Diving behavior of Magellanic penguins (Spheniscus magellanicus) at Punta Tombo, Argentina

2003 ◽  
Vol 81 (9) ◽  
pp. 1471-1483 ◽  
Author(s):  
Brian G Walker ◽  
P Dee Boersma
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Body Condition ◽  
Temporal Variability ◽  
Diving Behavior ◽  
Trip Length ◽  
Spheniscus Magellanicus ◽  
Magellanic Penguins ◽  
Foraging Ability ◽  
Breeding Seasons

Geographic and temporal variability in the marine environment affects seabirds' ability to find food. Similarly, an individual's body size or condition may influence their ability to capture prey. We examined the diving behavior of Magellanic penguins (Spheniscus magellanicus) at Punta Tombo, Argentina, as an indicator of variation in foraging ability. We studied how body size affected diving capability and how diving varies among years and within breeding seasons. We also compared diving patterns of Magellanic penguins at Punta Tombo with those of birds in two colonies at the opposite end of the species' breeding range. Larger penguins tended to dive deeper and for longer than smaller birds. Trips were longer during incubation and in the years and colonies with lower reproductive success, which suggests that in those instances birds were working hard to recover body condition and feed chicks. Average dive depths, average dive durations, and percentages of time spent diving were always similar. We found that the only parameter these penguins consistently modified while foraging was the length of their foraging trip, which suggests that penguins at Punta Tombo were diving at maximum rates to find their preferred prey. Increasing trip length, we suggest, is a physiologically conservative solution for increasing the likelihood of encountering prey.

The glucocorticoid stress response in Magellanic Penguins (Spheniscus magellanicus): comparing within and between breeding seasons, by age and colony, after fighting, and with other penguin species

2015 ◽  
Vol 93 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Brian G. Walker ◽  
P. Dee Boersma ◽  
John C. Wingfield
Keyword(s):  
Stress Response ◽  
Rockhopper Penguin ◽  
Weather Event ◽  
Spheniscus Magellanicus ◽  
Magellanic Penguins ◽  
Baseline Corticosterone ◽  
Breeding Seasons ◽  
Stress Patterns ◽  
Severe Weather Event ◽  
Penguin Species

Comparing baseline and stress-induced glucocorticoid hormone levels in animals is a popular tool to assess differences in stress experienced among groups. We compare corticosterone levels in Magellanic Penguins (Spheniscus magellanicus (J.R. Forster, 1781)) in situations where we hypothesize differences in stress patterns may exist. We compared penguins both within and between breeding seasons, birds breeding at two different locations, penguins at three different ages, penguins that had shown evidence of recent fighting, and, finally, how stress patterns differed for four different penguin species. Throughout a breeding season (settlement, incubation, and chick-rearing), we found no differences in either baseline or stress-induced hormone concentrations. Chick, juvenile, and adult penguins did not differ in baseline corticosterone levels, but juveniles had a reduced stress response. Penguins in one season showed a stress response to capture, likely due to a recent severe weather event. We found no differences in baseline or stress-induced hormone titers for birds from two different breeding locations. Evidence of recent fighting also did not alter baseline corticosterone levels. Finally, among four species of penguins measured (Magellanic, Humboldt (Spheniscus humboldti Meyen, 1834), Galápagos (Spheniscus mendiculus Sundevall, 1871), and Rockhopper (Eudyptes chrysocome (J.R. Forster, 1781)), baseline levels were always consistent, while stress-induced levels were significantly higher in the Rockhopper Penguin only.

scholarly journals Physiological Condition in Magellanic Penguins: Does it Matter if You Have to Walk a Long Way to Your Nest?

The Condor ◽  
2004 ◽  
Vol 106 (3) ◽  
pp. 696-701
Author(s):  
Brian G. Walker ◽  
P. Dee Boersma ◽  
John C. Wingfield
Keyword(s):  
Body Condition ◽  
Physiological Condition ◽  
Colonial Species ◽  
Ambient Temperatures ◽  
Spheniscus Magellanicus ◽  
Breeding Stage ◽  
Magellanic Penguins ◽  
Over Time

Abstract Colony edges, as opposed to interiors, are often considered less advantageous nesting places in colonial species. For temperate-breeding penguins, inland colony edges should be less desirable than other edges, as there are added costs of walking farther inland, and ambient temperatures are higher. During settlement and incubation, we compared body condition and baseline and stress-induced levels of the hormone corticosterone in male Magellanic Penguins (Spheniscus magellanicus) nesting on the sea edge of a colony with those nesting on the inland edge, >800 m from shore. Body condition in both groups was significantly lower during settlement than during incubation, but was similar in both groups within breeding stages. Corticosterone levels were similar between breeding stages and for groups within each breeding stage. While body condition can vary over time, penguins appear to be well buffered to physiological extremes, as they do not show modification of corticosterone levels with variations in nesting conditions. Condiciones Fisiológicas en el Pingüino Spheniscus magellanicus: ¿Tiene Importancia Caminar una Larga Distancia al Nido? Resumen. En especies coloniales, los bordes de la colonia son generalmente considerados como lugares menos ventajosos para el establecimiento de nidos. Para los pingüinos que crían en climas templados, los bordes de las colonias orientados tierra adentro deben ser menos deseables que otros bordes, ya que se suman los costos adicionales de caminar una distancia mayor desde la orilla y debido a que las temperaturas ambientes allí son más elevadas. Durante el establecimiento y la incubación, comparamos las condiciones corporales y los niveles de referencia e inducidos por estrés de la hormona corticosterona en los machos de Spheniscus magellanicus que anidaban en el borde de la colonia adyacente al mar con los que anidaban sobre el borde que mira hacia el interior, a más de 800 m desde la orilla. La condición corporal en los dos grupos fue significantemente menor durante el establecimiento que durante la incubación, pero fue similar en los dos grupos durante las etapas de crianza. Los niveles de corticosterona fueron similares para ambas etapas de crianza y para los dos grupos durante cada etapa de crianza. Aunque la condición corporal puede variar en el tiempo, los pingüinos parecen amortiguar bien los extremos fisiológicos, ya que no muestran modificación de los niveles de corticosterona con las variaciones en las condiciones de nidificación.

scholarly journals Relation of Automated Body Condition Scoring System and Inline Biomarkers (Milk Yield, β-Hydroxybutyrate, Lactate Dehydrogenase and Progesterone in Milk) with Cow’s Pregnancy Success

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1414
Author(s):  
Ramūnas Antanaitis ◽  
Vida Juozaitienė ◽  
Dovilė Malašauskienė ◽  
Mindaugas Televičius ◽  
Mingaudas Urbutis ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Reproductive Success ◽  
Milk Yield ◽  
Body Condition ◽  
Body Condition Score ◽  
The Body ◽  
Time Analyzer ◽  
Condition Score ◽  
Pregnancy Status ◽  
Body Condition Scoring

The aim of the current study was to evaluate the relation of automatically determined body condition score (BCS) and inline biomarkers such as β-hydroxybutyrate (BHB), milk yield (MY), lactate dehydrogenase (LDH), and progesterone (mP4) with the pregnancy success of cows. The cows (n = 281) had 2.1 ± 0.1. lactations on average, were 151.6 ± 0.06 days postpartum, and were once tested with “Easy scan” ultrasound (IMV imaging, Scotland) at 30–35 d post-insemination. According to their reproductive status, cows were grouped into two groups: non-pregnant (n = 194 or 69.0% of cows) and pregnant (n = 87 or 31.0% of cows). Data concerning their BCS, mP4, MY, BHB, and LDH were collected each day from the day of insemination for 7 days. The BCS was collected with body condition score camera (DeLaval Inc., Tumba, Sweden); mP4, MY, BHB, and LDH were collected with the fully automated real-time analyzer Herd Navigator™ (Lattec I/S, Hillerød, Denmark) in combination with a DeLaval milking robot (DeLaval Inc., Tumba, Sweden). Of all the biomarkers, three differences between groups were significant. The body condition score (BCS) of the pregnant cows was higher (+0.49 score), the milk yield (MY) was lower (−4.36 kg), and milk progesterone in pregnant cows was (+6.11 ng/mL) higher compared to the group of non-pregnant cows (p < 0.001). The pregnancy status of the cows was associated with their BCS assessment (p < 0.001). We estimated that cows with BCS > 3.2 were 22 times more likely to have reproductive success than cows with BCS ≤ 3.2.

Health state and reproductive output in Magellanic penguins (Spheniscus magellanicus)

2002 ◽  
Vol 14 (1) ◽  
pp. 19-28 ◽  
Author(s):  
J. Moreno ◽  
P. Yorio ◽  
P. Garcia-Borboroglu ◽  
J. Potti ◽  
S. Villar
Keyword(s):  
Reproductive Output ◽  
Health State ◽  
Spheniscus Magellanicus ◽  
Magellanic Penguins

Size does not matter for male Marbled Salamanders (Ambystoma opacum)

2015 ◽  
Vol 93 (10) ◽  
pp. 735-740
Author(s):  
D.A. Croshaw ◽  
J.H.K. Pechmann
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Reproductive Success ◽  
Large Male ◽  
Male Mating ◽  
Ambystoma Opacum ◽  
Positive Assortative Mating ◽  
Important Trait ◽  
Breeding Groups ◽  
Gravid Females

Understanding the phenotypic attributes that contribute to variance in mating and reproductive success is crucial in the study of evolution by sexual selection. In many animals, body size is an important trait because larger individuals enjoy greater fitness due to the ability to secure more mates and produce more offspring. Among males, this outcome is largely mediated by greater success in competition with rival males and (or) advantages in attractiveness to females. Here we tested the hypothesis that large male Marbled Salamanders (Ambystoma opacum (Gravenhorst, 1807)) mate with more females and produce more offspring than small males. In experimental breeding groups, we included males chosen specifically to represent a range of sizes. After gravid females mated and nested freely, we collected egg clutches and genotyped all adults and samples of hatchlings with highly variable microsatellite markers to assign paternity. Size had little effect on male mating and reproductive success. Breeding males were not bigger than nonbreeding males, mates of polyandrous females were not smaller than those of monogamous females, and there was no evidence for positive assortative mating by size. Although body size did not matter for male Marbled Salamanders, we documented considerable fitness variation and discuss alternative traits that could be undergoing sexual selection.

scholarly journals Occurrence of gastrointestinal parasites in Spheniscus magellanicus (Foster, 1781) located in Pontal do Sul, PR, Brazil

2018 ◽  
Vol 70 (2) ◽  
pp. 491-496
Author(s):  
M.S. Vanhoni ◽  
G.M. Arná ◽  
L.K. Sprenger ◽  
D.L. Vieira ◽  
L.W. Luis ◽  
...  
Keyword(s):  
Gastrointestinal Parasites ◽  
High Rate ◽  
Infected Bird ◽  
Brazilian Coast ◽  
Marine Animals ◽  
Spheniscus Magellanicus ◽  
Control Programs ◽  
Magellanic Penguins ◽  
Rehabilitation Centers ◽  
South Of Brazil

ABSTRACT Gastrointestinal parasitism is the main health problem faced by Spheniscus magellanicus, known as Magellanic penguins, in route on the Brazilian coast. The aim of this research was to report the occurrence and intensity of gastrointestinal parasites in S. magellanicus that reached Pontal do Sul, Paraná, South of Brazil. The study was performed at the Marine Study Center of the Federal University of Parana (CEM-UFPR) with 38 specimens, 31 were necropsied and seven were examined alive with coproparasitological exams. From the necropsied animals, 93.5% (29/31) were parasitized with at least one parasite species. Contracaecum pelagicum was the most prevalent 93,5% (29/31) parasite, followed by Cardiocephaloides physalis (64.5%) and Tetrabothrius lutzi (51.6%). Only one animal was free of parasites and the most infected bird had 1.076 parasites with an average of 194 worms. Willis-Mollay method revealed that 57.1% (4/7) had C. pelagicum eggs. In conclusion, the high rate of gastrointestinal parasites in S. magellanicus confirms the clinical exams, when animals had poor health conditions when they were found in the cost of Paraná. This study provides data to enrich the literature regarding the helminth fauna of the Magellanic penguins, assisting sanitary control programs in Rehabilitation Centers for Marine Animals.

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