Tražio sam neki WWW site sa informacijama koje si tražio no nažalost
nisam uspio pronaši ništa posebno
zadovoljavajuće. Ne znam koliko detaljno te zanima magnetsko osjetilo
ptica selica no općenito o migracijama ptica možeš naći na Audobonovom
webu Bird Migration Facts
ili na The
Mystery of Bird Migration . Također, možda više kao zanimljivost nego
odgovor na tvoje pitanje na siteu OPERATION
MIGRATION možeš pronaći informacije o projektu spašavanja ždralova
u USA i tome kako su ih uz
pomoć ultralakog aviona učili migracijske puteve!
Detaljnije, novije znanstvene informacije o migracijama i magnetizmu
kod ptica može se naći u slijedeća dva znanstvena rada čije sažetke prilažem
zajedno sa referencom časopisa u kojem su objavljeni. Radovi se mogu dobiti
tako da se piše autoru i zamoli kopija rada ili se mogu potražiti u Nacionalnoj
i sveučilišnoj knjižnici, no i sažeci već daju zanimljive informacije.Ja
ih na žalost nemam te ti ih ne mogu poslati.
U slučaju da te zanima nešto detaljnije ili ti moj odgovor nije dostatan
molim te da se javiš ponovo
Pozdrav,
Draško Holcer
Hrvatski prirodoslovni muzej
Demetrova 1, Zagreb
Drasko.Holcer@hpm.hr
Authors: Wiltschko W. Wiltschko R.
Reprint Author: Wiltschko W
Title: MAGNETIC ORIENTATION IN
BIRDS
Source: Journal of Experimental Biology. 199(1):29-38, 1996
Jan. ISSN 0022-0949
Author Keywords: Geomagnetic field. Compass orientation. Inclination
compass. Homing. Navigational map.
KeyWords Plus: Bobolink dolichonyx-oryzivorus. Young homing
pigeons. Migratory orientation. Initial orientation.Compass orientation.
Inclination compass. Celestial rotation. Savannah sparrows. European robins.
Garden warblers.
Abstract:The magnetic field of the earth is an omnipresent,
reliable source of orientational information. A magnetic compass has been
demonstrated in 18 species of migrating birds. In all species studied with
regard to its functional properties, it was found to be an 'inclination
compass', i.e. the birds derive directional information from the inclination
of the field lines, and thus distinguish between 'poleward' and 'equatorward'
rather than 'north' and 'south'. Such a mechanism means that birds from
the northern and southern hemisphere may rely on the same migratory programme.
Long-distance migrants, however, face the problem that their magnetic compass
gives bimodal information at the magnetic equator. Transfers of
information between the magnetic field and celestial sources of directional
information have been demonstrated; the two systems interact in a complex
way. The data on the use of magnetic parameters for position finding are
less clear. The experiments involve releases of homing pigeons; correlations
of their orientation with natural variations in the magnetic field and
the effects of magnetic manipulation reveal an enormous variability. The
role of magnetic parameters in the multifactorial navigational system is
poorly understood. [References: 88]
Language: English
Publication Type: Article
CC Categories: Experimental biology & medicine. Biology.
Reprint available from: Wiltschko W., UNIV FRANKFURT, FACHBEREICH
BIOL, SIESMAYERSTR 70, D-60054 FRANKFURT, GERMANY
Authors: Helbig AJ.
Title: GENETIC BASIS, MODE OF INHERITANCE
AND EVOLUTIONARY CHANGES OF MIGRATORY DIRECTIONS IN PALEARCTIC WARBLERS
(AVES, SYLVIIDAE)
Source: Journal of Experimental Biology. 199(1):49-55, 1996
Jan. ISSN 0022-0949
Author Keywords: Bird. Migration. Orientation. Innate directions.
Inheritance. Evolution.
KeyWords Plus: Atricapilla. Orientation. Population. Behavior.
Birds.
Abstract: The genetic basis, mode of inheritance and recent
evolutionary changes of migratory directions in birds are discussed on
the basis of published and new experimental evidence. Displacement experiments
with wild-caught migrants and orientation tests with hand-reared passerines
illustrate that inexperienced young birds possess genetic information about
the direction and approximate distance of migration, but not about the
geographic location of the winter quarters. Hand-raised blackcaps Sylvia
atricapilla from east and west of the Central European migratory divide,
when tested under identical conditions, exibited population-specific migratory
directions in orientation cages. Cross-breeding of birds from these two
populations demonstrated an intermediate mode of inheritance of this behavioural
character. New data on the orientation of an F-2 generation suggest that
the directional information is encoded by only a few major genes. Migratory
adaptations may have evolved recently, in some cases rapidly, as is illustrated
by the establishment of a new migration route of central European blackcaps
to winter quarters in the British Isles. This new route is shown (in a
captive breeding experiment) to be based on a novel, genetically rogrammed
westnorthwesterly migratory direction. It must have spread from almost
zero to 7-11 % frequency in parts of central Europe within only three decades.
The novel direction is also inherited phenotypically intermediately; its
rapid evolution may be mediated by assortative mating based on differential
arrival times at the breeding grounds. The evolutionary flexibility
of migratory adaptations is discussed in relation to changes in the environment,
both natural and accelerated by man. [References: 31]
Language: English
Publication Type: Article
CC Categories: Experimental biology & medicine. Biology.
Reprint available from:Helbig AJ, UNIV GREIFSWALD, VOGELWARTE
HIDDENSEE
D-18565 KLOSTER , GERMANY
E-školaŠ u suradnji
sa om
Održava Toni
Nikolić. Datum posljednje promjene 16. veljače 1999.