If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Free Content Factors Determining Number Fluctuations and Variation of the Breeding Success of an Urban Population of the Black-headed Gull Larus ridibundus (N-Poland)

 Download
(PDF 504.4kb)
 
Download Article:

Abstract:

In this paper a study conducted on a breeding colony of the Black-headed Gull Larus ridibundus between 1998-2004 is presented. The colony is located on an island on a small (4.6 ha area) artificial lake situated in the most abundantly visited recreational area of Bydgoszcz (53°07'N, 18°03'E). The island has an area of 0.9 ha and in some parts there are 25-30 year old Pinus silvestris; the banks are overgrown by Phragmites communis, Typha latifolia and Salix sp., and the remaining part of the island is covered by grasses and perennial pants. During seven breeding seasons remarkable fluctuations in colony size were noted (from 1877 pairs in 2000 to 998 pairs in 2003). Most, i.e. 71% of females started breeding between the 15th and 25th of April. In subsequent seasons they laid 2.2-2.8 eggs (mean 2.5 eggs). Egg losses during incubation varied between 9.7% and 17.6% (mean 13.7%). Mortality of chicks during the first three weeks of life was at an average level of 15.2% and varied in subsequent seasons from 5.6% to 29.4%. In consequence, breeding success of the studied population was at a level of 72.6%, and each pair raised on average 1.81 offspring. The collected data on numbers, phenology, dynamics of broods and selected parameters of reproduction (i.e. size of broods, egg losses and chick mortality) indicate that in the studied population – despite its specific location and several years of existence – there are no changes that would give evidence to the progressing process of synurbisation.

Keywords: BLACK-HEADED GULL LARUS RIDIBUNDUS; BREEDING SUCCESS; URBAN POPULATION

Document Type: Research Article

DOI: http://dx.doi.org/10.3409/173491605775789236

Publication date: October 1, 2005

More about this publication?
  • Folia biologica is an international quarterly journal that publishes papers on the broad field of experimental zoology, nuclear and chromosome research, and also ultrastructural studies. All papers are subject to peer reviews. Indexed in: ISI Master Journal List, Current Contents, Polish Scientific Journals Contents. I.F. 0.667
  • Editorial Board
  • Information for Authors
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more