All Around Tarvin
By Charles Bradley - 12th October 2020 6:00am
The "Bird Box Team" (Woodland Trustee and Tarvin's Tree Warden Peter Maiden, ably assisted by John Price) has recently undertaken the annual survey and refurbishment of all of the bird boxes in our woodland. We have a total of 56 moulded 'Woodcrete' bird boxes. These are robust structures made largely from a clever mixture of saw dust and cement and these have the benefit of being almost completely squirrel-proof. We have been helped to buy these over the years as a result of very generous sponsorship by Tarvin folk. This has meant that we could replace the vulnerable wooden boxes, into which squirrels were able to chew their way and which therefore rendered the brood highly susceptible to predation.
We have 55 of these 'Woodcrete' boxes in use and, of these, during this summer, 29 had been used by blue tits, 21 by great tits and 2 by nuthatches, with just 3 being unused. This maintains the overall occupancy rate of previous years of 94% — again, a remarkably high result. (It must be remembered that, in this survey, "occupancy" does not necessarily mean that the nest was used only for one brood (with the early good weather this year encouraging multiple broods) or that the brood (or broods) were in fact successfully reared. It would need continuing surveillance to obtain more accurate figures. However, it remains a very pleasing and optimistic, if not necessarily rigorous, statistic.)
There is just one wooden box which is still in place and is intended for use by kestrels. This has not so far been occupied by the target bird — but we live in hope. Of the 'Woodcrete' boxes, not all of them were occupied by the species of bird for which they had originally been designed. For instance, we have just 8 boxes which (because their hole is slightly larger than that preferred by Blue Tits) are aimed at Great Tits. In the event, the surveyors found evidence of occupation by a total of 21 pairs of Great Tits, indicating that 14 pairs of Great Tits had successfully built nests in boxes that were theoretically aimed at Blue Tits! As long as the birds are happy, we aren't worried! (See next paragraph to explain the apparent lapse in the maths!)
It is very encouraging to see that we have at least two pairs of nuthatches nesting in the woodland. One pair was in Nuthatch box 16, which is in the oak tree at the back of the "Orchard" glade, and the other pair was in box number 54 (a box intended for Great Tits), which is situated near to the back gate of the school. The photographs show the way that they have modified the entrance with mud to make it more suitable for them
The 'Woodcrete' boxes themselves are in really good order and they have proved a tremendously good investment. They should continue in use for many more years. There have been just two occasions on which damage has been caused to the boxes by remarkably sharp-toothed squirrels and, on both occasions, the supplier has replaced the box without charge.
Looking to the future, as the section of "new" woodland (adjoining the Saxon Heath estate) develops, the trees are beginning to mature well and, in just a few years, will be sufficiently grown to enable us to put up more boxes in the (by then, much larger) trees. Once woodland reaches its 'teenage' years, the trees begin to grow really rapidly and start to acquire a good size. At that point, the birds will have more cover and a greater area of insect-bearing leaves to help them feed their young, so that the conditions will then be just right to introduce a number of extra bird boxes into the still-developing woodland.