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Penguins Eudyptula Minor (penguin + eudyptula_minor)

Distribution by Scientific Domains
Life Sciences100%

Kinds of Penguins Eudyptula Minor

  • little penguin eudyptula minor
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    Selected Abstracts

    Survival analysis of Little Penguin Eudyptula minor chicks on Motuara Island, New Zealand

    IBIS, Issue 4 2001
    MARTIN RENNER
    Chick survival of Little Penguins Eudyptula minor was studied on predator-free Motuara Island, Cook Strait, New Zealand (41d,05'S, 174d,15'E), in 1995 and 1996. We used the Kaplan-Meier estimator and robust Cox regression to estimate chick survival rate (pL se) at 0.325 pL 0.044, leading to an estimated survival from laying to fledging of 0.13 or a reproductive output of 0.26 chicks per pair and breeding attempt. Starvation posed the greatest mortality risk, followed by unknown factors and rain. Risk of death due to rain was restricted to the guard stage, whereas starvation occurred throughout the nesting period, though with a peak in the early guard stage. Significant seasonal differences in survival rate were detected in both years, but with reversed trends, survival decreasing with the season in 1995 and increasing in 1996. Failure of adults to relieve their partner on the nest after chicks hatched accounted for 16% mortality or 34% of all chick deaths. Differences in chick survival rate between nest types were significant in 1995, a year with high rainfall, but not in 1996. Nests in the base of hollow trees had the highest chick survival rate. Of chicks in open nests - a nest type that is unusual for this species - 5.4% fledged. Our results suggest that on Motuara Island good breeding sites are scarce and that the food supply has been poor during the years of this study. [source]

    Acoustic properties of male advertisement and their impact on female responsiveness in little penguins Eudyptula minor

    JOURNAL OF AVIAN BIOLOGY, Issue 3 2003
    Masamine Miyazaki
    We examined the relationship between acoustic properties of male advertising calls, male body size and female responses in little penguins Eudyptula minor. Larger males produced calls of lower frequency. Playback experiments indicated that females were more likely to respond to low or medium pitched calls, than to high ones (although only 28% of females responded vocally to playback). This may reflect the interest of unmated females in large to medium sized senders as potential mates, or indicate a stronger territorial response to large intruders. [source]

    Increased survival and breeding performance of double breeders in little penguins Eudyptula minor, New Zealand: evidence for individual bird quality?

    JOURNAL OF AVIAN BIOLOGY, Issue 2 2003
    Edda Johannesen
    The little penguin Eudyptula minor is unique among penguin species in being able to fledge chicks from two clutches in one breeding season. Pairs laying two clutches in a given season make a higher reproductive investment, and may be rewarded by a higher reproductive success as they may raise twice as many chicks as pairs laying one clutch. The higher effort made by pairs laying two clutches could correlate negatively with survival, future reproductive performance or offspring survival, indicating a cost of reproduction. Conversely, a positive relationship between the number of clutches produced in a given breeding season and survival, future reproductive performance or offspring survival would indicate that birds laying two clutches belonged to a category of birds with higher fitness, compared to birds laying only one clutch in the season. In this study we used a long-term data set taken from an increasing population of little penguins in Otago, SE New Zealand. We modelled the relationship between the number of clutches laid in a breeding season and survival probability, reproductive performance in the next breeding season and first year survival of offspring using capture-recapture modelling. Birds laying two clutches produced 1.7 times more fledglings during a breeding season than pairs laying one clutch. We found that birds laying two clutches had a higher probability of breeding in the following breeding season, a higher probability of laying two clutches in the following breeding season and a higher survival probability. There was no overall difference in post-fledging survival between the young of birds producing one clutch and the young of birds producing two clutches. However, the survival of young of single clutch breeders declined with laying date, whereas the young of double clutch breeders had the same survival rate irrespective of laying date. For a subset of data with birds of known age, we found evidence that the probability of laying two clutches increased with age. However, there were also indications for differences among birds in the tendency to lay two clutches that could not be attributed to age. We tentatively interpret our results as evidence of quality difference among little penguin breeders. [source]