Titmice in the Braydon Forest: 2013 to 2021

As I have recently written a couple of pieces on Blue Tits in the Braydon Forest I thought I ought to have a look at the rest of them, as well as revisiting the Blue Tit figures. Previous work, because it was focused on the single species, only counted sessions in which Blue Tits were caught. This doesn’t work when incorporating other species into the equation, so I counted every session within the Braydon Forest carried out between 1st January 2013 and 31st December 2021. However, I also decided to exclude the sessions carried out at Blakehill Farm. It would massively skew the results against both Coal Tit and Marsh Tit, as there is no woodland to speak of where I ring at that site and no Marsh Tits have ever been seen there and we have only ever caught a single Coal Tit, in the hedgerow.

Despite the restrictions imposed on our ringing activities by Covid, and the restrictions placed on us by the Wildlife Trust, due to interference from members of the public with the increased footfall at Ravensroost Wood during and after lockdown, I have decided to include both 2020 and 2021 in the results, as they will have impacted all four species covered in this little analysis. These are the results:

Blue Tit:

Table 1: Blue Tits Ringed by Session

Unsurprisingly, these are the commonest of the titmice in the Braydon Forest. What is interesting is that there is no commonality between annual catches. We know that both 2016 and 2021 were poor breeding seasons for Blue Tits and the results show that.

Fig 1: Blue Tits Ringed by Session + Trend Line

As you can see from the chart, whilst the numbers ringed do go up and down on an annual basis, the trend (the red line) over this period has remained pretty well static.

Great Tit:

Table 2: Great Tits Ringed by Session

Not quite the same swings in numbers as seen with the Blue Tits. Of interest is the ratio of adults to juveniles. Unusually, more adults than juveniles are ringed each year. I will look at this in more detail at the end of the piece.

Fig 2: Great Tits Ringed by Session + Trend Line

As you can see from the trend line, the population is stable with a slight increase over time.

Coal Tit:

Table 3: Coal Tits Ringed by Session

I suspect I could massively increase the numbers of Coal Tit caught and ringed if I did sessions in the western part of Somerford Common, which is predominantly a conifer plantation. I might test this out in 2022.

Fig 3: Coal Tit Ringed by Session + Trend Line

As you can see from the graph, although at a lower density than Blue or Great Tits, the dynamic in the numbers caught follows a similar trajectory. What is concerning about this chart is that the trend is showing a decline in the catch over time. This might be habitat related which, as indicated above, I might well test out this year.

Marsh Tit:

Table 4: Marsh Tits Ringed by Session

Undoubtedly, to me this is the most important species of Tit in the Forest, being a Red-Listed rapidly declining species. I make no claims about the population size, as I have not done full surveys of each site. What I do know is how many we catch each year. Unfortunately, due to the restrictions imposed on my activities in Ravensroost Wood, a site where I would normally expect to ring eight or more birds per annum, it seriously impacted on my numbers for this year. It also wasn’t helped by my not getting access to Webb’s Wood until July. Obviously, that impacted my catch of all species but when you are dealing with an uncommon species with small numbers the impact can be magnified.

Fig 4: Marsh Tits Ringed by Session + Trend Line

As you can see from this, although it is starting from a very low base, it is the one species of Paridae in the Braydon Forest that is showing a positive upward trend in its population. Both Forestry England and the Wiltshire Wildlife Trust have committed to managing their sites sympathetically for this species, perhaps it is having an impact?

Adult to Juvenile Ratios:

Given that this analysis has primarily been based on the balance between adults and juveniles ringed by year, I have put together a table for comparison:

Table 5: Ratios of Adult to Juvenile Ringed by Species by Year

As you can see from table 5: we ring a greater proportion of Juvenile Marsh Tits than for any of the other three species. Obviously, the numbers are smaller, so the opportunity for a wider variance than in those species with much higher numbers of records is there, and I haven’t carried out the appropriate statistical analyses (yet – next rainy day maybe, once I have learnt R and / or Mark!). As previously mentioned, what is also interesting is that we ring more adult Great Tits than juveniles. I would never have guessed that would be the case.

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