Glossy Ibis Plegadis Falcinellus Research Articles

Waterbird community changes in the Wilderness Lakes, South Africa (Part 2 of 3): Shorebirds

Globally, many shorebirds, particularly the smaller migratory waders are declining, which can be attributed to multiple factors throughout their ranges. The Wilderness Lakes Complex in South Africa comprises two estuarine systems, that support diverse waterbird communities, including 17 abundant shorebirds. The study aimed to document long-term spatial and temporal patterns of abundance of shorebirds in the Wilderness Lakes Complex, and where possible identify potential causes for observed trends. The abundance of waterbirds on these wetlands was determined biannually from 1992 to 2019, with counts conducted from a boat following a standardised route. Historical abundance data from the 1980s were also used to describe long-term abundance changes. Ten shorebirds showed seasonal differences in abundances. Significant long-term decreases in abundance have occurred in seven shorebirds (Wood Sandpiper Tringa glareola, Marsh Sandpiper Tringa stagnatilis, Curlew Sandpiper Calidris ferruginea, Ruff Philomachus pugnax, Grey Heron Ardea cinerea, Greater Flamingo Phoenicopterus ruber, Black-winged Stilt Himantopus himantopus) and increases in three species (African Spoonbill Platalea alba, Little Egret Egretta garzetta, Glossy Ibis Plegadis falcinellus). Similar types of population changes occurred across multiple waterbodies and in different seasons. The similarity of shorebird abundance trends in spatially separated wetlands suggests either high interconnectivity of populations between wetlands systems and/or prominent drivers of change being broad scaled rather than system specific. Local reasons for changes potentially include the increasing spread of emergent macrophytes and resultant loss of open sandbanks, changing hydrodynamics, and alien fish proliferation, all likely changing food accessibility, as well as periodic high disturbance by waterbody users.Conservation implications: Changes in the abundances of several shorebirds, particularly small migratory waders, are substantial, with multiple likely local, regional and international drivers acting accumulatively. Recommended corrective actions include continuing involvement in the development and implementation of policies for waterbird conservation, and local management of emergent macrophytes, disturbance, and water level variability.

Blowin' in the wind: Dispersal of Glossy Ibis Plegadis falcinellus in the West Mediterranean basin.

The movement of organisms is a central process in ecology and evolution, and understanding the selective forces shaping the spatial structure of populations is essential to conservation. Known as a trans-Saharan migrant capable of long-distance flights, the Glossy Ibis Plegadis falcinellus' dispersal remains poorly known. We started a ringing scheme in 2008, the first of its kind in North Africa, and ringed 1121 fledglings over 10 years, of which 265 (23.6%) were resighted. Circular statistics and finite mixture models of natal dispersal indicated: (1) a strong West/Northwest-East/Southeast flight orientation; (2) Glossy Ibis colonies from North Africa and Southern Europe (particularly on the Iberian Peninsula) are closely linked through partial exchanges of juvenile and immature birds; (3) unlike birds from Eastern Europe, North African Glossy Ibis disperse to but do not seem to undergo regular round-trip migration to the Sahel; (4) young adults (>2-years-old) have a higher probability of dispersing further than individuals in their first calendar year (<1-year-old); and (5) dispersal distance is not influenced by sex or morphometric traits. Together, these results enhance our knowledge of the dispersal and metapopulation dynamics of Glossy Ibis, revealing large-scale connectivity between the Iberian Peninsula and Algeria, likely driven by the spatial heterogeneity of the landscape in these two regions and the prevailing winds in the Western Mediterranean.

Effects of Rice Field Phenology on Breeding Parameters of Heron Colonies in the East of the Iberian Peninsula

Rice fields have traditionally been considered key feeding grounds for many waterbird species, including herons. Studies show that field management and flooding cycles influence the reproductive parameters of these birds. L'Albufera de València, on the east coast of the Iberian Peninsula, has large areas of rice fields and is home to the third largest breeding colony of herons in Spain. Changes in water and rice field management that have occurred since the colony was last assessed (1990) may have affected the colony's reproductive performance. Clutch and brood size, and hatching, nesting and breeding success were estimated for Grey Heron Ardea cinerea, Purple Heron Ardea purpurea, Cattle Egret Bubulcus ibis, Little Egret Egretta garzetta, Squacco Heron Ardeola ralloides (Ardeidae) and Glossy Ibis Plegadis falcinellus (Threskiornithidae) in 2015–2017. The extent of flooding and cultivation of rice fields was assessed from February 2016 to June 2017. Reproductive parameters were related to the state of the rice fields. All reproductive output parameters were lower than those reported in the literature. In 2016, laying started earlier (at the end of April), when the fields were still dry and hatching started from May, after flooding. In 2017, peak hatching occurred in June, when the fields were sown. A significant relationship was found between breeding success and the area of sown fields, except for the Squacco Heron. We found that birds that initiated egg laying closer to the date of flooding had a relatively higher breeding success for the Little Egret, Glossy Ibis, Cattle Egret and Purple Heron. The success of nesting populations in this type of artificial wetland requires water management plans that synchronize flooding regimes and maintenance of flooded areas with the biological requirements of these species.

Unravelling diet composition and niche segregation of colonial waterbirds in a Mediterranean wetland using stable isotopes

Rice fields and waterbirds are an example of a synergy that can occur between agriculture and conservation. This connection is especially relevant during the farming period, when nesting waterbirds need to obtain resources to cover their energy requirements and those of their chicks in rice fields. However, new farming techniques may potentially put fulfilling this role at risk. Studies on how species use rice fields to feed during this critical period are essential to understand waterbird population dynamics and to optimize conservation measures. At present, several species of colonial birds in l’Albufera de València (Spain) that depend on trophic resources available in rice fields have decling populations and decreases in productivity. We therefore assessed trophic niche segregation in the diet of chicks of a waterbird community composed of seven species through stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) obtained from chick blood and tissue samples of potential prey. According to trophic niche widths, chicks of Black‐headed GullChroicocephalus ridibundusand Gull‐billed TernGelochelidon niloticashowed a similar diet, although Gull‐billed Tern had a major trophic specialization. The Western Cattle EgretBubulcus ibisfed its chicks in a wider range of different habitats, with organisms located at the base of the food chain and with a greater importance of terrestrial prey than other species. Conversely, the Glossy IbisPlegadis falcinellushad a more differentiated diet, mostly in freshwater habitats and mainly consuming odonates. Grey HeronArdea cinerea, Little EgretEgretta garzettaand Squacco HeronArdeola ralloidesshowed overlap between their niches, largely explained by the presence and abundance of cyprinid fish and odonates in their diets. Our results suggest a less important role than expected of Red‐swamp CrayfishProcambarus clarkii, and a more important role of odonates despite being a less energy‐rich prey. In conclusion, the diet of generalistic species of waterbirds in this study suggests that their trophic niches can overlap when relative prey abundance is high.

A native bird as a predator for the invasive apple snail, a novel rice field invader in Europe

Abstract Since 2009 the apple snail Pomacea maculata has become a new invader of Oryza sativa (rice) fields and wetlands in Europe, only invading the Ebro Delta (north‐eastern Spain) thus far. It is considered a highly invasive and damaging species, resulting in large economic losses worldwide. Despite the severe impact of the invasive apple snail on both cultivated and natural wetlands, it has become an abundant potential resource for native avian predators. In this study, stable isotope analysis was used to assess the consumption of the apple snail by the glossy ibis Plegadis falcinellus in the Ebro Delta. The results indicate the importance of the apple snail in the diet of this native bird. In particular, isotopic results indicated that apple snails and freshwater coleopterans were the main prey in the diet of glossy ibis chicks, accounting for 26–40% of their diet. Thus, this native bird species could potentially help in the biological control of this invasive snail, but is not expected to eradicate it. Although the spread of this pest in rice fields and wetlands is not desirable, we predict that the apple snail will follow a path similar to other invasive species, such as the red swamp crayfish Procambarus clarkii, in establishing itself as part of the wetland food web.

Facultative and non‐facultative sex ratio adjustments in a dimorphic bird species

If parental allocation to each offspring sex has the same cost/benefit ratio, Fisher's hypothesis predicts a sex ratio biased towards the cheaper sex. However, in dimorphic birds there is little evidence for this, especially at hatching. We investigated the pre‐fledgling 1) sex ratio, 2) body condition and 3) sex‐differential mortality in a population of the glossy ibis Plegadis falcinellus, in southern Spain between 2001 and 2011. We defined two age groups for the period between hatching and fledging. We also compared pre‐fledgling with the autumn sex ratio. Metabolic rates were estimated by the doubly labeled water (DLW) technique to establish that sons (the bigger sex) were 18% more energy demanding than daughters, and to compute the predicted Fisher's sex ratio (0.465). As population size increased between years, body condition decreased in both sexes, and mortality increased more for daughters than sons prior to fledging. At the same time, the proportion of males among chicks close to fledging increased (average sex ratio: 0.606) while the proportion close to hatching decreased (average sex ratio: 0.434, in line with Fisher's prediction). Furthermore, the proportions of males at fledging and the following autumn were negatively correlated across years. We suggest that, as population density increased and conditions worsened the larger sex had relatively higher survival. These differences in survival produce a shift from a facultative female‐biased sex ratio at hatching into a non‐facultative male‐biased sex ratio of fledglings. Additionally, the excess of males at fledging was counterbalanced by sex‐related dispersal during the autumn. Overall, glossy ibis sex ratio is a product of a combination of facultative and non‐facultative adjustments triggered by environmental conditions, driven by rapid population growth, and mediated by highly interrelated life‐history traits such as body condition, mortality, and dispersal.

Composition, structure and pattern of helminth assemblages associated with central European storks (Ciconiidae)

The composition, structure and pattern of helminth assemblages associated with the storks (Ciconiidae), ibises and spoonbills (Threskiornithidae) are poorly understood. Here we analyze the prevalence, intensity and diversity of the helminth component communities associated with the white stork Ciconia ciconia and black stork Ciconia nigra, and notice the findings of helminths on Eurasian spoonbill Platalea leucorodia and glossy ibis Plegadis falcinellus obtained in the Czech Republic in years 1962–2013. Comparison with datasets from multiple European countries supports the existence of well-defined local helminth component communities, which are subject to strong geographic variation. The estimated diversity of the helminth component communities reached 11.0±1.6 (C. ciconia) and 12.5±5.4 (C. nigra) species, with the Berger–Parker dominance index reaching only 0.24 and 0.21, respectively. Typically, the dominant species (Chaunocephalus ferox, Tylodelphys excavata and Dictymetra discoidea in C. ciconia, and Cathaemasia hians and Dicheilonema ciconiae in C. nigra) were considered as local, with intermediate host species available onsite. Altogether 10 of the 11 species with known life cycle were capable to complete their life cycle locally, which is in strong contrast with the situation in Czech egrets and herons. In C. ciconia and C. nigra, the highest helminth load was in juveniles, whereas Echinostoma sudanense, absent in the juveniles, was associated with intermediate hosts absent in the study area. Relative prevalence and frequency of helminths associated with male and female C. ciconia was similar to each other. The first systematically collected evidence of the intra-annual changes of the helminth assemblages in storks is provided.

Analysis of avian-biodiversity in rural wetland environs in Panipat district in Haryana, India

The present study has observed 67 species of wetland birds, belonging to, 10 orders and 18 families from rural wetland Environs in Panipat district located at a distance of 90 KMs north of Delhi on National Highway No.1 (29.39°N 76.97°E) in Haryana, India. Out of 67 species, 35 species were winter migrants, 18 residents, 10 local migrants and four species were summer migrants. Peculiar species of birds recorded in Panipat rural ponds are Painted Stork Mycteria leucocephala, White-necked Stork Ciconia episcopus, Asian openbill- Stork Anastomusoscitans, Lesser Adjutant Stork Leptoptilos javanicus, Black-necked Stork Ephippiorhynchus asiaticus, Oriental White Ibis Threskiornis melanocephalus, Black Ibis Pseudibis papillosa, Glossy Ibis Plegadis falcinellus, Eurasian Spoonbill Platalea leucorodia, Brahminy Shelduck Tadorna ferruginea, Comb Duck Sarkidiornis melanotos, Tufted Pochard Aythya fuligula and Green Sandpiper Tringa ochropus. On the other hand, familiar species include amongst others, Bar-headed Goose Anser indicus, Common Coot Fulica atra, Northern Shoveller Anas clypeata, Northern Pintail Anas acuta, Common Teal Anas crecca, Common Pochard Aythya ferina, Gadwall Anas strepera and Lesser-whistling Duck Dendrocygna javanica etc. Longest stay during winter season was demonstrated by birds like Northern Shoveller, Northern Pintail, Bar-headed Goose, Greylag Goose and Rudy Shelduck, whereas shortest winter sojourn was observed in case of Mallard, Eurasian Wigeon and Common Pochard. It is interesting to note that migratory birds like Northern Shoveller, Northern Pintail, Common Teal, Bar-headed Goose, Tufted Pochard, and Common Pochard come to Panipat rural ponds from very far off places like Central Russia, Caspian USSR, Siberia, Ladhakh and Central Asia, West and Central Asia and Siberia respectively.

Breeding of Large, Water-Associated, Colonially Nesting Birds of the North-Eastern Region of KwaZulu-Natal, South Africa

Little has been documented on large (>250 g), water-associated birds in the north-eastern KwaZulu-Natal, South Africa, that nest colonially and rely on suitable sites for breeding. The purpose of this study was to highlight these species and the importance of nesting sites for their effective conservation management. From 1920–2010, there were 622 records of 27 of these species breeding at more than 48 sites. Five sites accounted for 65% of these breeding events, four at Lake St Lucia, highlighting its importance for bird conservation. Several sites were abandoned. However, two new sites have established more recently (Nsumo Pan, Mkhuze Game Reserve; Nyamithi Pan, Ndumo Game Reserve) that are important in terms of number of individuals as well as variety of species. Some species (Pink-backed Pelican Pelecanus rufescens, Grey-headed Gull Larus cirrocephalus, Caspian Tern Sterna caspia, Great-white Pelican P. onocrotalus and African Spoonbill Platalea alba) have bred regularly but have used only a few sites, mainly at Lake St Lucia. Two species (Glossy Ibis Plegadis falcinellus and Black Heron Egretta ardesiaca) have bred once only on Lane Island (1961) and in trees at the mouth of the Hluhluwe River (before 1964) respectively. Two colonial sites hosted 10-12 species while others (n = 8) only two. Twenty-one sites were used by only one species. Two species (Pink-backed Pelican and Yellow-billed Stork Mycteria ibis) nest nowhere else in South Africa on a regular basis. Recommendations for the ongoing monitoring and conservation of these colonially-nesting birds in the region, particularly in terms of securing these sites, are made.

Breeding Flow Thresholds of Colonial Breeding Waterbirds in the Murray-Darling Basin, Australia

Biodiversity on floodplains is under increasing pressure as demand for water for human needs expands. Understanding how waterbirds respond to river flows feeding floodplain wetlands is critical for successful management. We analysed data on breeding by colonial breeding large waders—Eastern Great Egret Ardea modesta, Intermediate Egret Ardea intermedia, Little Egret Egretta garzetta, Nankeen Night Heron Nycticorax caledonicus, Australian White Ibis Threskiornis molucca, Glossy Ibis Plegadis falcinellus, Straw-necked Ibis Threskiornis spinicollis, and Royal Spoonbill Platalea regia—in response to river flow for three wetlands in the Murray-Darling Basin, Australia. Each wetland, which included Barmah-Millewa, the Macquarie Marshes, and Lake Merreti, has a distinctive geomorphology and hydrology. There were clear consistent thresholds of flow producing a >0.7 probability of attempted breeding by most species when a daily flow threshold was exceeded for 30–50 days. Flow characteristics were highly correlated and thresholds could also be expressed in terms of the total flow volume July–December and peak flow in September or October. Below thresholds, there was zero probability of breeding for most species. These minimum thresholds provide critical information for management of these wetlands. Our approach provides an analytical framework for estimating thresholds for other floodplains.

Compte rendu ornithologique camarguais pour les années 2001-2006

Summary. — Ornithological report 2001-2006 for the Camargue. – The present ornithological report for the Camargue covers six years (2001-2006). This time-period has been marked by an accelerated global warming (the summer 2003 was particularly extreme). Owing to a constant high observation pressure, 18 new species have been recorded and many rare species have been resighted in that region (Camargue, Crau, Alpilles). Among the species or group of species which are regularly censused, the number of breeding Greater Flamingos Phoenicopterus roseus and that of wintering ducks and coots did not show any significant change. The colonial herons have continued either to increase or to fluctuate at a high level. For example, the Great White Egret Casmerodius albus has definitely settled in the delta and the Squacco Heron Ardeola ralloides has reached a new peak of 505 pairs in 2006. More efficient prospection efforts gave more precise breeding numbers for two species of solitary herons, the Great Bittern Botaurus stellaris and the Little Bittern Ixobrychus minutus. New breeding species such as the Great Cormorant Phalacrocorax carbo, White Stork Ciconia ciconia, Eurasian Spoonbill Platalea leucorodia and Greylag Anser anser increased their numbers as well as the Glossy Ibis Plegadis falcinellus of which 14 pairs has bred in 2006 and the Purple Swamphen Porphyrio porphyrio which was found for the first time breeding in 2006. The breeding species showing the most serious concern are actually the breeding gulls and terns whose figures have dramatically decreased. Without human management, this situation will even become worse in a near future. Further remarkable observations were the first case of wintering Lesser Spotted Eagle Aquila pomarina in 2001/ 2002, a mixed pair of Black-winged Pratincole Glareola nordmanni x Collared Pratincole G. pratincola in 2001, the settling of the Rook Corvus frugilegus in Arles.

Waterbird breeding and environmental flow management in the Macquarie Marshes, arid Australia

AbstractColonial waterbirds breed in relatively few parts of Australia and the Macquarie Marshes are one of the more important wetlands for these species on the continent in terms of size of breeding colonies and frequency of breeding. Breeding data were collected for ten species of colonial waterbirds in the period 1986–2001: Little Black Cormorant Phalacrocorax sulcirostris, Little Pied Cormorant P. melanoleucos, Great Egret Ardea alba, Intermediate Egret A. intermedia, Little Egret A. garzetta, Cattle Egret A. ibis, Rufous Night Heron Nyctiorax caledonicus, Glossy Ibis Plegadis falcinellus, Straw‐necked Ibis Threskiornis spinicollis and Australian White Ibis T. molucca. Breeding of most colonial waterbirds in the Macquarie Marshes was positively related to flow in the three months before breeding and triggered when flows were usually above 200 000 Ml. Flow was also positively related to wetland area. These relationships allowed modelling of three different options for management of environmental flow, nominally an annual allocation of 125 000 Ml. Even though the Macquarie River is highly regulated, there were predicted to be major differences in breeding frequency, flow variability and wetland flooding for different options delivering environmental flows. Use of all environmental flows each year provided the least variable option while accumulating the flow in the major dam and delivering it at high thresholds provided considerably more variability for the Macquarie Marshes, increased breeding of colonial waterbirds and increased frequency of large floods. The size of a waterbird breeding event and flooding extent were still primarily affected by river flooding and diversions upstream, despite the amount of environmental flow and the predicted ecological differences among the environmental flow options. Copyright © 2005 John Wiley &amp; Sons, Ltd.

Reproductive success of wading birds usingPhragmites marsh and upland nesting habitats

Colonial nesting of long-legged wading birds (Ciconiiformes) in the coastal northeastern U.S. is limited primarily to islands, which provide isolated habitats that are relatively free of ground predators. Estuarine wetlands in this heavily developed region, including foraging wetlands and fringe marshes surrounding nesting islands, are often dominated byPhragmites australis. On Pea Patch Island in Delaware Bay, site of one of the largest and most enduring mixed-species heron colonies on the East Coast, wading birds nest inPhragmites marsh habitat as well as in adjacent upland shrubs and trees. BecausePhragmites is aggressively managed in Delaware Bay, we investigated the relative habitat value of marsh and upland nesting sites for the purpose of developing recommendations for marsh and wildlife management. Utilization of marsh habitat by nesting birds ranged from 27–82% during 1993–1998. Two species (great blue heronArdea herodias and great egretA. alba) never nested inPhragmites, four species (little blue heronEgretta caerulea, snowy egretE. thula, cattle egretBubulcus ibis, and black-crowned night-heronNycticorax nycticorax) nested in approximately equal proportions in both habitats, and one species (glossy ibisPlegadis falcinellus) was largely confined to marsh nesting. Productivity (egg and nestling production) varied between habitats for some species. Cattle egrets produced larger clutches and had higher hatching rates inPhragmites compared to upland habitat. Little blue herons were more successful in the uplands. Managers should retainPhragmites marsh at colony sites, such as Pea Patch Island, where it provides critical habitat for nesting wading birds both as substrate for nesting and buffer habitat to control human disturbance.

Changes in the waterbird community of the Lake Sevan–Lake Gilli area, Republic of Armenia: a case for restoration

Waterbird species richness (Gaviiformes, Podicipediformes, Pelecaniformes, Ciconiiformes, Phoenicopteriformes, Falconiformes, Anseriformes, Gruiformes, Charadriiformes, Passeriformes) has been significantly affected by a 19.5 m lowering of the water level in Lake Sevan (1933–2000), and the complete draining of nearby Lake Gilli (1960–2000) in the Republic of Armenia. Twenty-three former breeders are currently nonbreeders in the area. Four former breeders (black stork Ciconia nigra, glossy ibis Plegadis falcinellus, white-winged scoter Melanitta fusca, little crake Porzana parva) have been extirpated from the area. Four former nonbreeders (cattle egret Bubulcus ibis, red-breasted goose Branta ruficollis, sociable lapwing Chettusia gregaria, lesser black-backed gull Larus fuscus) have been absent from the area for at least 20 years. The red-breasted merganser Mergus serrator is the only former nonbreeder discovered breeding in the Lake Sevan basin. We recommend that management plans of the 1960s and 1970s be used to further develop and enact new efforts to increase the water level of Lake Sevan by at least 6 m, and that Lake Gilli and its surrounding wetlands be restored as a means of increasing waterbird species richness overall, and protecting regional populations of globally threatened or near-threatened species (Dalmatian pelican Pelecanus crispus, red-breasted goose Branta ruficollis, ferruginous pochard Aythya nyroca, white-headed duck Oxyura leucocephala, corn crake Crex crex, great snipe Gallinago media, black-winged pratincole Glareola nordmanni, white-tailed eagle Haliaeetus albicilla).

Impact of Water Diversions on Colonially-Nesting Waterbirds in the Macquarie Marshes of Arid Australia

-The building of dams and subsequent diversion of water from the Macquarie River have had a significant impact on the breeding of colonial waterbirds in the Macquarie Marshes, New South Wales, southeastern Australia. Annual flows (1978, 1986-1996), measured at Oxley where the Marshes begin, were significantly related to total colony size (number of nests) and sizes of six nesting Ciconiidae (Intermediate Egret Ardea intermedia, Rufous Night Heron Nycticorax caledonicus, Glossy Ibis Plegadisfalcinellus, Straw-necked Ibis Threskiornis spinicollis, Australian White Ibis Threskiornis mollucca and Royal Spoonbill Platalea regia) colonies. We used these results and available historical flow data extending back to 1944 to demonstrate the probable impact of water diversions on breeding in these colonial nesting species. The impact of Burrendong Dam, opened in 1967, and Windamere Dam, opened in 1984, on the numbers of nests would have been significant. Instead of a colony of more than 100,000 nests in 1969, a colony of less than 10,000 probably established. Similarly, in 1984, a colony of more than 100,000 could have been established with no water diversions, but in all likelihood the colony was less than 5,000. Generally colony sizes were significantly less (100,000 over 11 years) than would be expected without diversions of water upstream. Colony sizes of more than 100,000 nests estimated during the floods of the 1950s are unlikely to occur again. Numbers of annual breeding events also declined with water diversions from ten to seven (1963-1973); eight to seven (1974-1984) and eight to five (1985-1995). Received 18 December 1997, accepted 18 May 1998.

Egg Size, Clutch Size and Breeding Success of the Glossy IbisPlegadis Falcinellus

Glossy Ibis Plegadis falcinellus were studied at a freshwater marsh near Balranald, New South Wales, during fortnightly visits from September to November 1981. Glossy Ibis bred amongst Straw-necked Ibis Threskiornis spinicollis and Sacred Ibis T. aethiopica on top of knocked-down lignum Meuhlenbeckia cunninghamii. Egg-laying by Glossy Ibis extended for over five weeks and began after all the Straw-necked Ibis and Sacred Ibis had completed their clutches. Two to six eggs were observed per nest but the most frequent clutch was three eggs and the mean clutch size was 3.06 eggs. Of the clutches that were completed, 88% hatched some young and it was estimated that the average fledging success was nearly 1.0 young per nest. There was little evidence of predation of eggs or young and it was concluded that starvation of young caused the low breeding success. The timing and synchrony of breeding by the Glossy Ibis are considered in terms of predation and food availability.

La valeur ornithologique des zones humides de l'est Algerien

In the environs of the town of El Kala in northeast Algeria there are some extensive wetlands of great ornithological, and probably also other biological, importance. The most important are ‘Lake’ Tonga, a marsh of about 2700 ha with much Scirpus lacustris; Lake Oubeïra, a freshwater lake of about 2200 ha; Lake Mellah, where fresh water from brooks and sea water meet, of about 800 ha; Garaet el Mekhada, a Scirpus maritimus marsh of about 5600 ha and swamp forests, which could not be investigated. Many species of waterfowl were seen in the second half of May, 1976. From these and some other observations probable breeding may be derived in many cases. Important species in the region are: squacco heron Ardeola ralloides (about 100 seen), cattle egret Bubulcus ibis (about 2000 seen), little egret Egretta garzetta (about 65 seen), grey heron Ardea cinerea (rare), purple heron Ardea purpurea (about 60 seen, possibly far more present), little bittern Ixobrychus minutus, bittern Butaurus stellaris and night heron Nycticorax nycticorax. Beside herons, the following species were seen: ferruginous duck Aythya nyroca (about 100 seen, probably far more numerous and hidden by the vegetation), white-headed duck Oxyura leucocephala (some 50 seen, probably present in greater numbers), marbled teal Anas angustirostris, purple gallinule Porphyrio porphyrio (common in Tonga). Interesting birds of prey in the region were griffon vulture Gyps fulvus (up to 30), marsh harrier Circus aeruginosus (rather numerous in Tonga), tawny eagle Aquila rapax (probably breeding on one place) and Eleonora's falcon Falco eleonorae (up to 5). As to probable breeding birds, Tonga has the greatest density of species and individuals, but other wetlands also have important aspects. Probably the most important lake for breeding birds, Fetzara (near Annaba), was drained in 1937. Marbled teal, ferruginous duck and purple gallinule were very common there, and white-headed duck, purple heron, squacco heron, night heron, little egret, spoonbill Platalea leucorodia, glossy ibis Plegadis falcinellus, grey-lag goose Anser anser, red-crested pochard Netta rufina and gadwall Anas strepera used to breed. A brief review is given of wintering waterfowl, mainly based on counts by different observers in the period 1971–1979. Large numbers of waterfowl have been seen in Lake Oubeïra; up to 5000 pintail Anas acuta, up to 14000 wigeon Anas penelope, up to 27000 pochard Aythya ferina, up to 9000 tufted duck Aythya fuligula and up to 32000 coot Fulica atra, up to 850 black-necked grebe Podiceps nigricollis and up to 2300 little grebe Tachybaptus ruficollis. In Lake Mellah up to 9000 pochard have been seen, up to 12000 tufted duck, and up to 35000 coot. In Garaet al Mekhada up to 25000 wigeon, up to 5000 coot and up to 8000 grey-lag geese have been seen. It seems quite possible that the 95000 wigeon seen by Smart in the artificial lake of the Barrage de la Cheffia in 1974 fed in Mekhada. An insight of waterfowl averages during the different counts can be obtained from the reports, mentioned in the references. All large wetlands mentioned have a high, actual or potential, ecological value. Each of them deserves protection and, from the ecological viewpoint, Fetzara merits inundation. Protection should be aimed at the preservation of the special character of each of the wetlands and of their mutual relationship for birds. The region is the most important in Algeria for wintering duck and coot (an average of 93000 from 1974–1978) and probably also for breeding waterfowl (especially Tonga) in spite of the high quality of La Macta in West Algeria. For the preservation of this diversity, several factors are essential, e.g., water level, water quality, absence of exotic elements in the water fauna and a relatively low shooting pressure (with little disturbance). It is important to prevent drainage of the lakes and of their surroundings, afforestation of the adjacent land, deforestration and erosion in the catchment areas, introduction of exotic fish species—and it is important to introduce good rules concerning shooting. This complex of wetlands is part and parcel of an extensive area of high biological interest, of which the marine habitats and large semi-natural forests are also remarkable. It is to be hoped that this entity will be efficiently protected in the framework of the National Park of El Kala Project.

Need for conservation of creeks in North-East Flanders, Belgium

In the environs of the town of El Kala in northeast Algeria there are some extensive wetlands of great ornithological, and probably also other biological, importance. The most important are ‘Lake’ Tonga, a marsh of about 2700 ha with much Scirpus lacustris; Lake Oubeïra, a freshwater lake of about 2200 ha; Lake Mellah, where fresh water from brooks and sea water meet, of about 800 ha; Garaet el Mekhada, a Scirpus maritimus marsh of about 5600 ha and swamp forests, which could not be investigated.Many species of waterfowl were seen in the second half of May, 1976. From these and some other observations probable breeding may be derived in many cases. Important species in the region are: squacco heron Ardeola ralloides (about 100 seen), cattle egret Bubulcus ibis (about 2000 seen), little egret Egretta garzetta (about 65 seen), grey heron Ardea cinerea (rare), purple heron Ardea purpurea (about 60 seen, possibly far more present), little bittern Ixobrychus minutus, bittern Butaurus stellaris and night heron Nycticorax nycticorax.Beside herons, the following species were seen: ferruginous duck Aythya nyroca (about 100 seen, probably far more numerous and hidden by the vegetation), white-headed duck Oxyura leucocephala (some 50 seen, probably present in greater numbers), marbled teal Anas angustirostris, purple gallinule Porphyrio porphyrio (common in Tonga). Interesting birds of prey in the region were griffon vulture Gyps fulvus (up to 30), marsh harrier Circus aeruginosus (rather numerous in Tonga), tawny eagle Aquila rapax (probably breeding on one place) and Eleonora's falcon Falco eleonorae (up to 5).As to probable breeding birds, Tonga has the greatest density of species and individuals, but other wetlands also have important aspects.Probably the most important lake for breeding birds, Fetzara (near Annaba), was drained in 1937. Marbled teal, ferruginous duck and purple gallinule were very common there, and white-headed duck, purple heron, squacco heron, night heron, little egret, spoonbill Platalea leucorodia, glossy ibis Plegadis falcinellus, grey-lag goose Anser anser, red-crested pochard Netta rufina and gadwall Anas strepera used to breed.A brief review is given of wintering waterfowl, mainly based on counts by different observers in the period 1971–1979. Large numbers of waterfowl have been seen in Lake Oubeïra; up to 5000 pintail Anas acuta, up to 14000 wigeon Anas penelope, up to 27000 pochard Aythya ferina, up to 9000 tufted duck Aythya fuligula and up to 32000 coot Fulica atra, up to 850 black-necked grebe Podiceps nigricollis and up to 2300 little grebe Tachybaptus ruficollis.In Lake Mellah up to 9000 pochard have been seen, up to 12000 tufted duck, and up to 35000 coot.In Garaet al Mekhada up to 25000 wigeon, up to 5000 coot and up to 8000 grey-lag geese have been seen. It seems quite possible that the 95000 wigeon seen by Smart in the artificial lake of the Barrage de la Cheffia in 1974 fed in Mekhada. An insight of waterfowl averages during the different counts can be obtained from the reports, mentioned in the references.All large wetlands mentioned have a high, actual or potential, ecological value. Each of them deserves protection and, from the ecological viewpoint, Fetzara merits inundation. Protection should be aimed at the preservation of the special character of each of the wetlands and of their mutual relationship for birds.The region is the most important in Algeria for wintering duck and coot (an average of 93000 from 1974–1978) and probably also for breeding waterfowl (especially Tonga) in spite of the high quality of La Macta in West Algeria.For the preservation of this diversity, several factors are essential, e.g., water level, water quality, absence of exotic elements in the water fauna and a relatively low shooting pressure (with little disturbance). It is important to prevent drainage of the lakes and of their surroundings, afforestation of the adjacent land, deforestration and erosion in the catchment areas, introduction of exotic fish species—and it is important to introduce good rules concerning shooting.This complex of wetlands is part and parcel of an extensive area of high biological interest, of which the marine habitats and large semi-natural forests are also remarkable.It is to be hoped that this entity will be efficiently protected in the framework of the National Park of El Kala Project.