A bleak midwinter time for robins and other birds

The latest results from the British Trust for Ornithology (BTO) report a poor year for many of our birds, largely due to a cooler and wetter spring than average.

Findings show that breeding success was well below average (or in some cases, disastrous) pretty much across the board in 2021 thanks to the late spring and early summer weather, with birds either failing to fledge young or fledglings succumbing to the cold, wet conditions after leaving the nest.

Sadly, the weather in 2021 proved less than welcoming, with temperatures well below average throughout spring and heavy rainfall in May, a key stage of the breeding season. “Initial signs were promising,” explained Lee Barber, Demographic Surveys Officer at the BTO, “with many ringers noting good numbers of migrant warblers, such as Chiffchaff, Whitethroat and Sedge Warbler, returning and healthy populations of resident species, including Wren and Cetti’s Warbler.”

As predicted in a cold spring, nest recorders observed that many species were late to start nesting in 2021. “Those of you with nest boxes in your garden may have noticed that the Blue and Great Tits using them started to lay a few days later this year.” noted Dave Leech, the Head of the Ringing & Nest Recording Schemes, who added “Delays were even more pronounced for many migrant birds, including my own study species the Reed Warbler, and Pied Flycatcher, which started to breed almost a week later than the typical date. In some cases a late start can be beneficial, helping birds to track the advancing emergence of their insect prey but that was not to be the case in 2021.” 

 

Photo: Dawn Robinson-Walsh


The Report says:

Chaffinch and Greenfinch abundance continues to decline significantly. Once again, the number of adults of both species encountered were lower than in any previous year and the last five seasons represent the five lowest adult capture totals on record; Greenfinch numbers have declined  to such an extent that it is no longer possible to generate adult survival figures for this species. Data for Chaffinch indicate a 64% drop in adult overwinter survival, and it is possible that the decline in Greenfinch is also partly related to poor overwinter survival of adult birds, possibly due to the continued effects of the devastating trichomonosis outbreak that began in the mid-2000s. The other resident species displaying a decline in numbers in 2021 was Bullfinch, which may be linked to a significant reduction in productivity recorded during 2020.

So, what does this mean for 2022? Dave Leech says: “A lot will depend on the conditions over the coming winter. There will clearly be fewer young birds in the countryside this Christmas but if conditions stay mild, they may survive well, particularly as there will be fewer competitors to share their limited resources with. That could really help to reduce the impact of a 2021 breeding season to forget.”

Tell us what birds you’ve seen this winter in your garden, and feel free to share photos.

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