Spheniscus Humboldti Research Articles

Hematology and plasma chemistry values in free‐ranging Humboldt penguins (Spheniscus humboldti) in Chile

AbstractTo establish baseline hematologic and plasma biochemistry values in free‐ranging Humboldt penguins (Spheniscus humboldti), heparinized blood samples were collected from 51 apparently healthy, adult Humboldt penguins residing at two colonies off the Chilean coast. Thirty samples were collected in April, 1992, from penguins inhabiting the Ex‐islote de los Pájaros Niños in Algarrobo, Chile. In September, 1992, 21 samples were collected from birds inhabiting Isla de Cachagua, Chile. Hematologic values measured include packed cell volume, leucocyte count, leucocyte differential, and the presence of blood parasites. Plasma biochemistry values measured include glucose, blood urea nitrogen, creatinine, uric acid, calcium, inorganic phosphorous, sodium, potassium, chloride, total protein, albumin, globulin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, and creatine kinase. Only the mean values for chloride and for the number of eosinophils differed significantly between the two sample groups. No blood parasites were seen. © 1995 Wiley‐Liss, Inc.

Liver and plasma retinol (vitamin A) in wild, and liver retinol in captive penguins (Spheniscidae)

In rockhopper penguins (Eudyptes crestatus), liver concentrations of retinol (vitamin A) were significantly higher in post‐moult than in pre‐moult birds. In Magellanic penguins (Spheniscus magelianicus), plasma concentrations of retinol were significantly higher in post‐moult than in pre‐moult birds; liver retinol concentrations were also higher, but not significantly so.The pre‐ and post‐moult Magellanics had higher liver and lower plasma retinol concentrations than the pre‐ and post‐moult rockhoppers.Captive blackfooted (jackass) (Spheniscus demersus), king (Aptenodytes patagonica) and Humboldt (Spheniscus humboldti) penguins had liver vitamin A stores significantly lower than those of the free‐living rockhopper, Magellanic, gentoo (Pygoscelis papua), emperor (Aptenodytes forsteri), chinstraps (Pygoscelis antarctica) and Adélie (Pygoscelis adeliae) penguins.

Diving behaviour and prey of the Humboldt Penguin (Spheniscus humboldti)

Humboldt Penguins diving in clear water in Chile had two distinct behaviours; short dives\((\bar x = 13.3 s)\) where the birds remained within a metre of the surface and bounce dives, where the penguins descended the water column to the sea bed where they immediately returned to the surface. Here, dive time was correlated with water depth. Stomach pumped penguins had eaten predominantly pelagic school fish,Scomberesox, Engraulis andSardinops. Most prey (94 %) had been seized from below. We suggest that short, shallow dives are typical of travelling penguins. Bounce dives, however, would enable foraging penguins, which have an enhanced binocular field above the line of the bill, to perceive surface-swimming prey more easily because silvery clupeid fish appear as silhouettes.

On penguin porpoising

Speeds above which porpoising becomes energetically more economical than swimming are calculated from a hydro-mechanical model for Humboldt (Spheniscus humboldti) and emperor (Aptenodytes forsteri) penguins. Predicted minimum porpoising speeds for S. humboldti are significantly less than observed values. At low porpoising speeds time in air is low and may not be sufficient to permit efficient breathing. It is suggested that ventilatory requirements may set a practicable lower bound on porpoising speed. Other possible constraints on the lower limits to porpoising speed include the requirement of raising the centre of mass high enough for the animal to completely clear the surface and the influence of sea conditions.

Penguin Swimming. I. Hydrodynamics

Drag forces acting on the body (parasite drag) of a Humboldt penguin (Spheniscus humboldti) were determined by towing a cast of a wingless carcass. On the surface $D_{p-sur} = 2.27 U_{o}^{2.55}$ ($D_{p-sur}$ = parasite drag on the surface, N; $U_{o}$ = towing speed, m s⁻¹) and submerged $D_{pm-sub} = 1.48 U_{o}^{2.0}$ ($D_{pm-sub}$ = parasite drag for submerged model). The minimum drag coefficient, 1.1 x 10⁻², approximates that of a live macaroni penguin (Eudyptes chrysolophus) but is higher than that of a streamlined form with the same diameter:length ratio. The wingbeat was analyzed using high-speed film of submerged swimming Humboldt penguins. Wing data and parasite-drag data were used to compute the lift, thrust, and drag forces of a swimming penguin. Wingbeat thrust was computed using both blade element analysis (which required wind tunnel tests on penguin wing models) and lifting surface theory. Blade element analysis gave remarkably more reasonable results, which were used for subsequent computatio...

Penguin Swimming. II. Energetics and Behavior

Oxygen consumption ($\dot{V}O_{2}$) Of the Humboldt penguin Spheniscus humboldti was measured during swimming over the range 0.23-1.26 m s⁻¹. The fraction of time spent swimming submerged and on the surface was recorded simultaneously with VO₂. The power output ($P_{o}$), computed from surface:submerged swimming ratios and drag data, and the power input ($P_{i}$), from $\dot{V}O_{2}$, were determined for each speed. Overall energetic efficiency ($\eta_{o}$), the ratio $P_{o}$ :$P_{i}$, increased with swimming speed ($U_{b}$) as $\eta_{o} = 0.103U_{b}^{2.8}$ ($U_{b} = m s^{-1}$) with a maximum value of 0.192. The maximum propulsion efficiency ($\eta_{p}$), the ratio of $P_{o}$ :$P_{i}-less-maintenance-metabolism$, was 0.247. By changing from surface to submerged swimming as $U_{b}$ increases, the cost of transport remains constant at 13.4 J (kg.m)⁻¹ for $U_{b} = 0.5-1.26 m s^{-1}$. Increasing speeds without increasing transport costs enables the birds to reduce transit time to foraging locations without in...

Vision of the Humboldt penguin (Spheniscus humboldti) in air and water.

Refractive states measured by retinoscopy and photorefraction indicate that the eyes of the Humboldt penguin, Spheniscus humboldti, are approximately emmetropic in air and water. Extensive myopia in air, as predicted by earlier authors and by a recent anatomical study, is non-existent. Photorefractive measurements of the refractive state, in water, of the Humboldt penguin indicate that it can accommodate sufficiently to make up the loss of the refractive power of the cornea. The cornea of the Humboldt penguin is flattened relative to the overall size of the eye. In all these respects (corneal flattening, and accommodation in air and water) the eyes of Humboldt penguins are like those of gentoo, (Pygoscelis papua), rockhopper (Eudyptes crestatus), Magellanic (Spheniscus magellanicus), and king penguins (Aptenodytes patagonica).

Behavioral sex differences and activity patterns of captive humboldt penguins (Spheniscus humboldti)

AbstractThree female and two male captive Humboldt penguins (Spheniscus humboldti) were observed in an enclosed exhibit over a period of 10 months to examine behavioral sex differences and to establish whether captive Humboldt penguins exhibit behavioral activity patterns. There were no statistically significant differences between the behaviors of males and females in six categories: resting, self‐maintenance, locomoting, lack of visibility, agonistic behaviors, or pair‐directed behaviors. Although not statistically significant, the pair‐directed activities of bowing and ecstatic displaying were found to have potential use for sexual identification. Females bowing to males accounted for 77% of the observed bows. Further, males were observed performing 68% of the observed ecstatic displays, while females performed only 32%. Four behavioral phases were defined: molting, proximity, nesting, and “other.” Statistically significant behavioral differences occurred between the four phases for all ethogram behaviors with the exception of agonistic and pair‐directed behaviors. Although housed under natural daylight and in an exhibit simulating their habitat in the wild, the captive birds failed to demonstrate a breeding season but bred throughout the study. However, this may have been influenced by one or more of the following factors: a ready supply of food; an air‐filtered, temperature‐controlled atmosphere; and the presence of an adequate number of nesting sites.

The porpoising of penguins: an energy-conserving behavior for respiratory ventilation?

The leaps of porpoising captive Humboldt (Spheniscus humboldti) and blackfoot (Spheniscus demersus) and free-ranging Adelie (Pygoscelis adeliae) penguins were analyzed from film. Captive and free-ranging penguins leap with a mean (±SD) emergence angle of 32°(±5°), significantly different from the 45° angle assumed by some hydromechanical models. Captive bird leaps occurred over a maximum of 22% of the total distance travelled, making energy savings marginal. Although physically able to leap at 2.3 m s−1, captive birds showed a minimum swimming speed of 3 m s−1 for the onset of leaping behavior, providing minimum in-air time comparable to the measured respiratory inhalation time. Porpoising may minimize energy expended for ventilation.

Effects of the 1982–1983 El Nino on Humboldt penguin colonies in Peru

The Humboldt penguin Spheniscus humboldti is endemic to the Peruvian Current which flows northward along the coast of Chile and Peru. This species has greatly diminished from its former abundance. The coast of Peru is characterised by high biological productivity which concentrates fish such as the anchovy Engraulis ringens, the main prey item of marine predators including seabirds. In years of the abnormal oceanographic conditions of El Nino, the schools of anchovies become unavailable to the seabirds and they disperse in search of food. Massive mortality, especially of juveniles, results and there is nest desertation and lack of reproduction. This paper describes the effects of the 1982–1983 El Nino on Humboldt penguin colonies in Peru. There has been an overall population decline of 65% and the surviving population in 1984 was estimated to be between 2100 and 3000 adults. Although El Nino is a periodic event and the Humboldt penguin has evolved to adapt to such unpredictable changes, the environment has now been altered by man. Under these circumstances, the 1982–1983 El Nino has contributed to placing this species in a critical position.

Ornithodoros (Alectorobius) spheniscus n. sp. [Acarina: Ixodoidea: Argasidae: Ornithodoros (Alectorobius) capensis Group], a Tick Parasite of the Humboldt Penguin in Peru

Ornithodoros (Alectorobius) spheniscus n. sp., described from wild-caught and laboratory-reared females, males, nymphs, and larvae parasitizing the Humboldt Penguin, Spheniscus humboldti Meyen, is the fifth species of the Ornithodoros (Alectorobius) capensis group to be recognized in the Neotropical Region. A related Peruvian species, Ornithodoros (Alectorobius) amblus Chamberlin, also parasitizes S. humboldti but is recorded from a wider range of marine birds breeding on the Pacific coast and offshore islands, where the birds congregate to feed on the rich fish fauna usually produced by the Humboldt current. Differential criteria are provided for the new species, O. (A.) amblus, and Ornithodoros (Alectorobius) yunkeri Keirans, Clifford, and Hoogstraal of the Galapagos. These 3 members of the O. (A.) capensis group parasitize marine birds associated with the Humboldt current in western South America and the Galapagos. Persons visiting Humboldt Penguin breeding sites in caves and on barren coastal ledges are eagerly attacked by nymphal and adult O. (A.) spheniscus and suffer afterward from pruritus and slowly-healing blisters. The O. (A.) spheniscus life cycle required 128 to 193 days in the laboratory and, as typical of bird-parasitizing members of the subgenus Alectorobius, the first nymphal instar did not feed.

Maneuverability of the Humboldt penguin (Spheniscus humboldti) during swimming

Analyses of high-speed film of captive Humboldt penguins (Spheniscus humboldti) show that there is no correlation between the radii of submerged turns and swimming speed. The sharpest turns had a mean turn radius (n = 5) of 0.14 m (0.24 body lengths), were powered by beating wings, and used multiple steering structures (beak, tail, feet, wings) and a flexing body. This turn radius is similar to that of fast-swimming fish with rigid bodies and lunate tails but is greater than that of slower fish with flexible bodies. The maximum turning rate was 10.05 radians s−1. Maneuverability is augmented by neck-extending strike behavior and porpoising leaps.

Visual pigments and oil droplets in the penguin,Spheniscus humboldti

The photoreceptors of the penguin,Spheniscus humboldti, were examined using a microspectrophotometer. The cones could be divided into three classes based on their visual pigment absorbance spectra [λmax 403, 450 and 543 nm (Fig. 1)], and into five classes based on their visual pigment-oil droplet combination (Fig. 4). Oil droplets were of three types (Fig. 2). The rods contained a rhodopsin with λmax at 504 nm. No double cones were observed. The penguin should be capable of good wavelength discrimination in the blue-green region of the spectrum but with poor discrimination at longer wavelengths. It is concluded that the spectral properties of the cone types indicate that the photopic vision ofS. humboldti is adapted to the spectral qualities of its aquatic environment.

The Humboldt penguin in Peru

Numbers of Humboldt penguins Spheniscus humboldti, which live on the coast and islands of Chile and Peru, have been declining since the mid-1800s. Extracting guano for fertiliser has damaged their breeding sites; they have been exploited for food and skins and captured for pets or zoos; they are incidentally caught in fishing nets and recent over-fishing may have caused a food shortage. The author surveyed the Humboldt penguins in Peru in 1981 and here discusses the conservation measures that are being taken.

Heart rate and aerobic metabolism in Humboldt penguins, Spheniscus humboldti, during voluntary dives.

Heart rate and aerobic metabolism have been recorded from three Humboldt penguins, Spheniscus humboldti, freely diving on a freshwater pond (9 X 4.6 X 2.7 m deep), using an implanted radiotransmitter and an open circuit respirometer. Oxygen uptake at mean dive duration (46.2s) was 26% greater than the resting value, but the difference was not statistically significant. Heart rate was also similar to the resting value. It is concluded that voluntary dives of penguins are completely aerobic and that oxygen stores are sufficient to allow metabolism to continue at the rate estimated in the present study for 2.27 min during voluntary submersion. This is longer than that calculated for tufted ducks, probably because the penguins are more efficient at underwater locomotion and because they are almost neutrally buoyant.

An outbreak of malaria in penguins at the Farm-land Zoo.

In June of 1983 authors had investigated the occurrence of the avian malaria in the Humboldt penguins imported from Japan to the Farm-land Zoo in central district of Korea. The disease was characterized by acute course and high mortality. The peripheral blood smears from the affected penguins demonstrated different developmental stages of Plasmodium sp. in the mature erythrocytes. The predominant gross lesions noticed were pulmonary and epicardial edema and hepato-splenomegaly. Microscopically the lesions were characterized by extensive reticuloendothelial cell hyperplasia with striking feature of exoerythrocytic schizogony affecting a variety of tissues. The report also signifies the first description of a disastrous epizootic of avian malaria in Korea.

Providencia friedericiana, a New Species Isolated from Penguins

The name Providencia friedericiana sp. nov. is proposed for a well-defined group of organisms that were isolated from fecal specimens from penguins (Aptenodytes patagonica, Eudyptes crestatus, Pyoscelis papua, Spheniscus demersus, and Spheniscus humboldti). P. friedericiana strains are gram-negative, oxidase-negative, fermentative rods that grow on Endo agar, MacConkey agar, Wilson-Blair agar, and some other selective media for Enterobacteriaceae. They are acetate, adonitol, arginine dihydrolase, gelatinase, inositol, lactose, lysine decarboxylase, mannitol, ornithine decarboxylase, tartrate, trehalose, urease, and Voges-Proskauer negative, but fructose, galactose, glucose, glycerol, indole, catalase, KCN, nitrate reductase, mannose, methyl red, and phenylalanine deaminase positive. Simmons citrate is utilized weakly and variably. Gas is produced from glucose in small amounts or not at all. The organisms possess flagella when they are grown at 25°C. They show moderate motility at 25°C but are nonmotile or only slightly motile at 36°C. Capsules and slime layers are not produced. The type strain of P. friedericiana, strain 1/33, has been deposited with the Deutsche Sammlung von Mikroorganismen as strain DSM 2620.

Humboldt's penguins

Humboldt's penguins

Scheduled Displays of Behavior in Captive Humboldt Penguins

Scheduled Displays of Behavior in Captive Humboldt Penguins

The Comfort Behaviour of Adélie and Other Penguins

[Comfort movements include the behaviours of shaking, stretching, cleaning, preening, and washing. These were described and analyzed for Adelie Penguins. The function for some movements such as oil-preening was difficult to determine and could only be hypothesized. Cleaning, preening, washing, head-shaking, and sneezing function in the care of body surfaces and are responses to the presence of irritants or foreign material on surfaces. Stretching and other shaking movements may function to help prepare muscles and peripheral circulation for activity. Ruffle-shakes may function to dissipate heat and arrange plumage. Some movements of oil-preening and some areas of the body preened are performed in a predictable sequence ordered according to functional relationships among the different movements. Some movements are normally performed only after certain others have been performed. Bathing in penguins is a socially facillitated behaviour. The pattern of Adelie bathing is determined largely as an anti-predator strategy. Adelie, African, and Humboldt Penguins perform the same repertoire of comfort movements. The one exception is that both spheniscids allopreen but Adelies do not. The motor patterns of all other movements except for two are the same for the three species. The two spheniscids perform the jaw-stretch and the both-wings-stretch differently than does the pygoscelid. The comfort movement repertoires of several other penguin species were compared to these. Their repertoires were all very similar. Head-shaking is performed in Adelies during disturbance as a response to an increase in secretion rate of the salt gland. The increase in salt fluid secretion is probably a result of a change in autonomic activity. Head-shaking and social displays which include a form of head-shaking have been reported for several seabird species during disturbance or social interaction. In Adelie Penguins and albatrosses the increased head-shaking during these circumstances is a response to increased salt gland secretion. It is hypothesized that some of the head-shaking and head-shaking displays of other seabirds are caused in the same way. Head-shakes and other vigorous shakes and stretch movements probably have signal function during social interaction., Comfort movements include the behaviours of shaking, stretching, cleaning, preening, and washing. These were described and analyzed for Adelie Penguins. The function for some movements such as oil-preening was difficult to determine and could only be hypothesized. Cleaning, preening, washing, head-shaking, and sneezing function in the care of body surfaces and are responses to the presence of irritants or foreign material on surfaces. Stretching and other shaking movements may function to help prepare muscles and peripheral circulation for activity. Ruffle-shakes may function to dissipate heat and arrange plumage. Some movements of oil-preening and some areas of the body preened are performed in a predictable sequence ordered according to functional relationships among the different movements. Some movements are normally performed only after certain others have been performed. Bathing in penguins is a socially facillitated behaviour. The pattern of Adelie bathing is determined largely as an anti-predator strategy. Adelie, African, and Humboldt Penguins perform the same repertoire of comfort movements. The one exception is that both spheniscids allopreen but Adelies do not. The motor patterns of all other movements except for two are the same for the three species. The two spheniscids perform the jaw-stretch and the both-wings-stretch differently than does the pygoscelid. The comfort movement repertoires of several other penguin species were compared to these. Their repertoires were all very similar. Head-shaking is performed in Adelies during disturbance as a response to an increase in secretion rate of the salt gland. The increase in salt fluid secretion is probably a result of a change in autonomic activity. Head-shaking and social displays which include a form of head-shaking have been reported for several seabird species during disturbance or social interaction. In Adelie Penguins and albatrosses the increased head-shaking during these circumstances is a response to increased salt gland secretion. It is hypothesized that some of the head-shaking and head-shaking displays of other seabirds are caused in the same way. Head-shakes and other vigorous shakes and stretch movements probably have signal function during social interaction.]