Volume 16 - N. 2
December 1992

Avocetta
Volume 16 - N. 2



  1. Avocetta n.16 (2) - 1992

    Abstract     Read Article       Download
  2. Conservation programme for Audouin's Gull in the Chafarinas Islands

    Alvarez G.

    Abstract     Read Article       Download

    I review population changes from 1976 to 1992 in the Audouin’s Gull colonies of Chafarinas
    Islands National Game Sanctuary. Earlier studies showed that after increasing rapidly between 1976
    and 1983, the Audouin’s Gull population stabilized, and breeding success decreased until 1985. This
    decrease was linked to a rapid increase in Yellow-Iegged Gulls over the same period, and was attributed
    to predation and to limited nesting sites. Yellow-Iegged Gulls have been controlled since 1987 by
    narcotizing adults and sterilizing eggs. After 6 years culling, the Yellow-Iegged Gull population and
    the breeding success of Audouin’s Gulls were similar to those of 1983, but the breeding Audouin’s
    Gull pairs had doubled during the same periodo It is suggested that immigration of Yellow-Iegged Gulls
    reduces the effectiveness of culling. The rat population may also limit the breeding success of the
    Audouin’s Gull.

  3. Protection of Cory's Shearwater Calonectris diomedeaby Iimitation of a population of Feral Rabbits Oryctolagus on the Frioul Archipelago (Marseilles, France)

    BAYLE P. and FERNANDEZ O.

    Abstract     Read Article       Download
  4. Les programmes de marquage de Laridae avec bagues colorées en Mediterranée

    BEAUBRUN P.C.

    Abstract     Read Article       Download
  5. BOLDREGHINI P., MEININGER P. L. and SANTOLINI R.

    Abstract     Read Article       Download
  6. The use of salinas by breeding Charadriiformes: two italian cases

    BOLDREGHINI P., MONTANARI F. L., TINARELLI R.

    Abstract     Read Article       Download
  7. Birds and habitat conservation on Chios, Greece

    CHOREMI J. and SPINTHAKIS E.

    Abstract     Read Article       Download

    In this attempt to describe birdlife in Chios Archipelago we record ed 211 species, most
    of which are migrants and visitors. Large concentrations of birds appear during migration and suffer
    a heavy hunting pressure (shooting and liming). The most important bird areas are Psara and Dotia
    with mainly bushy vegetation. The authors propose the establisment of a marine and island park in
    Psara-Antipsara archipelago for the protection of birds during migration.

  8. Habitat use in Yellow-Iegged Gull(Larus cachinnans michahellis) coastal wetland coloniesof North-East Greece

    GOUTNER V.

    Abstract     Read Article       Download

    Yellow-Iegged Gull habitat use was studied at two colonies situated on lagoon islets (Lafri
    and Karatza) in North-East Greece. At the Lafri colony most nests (74.3070) were in high cover (>70%,
    overall average 78070). Sand dune and ruderal vegetation were avoided in preference for halophytic
    communities of Halocnemum strobilaceum (HS) and Halimione portulacoides – Arthrocnemum
    jruticosum (HP-AF); both were used in proportion to their availability. Both vegetation cover and
    type were important for nest placement and spacing. At the Karatza colony most nests (78.1 070) were
    in high cover (average 85 070). The most important plant communities were Asparagus tenuifolius
    (dominant) and HP-AF; both were used in proportion to their availability. In this colony vegetation
    cover seemed to be more important than vegetation type. This allowed a better breeding synchronization
    than at Lafri. Aspects of Yellow-Iegged Gull habitat use in the wider area are discussed.

  9. Armenian Gulls Larus armenicus in Egypt, 1989/90,with notes on the winter distribution of the large gulls

    MEININGER P.L. and S0RENSEN U.G.

    Abstract     Read Article       Download

    During a survey of Egyptian wetlands between December 1989 and late May 1990 significant
    numbers of Armenian Gulls Larus armenicus were observed. Total winter count was 442, and the
    species was present until early April , It was found to be relatively common along the Mediterranean
    coast east of the Damietta branch of the Nile, and in marine habitats of the three lagoons along this
    coast. Small numbers were seen along the Suez Canal and the Red Sea coast. No Armenian Gulls
    were found in any of the inland waters. Other large gulls counted in winter included Yellow-Iegged
    Gulls L. cachinnans (2340), Lesser Black-backed Gulls L. fuscus (120; including the first Egyptian
    record of L. f. heuglini), and Great Black-headed Gulls L. ichthyaetus (35).

  10. The nesting by the Herring Gull (Larus argentatus) in the Towns and Villages of Bulgaria

    NANKINOV D.N.

    Abstract     Read Article       Download
  11. Status and migration of the Siender-billed Gull (Larus genei) in Bulgaria

    NANKINOV D.N.

    Abstract     Read Article       Download

    The earliest Slender-billed Gulls arrive in Bulgaria after July 5. Some 72.70/0 migrate to
    the Mediterranean in August-October. A tiny number, 1.0 to 2.2% of the birds spend the winter and
    spring in Bulgaria. The Black Sea is the spring flight route. Nesting by the Slender-billed Gull may
    be expected in Lake Atanassovsko.

  12. The colony of the Audouin's Gull at the Ebro Delta

    ORO D. and VILLALTA A.M.

    Abstract     Read Article       Download

    We describe the Audouin’s Gull colony established in the Ebro Delta (NE Spain) since
    1981. The amazing growth of this colony, which is now the largest in the worId, with about the 60070
    of the species’ world population, was favoured in our view both by the complete protection of the
    breeding areas from human interference since 1987, and by its high reproductive success (maximum
    2.01 chieks/pair in 1988). This breeding success is the highest reeorded in Audouin’s Gull eolonies
    studied to date, and it seems 10 be due to the high availability of feeding resourees (demersal fish)
    from activities by the loeal fishing fleet. Moreover, disturbanee by breeding Yellow-legged Gulls was
    low. Changes in these faetors eould break the eolony stability, as happened with the moratorium on
    inshore fishing in 1991 and 1992. The fragility of the Audouin’s Gull population is mainly due to
    its generalized low breeding success in the main colonies, and its concentration in a few large eolonies.

  13. Pesticide residues in Cory's Shearwater eggs (Calonectris d. diomedea)

    RISTOW D., . HAORICH J., BAUM F. and WINK M.

    Abstract     Read Article       Download

    Oeserted eggs of Cory’s Shearwater from a colony off Crete were analyzed for chlorinated
    hydrocarbon content. Substantial concentrations of DDE and PCBs were found. High concentrations
    of DDE are correlated with those of PCBs. Almost at the top of the Mediterranean food chain, Cory’s
    Shearwater is a good bioindicator for the Mediterranean.

  14. Does Cory's Shearwater breed every yearor is there evidence for a sabbatical?

    RISTOW D., SWATSCHEK I. and WlNK M.

    Abstract     Read Article       Download

    A colony of Cory’s Shearwater (Ca/onectris d. diomedea) was studied for severa l years
    on a rocky island off Crete. Care was taken to distinguish breeding birds. including unsuccessful breeders,
    from the non-breeding population. From yearly retrap data of breeding birds it is concluded that they
    make a breeding attempt every year and do not take a sabbatical. This result differs from the finding
    that the Atlantic subspecies borea/is shows a sabbatical frequency of 7″10 (Mougin et al. 1985).

  15. The Dnestr Delta Black Sea: ornithological importance,conservation problems and management proposals

    Schogolev I.

    Abstract     Read Article       Download

    The Dnestr Delta is one of the most intaet wetland eeosystems in the Blaek Sea. In a total
    area of 220 krn-, dominated by extensive reedbeds, important populations of waterbirds nest in
    eolonies, some of them in numbers of international signifieanee. The seasonal floods of the river are
    the key faetor for the funetioning of this wetland eeosystem, but human intervention and the eonstruetion
    of a hydroeleetrieal dam are now having serious environmental impaet on the delta. A management
    plan for the waters of the river should be fully implemented and the delta should be designated as
    a National Park in order to halt and reverse its degradation.

  16. The Lagoon of Venice: a premigratory crossroads for Little Terns Sterna albifrons

    SERRA L., PANZARIN F., CHERUBINI G., CESTER D. and BACCETTI N.

    Abstract     Read Article       Download
  17. Eradication of the Brown Rat from the Toro Islets (Corsica):remarks about an unwanted colonizer

    THIBAULT J.C.

    Abstract     Read Article       Download

    Between 1986 and 1988 the Brown Rat (Rattus rattus) was introduced onto the Toro Islets,
    an important piace for breeding birds (Cory’s Shearwater Ca/oneetris diomedea, Storm Petrel
    . Hydrobates pelagieus, Pallid Swift Apus pallidus, and other birds). The aims of this paper are: (i)
    to describe and discuss the method used to eliminate the rats from these islets in 1991-1992, (ii) to
    show the consequences of the Brown Rat’s introduction on seabirds on Corsican islets. Keeping islands
    free from rats appears to be a major target for the conservation of seabirds in the Mediterranean.

  18. Known population and distribution of cormorants,shearwaters and Storm Petrels in the Mediterranean

    ZOTIER R., THIBAULT J.C. and GUYOT I.

    Abstract     Read Article       Download

    Five species of Procellariidae, Hydrobatidae and Phalacrocoracidae breed in the
    Mediterranean: the Cory’s Shearwater Caloneetris diomedea (57,000-76,000 breeding pairs), the
    Mediterranean Shearwater Puffinus yelkouan (18,000 known breeding pairs), the Storm Petrel
    Hydrobates pelagieus melitensis (8,500-15,000 known breeding pairs), the Shag Phalaeroeorax aristotelis
    desmarestii (about 7,000 breeding pairs) and the Cormorant Phalaeroeorax earbo (8,000 breeding pairs).
    Large populations of seabirds occur on the Balearics archipelago, in the Sicilian channel and in the
    north of the Tyrrhenian Sea. The status of birds in the Adriatic, Ionian and Aegean Seas needs to
    be c1arified by further survey.

  19. Book reviews

    Abstract     Read Article       Download