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SPN August, 1991 Spheniscus Newsletter vol. 4, number 1

In this Issue

The British and Irish Humboldt Studbook, 1990 1 Planning for the Future of North American Humboldts 1 Hand-rearing Humboldts at Sea World, San Diego 2

Building Better Nesting Sites for Spheniscus 8

A Survey of Spheniscus Field Studies 10 A Selected Bibliography of Spheniscus Penguins 16 This issue of SPN :

The major articles in this issue, with the exception of 'Nesting Sites for Spheniscus Penguins/" are from papers presented at the Spheniscus Workshop held at the AAZPA Regional Conference in Sacramento, California, in March 1990. Other papers presented at that workshop were included in the November, 1990 SPN, and it was intended to include all remaining papers in this issue. Unforhmate realities of printing costs/ however, forced a change in plan (see below for information on contributing toward production costs of this publication). Papers remaining, for our next issue, are: "/" "Incubation Behavior Patterns in Adelies/" "Molt Patterns of Black-footed Penguins," and "Diet, Feeding Regimen, and Growth Rates in Hand-reared Magellanic Chicks." Thanks to the authors and to the American Association of Zoological Parks and Aquariums, for permission to reprint these papers.

Publication information:

SPN Spheniscus Penguin Newsletter ISSN # 1045-0076 Indexed in Wildlife Review

SPN is published twice aIUlUally, with financial support from the Portland Chapter of the American Association ofZoo Keepers, and the Metro Washington Park Zoo. Subscription is free, to those with a serious interest in Spheniscus penguins. Contributions toward printing and postage costs arewelcome (and tax-deductible in the US) ;please make checks payable to "Portland Chapter, AAZK," and send to the Editor at the address below. Articles submitted for publication should be tYPed. For articles which include graphs (such as line or bar graphs) please include a separate sheet giving the data used to generate the graph. Authors who work on a Macintosh computer can help our layout process by sending their work on disk (accompanied by a paper copy just in case). Thedrawing which servesasourcover logo is reproduced bykind permission of the artist, Ann Munson. Thanks to Kathy Ivanov for help with word processing for this issue.

Please address all correspondence to: Cynthia Cheney, Editor Spheniscus Penguin Newsletter Washington Park Zoo 4001 SW Canyon Rd. Portland, Oregon 97221 USA Telephone: (503) 226-1561 FAX: (503) 226-6836 Field Studies of Spheniscus Penguins DAVID CAMERON DuFFY

THE POPULAR IMAGE OF PENGUINS IS ONE with marine OF ICE. HOWEVER, PENGUINS OF THE (Murphy, 1936). SPHENISCUS RARELY IF EVER SEE ICE AND The Galapagos Penguin has an ex- instead inhabit areas more tropical tremely restricted range, nesting only than polar. This has been both boon Long Island, New York on the west side of Isla Isabela and on and bane. The Spheniscus penguins Isla Fernandina in the western have taken the brunt of human ex- Galapagos Islands (Harris, 1974). The ploitation, while until recently being geographic names, so why not the is confined to the more or less ignored as research sub- ? George Gaylord upwelling of the jects compared to polar penguins. Simpson (976), the godfather of fossil of the west coast of , Human exploitation and research ne- penguinology, made the same plea. nesting from northern to Chiloe glect have now diminished, although Given the propensity of the vari- Island, (Araya, 1983; Hays, 1983). much remains to be done concerning ous to interbreed in captivity, The nests on the both conservation and research. a few words on their evolutionary re- Pacific coast, from central Chile, south What follows is a selective over- lationships are in . Genetically, around , and north on the view, but the papersci ted will provide there is at present only one study, by Atlantic, to central , as well access to the rest of the literature on Grant et a1. (in press), on the as on the Falklands and on several of each species. I would like to note that Humboldt, Magellanic and African Chile's offshore islands (Murphy, 1936; most of what we know is mostly the taxa, using electrophoretic analysis of Araya and Millie, 1986). The African result of work by a very few people: gene frequencies. The three species are Penguin nests from central Boersma on Galapagos Penguins; very closely related, suggesting that if south around the Scolaro on Magellanic Penguins; they are species, rather than subspe- and along the south coast of South Araya and Hays on Humboldt Pen- cies, they are very recent ones. The (Rand, 1960; Shelton et a1. 1984). guins; and Cooper, Rand, Randall, and Galapagos Penguin probably evolved Only the Magellanic and Hum- Wilson on African Penguins, presently from a stray colonization of the is- boldt overlap in breeding range, over the best known of the species. lands by Humboldt Penguins, approximately 1750km of Chilean although its double-breast pattern is coast (Duffy, 1987a; Duffy et aI., in more similar to that of the double- prep. a). Mixed pairs have been ob- banded Magellanic than of the served but not studied. We haven't a single-banded Humboldt. Similarly, clue as to how the species differ in There are currently believed to be the single-banded African Penguin their courtship and mating behavior four species of Spheniscus penguin: the may have evolved from the Magel- to prevent interbreeding in the wild. Humboldt Spheniscus humboldti, lanic or vice-versa. Galapagos Spheniscus mendiculus, Occasional individuals of the Afri- Magellanic Spheniscus magellanicus, canand, less frequently, the Humboldt, Colony Size And Distribution and the African, Black-footed, or Jack- have double stripes, suggesting either ass Spheniscus demersus, all with a very occasional immigration and past in- The Spheniscus penguins don't nest similar morphology (Livezey, 1989). terbreeding with Magellanics, or that in colonies so much as they nest where I prefer African as the common name a recessive gene for double-bandedness suitable access to the sea and suitable for the last species, as Jackass is also lurks in the best of . nesting sites occur, with nesting used for Magellanics and Humboldts, ranging from solitary Galapagos Pen- and Black-footed is singularly guins to immense colonies of uninformative. The other three have Distribution Magellanic and African penguins. The reasons for these differences need fur- David Cameron Duffy, The Spheniscus penguins range to ther study. The Galapagos Penguin Executive Director the Equator in the Pacific and stray nests in small, scattered groups The Seatuck Foundation almost to the Equator in the Atlantic (Boersma, 1977; Harcourt, 1980; Valle, P.O. Box 31 (: Shelton et. a1.1984), but they 1986). Much of its range appears too Islip, Long Island, NY 11751 are cool-water specialists, associating cliff-bound for birds to get ashore

SPlV August1991 page 10 Field Studies of Spheniscus Penguins

(Boersma, 1977), a problem faced by Magellanic Penguin, the Spheniscus The Magellanic Penguin, with a the other species. The Humboldt Pen- species can be found breeding population on the order of a million guin in Peru nests mostly in small throughout the year (Koepcke, 1970; birds or more, is increasing in Argen- colonies in sea-caves on islands and Boersma, 1978; Cooper, 1980) so that tina, perhaps because of changes in the coast or in on islands single counts, even at peak breeding, food availability or reduction of where it is slightly safer from intense miss many pairs that breed at other predators (Scolaro, 1985; Boersma et poaching pressure (Hays, 1983, Duffy times of year Randall et a1. (1986a) aI., 1990). The status of its population et aI., 1984a), whereas in Chile, where developed a method of counting in Chile is unknown, although the human disturbance is much reduced, birds throughout the year at species is common (Schlatter, 1984). it nests in much larger colonies on is- a frequency similar to the duration of The African Penguin has suffered a lands (Araya, 1983). The Magellanic moult, so that each moulting was population crash since the tum of the and African Penguins nest or nested counted only once. Assuming that century (Burger and Cooper, 1984; in colonies of 10,000 to 100,000+ birds do not move to other islands to Shelton, et aI., 1984) Between 1956and (Scolaro and Arias de Reyna, 1984; moult (Randall et aI., 1987), this would 1978, the population decreased from Scolaro et aI., 1980a, 1984; Shelton et give a 'true' count of the population. 230,000 to 100,000 (Burger and Coo- aI., 1984; Capurro et aI., 1988). Except per, 1984), but its recent dynamics have for several small colonies which may been complex, decreasing in the cen- suffer periodic bouts of catastrophic Population Fluctuations and Trends ter of its range and increasing or disturbance from humans and at least remaining stable to the north and east once from a (Panthera pardus) With the possible exception of the (Frost et aI., 1976a; Siegfried and (pers. observ.), African Penguins nest Magellanic Penguin, the Spheniscus Crawford, 1978; Shelton et al., 1984). on islands (Shelton et aI., 1984). penguins have suffered either short- These changes have been linked to Magellanics nest on both islands and term or historical population changes in fish stock (Crawford and the mainland, and it remains a mys- decreases. The Galapagos Penguin, Shelton, 1978, 1981; Burger and Coo- tery to me why terrestrial predators apparently otherwise stable at between per, 1984; Crawford et aI., 1985) and have notexterrninated whole colonies. 3,000 and 15,000 birds (Brasset, 1963; (Crawford and Shelton, Scolaro (1985) suggests that humans Harris, 1977; Boersma, 1977), lost 77% 1978, 1981), but the mechanisms for have reduced local populations of ter- of its counted population during the overfishing are unclear, as penguins restrial predators. strong El Nino oceanographic event and fishermen don't fish in the same in 1982-1983 and subsequently expe- areas (Broni, 1986; Wilson et aI., 1988) rienced poor reproduction through and fishery landings bear no relation Numbers 1984 (Valle and Coulter, 1987). More to penguin diet or growth (Duffy et recent data have not been published. aI., 1987a). Breeding success for pen- Counting Penguins Humboldt Penguins in Peru have guins at one island studied near. been in decline since the 19th century, fishing grounds was the same as that Not the least of problems involved perhaps in part because of the removal on a control island in an unfished area in studying penguins is counting them. of the substrate they used for (La Cock et aI., 1987). At present, we The Galapagos and Humboldt are their nests (Murphy, 1936). I believe that penguins and fishermen frequently counted from boats, pitch- suspect, however, that human exploi- compete during the pelagic first-year ing just beyond the surf, as observers tation for food has been and continues of life of the African penguin, when try to see birds in caves or under rocks, to be a serious, if not the principal juveniles from decreasing colonies (Boersma, 1977; Hays, 1984). As both problem (Duffy et aI., 1984a). The Pe- disperse to areas ofintense fishing and species are partially nocturnal on land ruvian and Chilean combined have low survival rates, whereas those or feed at sea during the day (Boersma, population was estimated to be ap- fram stable or increasing colonies dis- 1977; Duffy et aI, in prep a), day counts proximately 20,000 (Hays, 1983,1984) perse to unfished areas and survive are underestimates. Countsatcolonies before the 1982-1983 El Nino which better (La Cock et aI., 1987; Duffy and also have problems, as many nest sites reduced numbers by 65% in Peru to Cooper, 1990). are unoccupied, depending on time of 2,000-3,000 (Hays, 1986). Similar re- day (Frost et aI., 1976a; Hays, 1984; ductions occurred in Chile (Araya, Capurro et aI., 1988) and one par may 1984 ms; Araya and Todd, 1988). More visit several sites (Capurro et aI., 1988). recent data are not available. Even worse, with the exception of the please turn to page 12 SPN August 1991 page 11 Field Studies of Spheniscus Penguins continued from page 11

Natural and Unnatural Mortality tality of Magellanic Penguins in Ar- the southern distribution leaves too gentina (Jehl, 1975; Perkins, 1983; few daylight hours for dur- Accounts of the natural predators Boersma et aI., 1990). ing the winter (Duffy et aI., in prep a). of Spheniscus penguins are numerous NaturaI disasters, ranging from 10- (e.g. Galapagos Penguin: Boersma, caI heavy rains (Crawford et aI., 1986; Nest site 1977; Humboldt Penguin: Hays, 1984, Randall et aI., 1986b; Duffy et aI., 1988) 1986; Araya and Duffy, 1987; Magel- and anomalous cold-water events The biggest problem for nesting lanie Penguin: Boswall, 1972; (Schumann et aI., 1989) to species-wide Spheniscus penguins is the sun (Drent Rodriguez, 1983; Scolaro, 1985, Afri- El Nino-caused mortality (Vogt, 1942; and Stonehouse, 1971; Frost et aI., can Penguin: Cooper, 1974; Brooke and Boersma, 1978; Boersma, 1987; Duffy 1976b). They avoid it by nesting in Wallett, 1976; Frost et aI., 1976a; et aI., 1984a,b, 1988; Hays, 1986; La burrows and sea caves or under veg- I.Randall et aI., 1988). Parasites may Cock, 1986; Valle and Coulter, 1987; etation (Murphy, 1936; Scolaro and also be important (e.g. Boersma, 1977; Araya and Todd, 1988; Duffy, 1990), Arias de Reyna, 1984b), or, if surface- Randall and Bray, 1983; Duffy and havebeen well documented, but again nesting, doing so during the winter Daturi, 1987), but we have almost no the population effects have been diffi- (La Cock, 1988) or when there is a idea of the impact of either parasites cult to document because, with the strong windchill. When penguins nest or predators on penguins at the popu- exception of the Galapagos (Valle and on the surface, they tend to nest lation level. Such studies are urgently Coulter, 1987) and locally with the Af- densely, to protect their eggs and needed. rican (La Cock et aI., 1987; La Cock young against aerial predators Human exploitation ranges from and Hanel, 1987) and Magellanic (Siegfried, 1977). Burrow nests appear poaching (Duffy et aI., 1984a; Hays, (Boersma et aI., 1990) penguins, long- more successful than surface nests 1984; Schlatter 1984) to indigenous term population or breeding data are (Frost et aI., 1976a) which may be used clothing (Avery, 1985) and industrial not available. Computer models of when covered sites are occupied or glove production (Scolaro, 1986) to zoo penguin populations (e.g. Jackson et substrates are unsuitable for burrow- exports (Hays, 1984). Exploitation of aI., 1976; Scolaro, 1987b; Scolaro et aI., ing because of texture or susceptibility eggs (up to 500, OOO/year and 13 mil- 1981) may help assess the possible im- to flooding (Scolaro, 1984; La Cock, lion in 30 years: Siegfried and pact of natural, and unnatural, 1988). Nest sites must also be acces- Crawford, 1978) in disasters, long before we have direct sible to the sea and, for surface nesters, caused population decreases on atleast data (Duffy, 1990). essentially level, as penguins build someof the islands (Frost et aI., 1976a). only rudimentary nests (Duffy and La Oiling has been especially noticeable Cock, 1985). These require- off South Africa, on the route of much Nesting Biology ments combine to produce complex of the world's tanker traffic (Westphal mosaics ofnesting colony distributions and Rowan, 1971; Morant et aI., 1981), Breeding Seasons and nest densities (e.g. Bodano et aI., but there is some disagreement over 1982; Scolaro and Arias de Reyna, its impact. Frost et aI. (1976a) estimated Humboldt (Koepcke 1970; Castro 1984a,b; Scolaro, 1984; Scolaro et aI., the oiling rate to be only 0.7-0.9%/ and Ishiyama, 1985-1986) and Afri- 1979, 1984, 1985; Duffy and La Cock, year, but Randall et aI. (1980) working can Penguins nest throughout most of 1985; Capurro et aI., 1988). These in farther to the east considered oiling the year, (Cooper, 1980; Randall and turn complicate estimates of colony the main cause of adult mortality. A Randall, 1981, La Cock et aI., 1987) but size (discussed above). major public effort, the South African show strong seasonal which have been National Foundation for the Conser- linked to differences in food availabil- vation of Coastal Birds, operates a ity (Wilson, 1985c) and nesting success Breeding Behavior and Ecology permanent rescue and cleaning opera- (Wilson, 1985c; La Cock et aI., 1987). tion that has been highly effective in Boersma (1977, 1978) showed that nest- Breeding of the Spheniscus pen- returningbirds to the wild and in edu- ing by Galapagos Penguins can occur guins appears relatively similar across cating the public about oil throughout the year, in response to species, although we lack details for contamination (Randall et aI., 1980; appropriate oceanographic and food the Humboldt Penguin in the wild. Morant et aI., 1981). Oiling rates in conditions. In contrast, Magellanic Boersma (1977); Scolaro (1978, 1980, Galapagos and Peru are apparently Penguin nesting is strongly seasonal 1983,1984a,b,d), Scolaro et al. (1980a); low, but there is considerable concern (Scolaro, 1984a; Scolaro et al. 1980a; Cooper (1980), Hockey and Hallinan about oiling rates and resulting mor- Boersma et aI., 1990), perhapsbecause (1981), Randall (1983), Williams and

SPN August 1991 page 12 Cooper (1984), and Wilson (1985c) pro- the water (Boersma, 1977; Cooper, be biased by a variety of factors, in- vide details of various aspects of the 1978). For Magellanic Penguins, moult cluding methods of analysis, and breeding of Galapagos, Magellanic occurs during a relatively short, fixed comparisons of data can be hindered and African penguins, respectively. time of year, after breeding and prior by differing methods of presentation For the African Penguin, the normal to dispersal from the colony (Scolaro, (Duffy and Jackson, 1986). Another clutch is two eggs, laid about three 1984d). This fixed pattern appears to complication is differential digestion days apart, with an incubation period be a response to the strongly seasonal of prey species, which has led to stud- of 38 days, and both young are usu- and consistent pattern of climate and ies of penguin digestive rates (Furness ally raised in about 80 days, except food availability, not found in the en- and Laugksch, 1983; Duffy etaI., 1985a; during poor food conditions, when the vironments of the other species. Wilson et aI., 1985; Laugksch and youngerof the pair dies (Cooper, 1980; African and Galapagos Penguins can Duffy, 1986; Wilson et aI., 1989b). Williams and Cooper, 1984). For the be found moulting throughout the Diet reviews which summarize Magellanic Penguin, the incubation year, but African Penguins exhibit a previous work include: African Pen- period for the two-egg clutch is 38-42 strong seasonal peak in October- guin: Rand (1960); Randall and Randall days, with a two to four day period November (Randall and Randall, (1986); Duffy et a1. (1985a, 1987a,b); between eggs and an extremely vari- 1981). Moulting is a pre-breeding ac- Humboldt: Wilson et a1. (1989a); Duffy able growth of young to fledging tivity in Galapagos Penguins et a1. (in prep. a); Galapagos: Boersma (Boersma et al., 1990). The Galapagos (Boersma, 1977). lt occurs, although (1977) and Magellanic: Gosztonyi Penguin also lays two eggs, three or not in the same birds, both immedi- (1984); Scolaro and Bodano (1985). Ba- four days apart, has an incubation pe- ately before and after breeding in sically, Spheniscus penguins eat a wide riod of approximately 38 days and African Penguins (Cooper, 1978), but variety of species and sizes of prey, young reach adult size at thirty days, appears to be predominantly post- from 10 to 310 mm (Wilson and Wil- "although some chicks remained in breeding (Randall and Randall, 1981). son, 1990> but specialize on small, the nest until after 50 days of age" Galapagos Penguins moult twice a schooling fish, such as (Boersma, 1977), which is a very short year (Boersma, 1977), perhaps as a re- Engraulis spp. and Sardinops. fledging period compared to the other sponse to damage to by the two species. equatorial sun. If this is the case, a similar frequency of moult should oc- Distribution at Sea cur in Humboldt Penguins. Moult in Growth African Penguins and Magellanics ap- Measurement of distribution at sea pears to be annual (Randall and is extremely difficult, as penguins ride Growth of young in the field has Randall, 1981; Scolaro, 1984). low in the water and travel underwa- been extensively studied in African Moult appears to be extremely ter, reducing the chance of seeing Penguins (Cooper, 1977; Williams and stressful, and birds may be forced to them. The two traditional ways of Cooper, 1984; Duffy et aI., 1987a). return to the water to forage before studying them have been to measure Heath and Randall (1985) examined completion (Boersma, 1977), even the duration of foraging trips and to growth of African penguins fed dif- though they lack thermal protection run transects at sea. In the first case, ferent diets. Boersma (1977) provided against the cold (Erasmus et aI., 1981) the departure and return times of pen- the only growth data for theGalapagos and may be too slow to catch their guins, especially those with small Penguin, and Scolaro (1984d) and normal prey (Wilson, 1985b). young, are measured (Boersma, 1977; Boersma et a1. (1990) for Magellanics. Wilson, 1985a). By assuming a certain No published data exist for Humboldt traveling speed and time spent actu- Penguins. Foraging Biology ally foraging, a maximum range can be calculated (Wilson, 1985a,b; Duffy Diet et aI., 1987a; Wilson et aI., 1988). These Moult measurements are necessarily rather Early diet work involved killing crude. Moult takes approximately 20 days birds. The development of an effec- In the second case, direct observa- in Humboldt Penguins, 10-15 days in tive stomach pump (Wilson, 1984) tion, penguinsare counted on transects Galapagos Penguins, and 18 days in removed all necessity to slaughter pen- from moving vessels. Observations African Penguins, during which time guins for diet studies. Problems the birds fast and usually do not enter remain, however, as diet analyses can please turn to page 14

SPN August 1991 page 13 Field Studies of Spheniscus Penguins continued from page 13 include distance from shore, group A potentially serious problem with in murky waters. Most of our infer- size, social behavior, and attendance devicesand methodsof attaching them ences come from indirect observations in foraging groups (e.g. Rand, 1960; is the increased drag or water-resis- or devices measuring depth, speed, Siegfriedeta1., 1975; Duffy, 1983, 1989; tance they can create when the and duration of dive, size of foraging Broni, 1986; Wilson et aI., 1986b, 1988). penguins are diving. Drag may ham- group, stomach samples, and fish be- Unfortunately, transects require strong per foraging or cause birds to desert havior stomachs, are extremely expensive to their nests (Wilson et aI., 1986a), so Being flightless, Spheniscus pen- run, and are frequently interrupted by recent devices have tended to be as guins must encounter frequent, bad weather.The presence of a vessel small as possible. In addition, either inshore food sources, as the birds must may also influence penguin behavior. the devices or their attachments may swim, not fly, to their foraging More recently, methods have annoy the birds sufficiently to gener- grounds and underwater searching been developed to measure Spheniscus ate aberrant behavior. Wilson and visibilities are short (Frost et aI., penguin foraging at sea, through re- Wilson (1989b) developed a device to 1986a). Penguins seem to travel di- mote sensing. Small measurement count the number of pecks directed at rectly, often in groups (e.g. Siegfried packages are placed on the bird (e.g. devices, as a measure of disturbance. eta1., 1975; Boersma, 1977; Broni, 1986) Heath, 1987; Wilson and Wilson, Finally, the disturbance caused by cap- to a certain area, then begin searching 1989a) and either store data until re- turing the bird to install and remove (e.g. Wilson and Wilson, 1988; Heath covered or transmit them by radio. devices may be a serious problem, es- and Randall, 1989). We do not know Speed, depth and distance metersstore pecially perhaps for birds such as whether physical (e.g. depth, bottom data on x-ray film, using small Humboldt Penguins in Peru, that ap- topography, currents, wave height, amounts of radioactivity to mark the pear much more shy than other temperature) or biological (turbidity., film (Wilson and Bain, 1984a,b) or use Spheniscus populations (pers. observ.). presence of fish schools) clues lead a counter to store counts of propeller Automatic injection of sedatives by the birds to stop traveling and start turns (Wilson and Achleiter, 1985). remote control may reduce trauma searching, by diving. Locating the When combined with diet data from (e.g. Wilson and Wilson, 1989c). school at a fishing area may be done birds returning colonies, the devices During the breeding season, pen- by an individual bird, or it may be allow estimates of foraging effort guins return to shore. Frequently, attracted to calls by other penguins versus food ingested (e.g. Nagy et aI., especially when feeding young, so (Broni, 1986) or by foraging by other 1984). they tend to be distributed at sea near species (Duffy, 1983, 1989). Radio-transmitters provide con- their colonies. During their first year Most dives are relatively shallow tinuous signals while birds are on the of life and, while non-breeding, pen- (Wilson, 1985b), suggesting feeding on surface (Heath and Randall, 1989). In- guins may be pelagic for extended fish schools near thesurface. Most pen- terruption of the signal is caused by periods of time (Wilson et aI., 1988; guin prey form schoolsand, while this submergence, so the device can be Duffy and Cooper, 1990). may facilitate locating fish, penguins used to measure dive frequency and may find it difficult to target a single duration. Range of signal can be a fish, amongst tens or hundreds of problem, as penguins ride so low in Foraging Behavior thousands of similarly-sized, similarly the water that waves intercept signals. behaving fish. Based on bite marks on Also, triangulation of radio-signals Wilson and Wilson (1990) have re- fish, penguins attack from below, per- and pursuit of with airplanes cently reviewed Spheniscus foraging. haps silhouetting the fish against the or boats is necessary for locating the They report that Spheniscus penguins surface (Wilson and Duffy, 1986; Wil- birds at sea. Nevertheless, radio-trans- travel at 6.8 -7.4 kph underwater and son et aI., 1989a) and using their dark mitters can provide an abundance of at 12.3 kph while porpoising. Dives dorsal plumageas camouflage (Cairns, detailed data which can be combined can last as long as 146 sec and reach 1986). They may also use the alternat- with direct, simultaneousobservations mean maximum depths of 60+ m, al- ing black and white of the breast band of foraging situations and prey. Where though most dives are shallower.They as an aggressive display, herding the telemetry is not possible, a new dead- may travel as much as 72 km per day fish in a school closer and closer, until reckoning device may provide similar while providing food for young. the minimum distance between fish data, although it requires recovery of Unfortunately, we know relatively breaks down and the school structure the bird with the device (Wilson and little about actual foraging behavior, collapses (Wilson et aI., 1987). Pen- Wilson, 1988). as events take place tens of meters guins may also use group fishing to below the sea-surface, at high speeds break up school structure (Sumner,

SPN August 1991 page 14 1934; Boersma, 1977; Boswall and have basic ethograms of the four spe- nerable to terrestrial predators. Arti- Maclvor, 1975; Wilson et al., 1987) or cies, to allow comparison of their ficial burrows could raise the may join with other predators that ef- species-specific and sex-specific behav- 'carrying capacity' of such sites. fectively serve the same role (Boersma, iors in captivity (e.g. Merritt and King, 1977; Broni, 1986), although Wilson 1987; Scholten, 1989). Adding or re- (l985b) suggests that African Penguins moving breast bands would be an Conclusion forage on smaller schools of fish than interesting experiment to test the im- do other birds. Finally, penguins may portance of such coloration between This is a highly condensed review drive fish to the surface for other, more species (d. Ryan et al., 1987).lt would of the literature on field studies of shallowly-diving birds (Broni, 1986). also be interesting, without allowing Spheniscus penguins. It does not, for actual reproduction, to study the be- lack of space, do justice to many fine havior of mixed-species pairs in studies and to the physical environ- captivity. ments in which the birds nest and Contributions From Captive Studies Work on aging and sexing pen- forage or to the ecology of prey spe- guins is extremely important and cies. We know a great deal about Those who have an opportunity to useful (e.g. Cooper, 1972; Bulfon et al., Spheniscus penguins, especially their study the Spheniscus Penguins in cap- 1986; Boersma and Davies, 1987; nesting ecologies and diets, but, even tivity have much to contribute to our Scolaro, 1987a; Scolaro et al., 1983). with the development of increasingly basic knowledgeand research that will Measurements of captive birds, under sophisticated means of studying pen- aid in penguin conservation. Such re- constant conditions, over time will guins at sea, we are really only search can range from the intensive, greatly aid field studies (e.g. beginning to understand the marine such as behavioral studies, to low-key, Edgington, 1989). Determination of the part of their existence. Unfortunately, such as consistent measurements of growth of young (Cooper, 1977), en- field researchers can be criticized, with mass and body measurement of indi- ergetics (Erasmus and Smith, 1974), a few bright exceptions, for not apply- vidual penguins over time. and of ageoffirst-breeding under con- ingour knowledge to the management Careful measurements of several trolled, captive conditions would also and conservation of Spheniscus pen- generations of penguins, raised under be very useful for comparison with guins. The managers of captive constant conditions, will give us a similar measurements made in the penguins with their direct manage- much-needed idea of heritability of much more variable natural condi- ment experience, albeit at a very small body size. If we can measure the rela- tions. scale, can play an important role in tive contributions of envirornnental Birds, such as those kept at Sea applying the insights of field work to and genetic factors, we can perhaps World, Inc. in Mission Bay, San Di- the management of wild, as well as use changes in body size to monitor ego, may potentially play an important captive populations. n population dynamics of Spheniscus role in our understanding of how penguins (Duffy, 1987b). This will be penguins detect El Nino. Linda Henry invaluable in examining the possible and I have been examining data that References are included in the bibliography effects of competition with corrnner- seem to show that the Humboldt which follows. cial fisheries and of climate change. Penguins at Sea World stopped Measurement of known genetic lin- breeding during the severe 1983 El eages can also give us some idea of Nino.These birds were fed ad libitum,so the genetic basis for partial and com- food shortage was not responsible. plete double breast banding in African What clues caused them to stop (d. and Humboldt penguins and can be Merritt and King, 1987)? compared with molecular genetic Finally, the development of inex- studies. pensive, safe artificial burrows and We know something about the their testing in captivity would pro- courtship and mating behavior of two vide a useful management tool for of the species (e.g. Boersma, 1977; penguin managers in the field. For ex- Eggleton and Siegfried, 1979), but we ample,lack of sites on small islets may have little information about force penguins in Africa and Humboldts or Magellanics (Jouventin, Galapagos to nest on the mainland or 1982). lt would be extremely useful to on larger islands where they are vul-

SPN August 1991 page 15 A Selected Bibliography of the Spheniscus Penguins

DAVID CAMERON DuFFY

I have attempted to make this bibliography as complete as possible and it probably contains most of the more important Sphenisclls ecology papers published before 1987. Historical, local colony counts and more recent papers, especially those in regional journals, may have been omitted. I would appreciate references or reprints ofmissing recent papers.

Araya. 1983. A preliminary report on the status and distribution of the Humboldt Penguin in Chile. In J. Delacour (ed.). Proceedings of the International Foundation for the Conservation of Birds Symposium on Breeding Birds in Captivity, Los Angeles. pp. 125-135. Araya and Millie. 1986. Guia de Campo de las Aves de Chile. Editorial Universitaria, Santiago. Araya and Duffy. 1987. introductions to Isla Chanaral, Chile: their history and effect on . Cormorant 15:3-6. Araya and Todd. 1988. Status of the Humboldt Penguin in Chile following the 1982-83 El Nino. Spheniscid Penguin Newsletter 1:8-10. Avery. 1985. Late Holocene use of penguin skins: evidence from a coastal shell midden at Steenbras Bay, Luderitz Peninsula, South West Africa-Namibia. Annals of the South African Museum 96;55-65. Berry, Seely and Fryer. 1974. The status of the Jackass Penguin Spheniscus demersus on Halifax Island off South West Africa. Madoqua Ser. II 3:27-29. Bodano, Scolaro and Upton. 1982. Distribucion espacial de la nidificacion de Spheniscus magellanicus en Cabo Dos Bahias, Chubut, Argentina (Aves: Spheniscidae). Historia Natural 2 (27):241-251. Boersma. 1977. An ecological and behavioral study of the Galapagos penguin. Living Bird 15:43-93. Boersma. 1978. Breeding patterns of Galapagos Penguins as an indicator of oceanographic conditions. Science 200: 141-148. Boersma. 1987. El Nino behind penguin deaths? Nature 327:96. Boersma. 1988. Magellanic Penguins of . Spheniscid Penguin Newsletter 1:2-3. Boersma and Davies. 1987. Sexing monomorphic birds by vent measurements. Auk 104: 779-783. Boersma, Stokes and Yorio. 1990. Reproductive variability and historical change of Magellanic Penguins (Spheniscus magellanicus) at Punta Tombo, Argentina. In J. Darby and L. Davies (eds.), Penguins, Academic Press, Orlando, Florida Boswall. 1972. TheSouth African Otana byronia as a predator on penguins. British Ornithologists Club Bulletin 92: 129-132. Boswall and Maciver. 1974. The Magellanic Penguin. In. B. Stonehouse (ed.). The Biology of Penguins. University Park Press, London, pp. 271-305 Bowmaker and Martin. 1985. Visual pigments and oil droplets in the penguin, Spheniscus hum bold ti. Journal of Compara- tive Physiology A 156:71-77. Broni. 1982. First recorded mainland breeding by the Jackass Penguin Spheniscus demersus. Cormorant 10: 120. Broni. 1983. An apparent instance of courtship feeding in the Jackass Penguin Spheniscus demersus. Cormorant 11:63-64. Broni. 1986. Social and spatial foraging patterns of the Jackass Penguin Spheniscus demersus. South African Journal of Zoology 20: 241-245. Brooke and Wallett. 1976. Shark on seabirds in Natal waters. Ostrich 47;126. Brosset. 1963. La reproduction desoiseaux de mer des iles Galapagos en 1962. Alauda 31 :81-109. Bulfon, Bee de Speroni and Scolaro. 1986. An attempt at aging Magellanic Penguins Spheniscus magellanicus by histological analysis of feather follicles. Cormorant 13: 168-171. David Cameron Duffy, Burger and Cooper. 1984. The effects of fisheries on seabirds in South Africa Executive Director and Namibia. In D.N. Nettleship, CA. Sanger and P. F. Springer The Sea tuck Foundation (eds.) Marine birds: their feeding ecology and commercial fisheries rela- p.o. Box 31 tionships. Canadian Wildlife Service Special Publication, Ottawa, pp. Islip, Long Island, NY 11751 150-160.

SPN August 1991 page 16 A Selected Bibliography of the Spheniscus Penguins

Cairns. 1986. Plumage colour in pursuit-diving seabirds: why do penguins wear tuxedos? Bird Behaviour 6:58-65. Capurro, Frere, Gandini, Gandini, Holik, Lichtschein and Boersma. 1988. Nest density and population size of Magel- lanic Penguins (Spheniscus magellanicus) at Cabo Dos Bahias, Argentina. Auk 105:585-588. Castro and Ishiyama. 1985-1986. Algunas consideraciones acerca del Pinguino de Humboldt. Reuista de la Associaci6n Nacional de Biologos del Peru. 3:37-41. Cooper. 1972. Sexing the Jackass Penguin. SAFRING News 1:23-25. Cooper. 1974. The predators of the Jackass Penguin Spheniscus demersus. Bulletin of the British Ornithological Club 94:21-24. Cooper. 1977. Energetic requirements for growth of the Jackass penguin. Zoologica Africana 12:201-213. Cooper. 1978. Moult of the Black-footed penguin. International Zoo Yearbook 18:21-27. Cooper. 1980. Breeding biology of the jackass penguin with special reference to its conservation. Proceedings of the Fourth Pan-African Ornithological Congress, pp. 227-231. Cooper. 1982. Methods of reducing mortality of seabirds caused by underwater blasting. Cormorant 10:109-113. Cooper, 1984. Changes in resource division among four breeding seabirds in the Benguela up-welling system. Proceed- ings of the Pan-African Ornithological Congress, pp. 217-230. Cooper. 1986. Runt eggs of the Jackass Penguin Spheniscus demersus .. Cormorant 13:1 12-117. Cooper and Morant. 1981. The design of stainless flipper bands for penguins. Ostrich 52: 119-123. Crawford and Shelton. 1978. and interrelationships off the coast of South West and South Africa. Biological Conservation 14: 85-109. Crawford and Shelton. 1981. Population trends for some southern African seabirds related to fish availability. In I. Cooper (ed.) Proceedings of the Symposium on the Birds of the Sea and Shore, 1979. African Seabird Group, , pp. 15-41. Crawford, Cruikshank, Shelton and Kruger. 1985. Partitioning of a goby resource amongst four avian predators and evidence for altered trophic flow in the pelagic community of an intense, perennial upwelling system. South African Journal of Marine Science 3:215-228. Crawford, Williams and Crawford. 1986. A note on mortality of seabirds off western southern Africa, October 1985- February 1986. South African Journal of Marine Science 4:119-123. Drent and Stonehouse. 1971. Thermoregulatory responses of the Peruvian penguin, Spheniscus humboldti. Comparative Biochemistry and Physiology 40A:689-71O. Duffy. 1983. The foraging ecology of Peruvian seabirds. Auk 100:800-810. Duffy. 1987a. Three thousand kilometers of Chilean penguins. Explorers Journal 65: 106-109. Duffy. 1987b. Ecological implications of intercolony size-variation in jack-ass penguins. Ostrich 58;54-57. Duffy. 1989. Seabird foraging aggregations: a comparison of two southern . Colonial Waterbirds 12: 164-175. Duffy. 1990. Seabirds and the 1982-1984 EI Nino/Southern Oscillation. In P. W. Glynn (ed.) Global Ecological Conse- quences of the 1982/83 El Nino Southern Oscillation. Elsevier, in press. Duffy and La Cock. 1985. Partitioning of nesting space among seabirds of the Benguela upwelling region. Ostrich 56:156-201. Duffy and Jackson. 1986. Diet studies of seabirds: a review of methods. Colonial Waterbirds 9:1-17. Duffy and Daturi. 1987. Diel rhythms of tick parasitism on incubating African penguins Medical and Veterinary Entomology 1:103-106. Duffy and Siegfried. 1987. Temporal variations in food consumption by seabirds of two upwellings. In J. P. Croxall (ed.). Seabird .Feeding Ecology. Cambridge University Press, pp. 327-346. Duffy and Cooper. 1990. Distribution and survival of juvenile jackass penguins at sea: an explanation of population trends. South African Journal of Science, in press. Duffy, Hays and Plenge. 1984a. The of Peruvian seabirds. In J. P. Croxall, P. G. H. Evans and R. W. Schreiber (eds.). Status and Conservation of the World's Seabirds. ICBP Teclmical Publication 2, pp. 245-259. Duffy, Berruti, Randall, and Cooper. 1984b. The effects of the 1982-1983 warm-water event on breeding South African seabirds. South African Journal of Science 10:65-69. Duffy, Furness, Laugksch and Smith. 1985a. Two methods of measuring food transit rates of seabirds. Comparative Biochemistry and Physiology 82a:781-785. please turn to pagel 8

SPN August 1991 page 17 A Selected Bibliography of the Spheniscus Penguins continued from page 17 Duffy, Wilson, and Berruti. 1985b. Anchovy in the diets of Dyer Island penguins: a test of two models of anchovy distribution. South African Journal of Science 81:552-554. Duffy, Wilson, Ricklefs, Broni and Veldhuis. 1987a. Penguins and purse-seiners: competition or coexistence? National Geographic Research 3:480-.188. Duffy, Siegfried and Jackson. 1987b. The Benguela : seabirds as consumers: a review. South African Journal of Marine Science 5:771-790. Duffy, Arntz, Tovar, Boersma and Norton. 1988. The effects of El Nino and the Southern Oscillation on seabirds in the Atlantic Ocean compared to events in Peru. Acta XIX Congresus lnternationalis Ornithogici 1740-1746. Duffy, Wilson, Wilson, Araya and Klages. (in prep. a). The ecology of Humboldt and Magellanic penguins in Chile ms. Duffy, Wilson and Wilson. (in prep. b). The use of seabirds to monitor the recruitment of anchovy. Edgington. 1989. Behavioural and morphological sexing of the Humboldt Penguin (Spheniscus humboldti). Spheniscid Penguin Newsletter 2: 1.1-20. Eggleton and Siegfried. 1979. Displays of the Jackass Penguin. Ostrich 50:139-167. Erasmus and Smith. 1974. Temperature regulation of young Jackass Penguins Spheniscus demersus. Zoologica Africana 9:195-203. Erasmus, Randall and Randall. 1981. Oil pOllution, insulation and body temperatures in the Jackass Penguin Spheniscus demersus. Comparative Biochemistry and Physiology 69A:169-171. Frost, Siegfried and Cooper. 1976a. The conservation of the Jackass Penguin (Spheniscus demersus). Biological Conservation 9: 79-99. "J Frost. Siegfried and Burger. 1976b. Behavioural adaptations of the Jackass Penguin, Spheniscus demersus to a hot, arid environment.Journal of Zoology 179:165-187. Furness and Laugksch. 1983. An attempt to use barium meals and X-ray photography to determine gastric evacuation rate and gut retention time in Jackass Penguins Spheniscus demersus. Cormorant 11:3-6. Gosztonyi. 1984. La alimentacion del pingiiino magellanico (Spheniscus magellanicus) en las adyacencias de Punta Tombo, Chubut, Argentina. Centro Nacional Patag6nico Contribuci6n 95:1-9. Grant, Leslie, and Duffy. 1990. Molecular evolution of Spheniscus penguins. Proceedings of the Pan African Ornithological Congress. in press. Harcourt. 1980. Report on a census of the Hightless Cormorant and Galapagos Penguin. Noticias de Galapagos 32:7-11. Harris. 1974. A Field Guide to the Birds of Galapagos. Collins, London. Harris. 11977. Comparative ecology of seabirds in the Galapagos Archipelago. In B. Stonehouse and C. M. Perrins (eds ).Evolutionary Ecology. MacMillan, London, pp. 65-76. Hays. 1983. Informe preliminar sobre la situacion del Pingiiino de Humboldt en el Peru. Primer Symposio de Ornitologia Neotropical, pp. 61-68. Hays. 1984. The Humboldt Penguin in Peru. Oryx 18: 92-95. Hays. 1986. Effects of the 1982-83 EI Nino on Humboldt Penguin colonies in Peru. Biological Conservation 36: 169-179. Heath. 1987. A method for attaching transmitters to penguins. Journal of Wildlife Management 51:399-400. Heath and Randall. 1985. Growth of Jackass penguin chicks (Spheniscus demersus) hand reared on different diets.Journal of Zoology 205:91-105. Heath and Randall. 1989. Foraging ranges and movements of jackass penguins (Spheniscus demersus) established through radio telemetry. Journal of Zoology 217:367-379. Hockey and Hallinan. 1981. Effect of human disturbance on the breeding behaviour of jackass penguins Spheniscus demersus. South African Journal of Wildlife Research 11 :59-62. Hui. 1985. Maneuverability of the Humboldt penguin (Spheniscus humboldti) during swimming. Canadian Journal of Zoology 63: 2165-2167. Jackson, Siegfried and Cooper. 1976. A simulation model for the population dynamics of the jackass penguin, Transac- tions of the Royal Society of South Africa 42:11-21. Jehl. 1975. Mortality of Magellanic Penguins in Argentina. Auk 92:596-598 Jouventin. 1982. Visual and Vocal Signals in Penguins: their Evolution and Adaptive Character. Paul Prey, Berlin. Kerley and Erasmus. 1986. A note on transporting oiled penguins. South African Journal of Wildlife Research 16:109-111. Kerley, Bowen and Erasmus. 1987. Fish behaviour-a possible role in the oiling of seabirds. South African Journal of Wildlife Research 17: 128-130.

SPN August 1991 page 18 Koepcke. 1970. The Birds of the Department of Lima. Livingston, Wynnewood. La Cock. 1986. The Southern Oscillation, environmental anomalies, and mortality of two southern African seabirds. Climatic Change 8:173-184. La Cock. 1988. Effect of substrate and ambient temperature on burrowing African Penguins. Wilson Bulletin 100:131-1132. La Cock and Hanel. 1987. Survival of African Penguins Spheniscus demersus at Dyer Island, Southern Cape, South Africa. Journal of Field Ornithology 58:284-287. La Cock and Cooper. 1988. The breeding frequency of Jackass Penguins on the west coast of South Africa. Journal of Field Ornithology 59:155-156. La Cock, Duffy and Cooper. 1987. Population dynamics of the African penguin Spheniscus demersus at Marcus Island in the Benguela upwelling ecosystem: 1979-1985. Biological Conservation 40:117-126. Laugksch and Duffy. 1986. Food transit rates in cape and jackass penguins. Condor 88:117-119. Livezey. 1989. Morphometric patterns in Recent and fossil penguins (Aves: Sphenisciformes). Journal of Zoology 219:269-307. Martin. 1985. Through a penguin's eye. New Scientist 14 March 1985: 29-31. Merritt and King. 1987. Behavioral sex differences and activity patterns of captive Humboldt Penguins (Spheniscus humboldti). Zoo Biology 6: 129-138. Morant, Cooper and Randall. 1981. The rehabilitation of oiled jackass penguins Spheniscus demersus, 1970-1980. In J. Cooper (ed.). Proceedings of the Symposium on the Birds of the Sea and Shore, 1979. African Seabird Group, Cape Town, pp. 267-301. Murphy. 1936. Oceanic Birds of South Africa. American Museum of Natural History, New York. Nagy, Siegfried and Wilson. 1984. Energy utilization by free-ranging Jackass Penguins Spheniscus demersus. Ecology 65:1648-1655. Perkins, 1983. Oiled Magellanic Penguins in Golfo San Jose, Argentina. Marine Pollution Bulletin 14:383-387, Perkins. 1984. Breeding ecology of Magellanic Penguins Spheniscus magellanicus at Caleta Valdes, Argentina. Cormorant 12:3-13. Rand. 1949. Some early references to the Cape Penguin. Ostrich 20:2-5. Rand. 1960. The distribution, abundance and feeding habits of the Cape Penguin (Spheniscus demersus) off the south- western coast of the Cape Province. Investigational Report of the Division of Fisheries of the Union of South Africa 41. Randall, 1983. Biology of the Jackass Penguin Spheniscus demersus (L.) at St Croix Island, South Africa. Ph.D. thesis. University of Port Elizabeth, South Africa. Randall and Randall, 1981. The annual cycle of the Jackass Penguin Spheniscus demersus at St Croix Island, South Africa, In J. Cooper (ed.). Proceedings of the Symposium on the Birds of the Sea and Shore, 1979. African Seabird Group, Cape Town, pp. 427-450. Randall and Bray. 1983. Mortalities of jackass penguin Spheniscus demersus chicks caused by trematode worms Cardiocephaloides physalis. South African Journal of Zoology 18:45-46. Randall and Randall. 1986. The diet of jackass penguins Spheniscus demersus in , South Africa, and its bearing on population declines elsewhere. Biological Conservation 37:119-134. Randall, Randall and Bevan. 1980. Oil pollution and penguins-is cleaning justified? Marine Pollution Bulletin 1: 234-237. Randall, Randall and Baird. 1981. Speed of movement of jackass penguins over long distances and their possible use of ocean currents. South African Journal of Science 77:420-421. Randall, Randall, Cooper and Frost. 1986a. A new census method for penguins tested on Jackass Penguins Spheniscus demersus. Ostrich 57:211-215. Randall, Randall and Erasmus. 1986b. Rain-related breeding failures in Jackass Penguins. Le Gerfaut 76:281-288. Randall, Randall, Cooper, La Cock and Ros. 1987. Jackass Penguin Spheniscus demersus movements, interisland visits and settlement. Journal of Field Ornithology 58:445-455. Randall, Randall and Compagno. 1988. Injuries to Jackass Penguins (Spheniscus demersus): evidence for shark involve- ment. Journal of Zoology 214:589-599. Rodriguez. 1983. Estructura de la jerarquizaci6n de la predaci6n de huevos y pichones de Spheniscus magellanicus Doiiana, Acta Vertebrata 10:210-212. Rosenberg and Harcourt. 1987. Galapagos Penguin and Flightless Cormorant. Noticias de Galapagos 45:24-25. please turn to page 20

SPN August 1991 page 19 A Selected Bibliography of the Spheniscus Penguins continued from page 19 Ryan, Wilson and Cooper. 1987. Intra-specific mimicry and status signals in juvenile African Penguins Spheniscus demersus. Behavioural Ecology and Sociobiology 20: 69-76. Saburo and Scolaro. The eye of penguins, is it an adaptation for deep diving? Comunicadones biologicas 6:225-232. Schlatter. 1984. The status and conservation of seabirds in Chile. In J. P. Croxall, P G, H, Evans and R. W.Schreiber (eds), Status and Conservation of the World's Seabirds ICBP Technical Publication 2, pp, 261-269. Schmidt-Nielsen and Sladen. 1957. Nasal salt secretion in the Humboldt Penguin, Nature 181:1217-1218. Scholten. 1989. Individual recognition of Humboldt Penguins. Spheniscid Penguin Newsletter 2: 4-8. Schumann, Ross and Goschen. 1989. Old water events in Algoa Bay and along the CapeSouth Coast, South Africa, South African Journal of Science 84:579-584. Scolaro. 1978. El pingilino de Magellanes (Spheniscus magellanicus) IV. Notas biologicasy de comportamiento. Publicaciones Ocasionales dellnstituto de Biologia Animal, Series Cientifica 10: 1-6. Scolaro. 1980. El pingiiino de Magellanes Spheniscus magellanicus, VI. Dinamica de la poblacion de juveniles, His to ria Natural (25): 173-178. Scolaro. 1983. The ecology of the Magellanic Penguin Spheniscus magellanicus: a long-term breeding study of a temperate- latitude penguin in southern Argentina. M. Phil. thesis, University of Bradford, U.K. Scolaro. 1984a. Biologia y selecci6n de habitat de reproducci6n de Spheniscus magellanicus en Patagonia, Argentina, Facultad de Ciencias, Universidad de Cordoba, Spain. Scolaro. 1984b. Timing of nest relief during incubation and guard stage period of chicks in Magellanic Penguin (Spheniscus magellanicus) (Aves: Spheniscidae), His to ria Natural 4 (29):281-284. Scolaro. 1984c. Madurez sexual del pingiiino de Magellanes (Spheniscus magellanicus) (Aves: Spheniscidae). Historia Natural 4(31):289-292. Scolaro. 1984d. Revision sobre biologia de la reproduccion del pingiiino de Magellanes (Spheniscus magellanicus). El cicio biologico anual. Centro Nacional Patagonico Contribucion 91:1-26. Scolaro. 1985. Vertebrate species associated to breeding sites in a colony of Magellanic Penguins (Spheniscus magellanicus) (Aves: Spheniscidae). Historia Natural 5:23-24. Scolaro. 1986. La conservacion del pingiiino de Magellanes: un problema de conflicto e intereses que requiere de argumentos cientificos. Anales del Museo Historia. Natural de Valparaiso 17:113-119. Scolaro. 1987a. Sexing fledglings and yearlings of Magellanic Penguins by discriminant analysis of morphometric measurements. Colonial Waterbirds 10:50-54. Scolaro. 1987b. A model life table for Magellanic Penguins (Spheniscus magellanicus) at Punta Tombo, Argentina. Journal of Field Ornithology 58:432-441. Scolaro and Arias de Reyna. 1984a. Distribudon espadal achJalizada de la nidificadon y tamailo de la pobladon de Spheniscus mageIlanicus en Punta TomOO, Chubut, Argentina. (Aves: Spheniscidae). Historia Natural 4 (27:249-256. Scolaro and Arias de Reyna. 1984b. Principales factores ecologicos que afectan la nidificacion del pingiiino de Magellanes (Spheniscus magellanicus) en la colonia de Punta Tombo. Centro Nacional Patagonico Contribucion 97:1-14. Scolaro and Bodano. 1986. Diet of the Magellanic Penguin Spheniscus magellanicus during the chick-rearing period at Punta Clara, Argentina. Cormorant 13: 91-97. Scolaro, Hall, Ximenez and Kovacs. 1979. El pingiiinode Magellanes (Spheniscus magellanicus) 1. Evaluacion y estratificacion de densidades de su poblacion en Punta Tombo, Chubut, Argentina. Revista del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Ecologia 2(4):87- 102. Scolaro, Hall, Ximenez and Kovacs. 1980a. EI pingiiino de Magellanes (Spheniscus magellanicus) II. Biologia y desarrollo de la incubacion en la colonia de Punta Tombo, Chubut, Argentina. Revista del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, f.cologia 2(5):104-110. Scolaro, Rodriquez and Monachio. 1980. El pingiiino de Magellanes (Spheniscus magelianicus) V. Distribucion de las colonias de reproducdon en el territorio continental argentino. Centro Nacional Patagonico Contribucion 33:1-18. Scolaro, Ares, Alessandria, Estecondo, Ghersa, Gomez, Hoffmeyer, Prozco Storni, Perez and Zavatti. 1981. EI pingiiino de Magellanes (Spheniscus magellanicus) VIII. Aspectos de la dinamica de su poblacion en Punta Tombo (Chubut). His to ria Natural 2 (5):5-20. Scolaro, Hall and Ximenez. 1983. The Magellanic Penguin (Spheniscus magellanicus): sexing adults by discriminant analysis of morphometric characters. Auk 100:221-224. Scolaro, Bodano and Upton. 1984. Estimacion de la poblacion y estructura de la nidificacion de Spheniscus magellanicus en Punta Loberia, Chubut. Argentina (Aves: Spheniscidae). Historia Natural 4 229-238.

SPN August 1991 page 20 Scolaro, Bodano, Upton and Beloso. 1985. Ecologia de la nidificacion del pingiiino de Magellanes (Spheniscus magellanicus) en la colonia de Punta Loberia, Chubut, Argentina. Centro Nacional Patagonico ContribuciOn 103:1-17. Shelton, Crawford, Cooper and Brooke. 1984. Distribution, population size and conservation of the Jackass Penguin Spheniscus demersus. South African Journal of Marine Science 2: 217-257. Siegfried. 1977. Packing of Jackass Penguin nests. South African Journal of Science 73:186. Siegfried and Crawford. 1978. Jackass Penguins, eggs and guano: diminishing resources at Dassen Island. South African Journal of Science 74:389-390. Siegfried, Frost, Kinahan and Cooper. 1975. Social behaviour of Jackass Penguins at sea. Zoologica Africana 10:87-100. Simpson. 1976. Penguins: past and present, here there. Yale, New Haven. Sivak, Howland and McGill-Harelstad. 1987. Vision of the Humboldt penguin (Spheniscus humboldti) in air and water. Proceedings of the Royal Society B 229:467-472. Sumner. 1934. Does /protective coloration' protect? Results of some experiments with fishes and birds. Proceedings of The National Academy of Science 20:559-564. Valle. 1986. Status of the Galapagos Penguin and Flightless Cormorant populations in 1985. Noticas de Galapagos 43:16-17. Valle and Coulter. 1987. Present status of Flightless Cormorant, Galapagos Penguin and Greater Flamingo populations in the Galapagos Islands, , after the 1982-83 EI Nino. Condor 89:276-281. Vogt. 1942. A report on the guano-producingbirds of Peru. 132 pp./ translation and notes by D. Duffy. (subm. to Colonial Waterbirds). Westphal and Rowan. 1971. Some observations on the effects of oil pollution on the jackass penguin. Ostrich (Suppl.) 8:521-526. Williams and Cooper. 1984. Aspects of the breeding biologyof the Jackass Penguin Spheniscus demersus. Proceedings of the Fifth Pan African Ornithological Congress, pp. 841-853. Wilson. 1984. An improved stomach pump for penguins and other seabirds. Journal of Field Ornithology 55:109-112. Wilson. 1985a. Diurnal foraging patterns of the Jackass Penguin Spheniscus demersus. Ostrich 56:212-214. Wilson. 1985b. The Jackass Penguin (Spheniscus demersus) as a pelagic predator. Marine Ecology Progress Series 25:219-227. Wilson, R. P. 1985c. Seasonality in diet and breeding success of the Jackass Penguin Spheniscus demersus. Journal fur Ornithologie 126: 53-62. Wilson and Bain. 1984a. An inexpensive speed meter for penguins at sea. Journal of Wildlife Management 48:1360-1364. Wilson and Bain. 1984b. An inexpensive depth gauge for penguins. Journal of Wildlife Management 48:1077-1084. Wilson and Achleiter. 1985. A distance meter for large swimming marine animals. South African Journal of Marine Sciences 3:191-195. Wilson and Duffy. 1986. Prey seizing in African penguins Spheniscus demersus. Ardea 74:21 1-214. Wilson and Wilson. 1988. Dead reckoning: a new technique for determining penguin movementsat sea. Meeresforschung 32:155-158. Wilson and Wilson. 1989a. Tape: a package attachment technique for waterbirds, Wildlife Society Bulletin 17. Wilson and Wilson. 1989b. A peck activity record for birds fitted with devices. Journal of Field Ornithology 60:104-108. Wilson and Wilson. 1989c. A minimal-stress bird-capture technique. Journal of Wildlife Management 53:77-80. Wilson and Wilson. 1990. The foraging ecology of breeding Spheniscus penguins. In. J. Darby and L. Davies (eds.). Penguins. Academic Press, Orlando, Florida. Wilson, La Cock, Wilson and Mollagee. 1985. Differential digestion of fish and in Jackass Penguins Spheniscus demersus. Ornis Scandinavica 16:77-79. Wilson, Grant and Duffy. 1986a. Recording devices on free-ranging marine animals: does measurement affect foraging performance? Ecology 67:1091-1093. Wilson, Wilson and McQuaid. 1986b. Group size in foraging African Penguins Spheniscus demersus. Ethology 72:338-341. Wilson, Ryan; James and Wilson. 1987. Conspicuous coloration may enhance prey capture in some piscivores. Animal Behaviour 35:1558-1560. Wilson, Wilson and Duffy. 1988. Contemporary and historical patterns of African Penguin Spheniscus demersus distribu- tion at sea. Estuarine, Coastal and Shelf Science 26:447-458. Wilson, Wilson, Duffy, Araya and Klages. 1989a. Diving behaviour and prey of the Humboldt Penguin (Spheniscus humboldti). Journal fur Ornithologie 130:75-79. Wilson, Ryan and Wilson. 1989b. Sharing food in the stomachs of seabirds between adults and chicks--a case for delayed gastric emptying. Comparative Biochemistry and Physiology 94A: 461-466. Q

SPN August 1991 page 21