[CT Birds] A little gull talk

[Dennis Varza]

Hi Folks

After 2 months of counting gulls, it was time to step back and see  
where this was going. This analysis is rather superficial but it  
helps get a feel for the data. The Ring-bills are the most interesting.

Dennis Varza
Fairfield

Laughing Gull
Looking at Data from Cove Island Park Stamford, Southport Beach  
Fairfield, and Seaside Park Bridgeport, from September 19 to 30  
November, here are some generalities.
In mid- September Immature birds made up about 30 % of the population
By October, immatures are less than 10 %. By late October Immatures  
are gone except for the odd individual. Adults were last seen on 17  
November.

Ring-billed Gull
Earlier I noticed that immature gulls were more common inland (5% on  
the shore) A look at the data over time indicates something more  
interesting. Looking at the Bardsley Park data alone from 8 October  
to 6 December. On October 8 , immature gulls made up 30% of the  
gulls. On 8 November the number rose to 71%. On 6 December the nuber  
fell to 13% of the gulls. It looks like I caught the passage of  
immature birds through the area! The data is not solid enough to be  
absolutely sure, But something to look into next year. What will the  
rest of the winter bring? There is a slight indication of the pattern  
on the shore, The problem is to separate changes in behavior due to  
the tide.

Herring Gull
Nothing special of note here. On the shore, first winter Gulls make  
up about 13% of the gulls, inland it is about 4%.

Great Black-backed Gull
These gulls are never abundant. 23 birds at Seaside Park on 8 Oct is  
the largest number. Immature birds are infrequently seen. This  
combination makes data analysis difficult. the presence or absence of  
one bird even by chance makes a big difference. Immatures make up  
about 10% on the shore and 15 % inland.