Bittern (Botaurus stellaris). Steve Fletcher.
If anything distinguishes the Bittern (Botaurus stellaris) from other
large birds it is the difficulty for observation. Much of the reason
lies with their nocturnal habits, their ability to camouflage and also
scarcity, quite a challenge for any fan of birds. In Extremadura
there have not published bittern sightings until the late 1980s: one
was hit near Moraleja (Agustin Iglesias). The next record shad to wait
until September 1997, when a male was heard in the Laguna Grande de
La Albuera (Gragera Francisco). Since 1998 sightings were reported from
Arrocampo reservoir, the only regular presence in Extremadura. Against
all odds, the first confirmed case of breeding in Extremadura took place
at Casa Zafra Reservoir, Cáceres. In 2007 a male was heard rePeatedly
calling and finally, on 08.05.2007, two juveniles were observed. At Casa
Zafra a male was heard again in the spring of 2008, but this time breeding
could not be confirmed (Jerónimo Jaén). We had to wait until 2012 to
see the long suspected breeding bittern in Arrocampo reservoir. Specifically,
an adult and two juveniles were observed on 07.07.2012 (Sergio Mayordomo).
Therefore, the eight species of Iberian heron were all breeding, for
the first time in Extremadura, in this unique reservoir.
The maps shows the locations where it is aware of the presence of bittern inExtremadura until 2012 . In such areas for breeding Arrocampo and Casa Zafra, join Montijo reservoir (one in fall 2001), Talaván rservoir (a bird on 22.11.2003, 12.03.2006 and 30.12.1007) and Santa Amalia ricefields (one on 01.11.2011). In January 2012 it was discovered a bittern in Valdefuentes gravel pit, Galisteo (S. Mayordomo) and shortly after they were found two individuals present (Javier Prieta), observed one of them until 12.03.2012. The presence of two individuals in a wetland so small suggests that the number of wintering bitternsExtremadura could be much higher than observed. In 2011-2012 there were at least five bittern in Extremadura : three at Arrocampo and two at Galisteo. In December 2012 have seen three Arrocampo from an observatory and may be more in other areas of the reservoir. In December 2012 was seen a bittern in Galisteo ricefields, an inauspicious area, and in January 2013 has again seen one in the nearby gravel pit of Valdefuentes.
The graphs show
the temporal distribution of bittern in Extremadura with records up
to 2012. In the red figures is Arrocampo Reservoir, a place that has
75% of the observations. For months, a pattern typically seen in winter (December to February shows the maximum), with the minimum
being between June and August, when only one breeding pair remains. Regarding the annual trend highlights of 2012
when both Arrocampo as well as Galisteo became popular and were visited
by numerous observers. Although the graph is proportionately very large
in 2012, actually it is because of many observations of a few birds (half
a dozen or so). This annual chart is not representative of the spread
of the species, as the amount of effort depends heavily on information
collection, dissemination, and largely by chance when locating bitterns.
Observers: Javier Briz,
Francisco Lavado, Enrique Fernández Larreta, Saturnino Casasola,
Vicente Risco, Dave Langlois, Samuel Langlois, A. Hernández, Fundación
Global Nature, Monfragüe Vivo, Francisco Rámirez, Joaquín García,
Miguel Ángel Muñoz, Fernando Yuste, Juan Pablo Prieto, J. Traín, S.
Wood, Daniel López Velasco, Carlos González, Marta Zamora, Martin
Kelsey, C. Delgado, Óscar González, Manuel García del Rey, Antonio
Ceballos, Unai Fuentes, César Clemente, Javier Mahíllo, etc, etc, etc.
News and comments about the birds of Extremadura (SW Spain). Written by Javier Prieta (javierprieta@gmail.com) Translated by Martin Kelsey - http://birdingextremadura.blogspot.com.es/ (since May 2013), Dave Langlois (May 2010-September 2012), Steve Fletcher (October 2012-April 2013) and Martin Kelsey (April 2013-May 2014) - Versión en castellano: http://aves-extremadura.blogspot.com/
Showing posts with label bittern. Show all posts
Showing posts with label bittern. Show all posts
Wednesday, 20 February 2013
Monday, 26 November 2012
HERONS IN SPAIN AND EXTREMADURA. SURVEYS 2011.
SEO/BirdLife has published a monograph of the census results of breeding and wintering herons carried out in Spain in 2011 (Garrido et al. 2012). Although Extremadura is not renowned for its wetlands, rather the opposite, it ranks second after Andalusia, in terms of importance for wintering birds (32 900, 14% of Spain) and third in terms of breeding pairs (9,900 pairs, 15% of Spain, in 84 locations).
As a family, the herons are increasing and most of the studied species show increases in Spain. The night heron (Nycticorax Nycticorax) has risen from 1,300 in 1986 to 5,400 pairs in 2011. The squacco heron (Ardeolla ralloides) from 200 in 1980 to 2100 pairs in 2011. Grey heron (Ardea cinerea) from 168 in 1950 to 7,000 pairs in 2011. The purple heron (Ardea purpurea) from 2,000 in 1997-2003 to 5,400 pairs in 2011. The bittern (Botaurus stellaris) from 26 pairs in 1980 to 41 in 2011. And the great white egret (Egretta alba), which began breeding in 1997 in the Ebro Delta has gone to 53 pairs in 2011. By contrast decreases were detected in the little egret (Egretta garzetta), with a small drop in the last ten years, resulting in 2011 (9350 pairs) against 1990 figures (7,600 pairs) but lower than 2002 (10,400). The most abundant species is the only one who has suffered a significant decrease. We talked about the cattle egret (Bubulcus ibis), down from 70,000 pairs in 1989 to 40,000 in 2011. This is a species that has incresed during the twentieth century and whose population can fluctuate greatly depending on local conditions. Experts say that some species show strong expansions, then suffer a decline after which the population is consolidated and stabilized.
As a family, the herons are increasing and most of the studied species show increases in Spain. The night heron (Nycticorax Nycticorax) has risen from 1,300 in 1986 to 5,400 pairs in 2011. The squacco heron (Ardeolla ralloides) from 200 in 1980 to 2100 pairs in 2011. Grey heron (Ardea cinerea) from 168 in 1950 to 7,000 pairs in 2011. The purple heron (Ardea purpurea) from 2,000 in 1997-2003 to 5,400 pairs in 2011. The bittern (Botaurus stellaris) from 26 pairs in 1980 to 41 in 2011. And the great white egret (Egretta alba), which began breeding in 1997 in the Ebro Delta has gone to 53 pairs in 2011. By contrast decreases were detected in the little egret (Egretta garzetta), with a small drop in the last ten years, resulting in 2011 (9350 pairs) against 1990 figures (7,600 pairs) but lower than 2002 (10,400). The most abundant species is the only one who has suffered a significant decrease. We talked about the cattle egret (Bubulcus ibis), down from 70,000 pairs in 1989 to 40,000 in 2011. This is a species that has incresed during the twentieth century and whose population can fluctuate greatly depending on local conditions. Experts say that some species show strong expansions, then suffer a decline after which the population is consolidated and stabilized.
Garrido, J. R., Molina, B. y del Moral, J. C. (Eds). 2012. Las garzas en España. Población reproductora e invernante en 2010-2011 y método de censo. SEO/BirdLife. Madrid.
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