penguin conservation - the avian scientific advisory...

Penguin Conservationvol. 12, no. 1 1999

In this issue

News & Announcements 1including:

Penguin populations-request for dataThe Fourth International Penguin ConferenceFalkland Islands newsPenguin hand-rearing formula updatePublished standards for handling of feed fish

Humboldt Studbooks: Japan, North America 5

Circulating a-tocopherol and retinol in free-rangingand captive penguins 6

Nesting habits of Humboldt Penguins at Punta San Juan, Peru 12

PENGUIN CONSERVATION IS PROUD TO ACKNOWLEDGE THE GENEROUS SUPPORT OF THE

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phone: 541/899-1114fax: 541/899-1131e-mail: [email protected]

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Penguin Conservation

Publication information:ISSN # 1045-0076Indexed in: Zoological Record, Biological Abstracts, and Wildlife Worldwide (successor to Wildlife Review, produced by

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Previous title was SPN: Spheniscus Penguin Newsletter. Volume numbering continued from previous title.Printed on recycled pa per.

Penguin Conservation is published three times per year. Subscription is free, to those with a serious interest inpenguin conservation and research.

Contributions toward printing and production costs are welcome: please make checks payable to "ConservationPublications, Inc.," and send to the Editor at the address below. Checks from outside the US must have, printed onthe check, the name of a US bank with which the foreign bank is affiliated.

Conservation Publications, Inc. is a recognized 501c3 nonprofit organization under US IRS law; contributions fromUS taxpayers are tax-deductible.

Advertising is accepted; please contact the editor for rates.The drawing which serves as our cover logo is reproduced by kind permission of the artist, Ann Munson.Instructions for Authors: Articles submitted for publication should be typed, double-spaced; in addition, text and

data may be sent on a disk (preferably Macintosh, text files openable by MS Word 5.1 or Nisus Writer 5.1.3). Initialsubmission may be by fax or e-mail, prior to sending final copy. When graphs are used, a separate sheet should beincluded giving the data used to generate the graph, as well as sending a copy of the graph itself. Photographs andfigures should be labelled with figure number and brief description on the back; captions should be on a separate page.Include scientific name in the first mention of each organism; give latitude and longitude of locations if possible.For citations and reference lists, please follow the bibliographic format used in this issue.

This journal also welcomes more informal articles, brief notes, and anecdotal reports, of interest to our readers.Articles for the next issue must be received by June 1, 1999.Please address all correspondence to:

Cynthia Cheney, EditorPenguin Conservation8060 Upper Applegate Rd.Jacksonville, Oregon 97530USA

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Return to: Editor, Penguin Conservation, 8060 Upper Applegate Rd. Jacksonville, OR 97530 USA.I wish to support Penguin Conservation with my paid subscription as follows:o Individual (US$l5/year) for __ yearso Institution (US & Canada, US$25/year; others, US$35/ year) for __ yearsTotal amount enclosed: US$ _Please make checks payable to "Conservation Publications, Inc."; foreign checks MUST show,

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News & Announcements

Request for data:Antarctic &: Subantarcticpenguin populationupdate

In 1993, the SCAR (ScientificCommittee for Antarctic Research) BirdBiology Subcommittee published aninventory of all available penguinpopulation data for the Antarctic andSubantarctic islands (Woehler 1993).This inventory lists all population datafor Emperor, King, Adelie, Gentoo,Chinstrap, Royal, Macaroni andRockhopper Penguins at all knownbreeding localities.

An update was compiled andpublished in 1996 (Woehler & Croxall1996) that listed new and supplementary data not included in Woehler(1993). Another update is being prepared at the moment for SCAR. If youhave any new data for the 8 specieslisted above, or know of data that hasbeen collected by someone else, pleasecontact:

Eric WoehlerAustralian Antarctic DivisionChannel Highway, KingstonTasmania 7050 AUSTRALIA

fax +613 6232 3351email: [email protected]

All contributions will be fullyacknowledged, and all contributors willreceive a copy of the document whencompleted, in early 2000.

ReferencesWoehler E. J. (1993) The distribution

and abundance of Antarctic and Subantarctic penguins. SCAR: Cambridge.iv+76pp.

Woehler E.J. & Croxall J.P. (1996)The status and trends of Antarctic andSubantarctic seabirds. SC-CAMLR-XV/BG/29.76pp.

Fourth International Penguin ConferenceSecond Announcement:Call for Descriptive Titles and Registration

Continuing with the highly successful series of international penguinconferences, the Fourth International Penguin Conference (Penguin 2000!) will beheld in Chile. The conference will be held at the Caia de Compensaci6n de LosAndes, La Serena, Chile from 4 - 8 September 2000. This will be the first time thatthe penguin conference will have taken place in South America and we aredelighted to be able to show you some of the advantages of our beautifulcontinent.....

The conference center is located on the beach front next to the Avenida del Mar('Ocean Avenue') in one of the most popular tourist sites of La Serena. This avenueextends 10 km, linking the cities of La Serena and Coquimbo, and is simplypopping with all sorts of modern-day vice-inducing ventures: bars, restaurants withinternational cuisine, discotheques, casinos... In order to keep your feet firmly fixedon the ground, however, the major site we have selected for accomodation issimply a modern hotel with swimming pool, sauna and the odd one-armed bandit.Other accomodation possibilities will be relayed to you in the next announcement.

List of critical dates31 May 1999: Submission of preliminary descriptive titles30 July 1999: Notification of acceptance of presentations31 May 2000: Paymentofregistration fee31 May 2000: Receipt of final abstracts04 Sep 2000: Submission of manuscripts for Proceedings at exactly midnight(and not a minute later)04 - 08 Sep 2000: Fourth International Penguin Conference

Call for presentationsIf you wish to make a presentation, and are already able to send us an initial

abstract, so much the better. In any event, in sending your provisional descriptivetitle please state whether you wish to be considered for an oral or posterpresentation.

There is no restriction on the number of proposed presentations, but note thatwe favor only one oral presentation per senior author. Oral presentations will be15 minutes, plus 5 minutes for questions.

If you are already able to submit a preliminary abstract it should beapproximately 250 words (ca. half a page). Abstracts should be ideally written inWord or Word Perfect for Windows. We prefer you to send your abstractselectronically via the Internet (to [email protected]), but you may alsosend them by fax (+56-51-209 812 marked "Attention to: Guillermo LunaJorquera") or to the following address:

Guillermo Luna-Jorquera, Dept. of Marine Biology, Universidad Cat6lica delNorte, Larrondo 1281, Coquimbo, CHILE.

RegistrationThe conference fee will be US$ 200. Genuine students may pay a reduced fee of

US$ 100, but they will not receive the Proceedings. The registration fee will includethe Conference Programme and Abstract, morning and afternoon teas-coffee,evening ice-breaker (Sunday 3rd), opening cocktail party (Monday 4th) and closing

continued on page 2

Penguin Conservation vol. 12, no. 1 19991

Fourth International Penguin Conference

continued from page 1

buffet (Friday 8th). Costs also includetransport to a Humboldt Penguincolony and to the Elqui Valley. If youdon't make the 31 May deadline theregistration fee will rise to a horrendousUS$ 250 and 150 for professionals andstudents, respectively.

The registration fee does not includeother meals and accomodation.

Publication of the conferenceproceedings

We are already negotiating withpublishers in order to produce a highquality publication of the proceedingswith astonishing speed under theprovisional title of 'Penguins 2000: 225years after Cook'. This work should

highlight the enormous advances inour understanding of penguins some225 years after they were firstdiscovered-appropriately enough, atthe inception of a new millenium,where everything is reputed to bebigger and better!

Acceptance of submitted work forpublication in Penguins 2000 will bedependent on (1) the opinion ofreviewers and the editors and (2) theability of the authors to provide themanuscripts on time. This latterstipulation is necessary for us to be ableto ensure timely publication of thework-it would hardly be appropriatefor us to produce a volume entitled'Penguins 2000: 225 years after Cook'if, by the time it finally appeared itshould read 'Penguins 2007: 232 yearsafter Cook'! We hope to have the thingout sometime in 2001.

The Second InternationalPenguin Fun Run

The organising committee considersthe idea of a pengUin fun run,introduced by the Cape Town people,to be excellent and wishes to continuethis age-old tradition. For this reason,we have selected a 5 km track overwhich you may stretch your legs. Inorder to avoid having daily joggers (e.g.John Cooper, Andreas Ploes etc.) winall the prizes, we are considering somesort of handicap system. It may be,however, that the order of winnersreflects something other than runningcapacities anyway-the main stretchbeing along the Avenida del Mar whichhas a number of potential pitfalls forwould-be runners (see above). There isno entrance fee for the run but thereare glorious prizes to be won.

PHVA Report delayed

This issue of Penguin Conservationwas to have contained the second halfof a long article about the HumboldtPengUin PHVA held in Chile in late1998. The first part (Penguin Conservation,vol. 11 (3): 2-9, November 1998)described the workshop and thematerial presented there about threatsto the survival of Humboldt Penguinsin Peru and Chile. The second part willcontain the official recommendationsfrom the workshop, with regard toreducing these threats and promotingthe penguins' continued existence.

However, since the publication of theformal report has been delayed, thearticle here will be delayed likewise.It will appear in Penguin Conservationimmediately following publication ofthe official report.

Spanish was the official language ofthe PHVA Workshop, and the officialreport will be in that language.

-The Editor

2

Change in penguin hand-rearing formula

Curator Wendy Taylor at Sea World San Diego advises us that there has been achange in the penguin hand-rearing formula included in her recent article[NSeaWorld California penguin handrearing protocoC" Penguin Conservation,11(2):2-9,July 1998]. The decision has been made to remove the children's multivitamin drops from the formula, which is found on page 8 of the article. Thisdecision addresses a continuing concern about levels of some vitamins possiblybeing too high.

She notes that "the penguin guidelines are a work in progress," continually beingexamined for ways they can be improved.

Nations agree to reduce overcapacity in fishing fleetsbut not too quickly

The world's major fishing nations have agreed to move toward reducingovercapacity in the global fishing fleet.

Frequently described as a situation in which Utoo many vessels are chasing too fewfish," overcapadty is largely the result of countries continuing to subsidize the buildingof more, bigger vessels instead of scaling back to ease the pressure on fish stocks. Arecent report by the World Wildlife Fund estimated that 13 of the world's largest fishingfleets have a fleet capadty that is two and one-half times greater than necessary toensure a sustainable catch. The report estimated that those fishing nations need toreduce the size of their fishing fleets by two-thirds.

At the biannual meeting of the Fisheries Committee of the United Nations Food andAgriculture Organization (FAD) in Rome in February, FAD member nations agreed todevelop national plans to address fleet capadty and to control the size of distant-waterfishing fleets, preferably by 2003 and no later than 2005. The action plan is the first

please tum to page 11


REGISTRATION FORM

FOR THE FOURTH INTERNATIONAL PENGUIN CONFERENCE

Name

Institution

Postal address

City

E-mail address

Fax

State/province Country Postal Code

Do you plan to make a presentation? YES/NO

Provisional title ofpresentation

Authors

Author affiliation

Your presentation will be: ORAL POSTER

Will you have any spedal requirements for visual aids? Please spedfY

Will you participate in the Second International Penguin Fun Run?

Please mail this form to:Guillenno Luna-jorqueraDept. of Marine BiologyUniversidad Cat61ica del NorteLarrondo 1281Coquimbo CHILE

Or fax to +56-51-209 812, marked attention Guillermo Luna-J.Or send per e-mail [email protected]


YES/NO

3

Fish handling booklet available

New Falklands website

Falklands Islands information can befound on a new website [http://www.falklands.net/eru_hom.htm] putup by the Stanley-based EnvironmentalResearch Unit, Ltd. Of greatest interest tothose working with penguins are theextensive summaries of five works byMichael Bingham:

1) (in press) Millennium Baseline Datafor Falkland Islands Fauna and Flora.

2) (1998) The distribution, abundanceand population trends of Gentoo,Rockhopper and King penguins at theFalkland Islands. Oryx 32(3): 223-32.

3) (1996) Censo de los pingiiinos delas Islas Falklands. Unpublished Spanishresume of above.

4) (1998) Penguins of South Americaand the Falkland Islands. PenguinConservation 11(1): 8-15.

5) (1999) Penguins of the FalklandIslands and South America. ERUpublication. 97pp. Available from ERULtd, PO Box 434, Stanley, FalklandIslands. Price £49.50

Downloaded, this all-text page [http://memb ers .xoom.coml ER U2000/eru_resu.htm] amounts to about 75 pagesin a word processor file. Some charts andmaps from these publications are foundon the Gallery Page.

Pause in oil explorationoff the Falklands

According to the January/February1999 Newsletter of the Department ofMineral Resources, Falklands Islands,the consortia licensed to drill in theNorth Falkland Basin completed sixexploratory wells in 1998. Four wellshad hydrocarbons present in small (butnot commercial) quantities. Exploratory drilling will halt for a time whiledata from these six wells is studied. TheDepartment stated that, "Operationallythe program has gone very smoothlyindeed with some wells being drilled inhalf the time originally planned. Thecompanies mobilized a successfuldrilling campaign in the South Atlanticin under two years from their license


Falklands breeding declinemay be linked to oil

Another page [http://members. xoom.com/ERU2000/eru_news.htm] at thefalklands.net site carries current news,and at present gives a description ofdeclines in penguin and other seabirdbreeding success in 1997/8. AuthorMichael Bingham suggests thesemay bedue to a combination of the severe ElNifio, and the presence of oil in someland and ocean areas.

The follOWing paragraphs are reprinted, with permission, fromBingham's observations of the breedingseason:

[Oil exploration around the Falklandsbegan in April 1998-Editor]Within a fewweeks of [the exploratory oil rig's] arrivalthree separate oil spills occurred aroundthe Falkland Islands, oiling penguins andcormorants. Fortunately these spills wereall relatively small and affected onlycertain areas. It seems unlikely that theoil actually came from the rig, since [it]never actually found oil in significantquantities. The most likely explanation isthat the oil came from supply vessels orfishing boats operating in the area, butthe actual source was never traced.

The birds most affected by the oil werepenguins and cormorants. During thefirst two spills Magellanic and Rockhopper Penguins were not present in theFalklands, since they migrate northwardsup the coast of South America during the


Handling fish fed to fish-eatinganimals: a manual ofstandard operatingprocedures. Susan D. Crissey, Ph.D.Published by the United StatesDepartment of Agriculture, AgriculturalResearch Service, National AgriculturalLibrary, June, 1998. 21pp.

This booklet presents a complete setof recommended procedures to befollowed in all stages of fish-handling:ordering, inspection, storage, transportation, thawing, handling thawedfish, feeding, sanitation, and sampling

3D-year low in NSW LittlePenguin breeding success

According to the March 1999 issue ofAlbatross, published by the SouthernOceans Seabird Study Association, the1998/99 breeding season along thesouthern coast of New South Wales wasa "disaster" for Little penguins(Eudyptula minor).

Breeding activity at the Five Islandsstudy area began late. Fewer pairs bredthan usual, and the birds "generallywere well down on average weight."Many nests were abandoned, leavingchicks to starve.

"This was by far the worst season forbreeding in the thirty years we havebeen studying the Five Islandspopulation [of Little penguins]," theAlbatross states. "It's doubtful that anychicks... fledged at all."

According to reports from otherresearchers, the story was much thesame at colonies further south:Montague Island reported a fledgingrate of 6%, and Jarvis Bay/Bowen Islandbreeding was no better.

Albatrosses also had a very poorbreeding season, "with numbers welldown on past seasons."

The cause is not known, but theauthor of this article mentions "theswing from El Nino to La Nina" as apOSSibility.

[from Albatross, March 1999, no. 20;Lindsay E. Smith editor; P.O. Box 142,Unanderra, N.S.W. 2526, Australia;[email protected]]

for microbial and nutrient content.Appendices discuss the effects offreeZing upon the nutritional contentof fish, and the various infections andtoxins of foods that are relevant.

Frozen fish is often thought of as asterilized product, unchanging andsafe, but this booklet points out thatfreezing kills some but not all microbes,and those that survive (which caninclude spores of Clostridium botulinum,as well as other bacteria, molds, and


4 Penguin Conservation vol. 12, no. 1 1999

Captive Management Programs: lapan, North America

Japanese Regional Studbook for the Humboldt Penguin

Data Table (data from Japanese Regional Studbooks for the Humboldt Penguin, 1993-1997 inclusive)

Data current through 1993 1994 1995 1996 199731 Dec. of each year

Participating Institutions 72 70 72 72 73

# SSP animals managed 971 1029 1170 1219 1309303.274.394 297.279.453 316.304.550 351.341.527 369.374.566

# hatchings 148 184 250 229 254

(# institutions) (30) (39) (44) (40) (42)

# of deaths of SSP animals 88 124 144 170 16812.20.56 24.23.77 24.30.90 32.28.110 40.37.91

# of transfers 44 39 65 38 2811.6.27 20.10.9 11.16.38 9.11.18 6.7.15

The latest edition of the JapaneseRegional Studbook for the HumboldtPenguin (Spheniscus humboldti ) hasbeen published, containing populationdata current as of 31 December 1997.Michio Fukuda, at Tokyo Sea Life Park,is the Species Coordinator andStudbook Keeper. Data for 1997 andprevious years are summarized in thetable above [compiled by the Editor].

This edition of the studbook records254 hatches at 42 institutions; 148chicks (58.3%) were surviving on 31December 1997. Nineteen, or 7.5%, ofthe chicks were hand-reared; of these,ten (52.7%) survived to 31 December.Thirteen chicks were fostered, and nine(69.2%) survived to 31 December.

For more information, contactMichio Fukuda, SSC Coordinator andHumboldt Penguin Studbook Keeper, &Chairman, JAZGA Penguin TAG, atTokyo Sea Life Park, 6-2-3 Rinkai-cho,Edogawa-ku, Tokyo 134, Japan;fax 03-3869-5155; e-mail [email protected].

North American Humboldt Studbook for' 997

The 1997 North American RegionalStudbook for the Humboldt Penguincontains 263 (121.117.25) livingspecimens. This is a net increase of 29birds over the 1996 total of 234(107.104.23). With the deletion of St.Louis Zoo and the addition of LouisvilleZoo in 1997, Humboldt Penguins arenow maintained in 11 SSP memberinstitutions. St. Louis Zoo intends torejoin the SSP once major renovations totheir fadlities are completed. Denver Zooand Akron Zoo joined the SSP in 1998,therefore data from these zoos will beinduded in the 1998 studbook.

The deaths of 10 (3.7) established birds(birds ~ 1year old at death) and 13 (2.3.8)chicks are recorded in this edition. Three(2.1) of these birds were actual orpotential founders (MI34, M391, Fl03).Neither M134 nor M391 has liVing

offspring in the captive population. Fl03is survived by several offspring (both Fland F2 generations). However, it hasbeen determined that birds descendedfrom her may develop a congenital bonedeterioration condition and therefore aretypically excluded from SSP breedingrecommendations.

Fifty-one (51) hatches were recorded inthis edition of the studbook; forty-three(43) of these chicks survived ~ 30 days(84.3%). In 1996, twenty-four (24)hatches were recorded, with twenty-one(21) chicks surviving ~ 30 days (87.5 %).In 1997, among the eight chicks thatdied prior to 30 days of age, seven diedbetween 1 and 11 days; this critical twoweek post-hatch mortality peak seems tooccur consistently in this HumboldtPenguin population.

In 1997, eleven out of fifty-one chickswere hand-reared; nine (21.5%) of whichsurvived to fledging (90 days). Forty 1997chicks were parent-reared, with thirtytwo (80%) surviving to fledging (90days).

Twenty-three translocations ofHumboldt Penguins occurred in 1997.All SSP institutions were involved intransfers except Columbus, Aquarium ofNiagara, and Sea Life Park. HumboldtPenguins from the St. Louis Zoo colonywere sent to Brookfield, Milwaukee, andWoodland Park (Seattle) Zoos. [Thepreceding summaryappears in the Studbook.p. xii.]

For further infonnation, please contactGail Brandt, Studbook Keeper, BrookfieldZoo, 3300 Golf Rd., Brookfield, IL; fax708-485-3140.


Circulating a-tocopherol and retinol in free-ranging and captive penguins:speculation on dietary influences

Table 1. Summary of published papers recording the approximate proportion of preyconsumed (by type of prey) as a percentage of total ingested weight in penguin species.

JENNIFER J. COSGROVEELLEN S. DIERENFELD

fat-soluble vitamins, may provide someuseful gUidelines for feeding captivepenguins.

Published and unpublished data onvitamin Eand A concentrations in krill,squid, and fish are summarized. in Table 2.In these analyses, both fresh-frozen andfreeze-dried krill samples were used; allother samples were fresh-frozen. Noneof the samples is known to have beencollected in situ at penguin feedingsites, and some of the fish species areused as feed in zoos, but do not occurin the range of any penguin.

With the exception of vitamin A infresh krill and Ilex squid, concentrationranges for both nutrients appear tooverlap between the fish andinvertebrate species listed. Fromnutrient composition alone, then,there is little evidence to suggest

Reference

Brown & Klages 1987Brown & Klages 1987

Klages et al. 1990

Croxall & Furse 1980

Scolaro & Badano 1986

Volkman et al. 1980

Volkman et al. 1980

Wilson et al. 1989

Randall & Randall 1986

Volkman et al. 1980

5345

97

82fish

krill

sqUidkrill

Main Prey Approx. % FreshType Weight of Diet

krill 60-100

fish 83

krill 98

krill 85

fish -100

fish >85

RockhopperEudyptes chrysocome

Penguin Species

AdeIiePygoscelis adeliae

AfricanSpheniscus demersus

ChinstrapPygoscelis antarctica

GentooPygoscelis papua

HumboldtSpheniscus humboldti

KingAptenodytespatagonicus

MacaroniEudypteschrysolophus

MagellanicSpheniscusmagellanicus

New York, New York USA

Pygoscelis and Eudyptes preferinvertebrate prey (see Table 1). Despitethese ecological differences in preybase, captive penguin diets consistalmost exclusively of whole fish withvarying supplementation regimens.Differences in naturally-occurringnutrient concentrations betweenvertebrate and invertebrate feedstuffsmay be associated with differingmetabolic adaptations in variousspecies for utiliZing these nutrients.Hence, information on natural dietcomposition, particularly regarding the

Diet CompositionAnalyses of stomach contents

indicate that free-ranging Spheniscidpenguins consume predominantly fishbased diets, whereas species of

Jennifer J. Cosgrove l

Ellen S. Dierenfeldz

Dept. ofNutritionWildlife Conservation Society185th St. and Southern BoulevardBronx, NY 104601 [email protected] [email protected]

IntroductionVitamins Eand Aare essential for the

normal health and reproduction of anyanimal. In penguins specifically,evidence suggests that deficiencies ofthese vitamins can lead to poorfertility, early embryonic death,suppressed immune function and highchick mortality (Wallace et al., 1996).Because there is also the threa t oftoxicity as well as possible antagonismwith other fat-soluble vitamins(McDowell 1989), vitamin administration through both diet andsupplementation should be carefullymonitored.

A lack of information on thenutrient composition of penguin foodin the wild, and limited data on normaldrculating levels of these vitamins, hastriggered research to develop means ofassessing physiological nutrient status.Over the past decade, several authorshave reported plasma concentrationsof a.-tocopherol and retinol for wildpenguins (Ghebremeskel and Williams,1989; Williams et aL, 1989; Monroe,1993; Wallace et al., 1996), indicatingthat baseline data appear to vary byspedes.

This report summarizes informationfrom previ ously published papers,combined with unpublished laboratorydata from six institutions, and discussespossible relationships between circulating blood concentrations andcalculated dietary concentrations ofvitamins E and A in penguins.


Species Vitamin E Vitamin A Referencen (IV/kg DM) (IV/kg DM)

KrillEuphausia padfica 2 141.8±21.5 66990 ± 15010 Bernard & Allen 1997(fresh) Pennino et al. 1991

(dried) 2 86.15 ± 57.20 2283 ± 1579

Squid 1 459 204633!lex illecebrisus

Loligo spp 15 270.2 ± 105.9 36933 ± 22366

FishWhitebait 7 220.11 ± 69.12 48400 ± 27700(Allosmerns elongatus)

Ocean smelt2 102.37 ± 6.50 21033 ± 1633(Hypomesus pretiosus)

Capelin 29 116.3 ± 66.53 32600 ± 20566(Mallotus villosus)

Spearing7 166.66 ± 124.09 23933 ± 13566(Menidia menidia)

Rainbow smelt 2 331.63 ± 1.98 9566 ± 3200(Osmerus mordax)

Night smelt1 87.35 69733(Spirinchus starksi)

Columbia River smelt 1 106.22 38033(Thaleichthys padficus)

Mean 161.52 34756.86

Table 2. Summary of vitamin Eand Aconcentrations measured in prey analyzed at the Wildlife Conservation Society nutritionlaboratory; all values expressed as IV/kg on a dry matter basis (to July 1997). Fish species listed are those most commonlyfed to captive penguins in North American fadlities. Vitamin activities (IV/kg) were calculated as, vitamin E: 1 mg a-tocopherol= 1.49 IV; vitamin A: 1 IV = [ULg retinoIl0.3)*10oo]

different physiological or metabolicpathways necessary for dealing withconsistent variability in prey nutrientsamong penguin species.

Invertebrates overall (n = 20) showeda trend towards higher levels of bothvitamins compared with fish (n =49, allsamples combined): 254 IV/kg drymatter (DM) vs. 146 IV/kg DM vitaminE and approximately 45,000 IV/kg DMvs. 33,080 IV/kg DM vitamin A, respectively, with widely unequal variance.

Plasma Vitamin ConcentrationsVitamin E

Means and ranges of reported circulating a-tocopherol as a measure ofvitamin E status in selected wild andcaptive penguin species can be foundin Table 3. When more than onereport of dietary preferences was foundin the literature for a particular species(Table 1), data was used from thegeographic site closest to the areawhere blood samples (Table 3) werecollected from free-ranging penguins ofthe same species.

Values from free-ranging individuals(Table 3) may provide guidelines forthe normal concentration range of thisnutrient in penguins. All values in thistable are pre-molt if both pre- and postmolt levels were recorded.

Four of the five species from whichsamples were available averagedbetween 20 and 40 micrograms (Ilg)a-tocopherol/ml. The Magellanicpenguin (Spheniscus magellanicus) waslower than this range (6 to 9 Ilg/ml).Williams et a1. (1989) state in theirstudy that the Magellanics were heavier

continued on page 8


Circulating a-tocopherol and retinol in free-ranging and captive penguinscontinued from page 7

Penguin Species n a-tocopherol (ILg/ml) Retinol (ILg/ml)(Range) (Range)

Adelie - Zoo A 2 13.78 ± 2.57 0.75 (0=1)Pygoscelis adeliae (11.96 - 15.60)

African 7 25.97 ± 10.94 1.28 ± 0.75 (0=5)Spheniscus demersus (9.41 - 43.20) (0.19 - 2.24)

WCS 3 22.40 ± 12.78 0.19 (n=l)(9.41 - 34.97)

Zoo B 4 28.65 ± 10.39 1.55 ± 0.51(19.28 - 43.20) (1.04 - 2.24)

Zoo CA 15 37.10 ± 12.30 0.86 ± 0.40(12.20 - 59.40) (0.70 - 1.50)

Chinstrap 24 17.09 ±5.80 0.83± 0.22Pygoscelis antarctica (7.58 - 27.83) (0.45 . 1.28)

WCS 23 16.73 ± 5.65 0.82 ±0.22(7.58 - 27.83) (0.45 • 1.28)

Zoo A 1 25.32 0.99

Reference

Gulland et al. 1988

Gentoo 62 42.79 ± 14.14 0.85 ± 0.27Pygoscelis papua (18.32 - 91.63) (0.28 - 1.34)

WCS 15 42.79 ± 16.71 0.71 ± 0.22(18.32 - 80.71) (0.43 - 1.23)

Zoo AB 17 48.09 ± 18.52 0.96 ± 0.29(21.99 - 91.63) (0.28 - 1.22)

Zoo D 30 39.80± 8.40 0.85 ± 0.25(25.24 - 58.97) (0.31 . 1.34)

Free-rangeC 6 18.70 ± 3.20 0.68± 0.09 Williams et al., 1989(16.30 - 22.30) (0.52 - 0.77) Ghebremeskel &

Williams, 1989

Humboldt - Zoo E 165 22.44 ± 6.58 1.97± 0.57Spheniscus humboldti (10.91 - 48.55) (0.40 - 3.58)

Free-rangeC 30 18.77 ± 5.41 1.17 ± 0.44 Wallace et al.,1996(5.15 - 27.16) (0.38 - 2.05)

King - Zoo A 32 65.45 ± 24.29 1.10 ± 0.49Aptenodytes patagonicus (27.10 - 128.44) (0.40 - 2.15)

Macaroni - Free-rangeD 14 37.60 ±6.35 2.40±0.55 GhebremeskelEudyptes chrysolophus (27.5 - 51.4) (1.70 . 3.5) et al. 1991

Table continued on facing page; see Title and Notes at end of Table.


Penguin Species n a-tocopherol (j.lg/ml) Retinol (j.lg/ml) Reference(Range) (Range)

Magellanic - WCS 4 26.46 ± 10.93 0.67 ± 0.23Spheniscus magellanicus (15.16 - 38.60) (0.42 - 0.98)

Free-range 4 7.20 ± 1.10 0.67 ±0.09 Williams et al. 1989(6.10 - 8.90) (0.55 - 0.77) Ghebremeskel &

Williams 1989

Rockhopper 105 31.22 ± 14.60 0.97± 0.27Eudyptes chrysocome (15.54 - 87.08) (0.36 - 1.59)

Zoo AB 15 53.23 ± 20.78 1.17 ± 0.32(24.89 - 87.08) (0.72 - 1.59)

Zoo D 58 27.93 ± 8.90 0.91 ± 0.27(15.82 - 55.63) (0.36 - 1.34)

Lincoln Park Zoo 32 26.86 ± 10.00 0.98 ± 0.19(15.54 - 48.83) (0.69 - 1.33)

Free-range 12 31.30 ± 10.40 1.37 ± 0.27 Williams et al. 1989(21.70 - 50.80) (0.99 - 1.57) Ghebremeskel &

Williams 1989

Table 3. A summary of circulating plasma a-tocopherol and retinol levels of both wild and captive penguins from WCSunpublished data, other institutions, and previously published data. This table contains pre-moit values for wild penguins,if pre- and post-molt values were recorded (no post-molt wild animal values are recorded in this table); non-molting animalsare noted with "C". Values for captive birds are all of unknown (unrecorded) molt status, except where noted. The boldedmeans and s.d. are the mean of the captive values, if there was more than one institution for that species.

Apublished data; individual values were not available, therefore could not be included in the captive meanB these species from Zoo A were fed an experimental fish-based dietcnon-moltingDdata presented in the table is an average of the male and female values reported in the paper

than the gentoos in body mass andpotentially may have had differentblood lipid composition than the otherpenguins under the same conditions.The authors speculate that the differentlevels of a-tocopherol could be due toqualitative differences in dietary habitsand dietary specialization. However,no detail on dietary concentrations ofvitamins was provided.

Free-ranging gentoo (Pygoscelispapua; krill specialists) and Humboldt(Spheniscus humboldti; piscivores)penguins had almost identical atocopherol concentrations eventhough they consume different diets in

the wild. The fish-eating Magellanicpenguin was lowest (mean = 7.2j.lg/ml),while rockhopper (Eudyptes chrysocome)and macaroni (E. chrysolophus)penguins---both invertebrate specialistswere somewhat higher, with meanvalues of 31.3 j.lg/ml and 37.6 j.lg/ml,respectively. Hence there was noconsistent correlation between diettype and drculating concentration ofvitamin E in free-ranging penguins.The differing levels may be due more tospecies-specific physiologies thanactual dietary influences.

However, there are notable differences in a-tocopherol concentration

between free-ranging penguins andtheir captive counterparts. Data existfor free-ranging penguins of fourspecies. In three of the four, theaverage captive values are higher thanthe average free-ranging means.Rockhopper penguins, the fourthspedes, varied by facility. There is alsomuch more variability in the samplescollected from captive penguinscompared to free-ranging birds, likelydue to the fact that captive sampleswere obtained over multiple seasons asopposed to single-season samplingcomparison.



Circulating a-tocopherol and retinol in free-ranging and captive penguinscontinued from page 9

Some differences in circulating a

tocopherol levels of captive penguinsare apparent between and among zoos.Variations of storage and supplementation may be a significant factor;it has been shown that improperhandling of frozen fish can causenotable differences in the vitamin Econtent of the fish (Dierenfeld et aI.,1991). Unfortunately we do not havedetailed feeding and supplementationinformation for institutions other thanthe Wildlife Conservation Society(WCS), but interesting comparisonscan be made even among the fourpenguin species from Wc.s. All are fedessentially the same diet, calculated tocontain 50 IV vitamin E per kg fish(200 IV/kg DM), yet there are differences in circulating concentrations ofa-tocopherol, with Gentoo penguinsmuch higher than other species. Thecause could lie in species-specificphysiological differences and/orpossibly be a result of molting status.

There is documentation supporting asignificant difference in a-tocopherollevels pre- and post-molt, with postmolt values higher than pre-molt. Forexample, Williams et al. (1989)reported rockhopper (Eudyptes chrysocome) values of 31.3 ~g/ml pre-molt,compared with 42.4 ~g/ml post-molt,whereas Magellanic penguins were 7.2Ilg/ml pre-molt and 21.5 ~g/ml postmolt. The authors state that the rise inplasma a-tocopherol, in conjunctionwith a rise in total plasma lipidconcentration post-molt, implies thatsome a-tocopherol is stored in fatreserves and is mobilized with thelipids after molting, so knowledge ofstage of molt can be important forinterpreting plasma results.

For the captive penguins used forthis summary, stage of the moltingcycle when blood samples were takenwas not recorded. Therefore, the valuesmust be interpreted with caution whencomparing to values from free-rangingnon-molting adults.

Vitamin AMean values and ranges of circu

lating retinol, as a measure of vitaminA, for the summarized species can befound in Table 3. From these data, it canbe seen that most species fall into arange of 0.7 to approximately 1.4 Ilglml.It is inaccurate to use blood retinollevels as an indication of vitamin Astatus. Retinol is stored by the liver andblood plasma concentrations maintainrelatively stable ranges. Levels outsidethe normal range usually occur only inextreme cases of toxicity or defidency,when liver stores become overloaded ordepleted (McDowell 1989). The rangeof values reported here is somewhathigher than published values for otherbird spedes and mammals (0.3-O.8Ilglml)(SchWeigert et al. 1991). Additionally, thefree-ranging macaroni penguinsdisplayed very high average retinolconcentrations of 2.40 Ilg/ml; theexplanation is unclear.

There is more variability in retinolvalues within groups of captivepenguins, than is seen in samples fromgroups of free-ranging penguins. Sinceeach individual in a zoo group isoffered the same diet, the observedvariation may result from individualdifferences in consumption and/ormetabolism.

Differences in retinol values amongzoos, on the other hand, may be causedby differences in feeding and supplementation regimes. Whole fish andaquatic invertebrates contain Widelyvarying levels of vitamin A (see Table 2),but in general would appear to havemore than adequate vitamin A concentrations without the need for furthersupplementation of this nutrient. This,of course, assumes that fish are handled,stored, and thawed properly to minimize vitamin deterioration, and alsopresumes that poultry dietary requirements (1500 to 4000 lU/kg DM) for thisnutrient are an appropriate comparisonfor penguins.

Despite the apparent adequacy ofvitamin A in whole fish, some institutions may still be supplementing with

this nutrient, hence pushing dietaryvitamin A higher than necessary.

Vitamin Astatus in penguins may bemeasured in other ways, such as byassaying retinol in samples of liversfrom dead birds (Ghebremeskel et al.1989), or measuring the presence orabsence of vitamin A esters (utilized bycarnivorous mammals and birds as ameans of keeping vitamin A in a lesstoxic form) (Schwiegert et a1. 1991;Wallace et a1. 1992). These measurements, as well as more detailed studiesof metabolism and interactions amongthe fat-soluble vitamins (includingvitamin D) in this group of birds wouldassist our development of health assessments for these nutrients.

Conclusions1. While differences in natural prey

base may be considered when feedingpenguins in captivity, existing data donot show consistent differences inVitamins E and A concentrationsbetween invertebrate (krill, squid) andvertebrate (fish) prey.

2. Vitamin E concentrationsbetween 150 and 250 IV/kg DM, andvitamin A concentrations between35,000 and 45,000 IV/kg DM wouldappear to encompass average values ofthese nutrients measured in commonfeedstuffs currently utilized in captivefeeding programs.

3. Vitamin E supplementation incaptive feeding situations may beessential for proper health and tobalance out a lack of this nutrient infish-based diets, particularly those thathave been improperly stored orhandled. However, additional vitamin Asupplementation may not benecessary, is possibly detrimental, andwarrants further investigation.

4. Published data summarized fromstudies of free-ranging penguins showdrculating levels of a-tocopherol (as ameasure of vitamin E status) rangingfrom 20 to approximately 40 Ilg/ml;data from several zoological institutions showed average circulatinga-tocopherol values higher than free-


ranging counterparts, but neitherdietary regimens nor molting statusdetails were documented for captivebirds.

5. Molting status can be an important factor in evaluating vitamin Estatus, with post-molt a-tocopherollevels higher than pre-molt values;such physiological information shouldbe added to laboratory submissionforms for better interpretation ofresults.

6. In this summary, average retinolvalues for captive penguin speciesranged from 0.7 to 2.0 Jlg/ml, althoughmost fell under 1.0 Jlg/ml; free-rangingpenguin species means ranged from 0.7to 2.4 Jlg/ml, with the majority <1.0Jlg/ml.

7. While single samples must beevaluated with caution in any case,extreme values (either high or low,relative to the ranges reported) foreither of these nutrients might be causefor concern in evaluating health anddietary husbandry of captive penguins.

AcknowledgmentsWe would like to thank the institu

tions highlighted in this paper forpermitting use of unpublished data ontheir collection birds. The staff at theWCS Science Resource Center assistedwith literature searches; Jane McGuire,Nancy Katz, and Marianne Fitzpatrickassisted with laboratory assays.

Literature CitedBernard, J.B. and M.E. Allen. 1997.

Feeding Captive Piscivorous Animals:Nutritional Aspects of Fish as Food.In Nutrition Advisory Group Handbook,Fact Sheet 5: 1-11.

Brown, C.R. and N.T. Klages. 1987.Seasonal and annual variation in dietsof macaroni (Eudyptes chrysolophus)and southern rockhopper (E. chrysocome chrysocome) penguins at subAntarctic Marion Island. ,. Zool. Land.212: 7-28.

Croxall, J.P. andJ.R. Furse. 1980. Foodof chinstrap penguins Pygoscelisantarctica and macaroni penguinsEudyptes chrysolophus at Elephant

Island Group, South Shetland Islands.Ibis 122: 237-245.

Dierenfeld, E.S., N. Katz, J. Pearson, F.Murru, and E.D. Asper. 1991. Retinoland a-tocopherol concentrations inwhole fish commonly fed in zoos andaquariums. Zoo Bioi. 10: 119-125.

Ghebremeskel, K. and G. Williams.1989. Liver and plasma retinol(vitamin A) in wild, and liver retinolin captive, penguins (Spheniscidae).,. Zool. Land. 219: 245-250.

Ghebremeskel, K., T.D. Williams, G.Williams, D.A. Gardner, and M.A.Crawford. 1991. Plasma metabolitesin macaroni penguins (Eudypteschrysolophus) arriving on land forbreeding and molting. CompoBiochem. Physiol. 99A(l/2): 245-250.

Gulland, EM.D., K. Ghebremeskel, G.Williams, and P.J.S. Olney. 1988.Plasma vitamins A and E, total lipidand cholesterol concentrations incaptive jackass penguins. Vet. Rec.123: 666-667.

Klages, Norbert A., David Pemberton,and Rosemary P. Gales. 1990. The dietsof king and gentoo penguins at HeardIsland. Aust. Wildl. Res. 17: 53-60.

McDowell, L.R. 1989. Vitamins inAnimal Nutrition: Comparative Aspectsto Human Nutrition. Academic Press,San Diego, CA.

Monroe, A. 1993. Annual variationsin plasma retinol and a-tocopherollevels in gentoo and rockhopperPenguins. Zoo Bioi. 12: 453-458.

Pennino, M., E.S. Dierenfeld, and J.Behler. 1991 Retinol, a-tocopherol,and proximate nutrient compositionof invertebrates used as feed. Int. ZooYbk. 30: 143-149.

Randall, R.M. and B.M. Randall. 1986.The diet of jackass penguinsSpheniscus demersus in Algoa Bay,South Africa, and its bearing onpopulation declines elsewhere. Bioi.Conser. 37: 119-134.

Scolaro, J. A. and 1. A. Badano. 1986.Diet of the Magellanic penguinSpheniscus mageUanicus during thechick-rearing period at Punta Clara,Argentina. Cormorant 13: 91-97.

Schweigert, F. J., S. Uehlein-Harrell, G.v.Hegel, and H. Wiesner. 1991.Vitamin A (retinol and retinyl esters),a-tocopherol, and lipid levels inplasma of captive wild mammals andbirds. '. Vet. Med. A 38:35-42.

Volkman, N. J., P. Presler, and W.Trivelpiece. 1980. Diets of Pygoscelidpenguins at King George Island,Antarctica. Condor 82: 373-378.

Wallace, R., J. A. Teare, E. Diebold, M.Michaeils, and M.J. Willis. 1996.Plasma tocopherol, retinol, and carotenoid concentrations in free-rangingHumboldt penguins (Spheniscushumboldti) in Chile. ZooBiol. 15: 127134.

Wallace, R., S. Crissey, M.J. Willis, andP. McGill. 1992. The effect of dietaryvitamin A (retinol) and vitamin E (atocopherol) on serum status ofHumboldt penguins. SpheniscusPenguin Newsletter 5(1): 14-20.

Williams, G., K. Ghebremeskel, I. EKeymer and D. T. Horsley. 1989.Plasma a-tocopherol, total lipids andtotal cholesterol in wild rockhopper,Magellanic and gentoo penguinsbefore and after molting. Vet. Rec.124: 585-586.

Wilson, R.P., M. Wilson, D.C. Duffy,B. Araya, and N. Klages. 1989. Divingbehaviour and prey of the Humboldtpenguin (Spheniscus humboldti).,. Omithol. 130: 75-79.

Fishing overcapacitycontinued from page 2

international agreement committingmember states to determine whethertheir national fishing fleets are too big,and to develop plans for reducing thosewhich are.

Governments attending the meetingalso agreed to an International Plan ofAction on Shark Conservation andManagement that requires them todevelop national plans for effectiveconservation and management of sharkfisheries by 2001, and a global actionplan on seabird bycatch in longline

please turn to page 19


Nesting habits and nest characteristics of Humboldt Penguins at Punta San Juan, Peru

IntroductionThe Humboldt penguin is

considered one of the most endangeredspecies of penguin. The last censusesestimated a total population of 20,000wild individuals between Peru andChile (Araya 1988, Hays 1984); currentnumbers are unknown but likely to beconsiderably lower following the severeEl Nifio of 1997-98.

Humboldt penguins are verycommon in zoos and aquariumsaround the world with a Gaptivepopulation of approximately 2400individuals in japan, Europe and theUnited States (Kawata 1997, McGill &Brandt 1997, de Wit 1997).

Viability of the U.S. captive population was uncertain during the 1980'sbecause of its aging group of wildcaught birds, the lack of an accuratemethod for sex determination and alow reproductive success (McGill 1990,McGill 1991, Cheney 1990, McGill &Perkins 1993). The increase of thepopulation during the late 1980's andearly 1990's, and the securing of offspring from unrepresented founders,were largely achieved by hand-rearingbecause parent-reared chicks sufferedmuch higher mortality rates (McGill &Brandt 1995). In the world captivepopulation, high mortality of parentreared chicks remains a problem, alongwith failure to sex and individuallyidentify birds. In some cases, thecolonies consist of only a few birds andthe social 'cues' for breeding may bevery weak (McGill & Brandt 1995).

Combined efforts between zookeepers and field scientists areimportant in order to increase penguinpopulations both in the wild and in

Gabriella Battistinil

Rosana Paredes2

lAy. Central 310

Lima 27, [email protected] Bastidas 158/160San Miguel,Lima 32, [email protected]

Punta San Juan, PeriJ

captivity. Today's zoos are holding incaptivity breeding populations ofcritically endangered species that mayone day be reintroduced into theirhistorical natural habitats (Kleiman1989). Several captive breeding programs have been successful inreintroducing species into the wild.The Arabian oryx, the European bison,the Black-footed ferret, the Hawaiiangoose, the Peregrine falcon and theWhooping crane are some examples ofanimals that have benefited fromcaptive breeding (McNeely et al. 1990).Reintroduction may be made possible,amongst other things, by reproducingnatural conditions in captivity, andthus encouraging animals' naturalbehavior and promoting reproduction.

The most important events in the lifeof a bird take place in or near the nest,e.g. courtship, mate choice, and chickrearing. Thus it is crucial for this area tobe of good quality and provide thebreeding pair with the protection andoptimal environment they require. Inits natural habitat, the male penguin isin charge of selecting the nest that willbe the best for him, his mate and theiroffspring, but in captivity the possibilities of choice are limited. The lack ofstudies related to the Humboldt penguin's natural habitat makes it difficultfor zoo managers to recreate naturalconditions in their artificial breedingsites. Knowing more about the nest'ssize, shape, material, substrate andenvironmental conditions can helpimprove artificial housing facilities andbring about higher breeding success.

This paper presents information onthe physical and environmentalcharacteristics of Humboldt penguinnests and provides a reference guide to

GABRIELLA BATTISTINIROSANA PAREDES

the construction of suitable nestingsites for this species in captivity. Wealso present morphometric data concerning adults, chicks, and eggs whichmay be useful for comparative studiesof wild and captive penguins.

Materials and methodsStudy site

Data were collected between September 1993 and january 1997 as part of along-term study of the breedingecology of the Humboldt penguin atPunta San juan (15 0 22'S, 75 0 12'W),Peru. This reserve holds the largestpopulation of breeding Humboldtpenguins in the country (Hays 1984).

Punta San juan is a desertic54-hectare (133.4 acre) guano reservewith no vegetation, and cliffs of up to30 meters (98 feet)tall surroundingboth rocky and sandy beaches. A concrete wall was built in the 1950's toexclude terrestrial predators but parts ofthe wall are in ruins now and foxeshave killed both adult and chickpenguins.

The weather is mild throughout theyear due to continuous winds blowingfrom the southeast. Ambient temperatures average 19 0 C (66 0 F), sea surfacetemperature averages 15 0 C (59 0 F) andrelative humidity ranges from 60% to100%.

Penguin nests are found on each ofthe reserve's 18 beaches and theirsurrounding slopes and cliffs, butalmost 90% are concentrated in thesouthern part of the reserve.

Humboldt Penguins seem well adapted to the natural conditions and roughterrain of Punta San juan, and locatetheir nests in very hard to reach holesand rock fissures, as well as in the open.

The penguins nest in four kinds ofterrain: cliff tops, slopes, beaches, andsea-caves. There are three types of nest:burrow, crevice, and surface. All threenest-types are found in each kind ofterrain, with the exception of sea-caves


where the penguins nest either on thesurface or in rock crevices.

Almost 700A! (n=12(0) of the nests inthe reserve are located on cliff tops.However, moderately sloping areasappear to be the preferred nestingterrain, since nearly all the availablenest locations on such slopes are in use.With regard to nest type, surface nestsare the most common. Differences inthe distribution of nest types on eachbeach are directly related to the terraintopography (Battistini 1998).

Data collectionNest measurements were taken after

the pair finished nesting. Since aprevious study found no correlation,under natural conditions, between nestdimensions and reproductive success(Battistini 1998), the nests used in thisstudy were chosen without regard forthe pair's reproductive success.

A total of 219 nests, consisting of 139burrows, 25 crevices and 55 surfacenests, were measured. Nest depth,entrance width, entrance height andcup were measured to the nearest0.5cm with a metric tape or a I-meterwooden ruler. Inter-nest distance,measured only for surface nests, wasconsidered to be the distance betweenthe cup centers of two adjacent nestsand was measured to the nearest lcm.Nest orientation was obtained with acompass pointing in the oppositedirection of the entrance, e.g. a nestrecorded as facing 'south' means thatthe penguin walks in a northerlydirection to enter. Temperature andrelative humidity values inside andoutside the nests were obtained withHoBo Data Loggers (Onset ComputerCorporation). Data loggers werelocated at ground level of the mainchambers of the nests. Temperaturevariation was recorded in nests ofdifferent types on two occasions for 24hour periods (15 November 1996 and07 January 1997). Relative humiditylevels were obtained in different nest

Figure 1. Burrow nest. (All photos are by the author)

Figure 2. Crevice nest.


Nesting habits and nest characteristics of Humboldt Penguinscontinued from page 13

types over a four-day period (06 Maythrough 09 May 1996). Temperatureand humidity were registered at emptynests used by the penguins in theprevious breeding season.

ResultsNest type description

Humboldt penguins at Punta SanJuan use three different types of nests,two covered types (burrow and crevice)and one non-covered type (surface).

Burrows are dug in guano or mixedsubstrate (salt, guano, and sand) by thepenguins. These nests usually havetotal roof and side-coverage. They aretunnel-shaped and have a roundentrance. Most are straight but othersmay curve and have two or moreinternal chambers (Figure 1).

Crevices are formed underneathfallen rocks; these change size andshape frequently due to rock and soilslides from the upper parts of the cliffs.Crevice nests usually have total roofcoverage and some have more than oneentrance (Figure 2).

Surface or exposed nests are openscrapes poorly dug in soil or guano.They have a round or oval shape andhave either a very low border surrounding the nest or taller sides that looklike the back of a seat. These nests donot have roof coverage (Figure 3).

Nest dimensionsBoth covered nest types (Le., burrow

and crevice) have similar dimensions(Kruskal Wallis: height=3.96 cmwidth=O.09 P>O.05 D.F.=l). Because ofthese results, data were pooled toobtain more general information(Table 1).

For covered nests, entrance heightranged between 14 and 61 cm (5.5 to24.0 in.), entrance width 13 to 120 cm(5.1 to 47.2 in.), and nest depthbetween 22 and 232 cm (8.7 to 91.3in.). In surface nests, the cup diameterranged between 19 and 65 cm (7.5 to25.6 in.), the border height between 2and 14 cm (0.8 to 5.5 in.) and the backheight between 3 and 27 cm (1.2 to10.6 in.).

Figure 3. Surface nests.

OrientationMost of the nests (94% n=133)

monitored in this study were orientedto the south, thus facing the windalmost directly (Table 2). Nest entrancesat Punta San Juan are usually orientedto the sea and rarely face other nestentrances.

The nest environmentNest material

Nest material is commonly foundinside the nests. It consists mainly offeathers, bird bones, strands of sargassum (Macrocystis spp.), and plasticbags and bottles, that are carried by thepenguins from the shore to the nestsand arranged as nest lining in the mainchamber. These materials surround theeggs and the adults maintain thefeathers and other objects in placeduring incubation and rearing.

TemperatureCovered nests showed less tempera

ture variability than the ambient onboth experiment days, 15 November1996 and 07 January 1997. Coverednest temperatures were almost constantthroughout the day, with a temperature

range of 17° to 19°C (62.6. 66.2°F)and 20° to 21°C (68.0 - 69.8°p) on th etwo experiment days, while theambient varied up to 10 degrees with17° to 27°C (62.6 - 80.6°F) and 19° to29°C (66.2-84.2°F) (Figures 4a and 4b).

Both covered nests, burrow andcrevice-type, showed a similar temperature pattern, slightly warmer than theambient during the night and considerably colder during the day.

Relative humidityWhile the ambient relative hUmidity

varied over the four-day period from80% to 100% Rh, readings in coverednests were relatively stable throughoutthe day and the night (Figure 5).Average ambient humidity was 930/0Rh;for crevice nests the average was87.8%Rh and for burrows it was73.8%Rh.

Breeding groupsHumboldt penguin pairs rarely nest

in isolation, and may form groups of 2to 1000 nests. At Punta Sanjuan groupsare separated from each other mainlybecause of their location in any of the


Covered nests Surface nests

Height Width Depth Cup Border Back Inter-diameter height height nest

Average 25.1 55.07 103.2 44.21 6.84 17.96 76.04

S.E. 0.6 1.5 3.7 0.82 0.66 1.21 2.01

n 163 164 164 110 30 25 104

Table 1. Nest dimensions at Punta Sanjuan. Measurements in em. (l inch = 2.54 em)

Nesttype NW NE SE SW Total

Table 2. Orientation, by nest type, of nests at Punta San Juan.

18 beaches in the reserve, but naturalfeatures may also set groups apart.

Nest density is variable both betweenand within groups. Inter-nest distanceswithin a group ranged from 10 to 173em (3.9 to 68.1 in) and averaged 76.04em (29.94 in) (SD=20.5 N=104).

Nest-related behaviorDuring the incubation and rearing

period, both adults bring feathers orother nest material to the nest. The nestmaterial is then arranged in the nestcup providing a protective layer foreggs and chicks.

Humboldt penguins are rarely seenwalking alone back to their nestsimmediately after returning from thesea. They usually form groups of 10 to50 individuals and remain on the shorefor some time preening and drying outin the sun, as if waiting for a biggergroup to be formed. FinaIly, perhapswhen the group is large enough, they

start to walk back to their nests usingwel1-defined paths. Some climb upcliffs before reaching their nests whileothers cross the entire desertic point.By the time they reach their nests theyare dry.

AI1 age classes except small chicksdefecate outside of the nest. In bothcovered and surface nests, penguins goto the entrance or stand up and pointtheir backs outwards to defecate, thuskeeping the nest clean.


and reduction of humidity withinnests.

A previous study at Punta San Juanfound no correlation between variationin nest dimensions and reproductivesuccess (Battistini 1998). However, inboth the rock crevice nests and theexcavated burrow nests, the dimensions of entrance height and widthwere similar (between types) suggestingthat Humboldt penguins look for a nestsize pattern when selecting their nests.The size range may be determined, onthe one hand, by the need for a comfortably large passage in and out, and onthe other hand by the need to protectthe adults and chicks from excessiveventilation. It has been suggested thatsmaller entrances and nests may alsoforce or encourage penguins to defecateoutside the nest (Boersma, 1991).

In zoos, nest material provided to thepenguins is sometimes taken away forcleaning purposes after the eggs are laid(Harris 1989). The use of nest materialmay be important for maintaining anoptimal internal environment, so wesuggest replacing it with new materialafter cleaning.

Although the reason for the use ofnest material is stiIl unknown, severalhypotheses have been suggested.Lombardo et al. suggested it might beuseful because of the insulatingqualities of feathers and because they

20

141

121

67

54

13

DiscussionThis study has examined the phYSi

cal features of nests used by HumboldtPenguins under natural conditions.Many of these features may have implications for the design of better nestingsites in zoological institutions. Amongthe factors deserving considerationin this regard are size (of nest andentrance), entrance orientation, substrate and nesting material, location ofnests within the exhibit, ventilation,

3

66

632

2

o

2

4

6

Crevice

Burrow

Total



30.00

-~ 27.00

.!!!.a>()~ 24.00a>L-

::Ja; 21.00L-

a>0-

~ 18.00,- ....- --,., .. --=-'-........ ..".."'!!'------'~-..-- ..,...----..........- -

15. 00 -t--+---+---t---t----1f---+---t--+---+---+-~-aaa

a a a a a a a a a a aa a a a a a a a a a a.. .. ..C\J '<t to (]) a C\J '<t to (]) a C\J

C\J C\J

Time of day

- - - - - Crevice ---- - - - - Burrow ---- Ambient

Figure 4a. Temperatures of covered nests compared to ambient, on a spring day (IS November 1996).

30.0

-~ 27.0II)

Qi()~ 24.0

~::Ja; 21.0CD0-E~ 18.0

=-_.=...•.=._..::, :; ::.:.: :.: ;.._,.:: ::= :-:. 0::-...

15.0 +---+---I----+---+---I----+----+---+---+----+---+__aaa

a a a a a a a a a a aa a a a a a a a a a a., .. .. .. .. .. .. ..C\J '<t to (]) a C\J '<t to CXl a C\J

C\J C\J

Time of day

-----Crevice -------- Burrow ---- Ambient

Figure 4b. Temperatures of covered nests compared to ambient, on a summer day (07 January 1997). Temperatures increvice and burrow nests were identical from 1600 to 2300.


50

400 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 (\j V <0 <Xl 0 (\j V <0 <Xl 0 (\j 0 (\j V <0 <Xl 0 (\j V <0 <Xl 0 (\j(\j (\j ,.... (\j C'l

Time of day

100

90

80

70

60

--------- ---- ~-.

---------""- "----" ~--- .... ----..

-----Crevice ---.---- Burrow ----Ambient

Figure Sa. Relative humidity of covered nests compared to ambient, for first two days of four-day period.

50

400 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

0 C\l v <0 <Xl 0 C\l v <0 <Xl 0 C\l 0 C\l v <0 <Xl 0 C\l v <0 <Xl 0 C\lC\l C\l C\l C\l

Time of day

.",,'" ~,,-- '- - --'. --- .... ---,. -.... __ .. ------ --

----------------....,. ".------ ......-..........

100

90

~U 80"E..E 70Q)

~ 60a;a:

-----Crevice -------- Burrow ----Ambient

Figure Sb. Relative humidity of covered nests compared to ambient, for second two days of four-day period.



Table 3. Wild Humboldt penguin morphometric data.

A Flipper length was recorded for 98 males and 103 females.

Males FemalesVariables (n=112) n=111)

x±SE x±SE

Body mass (g) 4931.08 ± 56.05 4317.85 ± 52.15

Length of head (em) 13.52 ± 0.03 12.68 ± 0.03

Width of head (em) 5.13 ± 0.02 4.75 ± 0.02

Bill length (em) 6.54 ±0.02 6.08 ± 0.02

Flipper lengthA (em) 15.63 ± 0.06 14.93 ± 0.05

Bill depth (em) 2.56 ± 0.01 2.27 ± 0.01

may act as a barrier between parasitesand nestlings. Another reason for theoccurrence of feathers and otherelements may be territorial: feathersmay serve as a sign that the nest iscurrently in use and not available,thereby preventing fights.

Surface nest measurements such asborder height and cup diameter may beuseful when deciding the shape andsize of the cup inside the nest wherechicks and eggs will be kept, althoughin most captive situations (as in thewild) the cup is formed by the penguinsthemselves from the sand, gravel,twigs, or other material in the nest.

Nests may be more easily excavatedinto a slope and this may explain thepenguins' apparent preference forslopes. In areas where the ground isflat, nests are poorly dug and are onlyscrapes in the ground.

The covered nests which were monitored maintained relatively constanttemperature levels throughout the dayeven when external temperaturesvaried considerably. Surface nests, onthe other hand, are completely exposedto changes of temperature, humidityand wind, and accordingly measurements showed much greater variation.These results coincide with those foundby Frost in 1976, where covered nestsof African Penguins (Spheniscusdemersus) were warmer than theambient during the night and coolerduring the day. He also found, as wehave, that temperatures in surface nestswere higher than those in covered nestsduring the day and lower during thenight. Covered nests, then, provide aneffecti ve protection against solarradiation during the day and retainheat during the night.

Almost 90% of the nests at Punta SanJuan are located in the southern area ofthe point and have entrances orientedtowards the south, facing the prevailing wind. In this locale of warm daysand high ambient humidity, the windand sea breeze may counteract theeffects of the heat and maintain anoptimal level of ventilation inside thenest.

In addition, humidity was lower incovered nests than outdoors. Surfacenests are influenced by high andvariable ambient humidity levelsduring the day and are also directlyexposed to the intense winds.

It is crucial to keep chicks and eggsdry and protected from excessive levelsof humidity to avoid possible diseases.In zoological institutions, high humidity levels within nests or in the exhibitmay be related to the occurrence ofaspergillosis (McGill 1990), which isone of the most commonly reportedillnesses in captive penguins (Ellis1994).

Adult penguins at Punta San Juanarrive at their nests almost dry becausethey spend a considerable amount oftime preening and drying out beforethey go back to their nests afterforaging. This probably helps maintaina low level of humidity inside the nestsor at least a more stable environment.We recommend the location of nests inupper parts of penguin exhibits and faraway from the pool. This would notonly force the penguins to walk andexercise but to dry out before theyreach their nests.

Additional informationMeasurements of adults, chicks and

eggs are shown in Tables 3,4 and 5.

AcknowledgmentsWe would like to thank Carlos

Zavalaga for being there, for his discussions and constructive criticisms,and Nora Ampuero for her assistance inthe field.

We would also like to thank theOnset Computer Corporation fordonating the HoBos (data loggers) usedto monitor temperature and hUmiditylevels, and PROABONOS for providingthe permits and facilities to undertakethis study at Punta San Juan.

This study was supported by WildlifeConservation Society.

ReferencesAraya, B. 1988. Status of the Humboldt

penguin in Chile following the 198283 EI Nino. Spheniscid PenguinNewsletter 1(1):8-10.

Battistini, G. 1998. EI Nido delPinguino de Humboldt (Spheniscushumboldti) y su relaci6n con el exitoreproductivo. Thesis for the title ofLicentiate in Biology. UniversidadPeruana Cayetano Heredia.

Boersma, P. Dee. 1991. Nesting sites forSpheniscus penguins. SpheniscusPenguin Newsletter. 4(1):8-9.

Cheney, C. 1990. Spheniscus penguins:An overview of the world captivepopulation. Spheniscus PenguinNewsletter 3(1):12-17.


Table 5. Humboldt Penguin egg measurements taken at Punta San juan.

Chick age Weight Culmen length(g) (em)

Hatchlings 103.11 ± 23.85 1.64 ± 0.07(0-2 days) (n=99) (n=52)

Fledglings 3540 ± 340 5.04 ± 0.29(n=71) (n=71)

Table 4. Chick measurements (mean, SD, N)

McGill, P., Perkins, G. 1993. HumboldtPenguin SSP Report. SpheniscusPenguin Newsletter 6(1): 2-4.

McGill, P.; Brandt, G. 1995. HumboldtPenguin SSP: 1994 Report. PenguinConservation 8 (2):11-12.

McGill, P.; Brandt, G. 1997. HumboldtPenguin SSP: 1996 Report. PenguinConservation 10 (2):18-19.

McNeely, j.; Miller, K.R.; Reid,W.V.;Mittermeier, R.A.; Werner,T.B. 1990.Conserving the world's biological diversity. IUCN. Gland, Switzerland; WRI,CI, WWF-US and the World Bank.

61

n

102

102

Range

92 - 149

65.2 - 81.5

51.4-58.4

Stonehouse, B., Drent, R.H. 1976.Thermoregulatory responses of thePeruvian penguin Spheniscushumboldti. Compo Biochem. Physiol.40A:689-710.

Zuta, S.; Rivera,T.; Bustamante, A. 1978.Hydrologic aspects of the mainupwelling areas off Peru. In: Upwellingecosystems. Boje, R.; Tomczak, M.Berlin (eds.) Springer-Verlag.

74.12 ± 2.8

55.3 ± 1.69

125.5 ± 10.6

Average ±SD

Length

Weight

Width

Egg variables

Ellis, S. and Branch, S. (eds.) 1994.Penguin Husbandry Manual (firstedition). American Zoo and AquariumAssociation.

Frost, P.G.H.; Burger, A.E. 1976. Behavioural adaptations of the jackasspenguin, Spheniscus demersus, to a hotarid environment. Journal of Zoology179:165-187.

Harris, E.1. 1989. Humboldt penguinhusbandry at Woodland Park Zoo,Seattle. Spheniscid Penguin Newsletter1(2):1,10-13.

Hays, C. 1984. The Humboldt penguinSpheniscus humboldti in Peru and theeffects of the 1982-83 EI Nifio. Masterof Science thesis. University ofGainesville, Florida: 1-86.

Kawata, K. 1997. Penguins in japanesezoos and aquariums. Penguin Conservation 10:3.

Kleiman, D.G. 1989. Reintroduction ofcaptive mammals for conservation.BioScience 39(3): 152-161.

Lombardo, M.P.; Bosman,R.M.; Faro, c.A.;Houtteman,S.G.; Kluiska,T.S. 1995.Effect of feathers as nest insulation onincubation behaviour andreproductive perfomance of Treeswallows (Tachycineta bicolor). Auk112:973-981.

McGill, P. 1990. Spheniscus penguins:Panel discussion on field studies andcaptive management. SpheniscusPenguin Newsletter 3(1):2-11.

McGill, P. 1991. Humboldt SpeciesSurvival Plan Report. SpheniscusPenguin Newsletter 4(2):1, 18-19.

Pause in oil exploration off the Falklands Fishing overcapacity

continued from page 4 continued from page 2

award, [and] this is a remarkableachievement. The Falklands alsoproved to be a viable service center foroffshore drilling programs."

Mineral exploration is taking placeon land as well. Cambridge MineralResources were scheduled to haverepresentatives in the Islands duringjanuary and February. Geologists from

the British Geological Survey and theBritish Antarctic Survey were alsoplanning work in the Falklands, as wereseveral geologists from universities inthe UK. The Falklands Island Government has funded the preparation of ageological map of the Islands, copies ofwhich are now available for a fee.

10ngIine fisheries, which calls onfishing nations to develop conservationmeasures to reduce the mortality ofseabirds and eliminate the killing ofendangered species such as albatrosses.{reprinted from Seaweb Ocean Update,March 1999; an electronic publicationavailable from [email protected]]


Falklands breeding decline may be linked to oilcontinued from page 4

winter. In these instances only Kingpenguins, Gentoo penguins and cormorants were affected. The final spilloccurred just as the Rockhopperpenguins were returning to breed, andthey were also affected on this occasion.However, the relatively small scale natureof the spills meant that only a few siteswere affected. No further spills haveoccurred since the onset of breeding.

Nest counts were conducted aroundthe Falklands at the beginning of the1998/99 breeding season, and it soonbecame apparent that most breeding sitescontained a significant proportion ofdeferred breeders. Many of the adultswere below the weight that would beexpected at the start of the breedingseason, and it is apparent that they haveexperienced some difficulty in findingsufficient food during the winter monthsto reach peak condition for breeding.

Most seabirds are long-lived, and birdswhich are in poor condition prior to thestart of the breeding season can take ayear off from laying, called deferredbreeding. For a long-lived species it isbetter to rest for a year and regain fitness,rather than to begin the demandingprocess of breeding when there would belittle chance of success if the parent is inpoor condition.

Penguins, cormorants and albatrosswere all affected, but the King cormorantswere the worst affected with breedingnumbers down by around 40% since1997/98. Magellanic Penguins weredown by about 16%, and their population now stands at just one third ofwhat it was 10 years ago. Rockhopperpenguins were the only species to appearin good physical condition, and theywent against the general trend inshOWing a substantial populationincrease since 1997/98.

Those pairs that did lay have alsoshown lower than average chick survivalrates during the 1998/99 season. Gentoopenguins and King cormorants bothforage close to shore, and these twospecies showed chick survival rates wellbelow the average. Rockhopperpenguins, Magellanic Penguins andBlack-browed albatross all forage further

afield, and these species were generallymore successful at rearing chicks during1998/99.

These results are not surprising if onelooks at them in terms of food distribution. El Nino did not appear to affectthe marine food chains around theFalkland Islands during 1997/98,presumably because the waters aroundthe Falkland ISlands are shielded fromthe Pacific Ocean by the South Americancontinent. Nevertheless the watersaround the Falklands and Patagonia doflow northwards up from the southerntip of South America, so it is notunreasonable to suppose that the effectsof El Nino could eventually reach theFalkland Islands and beyond.

The abundance and distribution offish and squid populations can easily bedisrupted by these oceanic changes,causing them to move further off-shorewhere they are beyond the normalforaging range of in-shore feeding speciessuch as Gentoo penguins and Kingcormorants. Species with a greaterforaging range such as Rockhopperpenguins, Magellanic Penguins andalbatross are less easily affected becausethey have a greater chance of still beingable to reach sufficient prey to maintaintheir growing chicks.

Change in prey distribution andabundance was probably the majorfactor which brought about the reduction in breeding success this season.However, against that background therehas been a noticeable difference in thebreeding success of penguins at siteswhich were affected by oil spills compared to those which were not. For allspecies, those colonies in areas where oilspills occurred have shown lower chicksurvival rates than those in areas whichwere not affected.

...With only one season's data from alimited number of sites it is not possibleto be certain that the differencesobserved are genuinely the result of theoil. If they are, however, it suggests thateven small scale spills can affect marineecosystems in a way that we do not fullyunderstand. Normally one would hopeto acqUire more data in order to prove or

disprove the theory. In this case,however, it can only be hoped that moredata do not become available.

It seems likely that oil exploration willone day return to the Falklands, and it isunrealistic to expect any community togive up the financial prosperity which oildevelopment can bring in order to ensurethat oil spills can never occur. What isneeded is a sensible approach whichencourages the exploitation of anyexisting mineral resources, and yet whichat the same time minimises thelikelihood of environmental damage.

-Michael BinghamStanley, Falkland Islands

Fish handling booklet

continued from page 4

yeasts) will begin to multiply duringthawing. Proper techniques of thawingand handling can reduce risks to theanimals being fed.

The booklet also incl udes samplefroms for inspecting fish shipmentsand judging fish quality by acceptedvisual Signs, and for monitoring storageand handling procedures.

All standards and procedures complywith relevant regulations of the USgovernment.

The author is Director of NutritionServices at the Brookfield Zoo,Brookfield, Illinois.

While supplies last, single copies ofthis publication can be obtained at nocost from the Brookfield Zoo's AnimalCollection Administration, 3300 GolfRd., Brookfield, Illinois 60513-1060,phone 708-485-0263; fax 708-485-3532.

Also, copies can be purchased fromthe National Technical InformationService, 5285 Port Royal Road, Springfield, Virginia, 22161; phone 703-6056000. The price is not stated.


penguin conservation - the avian scientific advisory...

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