Herdade da Mitra Constant Effort Ringing Station: 5 years monitoring wintering birds

The Portuguese Association of Bird Ringers (APAA) runs a national project to monitor the wintering birds in Portugal since 2011. This project aims to gather long time series of data in order to assess the wintering trends of small birds, and to improve the knowledge on the geographical origin of these birds. At the moment there are 8 active ringing stations across the country (http://apaapt.wixsite.com/apaa/mai), the Herdade da Mitra being one of them.  The sixth year of the project has just begun (in the 15^th of November), and includes six ringing sessions until the 15^th of February, one each fifteen days.

Since the winter of 2011/12 we have captured 730 birds and recaptured 185 of them, in a total of 915 birds handled from 38 species. On average, 183±48 [SD] birds were captured yearly, with 2013 being the year with less captures (=121) and 2014 the best of the five years with a total of 250 birds (Fig. 1). Throughout the winter there is a huge variability between the birds capture per session (Fig. 2), with the highest numbers generally recorded in the first session – 45±23 [SD] (15 Nov – a Dec), and the lowest in the fifth session – 22±5 [SD] (15 to 31 Jan).

Figure 1 – Number of birds captured and recaptured per year in the Constant Effort Ringing Station of Herdade da Mitra – Universidade de Évora

Figure 2 – Average number of bird species captured per session betwen 2011-2015 at the Herdade da Mitra – Universidade de Évora

On average, 33±17 birds were captured per session, with the highest value recorded being 73 birds in one session! The top 5 species were the blackcap (n=243), the blue tit (n=102), the house sparrow (n=80), the chiffchaff (n=78) and the robin (n=56), together they represent 61% of all the birds captured. These values are very important since the blackcap, the chiffchaff and the robin are target species for the national project. Running such a project is only possible thanks to the participation of several people, who voluntarily give part of their time to the project. To all of them – thank you a lot!

As a curiosity, during the 5 years of the project we captured 2 chiffchaffs ringed in the UK, these small birds (6-7 g) have travel more than 1,600 km to winter in our gardens!

Our wish to the year 2017 is to reach the 1,000 birds captured and, with some luck, recapture a bird ringed somewhere in Europe!

Examples of some species captured in the project: (1) goldfinch Carduelis carduelis, (2) Iberian magpie Cyanopica cooki, (3) bullfinch Pyrrhula pyrrhula, (4) black redstart Phoenicurus ochruros.