Ynglefugle i Vejlerne - Dansk Ornitologisk Forening

60
45
30
15
0
31.01
02.03
01.04
01.05
Fig. 77. Rørspurv fænologi, syngende fugle på Selbjergtakseringerne,
gennemsnit af sum pr pentade, tre pentaders
glidende middel, data fra 1993-2002.
Reed Bunting phenology, singing males on "Selbjerg
tran sect", average sum for every 5-day period, smoothed
over three periods. Data from 1993-2003.
ne både i maj og september 1989, så den var forment
lig yng lefugl her. Den sydligste genmelding
af en Vej ler-mærket fugl er fra Algeriet i novem ber
(ene ste genmelding af en danskmærket fugl syd
for Middelhavet, Bønløkke et al. 2006), de øvrige
er fra Tyskland, Holland, Belgien, Frankrig og
Spa nien i tiden mellem 26. september og 1. marts.
De ring mærkede Rørspurve i Vejlerne udgør 4%
af to talen for hele landet (Bønløkke et al. l.c.).
Vejlernes rørspurvebestand er uden tvivl stor,
selv om der ikke er grundlag for et præcist be-
31.05
Summary: Breeding birds in Vejlerne
This paper gives a comprehensive overview of breeding
bird surveys conducted in the nature reserve Vejlerne
and its immediate surroundings (57°04' N, 09°01' E, Fig.
1). Vejlerne today represents one of the most important
breeding sites in North and West Europe for birds associated
with reed Phragmites beds, bulrush Scirpus marshes,
and freshwater meadows.
The area originates from two former shallow estuarine
inlets of the brackish Limfjord which has been embanked
by dikes since 1868, drained and attempted used
as agricultural areas. The land reclamation project only
proved successful after many years and several failed attempts,
but remained unprotable, and the drainage attempts
were nally abandoned during the First World
War, and all drainage pumps were dismantled and replaced
by sluices. The sluices only allow water ow out
of Vejlerne and keep the water levels in Vejlerne slightly
lower than that of the adjacent Limfjord. Hence Vejlerne
has ever since remained a wet – and now freshwater –
nature area with channels, dikes, lakes, reedbeds, mars-
30.06
30.07
Rørspurv 213
stands estimat. Anslået drejer det sig om i stør relses
ordenen nogle tusinde par ud af en landsbestand,
som ud fra punkttællinger er beregnet til ca
50.000 par i 1993-94 (Jacobsen 1997). Siden er
der hverken i Vejlernes materiale eller på landsplan
(Held bjerg 2007) konstateret nogen tyde lig
ten dens til frem- eller tilbagegang. Artens krav til
le ve sted er ikke så specialiserede som hos nogle
af de andre rørskovsfugle, eksempelvis n des
den med pæne tætheder i mange områder med
tør, lav og spredt rørskov, hvor Rørsangeren ikke
fo re kom mer, og hvor også tætheden af Sivsan ger
er lille. Der er således næppe nogen grund til at
mål rette forvaltningen af Vejlerne med hen blik på
Rør spurv.
hes and meadows. The area is divided in two independent
areas, the Eastern Vejler ("Østlige Vejler") and the
Wes t ern Vejler ("Vestlige Vejler"), separated by the former
peninsula Hannæs. The Eastern and Western Vejler
are both composed of several localities, which partly represent
different catchments, are topographically separated
by dikes, and in which water levels uctuations can
be managed independently. All areas below the 0 meter
contour line are designated as a nature reserve, which
since 1994 has been owned and managed by the Aage V.
Jensen Foundation, a private foundation which has acquisition
and optimal management of nature reserves for
conservation as a main objective.
In the 1920s and 1930s most Danish ornithologists
were based and active in the surroundings of Copenhagen,
but a few explored the inaccessible and unknown
parts of Jutland, and realized that the swamps and mar -
sh es of the partly failed Vejlerne embankments held
higher numbers and was important for several breeding
birds, that were rare elsewhere in Denmark. Some of