Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp. 1–2, 2008
Title: In memoriam Sándor Andrikovics (1947–2008)
Author: Kerekes, J.
Author's address: Environment Canada, 45 Alderney Drive, Dartmouth, N.S., B2Y 2N6, Canada, E-mail: Joe.Kerekes@ec.gc.ca
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp. 3–6, 2008 Title: Preface
Author: Andrikovics, S., Forró, L. and Kerekes, J.
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp. 7–11, 2008 Title: The dissolved oxygen determination method is 120 years old in memoriam Lajos Winkler (1863–1939) and Rezsõ Maucha (1882–1964)
Author: B. Entz
Author's address: H-8237 Tihany, Váralja u. 3/a, Hungary
Abstract: The measurement of dissolved oxygen is a convenient method of
measuring production and decomposition in bodies of water. The Winkler
Titration method was devised and modified by the Hungarian scientist
Lajos Winkler (1863–1939). The young 25 year
old chemist recognized the importance of dissolved oxygen in aquatic
life and developed a simple oxidation-reduction reaction routinely
performed by aquatic biologists. The relatively new oxygen-sensitive
electrodes facilitate continuous measurement and broadened our knowledge
in all aquatic ecosystems. The main problem with most oxygen probes
is that the delicate membrane over the electrode must be replaced
frequently. Today the oxygen-sensitive electrode is regularly calibrated
with the fundamental Winkler method. Winkler"s
student, Rezsõ Maucha became his partner
and together they developed a semi-micro field method to measure O2
in the late 1920"s. Maucha a founding member of the
International Society of Limnology (SIL) became a leading limnologist.
His star diagram is used to visually compare the ionic composition
of bodies of water both qualitatively and quantitatively. Ahead of
his time (before phosphorus was measured in water) he classified the
productivity of Hungarian lakes based on the oxygen produced by algae.
He broadened the three connecting biological activities – production,
consumption and decomposition with the concept of supply and accumulation.
Key words: Lajos Winkler, Rezsõ Maucha, dissolved oxygen
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp. 13–21, 2008 Title: The measurement of dissolved oxygen today – Tradition and topicality
Authors: Nagy, S. A.1, Dévai, Gy.1, Grigorszky, I.1, Schnitchen, Cs.1, Tóth, A.1, Balogh, E.2 and Andrikovics, S.3†
Authors' addresses: 1Department of Hydrobiology, University of Debrecen, H-4032 Debrecen, Egyetem tér 1, Hungary, E-mail: snagy@puma.unideb.hu Abstract: Today, the determination of the dissolved oxygen content of natural
waters is practically an essential duty whenever background data is
collected for investigations of a hydrobiological, ecological, and
nature or environmental protection viewpoint. If the method by which
the measurements are carried out is concerned, it can be stated that
the 120 year old, classical Winkler-method is inevitable even today.
However the development of hydroecological sciences have laid claim
to such expectations that the necessity of in situ oxygen determinations
have become increasingly important. In our work we present the survival
of the traditional Winkler-method in the present practice, we review
all those viewpoints which have facilitated the widespread application
of in situ oxygen determinations as well as the methods of all the
measurements that are presently regularly applied in the investigations
of natural waters.
Key words: dissolved oxygen determination, stratification, dynamic daily and seasonal changes
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
23–34, 2008 Title: Birds cause net heterotrophy in shallow lakes
Authors: Vörös, L.1, Somogyi, B.1
and Boros, E.2
Authors' addresses: 1Balaton Limnological Research Institute of the Hungarian Academy
of Sciences, Department of Hydrobotany, P. O. Box 35, H-8237 Tihany, Hungary. E-mail: vorosl@tres.blki.hu Abstract: Primary production, community respiration, and net C load from aquatic birds were studied in two Hungarian turbid soda pans during 2002.
The studied water bodies were hypertrophic. The gross primary production/respiration
(GPP/R) ratios were usually below 1, which indicated that these soda
pans were net heterotrophic during the study period. The respiration
did not correspond with the production but showed strong correlation
with net carbon loading from aquatic birds, which pointed out the
important role of allochtonous organic matter. Considering the relationship
between bacterio- and phytoplankton, the studied soda ponds formed
a separated group among lakes, which indicated that the bacterioplankton
depends mainly on the net carbon load of aquatic birds instead of
primary production. In spite of the well-accepted approach that lakes
above 17 µg l–1 chlorophyll a concentration
are net autotrophic, these hypertrophic soda pans (maximum chlorophyll
a >> 75 µg l–1) proved to be net heterotrophic.
The main factor causing net heterotrophy in these shallow soda ponds
is the large organic carbon load (14.8 g C m–2 year–1
in the "Kelemen-szék" pan and 35.6 g C m–2
year–1 in the "Zab-szék" pan) of aquatic
birds.
Key words: production, respiration, net heterotrophy, aquatic birds, soda pans
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Title: Chemical limnology and waterbird use of an urban constructed wetland
Author: A. Hanson
Author's address: Canadian Wildlife Service, P.O. Box 6227, Sackville, New Brunswick, Canada E4L 1G6, E-mail: al.hanson@ec.gc.ca
Abstract: The Sackville Waterfowl Park is a 19-ha shallow freshwater constructed
wetland located in Sackville, New Brunswick, Canada. The objectives
of this ongoing study are to determine the relationships between chemical
limnology, primary productivity, macroinvertebrate abundance and waterbird
density in this urban wetland and if these change with increasing
duration of flooding. Based on total phosphorous and chlorophyll-a,
this wetland would be categorized eutrophic. Annual mean concentrations
of total phosphorous, total organic carbon and chlorophyll-a, did
not decline during 1992–1996, a period from four to eight years
after the creation of this wetland. Total nitrogen concentrations
did however decline during this time period. Associated with high
nutrient availability there was an abundance of macroinvertebrates
with mean dry weight per activity trap ranging from 7–560 mg.
Six different species of fish were caught in minnow traps, with mean
number of fish caught per trap increasing from 10 to 27 during 1993–1996.
The urban setting of the park has not deterred wildlife from using
it, with over 160 species of birds being observed. There have been
26 species confirmed breeding in the park. There was an average
of 49 broods of waterbirds produced annually during 1993 –
96, one of the highest reported brood densities in Atlantic Canada.
These results suggest that constructing wetlands in an urban environment
can create excellent wildlife habitat.
Key words: constructed wetland, limnology, waterbird, habitat, waterfowl
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
45–60, 2008
Title: Limnological variables relevant to the presence of the endangered white-headed duck in southeastern Spanish wetlands during a dry period
Author: Armengol, X.1, Antón-Pardo, M.1, Atiénzar, F.2, Echevarrías, J. L.3 and Barba, E.2
Authors' addresses: 1Departament de Microbiologia i Ecologia/ICBiBE. Universitat de Valencia, Dr. Moliner 50, 46100 Burjassot. Valencia Abstract: We have studied the distribution of the white-headed duck (Oxyura
leucocephala), an endangered diving duck, living in wetlands in
Alicante (southeast Spain). Coordinated with these observations, we
made a limnological characterization of the water and sediment of
several lakes within these wetlands, selecting those both with the
presence and absence of the duck. Limnological variables analyzed
included those related with the trophic status (water transparency,
dissolved nutrients in the water, and chlorophyll a concentration),
those related with the water mineralization, depth, macrophyte cover,
and potential food items in the sediment (mostly chironomidae larvae
and macrophyte seeds). The study was done during a dry period (spring
and summer of 2005). In the examined period, a large reservoir (which
was the preferred place by white-headed ducks in previous years) dried
out in spring. Consequently, the population of white-headed ducks
in the area was much lower and the birds distributed themselves among
other water bodies in the surrounding wetlands. Using the limnological
variables, we performed a Principal Component Analysis (PCA). The
first, but especially the third factor, extracted from the analysis
showed an ordination of the samples which separated the water bodies
where the duck was present. Correlated with these factors, we have
found variables regarding morphometry, trophic status, and food availability
in the sediment of the lakes. Under these conditions of severe drought,
white-headed ducks were distributed preferably in deeper lakes with
more chironomid biomass, and also in lakes with a lower macrophyte
cover and greater turbidity. Within the range of conditions available,
the ducks did not show preferences for salinity and they were found
from mesotrophic to hipertrophic waters.
Key words: White-headed duck, endangered species, habitat selection, dry period
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
61–74, 2008 Title: Limnological conditions of Egerszalók reservoir and functional feeding guilds of aquatic birds
Authors: Milinki, É.1, Fitala, Cs.2,
Gere, G.3, Lakatos, Gy.4
and Andrikovics, S.1†
Authors' addresses: 1Department of Zoology, Eszterházy Károly College, H-3300 Eger Leányka u. 6. H-3300 Eger, Hungary, E-mail: alltan@ektf.hu Abstract: The reservoir situated at the foot of the Bükk mountains was
created in 1981 along the embankment of Laskó stream. it is currently
used for sports, leisure, spare-time activities, and angling. The
reservoir, created 22 years ago, was subject to serious contamination
from Laskó stream until 1990. The operation of a goose farm established
some years ago has now stopped, which accounts for an improvement
in water quality. The water quality of Laskó stream changes in
the reservoir: its salt, phosphorus, and nitrogen content tend to
drop substantially. The improvement of water quality is especially
apparent in reed beds of small size. The benthos, phyto- and zooplankton
offer a rich food for the nekton and water birds. Key words: reservoir, phytoplankton, zooplankton, aquatic bird, feeding of birds
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
75–83, 2008 Title: Phytophilous macrofauna assessments in an important aquatic bird area: The Kis-Balaton protection system
Authors: Deák, Cs., Gór, D. and Lakatos, Gy.
Authors' address: Department of Applied Ecology, University of Debrecen, H-4010 Debrecen, Egyetem tér 1, Hungary, E-mail: deacsa@freemail.hu
Abstract: Seventeen macrophyte species were sampled in the area of the Kis-Balaton
Protection System in order to explore the composition and the quantitative
characteristics of the macrofauna that colonize them. Neither the
mean densities, nor taxa richness or diversities have shown significant
differences. In all the samples of invertebrate macrofauna Chironomidae
and Oligochaeta were found to be dominant. Accordingly the proportion
of higher taxa, composite feeders and detritus feeders dominated in
most of the samples. Ordination method was used to compare qualitatively
the macrofauna composition and only the submerged Ceratophyllum
demersum L. seemed to have a different taxon constitution, while
the other macrophytes were more or less similar in this context.
Key words: phytophilous macrofauna, submerged and emergent macrophytes, functional feeding guilds, Kis-Balaton Protection System
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
85–93, 2008 Title: Composition of zootecton in the stony shore of Lake Balaton (2003–2005)
Authors: Varga, É., Krausz, E., Gór, D. and Lakatos, Gy.
Authors' address: Department of Applied Ecology, University of Debrecen, Egyetem tér 1, H-4010 Debrecen, Hungary, E-mail: vavica@gmail.com
Abstract: Lake Balaton, a shallow lake, is located in the western part of Hungary.
The water surface is 596 km2 with an average depth of 3.2 m.
The dominant ions in the water are Ca, Mg, and HCO3. The average
pH is 8.3. Apart from some publications, the role of the stony shores
covering 70–75% of Lake Balaton"s littoral zone (the whole
shoreline is 193 km) has not yet been studied completely. Ten sampling
sites were selected in Lake Balaton"s four basins of different
water qualities: in Keszthely Basin, in Szigliget Bay, at the Balaton
Limnological Research Institute of the HAS in the middle basin, and
in Fûzfõ Bay. Key words: Lake Balaton, zootecton, macroinvertebrate, waterbirds
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
95–109, 2008 Title: Spatial distribution and habitat preferences of wintering waterfowl in Central Bohemia
Author: Bíly, M.1, Mourková, J.2
and Bergmann, P.3
Authors' addresses: 1T. G. M.Water Research Institute, Podbabská 30, Praha
6, CZ-160 62, Czech Republic, E-mail: bily@vuv.cz Abstract: A Winter Waterfowl Census in Central Bohemia was carried out in Central Bohemia in the seasons 2003/04 and 2004/05 once a month between the
middle of November and the middle of March. 270 km of four rivers
and 31 reservoirs were a subject of investigation. The course of temperature
in the studied winters was very different and influenced total abundance
as well as spatial distribution of particular species. We distinguished
species assemblages characteristic for different types of winter sites.
Anas platyrhynchos was a dominant species in all localities.
Cygnus olor, Larus ridibundus, and Fulica atra were
found on rivers within human settlements, especially on the Vltava
River in Prague. Aythya ferina and A. fuligula were
the other dominant species in Prague. A river section representing
the largest river flow was characterized by Bucephala clangula.
Mergus merganser were found on all rivers. The only little river
was characterized with a high density of Cinclus cinclus. A
deep and large drinking-water reservoir with rugged banks hosted northern
diving species (M. merganser, B. clangula, Melanita
fusca, Gavia arctica). Sand pit lakes were important resting
sites (e.g. for M. merganser, A. ferina, A. fuligula
and A. platyrhynchos). Fishponds were characterized by A.
platyrhynchos and the largest fishpond also by Anser fabalis
and A. albifrons.
Key words: waterbirds, waterfowl, wintering, Central Bohemia, Czech Republic
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
111–122, 2008 Title: Habitat preference of Sylviidae warblers in a fragmented wetland
Authors: Preiszner, B. and CsÖrgõ, T.
Authors' address: Eötvös Loránd University, Department of General Zoology, H-1117 Budapest, Pázmány sétány 1/c, Hungary, E-mail: csorgo@elte.hu
Abstract: Degradation of wetland habitats usually begins with small scale fragmentation.
Species indicate this progress differently depending on their microhabitat
preferences. This study was carried out at the most fragmented, mosaical
part of the Ócsa Landscape Protection Area (Hungary),
in years 2002–2005. This work involves the results of the
3 most characteristic Passerine species of the area. Birds
were captured in different, representative vegetation types with 51
mist nets. Distributions were compared among the species; within the
species in separated periods and between age classes in the post-breeding
period. Processing the recapture data using GIS let us estimate the
mean home range of the different species in different life periods.
However the distribution patterns and home range sizes showed differences
among the studied groups, the habitat choice proved to be a very small
scale decision. This reinforced the importance of fragmentation for
conservationists. Monitoring avian community composition – after
collecting data using our model – could be a way to detect changes
in an area"s state of degradation. A model to estimate an area"s
value for nature conservation also has been processed.
Key words: Passerines, Sylviidae, habitat preference, fragmentation, wetland
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
123–130, 2008 Title: Changes in Wood stork (Mycteria americana) nestling success observed in four Florida bird colonies during the 2004, 2005, and 2006 breeding seasons
Authors: Griffin, G.1, Morris, J.1, Rodgers, J.2 and Snyder, B.1
Authors' addresses: 1Department of Biological Sciences, Florida Institute of Technology, 150 W University Blvd., Melbourne, FL 32901, USA. E-mail: jmorris@fit.edu Abstract: Concern for the declining population size of the wood stork in the
southeastern U.S. compelled federal authorities to list this species
as endangered in February 1984. Since this time, efforts have been
made to gather productivity data for wood storks nesting in all parts
of Florida in hopes of gaining further insight into the trends that
drive their fluctuating population size. Weekly surveys were conducted
at four east-central Florida bird colonies during the 2004, 2005,
and 2006 breeding seasons. Median nestling success decreased significantly
at Deseret Ranch (2 to 0 fledglings/nest), Bird Island (1 to 0 fledglings/nest),
North Fork (1 to fledglings/nest), and Pelican Island (1 to 0 fledglings/nest)
between 2004 and 2005. Median nestling success increased significantly
at Deseret Ranch (3 fledglings/nest), North Fork (3 fledglings/nest),
and Bird Island (2 fledglings/nest) during the 2006 breeding season.
When nest failures were excluded from the analysis, there was no significant
difference in median nestling success during 2004 and 2005. Median
nestling success observed at Deseret Ranch, North Fork, and Bird Island
did, however, differ significantly in 2006 when nest failures were
excluded from the analysis. Changes in productivity between years
appear to mirror shifts in the hydrology of local foraging habitat.
Key words: Mycteria americana, wood stork, Florida, productivity, survivorship
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
131–143, 2008 Title: Population limitation in dabbling ducks at Myvatn, Iceland
Authors: Gardarsson, A.1, Petersen, A.2 and
Einarsson, Á.3
Authors' addresses: 1University of Iceland, Department of Biology, Askja, Sturlugata
7, IS-101 Reykjavik, Iceland E-mail: arnthor@hi.is Abstract: Numbers of five dabbling duck (Anas) species were studied during
1975–2002 at Myvatn, Iceland, in relation to reproductive
success, abundance of aquatic insects and density. In Eurasian wigeon
(Anas penelope), spring numbers, proportion of yearlings and
numbers of young were studied. In gadwall (A. strepera), mallard
(A. platyrhynchos), pintail (A. acuta) and Eurasian
teal (A. crecca), only spring numbers were estimated annually.
Comparisons of spring numbers at Myvatn with numbers wintering
in Iceland (mallard) and Britain (the other four species) were made.
Change in habitat use and in total spring numbers of all five species
tracked chironomid abundance. Change in numbers of mallard, pintail
and teal was negatively associated with density in the year before.
Production of young wigeon was correlated with chironomid abundance
although weather played a role. Reproductive success, which was determined
by the availability of protein food (Chironomidae) on the breeding
grounds, was the main variable determining dispersion and return rates,
and hence annual change in spring densities on the breeding grounds
of all five species.
Key words: Anas, waterfowl breeding populations, reproductive success, resource limitation, density dependence
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
145–155, 2008 Title: Wagtails (Aves: Motacillidae) as insect indicators on plastic sheets attracting polarotactic aquatic insects
Authors: Bernáth, B.1, Kriska, Gy.2,
Suhai, B.3 and Horváth, G.3
Authors' addresses: 1Department of Zoology, Plant Protection Institute of the Hungarian Academy of Sciences, H-1525 Budapest, P. O. B. 102, Hungary Abstract: The polarization-based water detection of aquatic insects has evolved
in a natural environment with scarce misleading polarization
cues. In the last century man produced innumerable highly and
horizontally polarizing surfaces acting as supernormal visual stimuli
for water-seeking polarotactic insects. Typical examples are the black
plastic sheets used in agriculture. To investigate the effects of
horizontal plastic sheets on insects and birds, dual-choice field
experiments were carried out from 1995 to 1997 with a pair of huge
black and white plastic sheets laid on the ground in Hungary. The
number of wagtails (Motacilla alba, M. flava) feeding
in flocks on the plastic sheets and their feeding rate were counted
to estimate the number of insects lured to the plastic sheets. According
to our estimation, a raised-bed strawberry plantation of 10 hectares
covered by shiny black plastic sheets can kill about 1 ton of aquatic
insects day by day. Thus, the possible detrimental effects of such
agricultural technologies may be serious and should be investigated
thoroughly in the future.
Key words: plastic sheets, polarotaxis, visual deception, insectivorous birds, insect indicator, Motacilla alba, M. flava
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
157–165, 2008 Title: Do brown pelicans mistake asphalt roads for water in deserts?
Authors: Kriska, Gy.1, Barta, A.2,
Suhai, B.2, Bernáth, B.3 and
Horváth, G.2
Authors' addresses: 1Group for Methodology of Biology Teaching, Loránd Eötvös University, H-1117 Budapest, Pázmány Péter sétány 1,
Hungary; *E-mail: kriska@ludens.elte.hu Abstract: Recently, brown pelicans (Pelecanus occidentalis) have been
observed to crash on roads in Arizona. It was hypothesized that the
pelicans have mistaken the heat-induced shimmer of the asphalt surface
for lakes. Here we propose two counter-arguments for this proposition:
(i) The edge of a mirage can never be reached, because it continuously
moves away when the observer tries to approach it. (ii) We show by
computation that the edge of the mirage from a landing brown pelican
is so distant that the bird cannot reach it by gliding, even if the
edge did not move off, independently of the beginning height of gliding.
Consequently, the brown pelicans should have known at the moment of
decision for landing that they could not reach the distant shimmering
part of the asphalt road by gliding, and thus they would be forced
to land on the asphalt. If the dry asphalt surface is smooth enough,
the reflection of sunlight from the asphalt could deceive water-seeking
flying pelicans, which is explained in detail here. Another explanation
could be that brown pelicans may not be "intelligent" enough
to grasp that they can never reach the continuously moving off shiny
distant part of an asphalt road.
Key words: brown pelican, Pelecanus occidentalis, desert, asphalt road, mirage, visual deception
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
167–175, 2008 Title: Study on breeding site fidelity of Acrocephalus warblers in Central Hungary
Authors: Vadász, C.1, Német, á.2,
Karcza, Z.3, Loránt, M.2, Biró,
C.2, and Csörgõ, T.1
Authors' addresses: 1Eötvös Loránd University, Department of General
Zoology, H-1117 Budapest, Pázmány sétány 1/c, Hungary; E-mail: csorgo@elte.hu Abstract: Breeding site fidelity of reed-nesting Acrocephalus warblers
was investigated at Lake Kolon in Central Hungary. Sampling was carried
out during the breeding seasons of 2001 to 2005 by mist-netting. We
analyzed data of more than 20,000 capture and recapture records belonging
to four species (Moustached Warbler Acrocephalus melanopogon,
Sedge Warbler Acrocephalus schoenobaenus, Reed Warbler
Acrocephalus scirpaceus, and Great Reed Warbler Acrocephalus
arundinaceus), differentiated between age and sex groups. The
landscape-scale site fidelity varied significantly between both the
four species and the age groups. Of the four species, the Moustached
Warbler showed the highest returning rate, which could be explained
by the strong habitat preference of this species that may have resulted
in lower dispersal rate. Also, in the case of all species, adults
showed 4.03 to 6.10 times higher returning rate than juveniles. Adult
males were more faithful to their breeding area than females, which
is likely to be explained by the higher breeding dispersion rate of
females. The natal site fidelity of males was higher than that of
females in the case of all species but the Moustached Warbler, which
could probably be caused by the higher mortality of males between
fledging and their first breeding season. In general, adults showed
preference for occupying the same territory or its close neighbourhood
in consecutive years.
Key words: Lake Kolon, natal site fidelity, reedbeds
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
177–188, 2008 Title: The effect of reed cutting on the abundance and diversity of breeding passerines
Authors: Vadász, C.,1 Német, Á.,2
Biró, C.2 and Csörgõ, T.1
Authors' addresses: 1Eötvös Loránd University, Department of General
Zoology, H–1117 Budapest, Pázmány sétány 1/c, Hungary,
E-mail: csorgo@cerberus.elte.hu Abstract: Reedbeds support high conservational value with their unique avifauna.
Inadequate reed cutting methods can cause serious declines in the
abundance of these bird species. The aim of this study was to investigate
the influence of reed cutting on the abundance and diversity of breeding
passerine species, mainly Acrocephalus warblers. The study
was carried out at Lake Kolon in Central Hungary, in homogenous reed
(Phragmites communis) vegetation. Sample areas of 1 hectare
in size were cut during 4 consecutive winters. Areas not cut but of
the same size functioned as control areas. Sampling was carried out
during the breeding season by mist-netting. Lake Kolon"s passerine
avifauna at the cut areas showed decreased species richness and decreased
abundance of most of the reed-nesting species, which also resulted
in decreased diversity. The Savi"s Warbler (Locustella luscinioides),
the Moustached Warbler (Acrocephalus melanopogon), the Sedge
Warbler (A. schoenobaenus), and the Reed Warbler (A. scirpaceus)
showed definite avoidance of the cut areas. Only the Great Reed Warbler
(A. arundinaceus) showed preference for the cut areas. The
study also revealed that edges created between cut and non-cut areas
are much less preferred by passerine species than natural edges.
Key words: Acrocephalus spp., edge effect, habitat preference, reed cutting, reedbed management
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
189–206, 2008 Title: The role of aquatic birds in the regulation of trophic relationships of continental soda pans in Hungary
Authors: Boros, E.1, Forró, L.2, Gere,
G.3, Kiss, O.4, Vörös,
L.5, and Andrikovics, S.4†
Authors' addresses: 1Naturglob Ltd., H-1196 Budapest, Kossuth L. u. 76, Hungary,
E-mail: drborose@gmail.com Abstract: The aim of this study was to estimate the population sizes, food resources,
food selection and trophic regulation of aquatic birds in these soda
pans. We classified the estimated density of birds into 3 simple nutrient
cycling guilds: net-importer, exporter-importer and the net-exporter.
The most important aquatic bird guild was the net-importer guild (51–70%),
and the second was the exporter-importer guild (41–27%), while
the relative densities of the net-exporter guild was the lowest (8–3%)
in the investigated 2 pans. The captive foraging experiment demonstrated
that the filter-feeder wildfowl (Anas species) could successfully
remove the microcrustacean plankton and invertebrate nekton from the
water. The biomass of planktonic crustaceans was significantly more
by an order of magnitude than the biomass of the other invertebrates
(benthos, nekton). The relatively simple trophic relationships demonstrate
the bottom up function of some keystone herbivore aquatic bird species,
while the top down control is determined by several wildfowl and wader
species. The external nutrient load of the aquatic birds causes hypertrophic
level of inorganic nutrient resources for the algae, while the planktonic
primary production varied only between oligotrophy and mesotrophy
because of the extreme physical conditions of these waters. The observed
net heterotrophy and several trophic relationships seem to be regulated
by aquatic birds.
Key words: soda pans, aquatic bird guilds, bottom up and top down control, trophic relationships, heterotrophy
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
207–224, 2008 Title: The effect of aquatic birds on the nutrient load and water quality of soda pans in Hungary
Authors: Boros, E.1, Nagy, T.2, Pigniczki,
Cs.2, Kotymán, L.3, Balogh,
K. V.4 and Vörös, L.4
Authors' addresses: 1Naturglob Ltd. H-1196 Budapest, Kossuth L. u. 76. E-mail:
drborose@gmail.com Abstract: This study implemented the following guild model concept to demonstrate
the role of aquatic birds in the nutrient load of lakes: net importer
guild, importer-exporter guild, and net exporter guild. The net C,
N, and P load by aquatic bird guilds were estimated by the counted
numbers of the aquatic birds. C-, N-, and P-contents and volumes of
bird excrement based on our own and literature data of the six most
important soda pans and a control site (without birds) in the southern
part of Hungary. The following selected water quality parameters were
also measured: salinity, pH, and the concentration of nitrate-nitrogen
(NO3-N), orthophosphate-phosphorus (PO4-P),
total phosphorus (TP), total organic carbon (TOC), and dissolved organic
carbon (DOC). Key words: aquatic bird guilds, soda pans, nutrient load, hypertrophic status, buttom up function
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
225–238, 2008 Title: Relation between water quality and dorsal thickness of mussel (Mytilus
edulis) and its ecological implications for wintering oystercatchers
(Haematopus ostralegus)
Authors: Nagarajan, R.1,2, Lea, S.E.G.1 and
Goss-Custard, J. D.3
Authors' addresses: 1School of Psychology, Washington Singer Laboratories, Perry
Road, University of Exeter, Exeter EX4 4QG, UK; E-mail: R.Nagarajan@ex.ac.uk Abstract: The Individual Behaviour Based Model developed using Oystercatchers
(Haematopus ostralegus) as a model species is successful
in predicting the impacts of environmental changes in aquatic ecosystems.
At its heart is a food depletion model which assumes that consumers
will tend to starve in highly depleted areas and seasons. Since dorsal
hammering Oystercatchers selectively deplete dorsally thin-shelled
mussels (Mytilus edulis), we measured the dorsal thickness
of the shells of small (34–46 mm), medium (44–46 mm) and
large (54–56 mm) length classes and assessed the water quality
across the seasons (September to March) in the Exe estuary, Southwest
England. Water temperature decreased across the season from autumn
whereas salinity increased until late October and then decreased during
rest of the season. In parallel, mussel shell thickness decreased
until mid-winter and then started to increase. This increase could
be associated with the Oystercatchers" selective predation on
thin-shelled mussels. Multiple regressions confirmed that the changes
in the salinity across the season were associated with the overall
thickness variations of the shells. We conclude that salinity had
a significant influence on the thickness variations of medium and
large classes of mussels, and water temperature significantly influenced
the dorsal thickness of large mussels. Changes in water quality did
not significantly influence small mussels. Our result suggests that,
despite the selective removal of significant numbers of thinner-shelled
mussels by Oystercatchers, the density of thin-shelled prey available
to them may increase because of changes in the salinity and water
temperature.
Key words: mussel thickness, Oystercatchers, salinity, water temperature, wintering season
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
239–250, 2008 Title: Food habits of redheads (Aythya americana) Wintering in seagrass
beds of coastal Louisiana and Texas, USA
Authors: Michot, T. C.1, Woodin, M. C.2 and Nault, A. J.1,3
Authors' addresses: 1U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Boulevard, Lafayette, Louisiana 70506, U.S.A., E-mail: michott@usgs.gov Abstract: Diets of wintering redheads (Aythya americana) have been studied
in the past, but none of the previous studies compared diets of the
upper gastrointestinal tract to determine if they differed due to
sex, age, location, year, or time of year. We compared diets of redheads
collected over seagrass beds at Chandeleur Sound, Louisiana (n = 287)
and Laguna Madre, Texas (n = 495) during the winters of 1987–1988
to 1989–1990. We found no significant differences due to location,
year, sex, age, or time of year. Halodule wrightii (shoalgrass)
was the primary food of birds from both locations and comprised 74%
(dry mass) of the combined esophageal and proventricular contents.
Mollusks were of secondary importance and accounted for 21% (18% gastropods,
3% pelecypods) of the diet. Because wintering redheads depend almost
entirely on a single seagrass species and associated fauna, protection
and enhancement of Halodule beds should be the highest conservation
priority within the winter range of this species.
Key words: Chandeleur Sound, diet, Halodule, Laguna Madre,
snail
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
251–264, 2008 Title: Salt gland development in migratory redheads (Aythya americana)
in saline environments on the winter range, Gulf of Mexico, USA
Authors: Woodin, M. C.1, Michot, T. C.2
and Lee, M. C.3
Authors' addresses: 1U.S. Geological Survey, Texas Gulf Coast Field Research Station, Corpus Christi, Texas, USA E-mail: marc_woodin@usgs.gov Abstract: Redheads (Aythya americana) migrate annually from their breeding
range in the interior of North America to winter along the coasts
of the United States and Mexico. Two of the most important areas where
redheads traditionally concentrate in winter are the Laguna Madre
and nearby bays in southern Texas and the Chandeleur Sound in southeastern
Louisiana. Redheads experience saline-to-hypersaline (>> 35 ppt) conditions
in southern Texas, where they have ready access to numerous coastal
ponds for drinking water. Redheads in the Chandeleur Sound experience
reduced salinity (<< 30 ppt), and they seldom use supplemental fresh
water. We weighed and analyzed supraorbital salt glands from redheads
wintering in Texas and Louisiana. Mean mass of salt glands was lowest
in November and became stabilized in size by January. Mean mass of
salt glands in Texas did not differ between the two winters. The mass
of salt glands of redheads from Texas (winters combined) was intermediate
to, and significantly different from, the mean masses of salt glands
of redheads from two different winters in Louisiana. Females exhibited
smaller salt glands than did males in both Texas and Louisiana, suggesting
that they were under less osmotic loading than males. Young birds
during the second winter in Louisiana exhibited the heaviest salt
glands, and therefore the most osmotic loading, of all birds in both
states. Water balance concerns and osmoregulatory costs should be
integrated more fully into future foraging and energetics studies
of water birds in marine, coastal, and estuarine systems.
Key words: Aythya americana, Louisiana, redhead, salinity, salt gland, Texas
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Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
265–269, 2008 Title: Habitat use by breeding Common loons (Gavia immer) in the Atlantic Region National Parks in Canada
Author: Kerekes, J.
Author's address: Environment Canada, 45 Alderney Drive, Dartmouth, N.S., B2Y 2N6, Canada, E-mail: Joe.Kerekes@ec.gc.ca
Abstract: The breeding common loon populations are monitored where they occur
in the National Parks in the Atlantic Region (Kejimkujik. Cape Breton
Highlands, Fundy, Terra Nova, Gros Morne) and in the Experimental
Ponds Area, ~100 km west of Terra Nova National Park in Newfoundland.
The monitoring effort goes back to 1982 in Kejimkujik National Park
while it commenced in 1997 in Terra Nova, Gros Morne National Parks.
The lakes range from oligotrophic to ultra-oligotrophic. Overall,
the adult population remained stable, with considerable year to year
variation in reproductive success. Nutrients (phosphorus) through
fish production controlled the lake size that is required to
breeding success. In oligotophic lakes >> 40 ha were required to
support a chick to fledging while in ultra-oligotrophic lakes >>120
ha or several smaller lakes were needed as a territory to raise chicks.
Smaller lakes <<20 ha or less, close to the sea or to large lakes,
where adults could fly to feed were able to support chicks to fledging
(Fundy, Terra Nova). In spite of the great abundance of lakes of different
sizes, breeding loons were observed only in one lake in Gros Morne
National Park in Western Newfoundland. A mountain range on the Eastern
boundary of the park prevents loons from moving in from the Atlantic
side of Newfoundland.
Key words: Common loon, loon breeding success, national parks
2Nyírségvíz Ltd., H-4400 Nyíregyháza,
Tó u. 1, Hungary
3Eszterházy Károly College, Department of Zoology, H-3300 Eger, Leányka u. 6–8, Hungary
2Naturglob Ltd. H-6000 Kecskemét, Patak u. 6.
Acta Zoologica Academiae Scientiarum Hungaricae 54 (Suppl. 1), pp.
35–44, 2008
2"Cavanilles" Institute of Biodiversity and Evolutionary Biology, University of Valencia, PO Box 22085, 46071 Valencia
3Parc Natural El Fondó, Finca El Rincón, Azarbe de
Afuera s/n. 03158 San Felipe Neri Consejería de Territorio y
Vivienda. E-mail: javier.armengol@uv.es
2Bükk National Park Directorate, H-3301, Eger Sánc
u. 6. Hungary
3Department of Systematic Zoology and Ecology, Eötvös
Lóránd University, H-1117 Budapest, Pázmány Péter sétány 1/C,
Hungary
4Department of Applied Ecology, Debrecen University, P. O. Box 22, H-4010 Debrecen, Hungary
Cyanobacteria from Laskó stream are transported into the reservoir.
The quality of water improved substantially after leaving the reservoir.
After the goose farm was closed, the decrease in water levels caused
problems for wildlife. Out of the 217 bird species documented, 97
species nest and 120 species migrate and wander in the vicinity of
the reservoir. Notwithstanding the observed fluctuation of and decrease
in water level, we have found 100 aquatic bird species along the largest
water surface at the foot of the Bükk mountains. The reservoir
is an essential feeding and resting location for groups of geese,
mallards, and shorebirds. In the first years following the establishment
of the reservoir, the migrating exporter-importer groups proved to
be the first important functional feeding guilds of aquatic birds.
During low water periods, the activity of shorebird species increased.
recently, the ratio of the exporter-importer functional group has
decreased. currently, decomposition-accelerators make up the majority
of the avifauna. The ratio of nesting species within each guild is
lower when compared to the avifauna of other reservoirs that were
established earlier.
The results of plankton, nekton, and water chemistry studies in evaluating
the functional feeding guilds of aquatic birds show that these birds
play a major role in the decomposition of organic matters contained
in reservoirs. Thereby, aquatic birds contribute to the progress of
natural succession processes.
The changing compositions of zootecton were studied, which was influenced
by the weather and water supply. For example, in 2003 the low water
level was characteristic for the lake. The taxonomic composition,
the situation, and the substrate features given of the littoral zone
have an outstanding role in the life of Lake Balaton, because this
zone provides food resources and nesting habitats for waterbirds.
We also found that the filtering in 2003, in 2004, and in 2005 as
well, the predacious zoo-organisms were found in the largest number
in the zootecton.
2Department of Zoology, Faculty of Science, Charles University
Vini<@232>ná 7, Praha 2, CZ-120 00, Czech Republic
3Uralská 6, Praha 6, CZ-160 00, Czech Republic
2Florida Fish and Wildlife Conservation Commission, 4005 S. Main Street, Gainesville, FL 32601, USA
2Icelandic Institute of Natural History, P. O. Box 5320, IS-125
Reykjavik, Iceland
3Myvatn Research Station, IS-660 Myvatn, Iceland
2Group for Methodology in Biology Teaching, Loránd Eötvös
University, H-1117 Budapest, Pázmány Péter sétány 1,
Hungary, E-mail: kriska@ludens.elte.hu
3Biooptics Laboratory, Department of Biological Physics, Institute
of Physics Loránd Eötvös University, H-1117 Budapest, Pázmány
Péter sétány 1, Hungary
2Biooptics Laboratory, Department of Biological Physics, Loránd
Eötvös University, H-1117 Budapest, Pázmány Péter sétány 1,
Hungary
3Department of Zoology, Plant Protection Institute of the Hungarian
Academy of Sciences, H-1525 Budapest, P. O. B. 102, Hungary
2Kiskunság National Park, H-6000 Kecskemét, Liszt
Ferenc utca 19, Hungary
3Birdlife Hungary, H-1121 Budapest, Költõ u. 21,
Hungary
2Kiskunság National Park, 6000 Kecskemét, Liszt Ferenc
utca 19, Hungary
2Hungarian National History Museum, Department of Zoology, H-1088 Budapest, Baross u. 13, Hungary
3Department of Systematic Zoology and Ecology, Eötvös
Lóránd University, H-1117 Budapest, Pázmány Péter sétány 1/c,
Hungary
4Department of Zoology, Eszterházy Károly College Leányka u. 6, H-3300 Eger, Hungary
5Balaton Limnological Research Institute of the Hungarian Academy
of Sciences, Department of Hydrobotany, H-8237 Tihany, P.O. Box 35, Hungary
2Kiskunság National Park Directorate, Kecskemét,
H-6000 Kecskemét, Liszt F. u. 19.
3Körös-Maros National Park Directorate, H-5541 Szarvas,
Anna-liget. P.O.Box 72
4Balaton Limnological Research Institute, H-8237 Tihany, P.O.Box
35
It was demonstrated that investigated soda alkaline waters had high
TOC and DOC concentrations and hypertrophic levels of TP, but the
nitrogen-phosphorus ratio was unusually below 1. It was concluded
that the low N/P ratio was caused by high pH (pH >> 9).
The aquatic bird contribution to the total external nutrient load
was estimated to be approximately C: 50%, N: 35%, P: 70%. Significant
linear regression was indicated between the yearly total carbon load
(mg m–2 year–1) by aquatic birds and the yearly
average TOC concentration (mg L–1), as well as between
the yearly total phosphorus load (mg m–2 year–1)
by aquatic birds and the yearly average TP concentration (mg m–3).
2PG and Research Department of Zoology, Wildlife Biology and Biotechnology, A.V.C. College, Mannampandal–609305, Tamilnadu, India
3Havering, Church Road, Lympstone, Devon, EX8 5JT, UK
2U.S. Geological Survey, Texas Gulf Coast Field Research Station, Corpus Christi, Texas, U.S.A.
3Current address: University of Minnesota Veterinary Medical Library, St. Paul, Minnesota U.S.A.
2U.S. Geological Survey, National Wetlands Research Center,
Lafayette, Louisiana, USA
3U.S. Fish and Wildlife Service, Ecological Services Office,
Corpus Christi, Texas, USA