This weeks ringing activities ended with a decidedly mixed weekend. Saturday started with strong winds and heavy rain whereas Sunday was still and calm after a clear night. We had planned one of our public events on the Saturday morning and were on the verge of calling it off when the rained eased and the wind dropped. The adverse overnight weather was not ideal for a good ringing total but that did mean that we had time to discuss the birds we caught in detail with our guests. We struggled to a total of only 37 birds which included Sedge (8), Reed (8), Grasshopper (2) and Cetti's Warblers (1), Whitethroats (8) and Blackcaps (4). As with most ringing sessions there is usually a stand out species and this sessions was a stunning juvenile male Eurasian Sparrowhawk. This was the first Sparrowhawk we have ringed this year and it certainly proved to be a crowd pleaser.
|Juvenile Male Eurasian Sparrowhawk|
It is relatively straight forward to age and sex Sparrowhawks, males are much smaller than females and therefore biometric measurements of a wing or tarsus can determine sex. Age is determined by the presence of chestnut fringing to the upper parts and bold heart shaped markings on the underparts. The iris colour is described as grey-olive in Baker (1993) for a first winter, becoming bright yellow, sometimes with a hint of orange in a second winter. This individual had a bright yellow iris which may suggest it was from an early brood. For comparison I have included an image of a second winter male that ringed in December 2012.
|Second winter male ringed in December 2012|
In the image below the heart shaped tips to the feathers on the underparts are clearly evident as is the chestnut fringing on the subsequent images.
|Juvenile Sparrowhawk showing heart shaped tips|
|Juvenile male Sparrowhawk showing broad chestnut fringing to upperparts|
|Juvenile male Sparrowhawk showing broad chestnut fringing to upper parts and tail|
By contrast Sunday can only be described as a bit manic. The previous nights weather had evidently halted migration for a while and birds were desperate to get going. Our total was an excellent 324 birds including Sedge (108), Reed (49) and Grasshopper Warblers (40). Blackcaps had evidently started to move with 80 ringed, and Common Whitethroat numbers remained strong with another 14 ringed. Other species included a further 15 Willow Warblers, eight Chiffchaff, two Garden Warblers and our first Pied Flycatcher of the year.
I have updated the graph and table which compares this years total up to the 31st August with those of 14th September for the years 2010 to 2013. The outstanding total remains that of Willow Warbler which is evidently a record year for us. All the other key migrant species also appear to have had a good breeding seasons with the majority of the totals being above average and some, such as Reed and Cetti's Warblers already being above of close to the September 14th totals of previous years.
Regular readers of this blog may have noticed that I have been making some changes. One of those changes in the addition of a new page which provides some recent recoveries from the Haven, which is viewable by clicking on the tab at the top of the page.