Wednesday, 5 January 2011

To feed or not to feed?

The recent severe weather has been tough for Bitterns, with many being seen around the remaining areas of unfrozen water, frequently in unusual situations.  Bitterns traditionally suffer in such cold winters.  At least 17 sites attempted to feed their Bitterns, usually with Sprats or Sardines, during the coldest spell of weather and 8 sites report that Bitterns were seen taking the fish. See Steve Blain's video of a Bittern eating sprats  (or below) provided by local birders at Stewartby Lake.  At Leighton Moss, three Bitterns came to the feeding site regularly (about once every half hour), took some fish and then returned regularly during the day.  At most of the other sites, Bitterns were seen in the vicinity of the food and may well have taken it.  So it would appear that feeding in hard weather may help some Bitterns survive.  We feed Blue Tits, so why not a bird that is a conservation priority in the UK?

On the other hand, is this just another example of unnecessary human tinkering?  Will it make any difference at all to the population in the coming spring, or will it even hinder a natural dispersal of young birds to new sites?  What do you think?

Edit - In a rather low poll, 16 out of 16 respondents thought we should be feeding Bitterns.

1 comment:

Paul Tout (NE Italy) said...

Given that there remain a lot of unoccupied potential Bittern territories and that UK + Eire Bittern numbers remain precariously low I think there is a case for feeding at the moment. At a certain point though (100 males the previous summer?) then feeding could probably be safely left to interested parties such as those feeding at Stewartby Lake. It's a toughie but if these hard winters become a regular feature it'll be interesting to watch how British bitterns respond. They'd have to come up with some sort of regular strategy (such as moving to the south-west or the French Atlantic coast).
With this scenario there is then a case (valid for other rare UK resident UK species such as Cetti's Warbler) of creating wetland refuges, even small ones (0.5 - 1 ha) in sites with a particularly favourable microclimate (for example landward of SW-facing sea-bays between Hampshire and Cornwall).
Feeding would help them 'tough it out' in UK but the evolution of strategies to deal with climate deterioration (such as dispersal south and west / emigration .... basically what C. European bitterns do) could only come about (and be easier to arrive at) if you are working with a total population of several hundred birds. Feeding long-term (once a viable population is reached) can only favour 'sprat junkie' and 'sticky' bitterns within the gene pool that refuse to move whatever the weather.
(FWIW I'm absolutely dead against the RSPB policy line of the summer feeding of garden birds - but that's another issue).