Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1980-1984  (3)
Material
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 56 (1983), S. 318-322 
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In many species, fecundity is dependent on age. For some populations — particularly those exploiting temporally variable environments — these age-specific fecundities may themselves vary with time. In this report, we investigate the general effects of age and time on clutch size in a wild population of Lesser Snow Geese (Anser caerulescens caerulescens). We show that both factors affect clutch size independently. Age effects are confined almost exclusively to the two, three and four year old age classes. Mean clutch sizes of all age classes show considerable inter-seasonal variation. These temporal differences in fecundity will ultimately influence the dynamics of the population. In particular, they imply that there will be no convergence to a constant growth rate or a stable age distribution.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Behavioral ecology and sociobiology 12 (1983), S. 153-159 
    ISSN: 1432-0762
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We examined the spatial distribution of nesting cohorts of female Lesser Snow Geese (Anser caerulescens caerulescens) in a small colony located at La Perouse Bay, Manitoba. In general, cohorts show a heterogeneous spatial distribution, which arises from a tendency of females of the same cohort affiliation to cluster together. Further-more these associations are maintained through time, such that cohorts tend to dominate particular regions of the colony over several breeding seasons. These findings provide further evidence for breeding site fidelity among female lesser snow geese.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of ornithology 125 (1984), S. 473-477 
    ISSN: 1439-0361
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Eight ♂ and eight ♀ each of the mainland (T. g. castanotis) and the island race (T. g. guttata) were kept together in a large outdoor flight cage (22×8×5 m). Over a two months period, the pattern of pair formation was observed. In this time seven pairs of the mainland and four pairs of the island race were formed. No pair-formation was observed between members of the opposite race even though at the end of the experiment unpaired individuals of only the opposite race were available as potential mates. Social interactions between the races were rare. It can be concluded that under the semi-natural conditions of the experiment the two races of the Zebra Finch behaved like separate species.
    Notes: Zusammenfassung In einem großen Freiflugraum wurden jeweils acht ♂ und acht ♀ der Festlandrasse (Taeniopygia guttata castanotis) und der Inselrasse (T. g. guttata) des Zebrafinken zusammengebracht und die auftretenden Paarbildungen verfolgt. Im Verlauf des mehr als zweimonatigen Versuchs bildeten sich sieben Paare der Festland- und vier Paare der Inselrasse. Mischpaare wurden nicht beobachtet, obwohl am Ende unverpaarte Vögel nur der jeweils anderen Rasse als potentielle Partner zur Verfügung standen. Auch soziale Interaktionen zwischen den Rassen waren selten. Unter den halbnatürlichen Bedingungen des Experiments verhielten sich die beiden Rassen somit wie zwei getrennte Arten.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...