Tuesday, 18 April 2017

Can you find too many nests?

Finding nests is great. It's the best survey and without doubt I am totally addicted. From March onwards it's like a drug but can you find too many nests?

Good quality data is of utmost importance to me, not the number of records submitted. Records with sufficient visits rather than lots of single visits. While single visits are acceptable to a degree so much more information can be gained from two visits or more. Of course there's always the possibility that the nest had failed on the second visit but that I'm afraid is out of our control.

The BTO have a priority species lists which includes three species in my woods - Song Thrush, Robin and Wren. The species have been listed in order of nest records received the most popular being Song Thrush. In a way this makes me want to try to put more effort into Wren nests, nationally the picture is very up and down. In recent years as little as 165 Wren nests submitted nationally, other years 400.

Now, my issue is that I work alone and have a scheme of 190 boxes. Male Wren's will build up to 6 "cock" nests in a territory of which one is then chosen by the female to line and lay eggs meaning all nests on the territory need to be found. It could be two nests, three nests etc, who knows? I checked a Wren nest at N4 tonight, it still isn't lined so carried out a thorough methodical search for more, - and found nothing. So, imagine five or six nests have been built, not all male wren's are monogamous meaning that a second female could have lined and used a nest in that territory. To avoid missing that record all nests have to be checked, another may be used for a second brood, meaning that three maybe four of the five or six nests "could" be used. Then there's the issue of next year in that some of the nests this year could be re-furbished in 2018 meaning that you may have to find and relocate two years worth of nests. One nest I found that wasn't used last year and still present three weeks ago has now been dismantled and rebuilt three feet away this year and has now been lined. If I didn't spot this subtle difference a record could have been lost.

I also have Song Thrush nests on the go, some predated some still active. Where will they raise their second brood? In their first nests or will I have to search and find again? So with probably over 25 Wren territories in the woods, along with Song Thrush nests, LT Tit nests and 190 boxes I have to be very careful that the whole project doesn't run away with me and my data suffers (and then it rains).........

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