendices 3 and 4.

These data ·ets can be used, in a sociation with others. in Appendi - I, to arrive at temporal (monthly) and spatial estimate of the amounts of mineral elements contained in the populations of eggs of individual species of seabird on arion ]sland. It suffices here to summarLe the total annual increments of mineral elements contributed by the eggs of 12 species of urfacc-nesting seabirds to the ecosystem at Marion Island (Table 4). As might be expected, calcium predominates (8 273 kg) among the mineral elements, but substantial quantities of nitrogen and pho. phorus, too, are potentially available for iiicorporation into the island's bio- geochemical cycles of nutrients.

Discussion

There is relatively little pL1bli. hed information dealing with comprehensive and ,1ccurate censuses of whole breeding populations of seabird inhabiting oceanic islands in the ub- Antarctic (Williams el al. 1979). There is even !es information on the amounts of e1iC1'gY and mi,1eral ele111C1i!.al c-on- centrations in the egg of pelagic eabirds. Our data, while

"'

1l

E _::,

C

"

..r::.

v C

"

,.,-

c 0 N

' -0

>.

u C

"'

^0._::,

<J

0 u

N N

N 00 0

'-D M

ONO'S!' O N ' S t ' - D ' S ! ' O v t-Lri(".l r- - 1noo - O!"'";•n

IJ"iOO'I

°'

^{r - - -}

N 'S!' f'", r--

O N

N'St ^N

o o o o o o o v v v v N O oo a,., 0 \ 0 0 0 f " . I 00 oo r-- (',1.00 t-. l.r'l \.O

o--,~\O -co

r-1 lr'J 00 ""1"

"d" ("11r\

0

,..,

⁰^v ^v^O'. ⁰⁰⁰ ^ST^N

" ' N

f'".IVO"Q"co "..cONOOOOl,,0,0

"-O("'-..l lf'lt"- 00 - ~Ml,,,,0 ... - l r l

V)O-t-r---V'I 00 - r-r-iC"l-

•n - - t n

00 ~ 1""""1

00

r,.1 0 0 "Cl

" ' 'I")

'°

0 co

'-D<>OCOOsO 0 0 1 . C O s O I O , : t -o-..r-10-,.i.r, 0 - 0 0 0 - 0 0 0 00 1!"'"', 0 0 0 "Q"

N 00

0 N

"'

0

V, ,-

N

N ,-

71

er,

"'

0

<J

o E

~

g

M

~ ~

M C

-5 d

..,

0 E

"O C

!::

C

(4)

78 S. Afr . . Antarkl. N v .• Deel 8. 1978

Table 2

umber and m~. 0-.i! dry wcighl) of ,:gg d·p . itcd annually by 13 ·p::cie~ of :eahircb on 1ari 11 I land.

Ma

or

^onknh

Ma·

r

^~fa~~^(lf o. egg~ I ,t

or

egg, los1

1 o. egg., laitl egg,, laid egg hell and or failing _{and or}failing 10 hatch

t(l hat h

King penguin 21 234 22 263 331 76 X3Y 4 973

Gentoo penguin

.x

^I^I^, ^.t) X9J -0

lacaroni penguin 899 784 33 588 12 444 570 0...2 12 0, 7

Rockhopper penguin 186 72 9, I 855 1-3 967 I 996

\ andcring albatross I 85- ^_70 ⁷⁰ ⁵⁶ ⁶⁰

,rcy-hcmied albatross J 370 274 71 I 40 92

ooty albatros· 2 OJ2 145 J6 709

: 11

Ligh1-mani led 001y albalros, 17(, IJ ^] 54 .l

orthcrn giant petrel 20/i 15 4 -17 2

Southern gian1 petrel I . ."\7 IO(i 30 J52 20

I mpcri.al cormorant 711) 8 J _7 I

Sub-Antarctic skua 791 24 ^(, 122 2

Kelp gull 33 8 I 66

I .ll 6, 9 61, 6 22 9(n 775 45:\ 19 00

Tnblc J

la~ (l,.g dr) 11eigh1) uf egg dcp 1,i1c I c:, ·h mllnlh h} IJ ,p..::ic, of ·e:.ibird, 0:1 t\l:Lri n hlan

Jan. I-ch. pr.-t\la) June Jul. ug. cpl. Oci. ^{) \}^, De .

King penguin Gcntoo renguin

1acaroni penguin Rockhopper penguin

:I J.l9

\J andcring albatross 111 Grcy-hendcd albatro,· Snoty albatro,s Ligh1-man1 led 001y

nlbatross

Northern giant petrel Southt:l'n giant petrel

I mpcrial c·ormorant Sub-Antan.:li'.: ·kua Kelp gull

J -1. I

Table -I 90

890

Toial amount of encrg} 11...J) and miner.ti ckmcnh ( 1,.g) con wined in the annual population~ or cggi, or 12 IX'Cie of ,cub1rd, t~c·

1 pcndi, J) l1" ~la.non !,land

0111ent of C!J.!J.> lotal eggs laill lo,t and or

failing 10 hat ·h

nerg) Negligible 48J 10" .t. J 10'

u 0.098 0.0.56 0.15-1

d 0.()()7 _U.010 0.017

Zn 0.062 ^{(),$I ..} ().877

Mn 0.054 U.02.l 0.077

Sr 9.147 0.29.1 9.440

Mg 41.20 IU09 -19,706

K 16.49 I IJ,06 129. ·5

a 35.80 l,U.I~ -17,97

Ca 8 191,05 81.73 N 173,7,

p 78.~7 115.76 l\l-1,1

N 290.7] I 514.97 I 80 .71

4.X 77 .. 1-t· 10.(, 11

l 56.,

275

145 1.1 15 . .l

80.8 25.1 I.:!

J,7

-+ 8 77 ... 91.-1 OJN

4 452

61 _J~

c,1.1 I H

(,,.1 _(),5

70 545 IJ 35

315

1,0 (l.3 8,1 1.l Ii, J

1101 )Cl ·omplete for all the pccics on .irion l~land. are the mo l comprchcn i1e .et published for penguin anu albatro sc .

We are unable ro prm idc dcfinith c c,plamllion. for the differen ' apparent in th clement.ti 1:ompo,itinn f eggi of t.lilTerent peci '. omc of the peculiarities ma) be ons - quences or imilar ph_ siol gical run ticll1 r m1trienl uptake of taxonomical! allied pe ic·: I" r in. t,111ce. the rdati ely high concentration or pho ·phoru · in th egl! . hell. of penguins. Tn any event .. corr lation between c n cntration of difli rent elemems in plant ar·c known LO c,d'i. and thee a. sociaiic n. are importanl in Iran. J'cr procc· ·cs \ ithin 111incral cycles in ecosy tern (Garlcn, 1976).

ll is difficult to ay how impmtant tl1e birds· contribuiions of nutrients might be for primary production. :ii Marion Island. until more i_ known about con ntr,ttions, standing crop and n:cycling rates of mineral in the urg,rnic ·oils and in the li sue or plants on lhe i land. It cl e .• howc er, a1 pear that ccrttlin inorganic nulri n dcmc11 , hich arc pr cnt in

(5)

S. Afr. J. Antarct. Res., Vol. 8., 1978

relatively high quantities in the eggs of seabirds, are present at very low levels in the island's standing water, soils and plants (cf. Smith, 1976). Although the total annual quantity of mineral nutrients potentially derived from the eggs of pelagic seabirds is relatively high on Marion Island, we suspect that much of it is not available to plants in the terrestrial ecosystem.

Eight of the 13 species of seabirds considered here are colonial breeders, and thus may alter significantly the mineral status of localized areas and produce marginal effects else- where. It seems likely that a considerable proportion of the avian mineral products is returned to the sea by leaching into the intertidal zone. Parts of the large colonies of king and macaroni penguins are located on bare, muddy areas which slope directly into the sea. Conceivably, the eggs of these species might be a smaller source of potential nutrients for plants of the terrestrial ecosystem than the much smaller populations of eggs of the gentoo penguins and the albatrosses, which tend to be spread more evenly on higher, better-vegetated ground. However, sub-Antarctic skuas and lesser sheathbills are potentially important as secondary distributors of minerals derived from penguins' eggs.

Finally, we are aware of some of the shortcomings of our methods and results. Larger samples of eggs would have helped to strengthen the validity of the biochemical data, but Marion Island is a nature reserve and the collection of biological specimens is restricted. We know that the elemental concentrations in the eggs of a species can vary, and we suspect that embryonic seabirds behave similarly to the embryonic fowl, Gallus ga/fus, which uses about 5 per cent of the calcium of the shell for skeletal development (Simkiss, 1967). These and other potential variables lead to the con- clusion that our results, at best, represent estimates of the amounts of energy and minerals containeclin the populations of eggs of selected seabirds breeding at Marion Island. We regard these estimates as conservative first approximations.

Acknowledgements

Scientific research at the Prince Edward islands is carried out under the auspices of the South African Scientific Com- mittee for Antarctic Research. Financial and logistical sup- port is provided by the South African Department of Trans- port. We thank K.C. Davies, S.K. Frost, T. Harcus, G.M.

Crouse, L.D. Cwati, L.F. Mansfield, H.G. Robertson and G.A. Eagle for their help.

References

Barrat, A. Quelques aspects de la biologie et de l'ecologie de manchot royal (Aptenodytes patagonicus) des iles Crozet.

CNF RA, 40, 9-52, 1976.

Berruti, A. & Harris, A. Breeding schedules of Antarctic and Kerguelen terns at Marion Island. Notornis, 23, 243-245, 1976.

Burger, A.E. Terrestrial invertebrates: a food resource for birds at Marion Island. S. Afr. J. Antarct. Res., 8, 86-98, 1978.

Garten, C.T. Correlations between concentrations of elements in plants. Npture, 261, 686-688, 1976.

Grodzinski, W., Klekowski, R.Z. & Duncan, A. Methods for Ecological Energetics, IBP Handbook No. 24. Oxford, Blackwell, 1975.

Pringle, B.H., Hissong, D.E., Katz, B. & Mulawka, S. Trace metal accumulation by estuarine molluscs. J. sanit. Engng, Div.

Am. Soc. Civ. Engn., 94, 455-475, 1968.

Richdale, L.E. A Populalion Sludy of Penguins. London, Oxford University Press, J 957.

Siegfried, W.R. Ornithological research at the Prince Edward islands: a review of progress. S. Afr. J. Antarct. Res., 8, 29-33,

79 1978.

Simkiss, K. Calcium in Reproductive Physiology. New York, Reinhold, 1967.

Smith, V.R. Standing crop and nutrient status of Marion Island (sub-Antarctic) vegetation. J. S. Afr. Bot., 42, 231-263, 1976.

Taras, M.J., Greenberg, A.E., Roak, R.D. & Rand, M.C. Standard Methods for the Examination of Water and Waste Water. Wash- ington, D.C. American Public Health Ass., 1971.

Tickell, W.L.N. & Pinder, R. Breeding biology of the black-browed albatross Diomedea me/anophris and grey-headed albatross D.

chrysostonia at Bird Island, South Georgia. Ibis., 117, 433-451, 1975.

Vogel, A.I. A Textbook of Quantitative Inorganic Analysis. London, Longmans, 1939.

Watling, H.R. & Watling, R.J. Preliminary preparation of molluscs for trace metal analysis. FIS Special Rep., 76, CSIR, Pretoria, 1975

Williams, A.J. Geology ar:d the distribution of Macaroni Penguins at Marion Island. Polar Record, 19, 279-281, 1978.

Williams, A.J., Burger, A.E., Berruti, A. & Siegfried, W.R. Ornitho- logical re~earch on Marion Island 1974-75. S. Afr. J. Antarct.

Res., 5, 48-50, 1975.

Williams, A.J., Siegfried, W.R., Burger, A.E. & Berruti, A. The Prince Edward islands: a sanctuary for seabirds in the Southern Ocean. Biol. Conserv., 15, 59-71, 1979.

APPENDIX 1

Demographic data for selected species of seabirds breeding at Marion Island.

KING PENGUIN Aptenodytes patagonicus

Aerial photographs were taken in March when the annual moult was over, leaving only breeding birds in the colonies. Spatial plotting of the colonies is accurate, since each colony is discrete.

Data on the timing of egg-laying are based on estimates only. No data exist for the proportion of second-egg layings by failed breeders. The few breeding attempts which are made by isolated pairs at beaches normally only used as moulting sites have been ignored.

Mass of breeding bird Breeding population Clutch size

12,0 kg (fresh weight) 215 234 pairs 1 egg Mean mass (g wet weight) of fresh

egg ·' 325,0 (S.D. = ±31,4; n=98)

Mean mass (g dry weight) of egg shell 38,71 (S.D.= ±2,90; n=11) Mean mass (g dry weight) of contents

of egg 64,73 (S.D.= ±10,85; n=11)

Egg mortality 35,7 % (Barrat, 1976) No. eggs laid per month

J F M

32 285 8 609 2 152 Census

No.

Grid breeding reference pairs

B16 14 702

C17 78 835

CJ8 7 871

D20 9 581

125 3 000

023 200

Q21 80000

Q10 21 045

215 234 .

A-0 N

43 047 D 129 140

No. eggs No. eggs lost or

laid failed 14 702 5 249 78 835 28 144 7 871 2 810 9 581 3 420 3 000 1 071

200 71

80000 28 560 21 045 7 513 215 234 76 838

Total 215 234

No. eggs hatched 9 453 50 691 5 061 6 161 1 929 129 51 440 13 532 138 396

(6)

80

GENTOO PENGUIN Pygoscelis papua

Data on egg mortality are not available. Consequently, we have used Richdale's (1957) estimate of 22 per cent for the yellow-eyed penguin, Megadyptes antipodes, since this species has a breeding regime similar to that of P. papua. However, our observations indicate that mortality is higher for replacement clutches, and we have used a 50 per cent mortality for these. It is assumed that all first clutches lost are replaced.

6,0 kg (fresh weight) 1 345 pairs

2 eggs Mean mass (g wet weight) of fresh

egg 125,4 (S.D.= ±21,5; n=46)

13,34 (S.D.=±1,29; n=8) 22,63 (S.D. = ±1,63; n=8) See above

Mean mass (g dry weight) of egg shell

Mean mass (g dry weight) of contents of egg

Egg mortality

No eggs laid per month

J-M J J A

164 2 099 394

Census

No.

Grid breeding

reference pairs

A9 32

B13 78*

B16 33

C18 56

D19 95

D20 69

E21 72

F22 64

H23 208

124 17

J25 213

K25 129

L24 71

M24 71

N23 28

R21 20*

Ql4 54

J2 35

1 345

*Estimate only.

s

322

No. eggs laid

78 190 81 138 232 168 176 156 508 42 520 315 173 173 68 49 132 86 3 285

0 N-D

289

No. eggs lost or

failed 21 51 23 38 63 45 48 42 138 12 141 86 47 47 18 14 36 23 893

MACARONI PENGUIN Eudyptes chrysolophus

Total 3 285

No. eggs hatched

57 139 58 100 169 123 128 114 370 30 379 229 126 126 50 35 96 63 2 392

Aerial photographs were taken in March, when all breeders were back at their breeding colonies for moulting.

Mass of breeding bird 4,6 kg (fresh weight) Breeding population 449 892 pairs

Clutch size 2 eggs, the second (B egg) is markedly larger than the first (A egg)

Mean mass (g wet weight) of fresh

egg (A)

(B)

Mean mass (g dry weight) of egg

shell (A)

(B)

Mean mass (g dry weight) of contents of egg (A)

(B)

98,5 (S.D.=±10,4; n=l25) 156,2 (S.D.= ±13,0; n=127) 9,96 (S.D.=±l,42; n=8) 17,70 (S.D.= ±1,93; n=9) 19,50 (S.D.=±1,93; n=8) 27,50 (S.D.= ±1,80; n=8)

S. Afr. T. Antarkt. Nav., Deel 8. 1978 Egg mortality (A)

(B) No. eggs laid per month

J-S 0

99,7% 27,0%

N D

62 985 836 799

Total 899 784

Grid reference B12 Cl8 D21 E21 F22 123 124 125 J25 L24 M23 023 P23 Q21 Q22 R20 Ql7 QIO Q8 Ml J2 F6

No. No. eggs laid breeding. _ __ _ _ _

pairs A B

1 1

10 10 10

35 35 35

750 750 750

40 40 40

50 50 50

1 710 1 710 1 710

300 300 300

400 400 400

209 280 209 280 209 280 1 190 1 190 1190

820 820 820

3 480 3 480 3 480

390 390 390

202 430 202 430 202 430

30 30 30

700 700 700

7 000 7 000 7 000 5 000 5 000 5 000 7 945 7 945 7 945 7 571 7 571 7 571

760 760 760

No. eggs lost or failed

No. eggs hatched A

1 10 35 748 40 50 1 705 299 379 208 660 1 190 818 3 470 389 201 826 30 698 6 980 4 990 7 925 7 548 758

B

0 3 9

A 0 0 0 2 0 0

B 1 7 26 548 29 36 202

11 14 462 81

5 1 248

108 1

56 506 628 152

321 4

220 2

940 10

105 1

54 656 609 147

8 0

189 2

219 292 774 869 599 2 540 285 774 22 511 1 890

1 350 2 145 2 044

21 5 110 5 3 650 24 5 800 23 5 527

205 2 555

449 892 449 892 449 892 448 552 121 470 1 340 328 422

ROCKHOPPER PENGUIN Eudyptes chrysocome

Accurate counts of breeding rockhopper penguins were obtained in only a few small areas. Census-taking was difficult owing to the extensive distribution of the species and its habit of nesting in hollows amongst boulders. The entire coastline of the island was covered on foot during January and February, and our survey made then probably included 75 per cent of the breeding population.

Mass of breeding bird 2, 7 kg (fresh weight) Breeding population 93 286 pairs

Clutch size 2 eggs, the second (B egg) is markedly larger than the first (A egg)

egg (A)

(B)

76,0 (S.D. = ± 7,0; n= 121) 109,1 (S.D.=±8,1; n=118) Mean mass (g dry weight) of egg

shell (A)

(B) Mean mass (g dry weight) of contents of egg (A)

(B) Egg mortality (A) (B) No. eggs laid per month

J-0 N

176 311

8,74 (S.D.= ±1,02; n=ll) l 1,15 (S.D.= ±1,28; n=8) 14,00 (S.D.=±1,78; n=ll) 19,59 (S.D.= ±2,24; n=8) 82,90%

50,04% D 10 261

Total 186 572

(7)

S. Afr. J. Antarct. Res., Vol. B., 1978

en u

Grid referenc·

E21 22 F22 22 23 H2 1.2 124 125 J2

K2 L24 M24 M23 23 2J P23 P22 022

21 R21 R20 RI

B7 88 8

9 10 II 12 IJ BIJ BIS 816 B17 18 Cl9 D20 D21 RI, Q17 QJ6 QI

Ql4 RIJ Rl2 R II RI() QJO Q9 R Q8

07

R7 R6 R5 R4

4

Q

o.

breedin pair

361

'61

361 121 314 10.

14 314 174 I _15 I_()() I 2 730 730 46 I 37 2 I 2

714 15 587

7 701 702 128

(,4 114 II 57- 229 345 361 1, 420 420 I 508 2 850 5 386 592 483

• 465 94 t\

s·s

I 750 J 750

I 750 I 00 I 500 3900 J 000 450 750 I 500 450 J 200 750 20, 208 :W,

_o,

343 43

No. eggs laid

B

3 I 361 361 361 361 361 121 121 31-1 31-1 105 JO JI 314 JI 314 _74 274 I _I I 215 I 200 J 200 I 2 I - 730 730 730 730

46 46

I J78 I 37 2 142 2 142

714 71-1 158 15 587 587 587 587 701 701 7( 2 702 1_8 12 446 446

M 114 114 1!5 115

572 72

22 2 9

345 34.

3(11 361

I 18

420 -120 420 4_0 I 508 I 508 2 850 2 850

,5 31!6 386 592 ·92 4 J -I J 346 . 465 945 9-15 6, 55 1

ro

I 750 I 750 I 500 I 50Cl I 500 J

·oo

900 J 900 J 000 .HJOO 450 4 0 750 750 I 500 I 500

-1:0 I 200 750 20 208 20 208 343 34

29 I I 299 I C) 299 181

JOO 60 260 157

7 52

260 157 -60 1 ·7 227 137 I 007 607 995 600 151 91 60. 65 605 365 701 423 I 142 C..'19 I 776 l 071

·92 J57

IJ[ 9

87 294 4, 7 _94

·1-11 J 0 8! . 51

100

r,-t

3 0 _3

5 J2

5 57

!>" 7

474 21<6 190 114 2 6 172 299 l 'O I 6 9-1 34, 210

34 _JO

I 2 0 754 2 363 I 42

73 4-12 320 19) 491 29(, 400 241 _ 872 I 732 7 ·' 472 S 6 .1 H27 I 4"1 7.

I 451 875 I 451 75 , _-1-l

ro

I 244 750 J 23.1 I 950 2 4 7 l 500 . 7J '.L5 622 J75

1-44 70

173 _15 995 600 622 .175 I 2 l().l 172 [04 172 104 )7_ 104 _84 171 2 4 171

Nu. egg.

hatched

A B

6_ ISO 62 I I 62 180

21 61

·4 157 J 54 157 54 157

4 I 7

208 608 -05 60() JI 91 125 .165

,_s

³⁶⁵

14 -LJ 2J6 6 9 366 J 071 122 • 57

'27 79 100 294 100 294 120 3 I 1_1 351

22 64

76 · _23

I I 2

19 57

20 5

' ' 286 39 115 59 173

<i2 J I

32 94

n _,o

7_ 210 2

·s

7.4 41!7 I 425 151 4-1.'1 66 193 JUI 296 J 24- 59J I 7 •• ,

162 47J I 172

299 299 299 2 "

25(.

667 13

77 2_

I S 375 2·<i TO 77 22.

205 6 0

,_, ns

J(l 104 .6 104 36 104 36 104 9 172 59 17

Q2 P2 l'I.

01

[ I

LI 2 K2 J2

,_

H2 HJ 4

·4 F"

F6

6 7 915 I 016 I 016 _ I 5 2 175 2 796 2 796

• 91 81!5 10 I 6 8 2 94' I 71 I O 7

no

6 7J5

7 6 7 I 915 I 016 I 016 I 016 1 Ol<i - 17. 17 2175 2175 2 796 2 7 fi 2 96 _ 796 5 59 L 5 9 l S85 8K5 10 I 6 8 2 94

I 71 () IO 7 720 720 6 735 6 73.·

570 J43 759 457 1'!42 .08

!l42 50, J 'OJ I 0-17 I 803 I 087 2 JI, I J 2 .lie I. 9 46J5 2795

734 4--12 671 40:

I .\99 .,t 2444 1474

141 T

901 ·.n

597 360 5 . 8J J J67

81

117 344 1-6 -158 17.J 08 174 .50 H2 I 0, 7 J7'.! I 088 47, I 39 478 I J9c' 956 2 795

!51 442 139 405

289 4~

504 I 474 292 .5·

l!l!l 5,H 123 '60 I I - J 36

J 286 3 2 6 9J 2 6 77 334 -16 633 I 9.52 -16 653

LB TROS. Diomedea e.\/1/an, n accura1c and ·omplct

con picuous bird. la·~ 1 f breeuing t ird Breeding popul:Hie1n

·1u1ch ·izc

Mean ma~~ (, 1wt 11cight of fnd1

9,0 J..g (fre.,h weight) I c52 p;11r·

I !/.'

egg 50 .J ( .D. 1 -10,6: n 6 J

lean ma,, (g dry 1H·igh1J of egg

,h•II .1 .19 .D. 5,67; 11 • l

Mean ma , (g dr·:- weight) llf content~ f egg

gg mortality

1 • egg· luid per 111011111

J F-

76"

CfhU.

GriJ rcrercn e Q7

87 B8 U9 9

UIO 10

12 Bil BIJ Rl4 HJ5 Cl5 '16 17 B16 I, D17 DI.J D15

(),

hrcedtng pair..

5 5 4 24

12 I

5 8 65 13 64

(,:

2

~ .

J 1-1 8

...

29

(.

19 11

o. eggs laiJ

5

12

rx 5 8 65 D 6-1 52 65 . X 11.J

48 29 5,

I 19 JI

107.~6 ( .D. 6.91; 11- JJ 30,4 "u

ll.

egg, hht llf railed

2 '.!

7

2 20 -I 19 16 20 IX .15 _(i

I.

9 I,

5 6 3

o. egg, hatched

J J 17 6

JJ J (, 45 9 45

3(1

45 40 7t 59 JJ 20 -10 I

I}

8

(8)

82

D16 Q Q 4 Q p NI

2 L2 K2 J2 11 HJ H4

19 D19 01 D20 D21

21

·22 F21 F22

21 22 23 H22 H2 123 J 4 J24 J25 K1 24

K-

23 L24 12 23 P22 Q21 Q22

4 6 7 7 7 4 4 6 6 104 104

41 19 19

I

0 19 10 60

j_

5 6 I 10 24 10 13 6 I 15

4 17 9 10 24 I II 14 19 lJ 4

I 52

6 7 7 9

·4

·4 36 36 104 104 41 41 19 19 20 19 JO 60 12

6 4 I 10 24 10 I

6

3 IO 2

12 II

I

I 11

.I I 2 2 2 2 3 I II II 2 32 12 I

6

6 .19 17 1 0

I 7

2 2

5 12 3 7

4 6 3 1 2 1

3 4

5 5 6

3 25

5 72 2 29 _g 13 13 13 14 13 7 41 3

I 7 17 7 9 4 1J 10 24 12 27 7 17

1{) 13

3

1 2 7

GR Y·H D D 'BATR Diumedea chry ·os/01110

ra of breeding bird Breeding population Clutch ize

lean ma g wet weight of fresh egg

1can ma s (g dry wei hn o egg hell

1can rna!iS (g dry weight) of content~

r

egg

gg m r1ali1y

o. egg laid per m nih J.

22

J, 7 kg (frc h weight) ( ickc II

& Pinder, 1975 3 370 pair.

1 egg 7

.o ( .

(Tickell

i 14.2: 11 I 17) Pinder, 197 J 21,3 interpolation nly)

60,2 (intcrpolallon only) 4 • 7 ° 0 (Tickell & Pinder.

1975)

r -D tal

2 220

S. A r. T. Antarkt. Nav., Deel 8. 1978

rence PIO QIO Q9 Q8 Q Q6

pairs I 2 0 90 700 580 -100 20 3

.no

o. egg laid I 280 390 700 580 400 20 3 370

No.

eggs lot or failed

5 17 J20 26

9 I 540

o. egg hatched

69 212

0 l 217

II 1 830

0 T B TR Plioebetria f,ura

An accuraie and a complete censu of the e bird because ome n I on inacces i le lift: and c.annot frorn the land.

a· difficult, ob erved

la of breeding bird Breeding population Clutch ize

Mean mass (g wet weight of fresh

2,5 kg Tr h u·e1gh1) 2 032 pairs

l egg

egg 243, ( .D.- = 14,1; n-

Mcan ma, s (g dry weight) of egg

hell I .I .D.- J:J,I: 11- 3

enn ma s (g dry weight) of content of egg

Egg mortalit

. of eggs laid per month

J •. 0

2 032

Grid No.

reference

11

. ,

12 19 D20 021 21 -22 123 124 K2.

24 24 23 2J 2.1 P2 Rl8 PIO QlO Q QB Q7 Q6 P3 ,4

5 E6 6

breeding pairs•

100 100 25 10 15 JS 200 100 90 27 2 4 4 22 90 90 200 50 2 22 130 100 70 70 3·

140 30 30 210

o.eg laid JOO

10

2 100

90 27 2 4 4 22 90 90 2<X>

0 2 22 130 100 70 70 3 140

30 30 220

53,_7 (S.D. · 2, I· 11

5,0%

-D Total

l2 70

2 9

32 32 70 18 1 8 46 3 2 25 12 49 II II 77

709 pecifi.ed.

2 0 2

o. egg hatched

14

14 4 6 45 45 23 9) 19 10 143 I 04

(9)

S Afr. J. Antarct. Res., Vol. 8., 1978

LIGHT-MANTL D SOOT ALBATROSS Phoebe1ria palpebra/a

The problems encountere.d 111 censusing oot albatrosses also apply to P. palpebrata

2,8 kg (fre h weight 176 pair

I egg Mean mass (g wet weight) of fresh

egg 258,2 (S.D . ...±:15,J: 11= 1·0)

hell 19.31

Mean 111a s (g dry weight) of content. of egg

Egg mortality

o. egg. laid per month

Cen us

Grid reference

HIS JJ9 H23 J2.l M2J M24 .P22 OJ

17 16 Q14 Q15 Q.16 Q7 Q8 Q9 PJ LJ M2 H4 H5 5 6 E6 G7 CJJ DI' CJ6 G17 F17 Q17 Cl9 D20 021 E21 E22

J-S 0

o.

breeding pairs*

4 12 J 2 2 2 3 5 2

4 4 7 9

4 2 2 3 3 18

2 3 2 5 4 6 7 2

10 9 153

176

No. eggs laid

4 12 J 2 2 2 J 5 2 J 3

4 4 7 9

I 4 2 2 3

18 2 2 3 2 5 4 6 7 2

JO 9 153

55,67 35.0°;.

-D Total 176

o.

eggs lost r failed

4

l 2

2 3 0

6

2 J 2

I 0 4 J 54

• elude· 23 pair breedi.ng at sites nor specified.

NORTHERN GIA T PETREL Macro11ec1e. lwlli

o. egg hatched

3 8 2

2 3 I 0

2

2 3 3

I J

I 2 2 12

2 I

3 J 4 5 J 0 I 6 6 99

Thi i a difficult pecie to censu , because breediag begia in

83

the winter when the weather is al its worst. Moreover, the birds are relatively incon picuou , breeding in dispersed group amongst rocks and boulder . Our figure for the total breeding population i probably too low, and there may be as maoy a 50 more pairs on Lhe i·Jand.

Mas of breeding bird Breeding population

lutch size

ean mass (g wet weight) or fresh egg

Mean mass (g dry weight) of egg shell

Mean mass g dry weight) f content or egg

Egg mortality

o. eggs laid per month

4,0 kg (fresh weight) 208 pair

I egg

243,4 (S.D.=±16,2; 11=81 2l 25(S.0.= I.15;n=J)

52,34 (S.D. = ±5,42; 11=3) 23,8%

J-J A S-D Total

en u.

o.

Grid breeding referenc pair

J25 15

.124 15

K24 5

K.2~ 5

1315 5

9 12

G4 17

J2 16

ML 5

NI 4

P14 10

Q14 12

H23 5

22 7

F22 9

D20 17

P22 13

BIJ 5

16 22

17 19

208

o. eggs laid

15 15

5 5 12 17 16 5 4 10 12 5 7 9 17 .I 3 5 22 8

20

208

No.

eggs losl r failed

4 J

l J 4 4 1

2 J 1 I 2 4

2 0 47

No. eggs hatched

II 12 4 4 4 9 13 12 4 3 8 9 4 6 7 13 10 4 17 6

161

SO THER GTA T PETREL Macronectes giga11te11s

Ea ier to cen us than M. /,a/li, the outhern giant petrel i a colonial nester at relatively open sites.

Mass of breeding bird 4.5 kg (fresh weight) Breeding population I 337 pairs

Clutch size I egg

egg 268,7 S.D.=±17,7;n- 149)

shell 22,48(S.D.=±2,08·11 6)

Mean mas (g dry weight of contents of egg

Egg mortality

No. eggs laid per month

.l-A S

1 016

0 321

57,00 (S.D.=±J,45; 11=6) 26,3%

N-D Total JJ37