Monday 4 March 2019

Siskins in short supply.

Things had been looking quite promising for Siskins in the garden this spring with birds starting to visit the feeders back in late December and then more regularly through January and into early February. Up to five were seen visiting the feeders in late December and that increased to between five and ten through January and into early February but then numbers fell away. That sudden and unexpected drop off in numbers was also mirrored by Goldfinches and other species so it wasn't just a Siskin thing which makes it a bit harder to understand.

The prospects for the spring looked to be good at the end of January with up to 10 Siskins visiting the feeders.

This is one of 7 feeders in the garden. All were well used in late January and needed topping up or filling every day.

The drop off in numbers of all species started ahead of the spell of exceptionally warm weather that came in late February but that doesn't mean the weather wasn't a factor. Temperatures could be involved as it has been quite a mild winter overall but wet or dry conditions can make a difference too. Cones on alder and conifers open and close in response to moisture levels which can make their seeds more or less easily accessible and their productivity also varies from year to year. The mild conditions have caused some tree buds to develop early and willow catkins to emerge which are another energy rich food source for Siskins and other finches. The fact that Siskins are variable migrants in terms of numbers and distances involved and can be very early breeders all adds to the complexity but it is all food related in one way or another. Bottom line it is currently looking like being a relatively poor spring for Siskins in my garden this year. Currently a maximum of three are visiting the feeders at any one time and then only on a fairly intermittent basis. If it was going to be a good spring for Siskins I would expect counts to be in double figures by now (18 were ringed in the garden on 6th March last year) with birds being seen in the garden throughout much of the day.

Ringing revealed there were a few more Siskins visiting the feeders than the counts alone had indicated, as is often the case, but the overall picture was the same. At least 7 different individuals visited the feeders in late December and one of those was a retrap that was originally ringed in February 2018. In January and February a total of 16 different individuals were captured: of these 12 were new birds, 3 were retraps that had been ringed in December and another retrap had been ringed in December 2017. In the past Siskins were exclusively late winter and spring visitors to the feeders but the last few years have seen small numbers arriving much earlier in the winter with some being ringed returning birds. It will be interesting to see if this trend of early arrival and winter to winter retraps continues or even increases in the coming years.

Male Siskin 31/01/2019.
I took a series of photographs of this bird and managed to read part of the ring number which pointed to it being one of the returning wintering birds.

Female Siskin 31/01/2019
There is still time for numbers to increase as we move further into spring but any build up in numbers will be much later than usual and is likely to involve fewer birds than last year, if it happens at all.  


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