BSNHS

©BSNHS 2014

Introduction

The society's long involvement with Hatfield Forest has resulted in the production of many reports, particularly on the birds of the forest.   This report, the eleventh in the series, continues on the theme of a "Big Forest Bird Watch", in which members of the Society spent a morning recording as many as possible of the birds present in the area being surveyed.   The number of areas surveyed depends on the number of people present; this year eight members attended on the day and this enabled surveys to be made in all of the five areas into which the forest has previously been divided for this purpose.    The weather was cloudy but bright with a light breeze.


Acknowledgements

The Society is indebted to The National Trust for their interest in such surveys and for their encouragement and the positive attitude always shown to the Society's members.   Grateful thanks are due to the participants for their time and interest in undertaking such survey work.


Participants

Claire Bertschinger, Jim Fish, Tim Fuller, Robert Phillips, Bob Reed, John Slee, Chris Swan, Dave Webber.


Methodology

The Forest has traditionally been divided into five areas, described as northwest, northeast, southwest, southeast and lake.   These are shown on a map which is appended as a pdf document and this is the map that has been used in previous surveys.   This year the surveyors sampled all of the five areas.   The surveyors covered as much of their areas as was practicable and recorded both the total numbers seen for each species and also noted whether birds were breeding using the usual commonsense indicators, such as birds observed holding territory, sitting on nests, carrying food or nesting material, or the presence of young birds.   Where young birds were counted, numbers are shown; otherwise "Y" is entered to indicate that breeding is considered likely to have occurred using the other criteria.


Survey teams were arranged as follows:

Northwest: Jim Fish, Tim Fuller.

Northeast: John Slee.

Southwest: Robert Phillips, Dave Webber.

Southeast: Claire Bertschinger, Bob Reed.

Lake: Chris Swan.


Results

The results are presented in a spreadsheet that is appended as an Excel document.   For purposes of comparison and interest, the total numbers of birds recorded in the 2016, 2017 and 2018 surveys are shown in addition to this year's results.


Discussion

As with the surveys of previous years, it must be remembered that a survey such as this is not claimed to be comprehensive; it is simply a "snapshot" of those species seen on a particular occasion.   As a result, a repeat survey a few days or even a few hours later may give different numbers of species, and indeed even additional or fewer species compared with this exercise.   Nevertheless, since the methodology is essentially unchanged, the results may be compared with earlier years and valuable information may be gleaned on the status of the various species observed.   Some duplication may occur; for example, the corvids are very mobile and it can be difficult to obtain accurate counts as the birds constantly come and go.   It is also difficult to be certain that the same group of birds is not counted twice as a result of moving from one survey area to another during the morning.


There are several encouraging aspects of this year's survey.     The Common Tern is again nesting on the new tern raft and one of the two birds was observed sitting on the nest.    Four Mute Swan cygnets were observed.   Three male Reed Warblers were holding territory in the reed bed and a Reed Bunting was exhibiting territorial behaviour in the marsh area.   A Swallow was observed visiting its nest in the Fishermen's Shelter and judging by the numbers seen, Jackdaws have had another successful year.


A Nuthatch was observed, confirming the view that in previous surveys although apparently missing, they were almost certainly around and may simply have been in another area of the forest.   The relative paucity of breeding evidence for some species should again not be viewed with too much gloom.   Many species breed very early in the year and it is therefore not surprising that young are quite well developed by late May and become more adept at hiding from view.   This is particularly true for the Dunnock, where low numbers on this survey should not be seen as a cause for alarm.


Yet again no Turtle Doves were noted and this species has now disappeared from the area.   Although the Cuckoo has been heard in the forest in recent days, none were heard during this survey and it is clear that this species is also experiencing a severe decline.   The total of 46 species observed this year is slightly lower than the average of the previous years' surveys, but the total number of adult birds seen, at 746, is the highest since the 2010 survey.   In addition to the birds seen, several butterflies were observed and mammal sightings included Rabbits, Fallow Deer, Grey Squirrel and evidence of Moles from freshly excavated molehills, together with the pleasant picture of a contented herd of Red Poll cattle with many calves.   


Chris Swan

27th May 2019

HATFIELD FOREST BIRD WATCH - Sunday 26th May 2019