At Tring, bitterns are regular winter visitors to Marsworth but are more rarely seen at Wilstone.
Since 1998, we have had well over 100 records of Bitterns from Marsworth, with other records from FoTR's own site at Tring Water Treatment Works (WTW), as well as a few noted simply as Tring Reservoirs.
Marsworth and the WTW
This is a summary of the records for these sites (including those simply recorded as Tring Reservoirs):
Year |
Number of |
Months Recorded | Highest number seen |
|---|---|---|---|
| 1998 | 11 |
Jan | 1 |
| 1999 | 1 |
Feb, Mar (booming heard), April (booming heard) | 2 |
| 2000 | 11 |
Jan, Feb, Mar, Dec | 2 |
| 2001 | 3 |
Feb, Dec | 1 |
| 2002 | 18 |
Jan, Feb (booming heard), Mar, Jul, Nov, Dec | 3 |
| 2003 | 27 |
Jan, Feb, Mar, Nov | 5 |
| 2004 | 12 |
Jan, Feb, Mar, Dec | 2 |
| 2005 | 18 |
Jan, Feb, Nov, Dec | 3 |
| 2006 | 10 |
Jan, Feb | 1 |
| 2007 | 3 |
Feb, Dec | 2 |
| 2008 | 27 |
Jan, Feb, Mar | 2 |
| 2009 | 25 |
Jan, Feb, Mar, Dec | 2 |
| 2010 so far |
2 |
Jan | 1 |
Wilstone
There are far fewer sightings from Wilstone.
Year |
Number of |
Months Recorded | Highest number seen |
|---|---|---|---|
| 1998 | none |
--- | - |
| 1999 | 1 |
Feb, Mar (booming heard) | 2 |
| 2000 | 1 |
Dec | 1 |
| 2001 | (2) |
(Nov/Dec, and/or Mar)* | 1 |
| 2002 | 2 |
Jan, Nov | 2 |
| 2003 | 1 |
Mar | 1 |
| 2004 | none |
- | - |
| 2005 | 4 |
Nov | 1 |
| 2006 | (2) |
(Nov/Dec, and/or Mar)* | 1 |
| 2007 | (2) |
(Nov/Dec, and/or Mar)* | 1 |
| 2008 | 3 |
Mar | 2 |
| 2009 | 4 |
Jan, Feb, Mar | 1 |
| 2010 so far |
1 |
Mar | 1 |
* estimated based on incomplete data.
The call of the male that 'boomed' at Marsworth during the spring of 1999 was recorded by the RSPB’s Research Dept, and as every bird has a distinct song registration, it is possible to track individuals. Having left Marsworth without finding a mate, it was subsequently heard again at Fowlmere in south Cambridgeshire.
(Last updated 05/2010)