Tag Archives: Garden

Garden bird feeders are boosting blue tit numbers – but leaving other species hungry

Posted on by

From The Conversation

We’ve filled feeders with seeds and nuts since many of us were children and loved seeing which birds arrive. And, we’re not alone – around half of all UK households do the same nowadays, spending £250 million on 150,000 tonnes of bird food each year. That’s enough to feed three times the breeding populations of the ten commonest garden species if they ate nothing else all year, with one feeder for every nine birds that use them.

Have you ever wondered how all of that additional food might be affecting wild birds? How much has our generosity changed their natural diet, and what of the bird species we don’t see visiting garden feeders?

If you live in the UK and the Channel Islands, one garden visitor you’re probably used to seeing is the blue tit. Blue tits are small, fast and often feed high in trees on tiny insects. Seeing exactly what they eat is tough. But with new molecular technology, it has been possible to test blue tit faeces from 39 woodlands across Scotland – some close to houses, some on remote mountainsides and some by the sea – and gain a fascinating insight into their average diet.

What was found, came as a surprise. A small moth caterpillar (Argyresthia goedartella) that lives on birch trees was their most common natural prey item, present in a third of the faeces sampled. But among hundreds of species of insect prey, there was also garden bird food – and lots of it.

Peanuts were present in half of all the faeces – the most common food item for Scottish blue tits – and sunflower seeds in a fifth. And the birds weren’t just popping next door to find these garden treats. Some were travelling as much as 1.4km from remote areas to nibble on their favourite garden snacks. Clearly this has become part of their staple diet.

A blue tit bonanza

Eating the food we provide gives blue tits more energy to lay eggs – five days earlier than blue tits that don’t. These earlier breeders are likely to raise more healthy chicks. Eating bird food was also linked to a nearly four-fold increase in the proportion of adults available to breed in a given area. Where there used to be one pair of blue tits nesting, garden bird feeders nearby meant there was now likely to be almost four pairs sharing the same space.

Other woodland species such as great tits, nuthatches and great spotted woodpeckers that enjoy garden bird food are doing very well too. Their UK populations have increased on average over the last 25 years that bird feeding has really taken off.

All this feeding might be giving these species an unfair advantage. These species have natural competitors in the woods that aren’t using bird feeders as much or at all, either because they’re shy or because they’re bullied by more dominant species, or because they don’t like the food people provide. These species include the marsh tit, willow tit, pied flycatcher, wood warbler and lesser spotted woodpecker. What’s happening to them is, sadly, not such good news.

How to help all woodland birds

On average, woodland birds that don’t use garden bird feeders have declined over the past 25 years, some to the point where they have almost disappeared from the UK countryside. Nobody knows exactly why, and while this may be partly due to their habitat fragmenting and the climate warming, garden bird-feeding may have also played a role.

Due to people feeding them, there are now more dominant blue and great tits in the woods than 25 years ago, eating more of the limited natural food and evicting other species from their nests. There are also more great spotted woodpeckers and squirrels, which eat the chicks of some birds. Perhaps an extra 700,000 pairs of very healthy and dominant great tits in woodlands is too much for the UK’s remaining 2,000 pairs of shy and subordinate willow tits.

While results suggest there’s a link between how much woodland birds visit feeders and their population trends, they don’t show a direct cause, so we shouldn’t panic yet. While scientists study this problem, responsible bird lovers can help.

Consider contributing to the garden bird surveys organised by the RSPB, British Trust for Ornithology and Action for Wildlife Jersey/Birds On The Edge to help scientists keep track of where birds are, in what numbers and what they’re doing. If you’re lucky enough to live where rare woodland bird species can still be found, consider providing less bird food to common species and cleaning your feeders regularly.

Meanwhile, there are more natural ways to encourage wild birds into your garden. Planting native shrubs and trees like rowan, hawthorn, silver birch, spindle and guelder rose is one option. They are all beautiful year-round, fairly small and provide excellent habitats for wild birds. Other ideas include mowing lawns less often and digging ponds.

As some rare species nest close to the ground, please keep dogs on leads while walking in woodlands during the spring too. But most importantly, keep enjoying these beautiful birds – in all their miraculous diversity.

Further reading:

Faecal metabarcoding reveals pervasive long-distance impacts of garden bird feeding

A national scale inventory of resource provision for biodiversity within domestic gardens

Wild bird feeding in an urban area: intensity, economics and numbers of individuals supported

 

 

Jersey’s Great Garden Bird Watch – 18 years of citizen science in Jersey

Posted on by

H Glyn Young and Andrew Koester

No one can have failed to pick up this week that our environment and the biodiversity that we are a part of is under severe threat. Our very future is being debated. The Great Garden Bird Watch in Jersey may seem trivial by comparison but, like its counterparts in the UK (this year’s 40th Big Garden Birdwatch) and elsewhere, it represents a remarkable piece of citizen science that is truly encouraging in the face of such gloom. Each year, supported by the Jersey Evening Post, we encourage people across the Island to spend time on one day over a February weekend to count the birds they see in their garden, typically with the annual threat of atrocious weather, and tell us how many they see.

During this year’s count, our 18th since we started in 2002, 231 households sent us records of their birds. It wasn’t the highest number that we’ve had back but it has been important in establishing very visible trends, showing how those birds that live the closest to us are faring in today’s world. We need this kind of information if we are going to persuade our governments and those around us that Nature needs our help. Don’t forget, if the birds that have chosen to live closest to us are not doing well, what does that say about our own future?

Counts like this are also good for us, we can watch our birds, enjoy their presence and make ourselves happier and healthier. Proximity to and enjoyment of Nature are well known to help our own mental wellbeing (see discussion here) while another study of people who feed and watch birds found that people generally believed that their bird feeding benefits garden birds. They indicated that natural factors (e.g. bird abundance, disease prevalence) and abiotic factors (i.e. cold temperature) had more of an influence on how much they feed birds than internal constraints such as time and money (see link below). We like feeding ‘our’ birds and its good for their survival and its good for our health.

Back to our latest count (here) Jersey’s counters reported 40 different bird species in our gardens. Well 40 birds and red squirrels. Some birds are very rarely counted and hard to analyse so we base or long-term study of population trends of the 16 most reported species, the Big 16. We don’t include herring gulls as many people actively dissuade them so that counts of them may be skewed. See full results for the Big 16 here

Each year, members of The Big 16 may change position in our little table. In 2019, in order of commonness they were:

Species: Average per reporting garden

  1. House sparrow 6.9
  2. Goldfinch 2.8
  3. Chaffinch 1.8
  4. Wood pigeon 1.77
  5. Starling 1.75
  6. Great tit 1.6
  7. Blue tit 1.6
  8. Collared dove 1.4
  9. Magpie 1.4
  10. Robin 1.3
  11. Blackbird 1.0
  12. Greenfinch 0.33
  13. Song thrush 0.26
  14. Pheasant 0.22
  15. Blackcap 0.16
  16. Great spotted woodpecker 0.12

Our honorary bird, the red squirrel, at 0.4 per garden, would have been 12th.

The relative fortunes of the Big 16 over the 18 years of the count can all be seen in our report (here). There has been a slow decline in overall numbers of the 16 with some very obvious losers, species that are losing ground like greenfinch and starling, and winners like goldfinch, wood pigeon and blackcap. One very encouraging trend has been the recovery of the house sparrow, a species inextricably connected with people that had been disappearing from large parts of the British Isles. It’s doing ok in parts of Jersey!

Of further interest to us is this year’s Top 10 in the UK (from RSPB):

Species: Average per reporting UK garden

  1. House sparrow 4.4
  2. Starling 3.1
  3. Blue tit 2.6
  4. Blackbird 2.3
  5. Wood pigeon 2.3
  6. Goldfinch 1.8
  7. Great tit 1.5
  8. Robin 1.0
  9. Chaffinch 1.3
  10. Magpie 1.2.

There are some interesting comparisons. We have more of those lovely house sparrows while starlings and blue tits are definitely missing out in Jersey.

So, in Jersey we can see well how our bird neighbours are doing. And it is undoubtedly a mixed picture. We need to highlight what’s happening, we need to continue to help our garden birds and we need to take part in next year’s count. Watch this space!

Read the report Observations at backyard bird feeders influence the emotions and actions of people that feed birds here