Egyptian Geese Research Articles

Satellite telemetry of Afrotropical ducks: methodological details and assessment of success rates

Despite widespread and increasing use of solarpowered satellite transmitters to tag wild birds, there are few published articles that detail how transmitters should be attached to different species and even fewer assessments of the overall field success of telemetry projects. The scarcity of this information makes it difficult to plan and budget for telemetry projects effectively. In this paper we present relevant information from a study involving a total of 47 individual ducks of two Afrotropical anatid species, Egyptian Goose, Alopochen aegyptiaca, and red-billed teal, Anas erythrorhyncha, using solarpowered GPS satellite transmitters of two different sizes (30 g and 22 g, respectively) at three very different southern African sites (Strandfontein wastewater treatment works in the Western Cape Province of South Africa, Barberspan Nature Reserve in the North West Province of South Africa, and Lake Manyame in north-central Zimbabwe). We present a full description of harness design and attachment and a survivorship analysis of the transmitters. Our results suggest that the 30 g units last longer than the 22 g units, with approximately 60% and 30%, respectively, of these PTTs (position tracking terminals) lasting longer than a year; 45% and 5%, respectively, lasting longer than two years; and 20% and 0%, respectively, lasting longer than three years. We strongly encourage the publication of comparable data sets so that future studies that rely on telemetry data can be planned with a realistic set of assumptions and limitations in mind.

Satellite Telemetry of Afrotropical Ducks: Methodological Details and Assessment of Success Rates

Despite widespread and increasing use of solar-powered satellite transmitters to tag wild birds, there are few published articles that detail how transmitters should be attached to different species and even fewer assessments of the overall field success of telemetry projects. The scarcity of this information makes it difficult to plan and budget for telemetry projects effectively. In this paper we present relevant information from a study involving a total of 47 individual ducks of two Afrotropical anatid species, Egyptian Goose, Alopochen aegyptiaca, and red-billed teal, Anas erythrorhyncha, using solarpowered GPS satellite transmitters of two different sizes (30 g and 22 g, respectively) at three very different southern African sites (Strandfontein wastewater treatment works in the Western Cape Province of South Africa, Barberspan Nature Reserve in the North West Province of South Africa, and Lake Manyame in north-central Zimbabwe). We present a full description of harness design and attachment and a survivorship analysis of the transmitters. Our results suggest that the 30 g units last longer than the 22 g units, with approximately 60% and 30%, respectively, of these PTTs (position tracking terminals) lasting longer than a year; 45% and 5%, respectively, lasting longer than two years; and 20% and 0%, respectively, lasting longer than three years. We strongly encourage the publication of comparable data sets so that future studies that rely on telemetry data can be planned with a realistic set of assumptions and limitations in mind.

Phenotypic flexibility of a southern African duck Alopochen aegyptiaca during moult: do northern hemisphere paradigms apply?

Phenotypic flexibility during moult has never been explored in austral nomadic ducks. We investigated whether the body condition, organ (pectoral muscle, gizzard, liver and heart) mass and flight‐feather growth Egyptian geese Alopochen aegyptiaca in southern Africa show phenotypic flexibility over their 53‐day period of flightless moult. Changes in body mass and condition were examined in Egyptian geese caught at Barberspan and Strandfontein in South Africa. Mean daily change in primary feather length was calculated for moulting geese and birds were dissected for pectoral muscle and internal organ assessment. Mean body mass and condition varied significantly during moult. Body mass and condition started to decrease soon after flight feathers were dropped and continued to do so until the new feathers were at least two‐thirds grown, after which birds started to regain body mass and condition. Non‐moulting geese had large pectoral muscles, accounting for at least 26% of total body mass. Once moult started, pectoral muscle mass decreased and continued to do so until the flight feathers were at least one‐third grown, after which pectoral muscle mass started to increase. The regeneration of pectoral muscles during moult started before birds started to gain overall body mass. Gizzard mass started to increase soon after the onset of moult, reaching a maximum when the flight feathers were two‐thirds grown, after which gizzard mass again decreased. Liver mass increased significantly as moult progressed, but heart mass remained constant throughout moult. Flight feather growth was initially rapid, but slowed towards the completion of moult. Our results show that Egyptian geese exhibit a significant level of phenotypic flexibility when they moult. We interpret the phenotypic changes that we observed as an adaptive strategy to minimize the duration of the flightless period. Moulting Egyptian geese in South Africa undergo more substantial phenotypic changes than those reported for ducks in the northern hemisphere.

Invited article: The impacts of non‐native species: a review of the British Ornithologists’ Union's Autumn 2008 Scientific Meeting

Invited article: The impacts of non‐native species: a review of the British Ornithologists’ Union's Autumn 2008 Scientific Meeting

Assemblages and movements of waterfowl at cattle feedlots across Gauteng, South Africa

Assemblages of waterfowl (Anatidae) at two cattle feedlots 120 km apart in Gauteng province, South Africa are described. Yellow-billed, Fulvous and White-faced Ducks, Cape Shoveller, and Cape and Red-billed Teals benefited directly from the cattle feedlots. Food items, such as undigested maize seeds, were obtained from the pen floor and aquatic invertebrates were consumed from dams that were enriched with manure runoff. Comb Duck and Egyptian Goose also fed on maize seeds on the pen floor, while African Black Duck, although primarily river-bound, fed in manure runoff dams in summer. Conversely, Southern Pochard, Comb and Maccoa Ducks were not strongly associated with dams enriched by manure runoff. Long- and short-distance movements by waterfowl may be triggered not only by rainfall, but also by the productivity of water bodies.

Sjeldne fugler i Norge i 2008 - Rapport fra Norsk sjeldenhetskomité for fugl (NSKF)

This is the 33rd annual report from the Norwegian Rarities Committee (NSKF). The majority of records treated here are from 2008, but more than 100 older records are also included. The Norwegian rarities committee follow advises given by the Taxonomic Advisory Committee (TAC) of the Association of European Records and Rarities Committees (AERC) on issues concerning taxonomy and nomenclature. The systematic list of accepted records is set out in the following system: (1) The bird's Norwegian name, (2) scientific name, (3) the numbers in brackets, e.g. (2, 30/32, 1), refers respectively to the (i) total number of records/total number of individuals up to and including 1974, (ii) total number of records/total number of individuals from 1975 (the foundation year of NSKF), except (iii) records/individuals in 2008, (4) any breeding, (5) year, (6) county, (7) number of individuals, age (1K = first calendar year etc.), sex (if known) and sometimes circumstances («rm.» means that the bird was ringed, «sy.» indicates a singing male), (8) site and municipality, (9) date, (10) * indicates if the record was complemented by positive evidence, and type of the evidence (F = photo, V = video-recorded, L = tape-recorded), (11) observers' names in brackets, main observer(s) is specified first and emphasized with *, (12) roughly gives the species' distribution and (13) comments concerning the records.Species and subspecies new to the Norwegian listTwo new species were accepted to the Norwegian Category A list from 2008. Both of these were Nearctic waders, namely a Hudsonian Godwit Limosa haemastica from Røstlandet on June 24th and a Western Sandpiper Calidris mauri from Jæren on July 12th-13th. In addition there were three new subspecies accepted: Buff-bellied Pipit Anthus rubescens japonicus (Karmøy, January to April), Yellow Wagtail Motacilla flava feldegg (Utsira, 3rd to 5th June) and White Wagtail M. alba leucopsis (Lista, 1st-2nd November).General trendsRecord numbers for Norway was recorded for Grey Phalarope Phalaropus fulicarius (14/23) during 2008. Also the following species showed an occurrence above average during 2008: Great White Egret Ardea alba, Black Kite Milvus migrans, Pectoral Sandpiper C. melanotos, Red-rumped Swallow Cecropis daurica, Citrine Wagtail M. citreola, Blyth's Reed Warbler Acrocephalus dumetorum and Rose-coloured Starling Sturnus roseus. Also published here are the 6th Egyptian Goose Alopochen aegyptiaca (Cat. C), 3rd Lesser Scaup Aythya affinis, 8th Harlequin Duck Histrionicus histrionicus, 5th to 7th American Golden Plover Pluvialis dominica, 4th Laughing Gull Larus atricilla, 6th Franklin's Gull L. pipixcan, 6th and 8th Oriental Turtle Dove Streptopelia orientalis, 8th Blyth's Pipit A. godlewskii, 2nd Siberian Rubythroat Luscinia calliope, 5th Isabelline Wheatear Oenanthe isabellina, 10th Lanceolated Warbler Locustella lanceolata, 4th Melodious Warbler Hippolais polyglotta, 3rd Eastern Bonelli's Warbler Phylloscopus orientalis and 4th and 7th Steppe Grey Shrike Lanius meridionalis pallidirostris.

Variations by Sex in Anatomical and Morphological Features of the Tongue of Egyptian Goose (Alopochen aegyptiacus)

Tongue specimens were collected from 18 healthy adult Egyptian geese (Alopochen aegyptiacus) of both sexes. We measured and analyzed the whole, anterior, middle and posterior length and width of the tongue parts. The dorsal mucosal surface of each tongue was investigated by SEM. The length of whole tongue, widths at anterior and middle ends of its root showed significant differences between sexes. By gross morphology, the tongue showed 3 parts (anterior, middle and posterior). The anterior part represented 1 half of the tongue, while the 2 remaining parts comprised the other half. A clear median longitudinal groove was observed macroscopically along the forward half of the anterior region. The caudal part of the body had a central circular depression in front of giant conical papillae arranged in transverse row. On both sides of the tongue, cylindrical lingual papillae were compactly distributed and divided into anterior and posterior groups which increased in size and decreased in number caudally. By SEM, both giant conical and large cylindrical lingual papillae were lined with extensively modified mucosal surfaces that appeared as finger-like projections with scales. The tongue, which plays an important role in food intake in Egyptian geese, exhibited significant morphological variations in dorsal mucosal lining between sexes. Morphological observations recorded significant gender differences in total length and widths of the tongue at anterior and middle segments of its root.

Waterbirds at Paarl Waste Water Treatment Works, South Africa, 1994–2004: seasonality, trends and conservation importance

Numbers of waterbirds were counted monthly from May 1994 to April 2004 at Paarl Waste Water Treatment Works, South Africa. Seventy-two waterbird species were recorded, of which 33 species (46%) were recorded breeding. Mean summer and winter counts were 2822 ± 504 and 1651 ± 251 birds, respectively. Summer peaks were driven primarily by large numbers of White-winged Terns (mean summer count = 858 or 34% of total count). Resident species dominated from December to April, whereas Palaearctic migrants peaked from December to March. Ducks and geese had greatest numbers from December to April and resident waders and grebes peaked from April to July. Flamingos peaked in October and November with another small peak in June. Gulls and terns had two peaks, one in November–March, driven by migrant White-winged Terns, the other in July and August, driven by abundance of resident Benguelan (Hartlaub's) Gulls. White-winged Terns showed the greatest decline (82%) of all species. Influx of Little Grebe and Red-billed Teal during winter showed a positive correlation with rainfall, while Egyptian Goose, Yellow-billed Duck and Cape Shoveler numbers declined as winter and spring rainfall increased. Paarl Waste Water Treatment Works ranked as the second-most important wastewater treatment works for waterbirds in the Cape Town metropole. It supported globally and regionally important numbers of 11 species and qualifies as a global and/or subregional Important Bird Area and Ramsar Site.

Risk factors for seropositivity to H5 avian influenza virus in ostrich farms in the Western Cape Province, South Africa

In a 2005 serological survey, carried out in response to an outbreak of H5N2 avian influenza (AI) in ostriches in the Eastern Cape Province, 16.3% of ostrich farms in the Western Cape Province of South Africa were found to be seropositive to H5 AI virus. We subsequently carried out a questionnaire-based census survey on all available registered Western Cape ostrich farms that still existed at the end of 2005 (367 farms, of which 82 were seropositive), in order to identify risk factors associated with farm-level seropositivity. A farm was classified as seropositive for H5 AI virus if one or more birds had tested positive (haemagglutination inhibition titre >1:16) in the 2005 survey, which had been designed to detect a minimum within-group seroprevalence of 10%. For each farm, risk factor information was collected using a questionnaire administered during a face-to-face interview with each farm owner or manager. Information was obtained on the ostrich population, movements of birds, environmental factors, management practices, and frequency of contact between ostriches and various wild bird species. Multiple logistic regression models were developed for the whole Western Cape Province and also for the two largest ostrich farming regions, “Klein Karoo” and “Southern Cape”. Seroprevalence differed between regions, being highest in the Klein Karoo (31.6%). In all three models, increased risk of farm-level H5 AI virus seropositivity was associated with increasing numbers of ostriches, excluding chicks, present on the farm. Increased risk of seropositivity was associated with reduced frequency of cleaning of feed troughs (<1×/week vs. >1×/week), both overall (odds ratio (OR) = 4.5; 95% confidence interval (CI): 1.5, 13.3) and in the Southern Cape (OR = 53.6; 95% CI: 3.3, 864), and with failure to clean and disinfect transport vehicles, both overall (OR = 2.3; 95% CI: 1.1, 4.8) and in the Klein Karoo (OR = 2.6; 95% CI: 1.1, 6.5). Increased risk of seropositivity was also associated with increasing frequency of contact of ostriches with certain wild bird species: overall with white storks ( Ciconia ciconia), in the Southern Cape with gulls ( Larus spp.), and in the Klein Karoo with Egyptian geese ( Alopochen aegyptiaca).

Sjeldne fugler i Norge i 2006 - Rapport fra Norsk sjeldenhetskomité for fugl (NSKF)

This is the 31st annual report from the Norwegian Rarities Committee (NSKF). The majority of records treated here are from 2006, but some older records are also included. The Norwegian rarities committee follow advises given by the Taxonomic Advisory Committee (TAC) of the Association of European Record and Rarities Committees (AERC) on issues concerning taxonomy and nomenclature. The systematic list of accepted records is set out in the following system: (1) The bird’s Norwegian name, (2) scientific name, (3) the numbers in brackets, e.g. (2, 30/32, 1), refers respectively to the ( i ) total number of records/total number of individuals up to and including 1974, ( ii ) total number of records/total number of individuals from 1975 (the foundation year of NSKF), except ( iii ) records/individuals in 2006, (4) any breeding, (5) year, (6) county, (7) number of individuals, age (1K = first calendar year etc.), sex (if known) and sometimes circumstances («rm» means that the bird was ringed), (8) site and municipality, (9) date, (10) * indicates if the record was complemented by positive evidence, and type of the evidence (F = photo, V = video-recorded, L = tape-recorded, DNA = DNA-analysis, D = found dead), (11) observers’ names in brackets, main observer(s) is specified first and emphasized with *, (12) roughly gives the species’ distribution and (13) comments concerning the records. Species, subspecies and hybrids new to the Norwegian list: With 245 accepted records presented in this report, 2006 was another good year for rare birds in Norway. A total of 42 accepted records from previous years complete the status of rare birds on the Norwegian list. There are five records presented that have been shelved. Also presented are 26 records that for some reason have not been accepted. All previous records of Booted Warbler Hippolais caligata ssp. and Bonelli’s Warbler Phylloscopus bonelli ssp. have been reassessed following the recent split of these two species. The two formerly accepted records of Snow Bunting Plectrophenax nivalis of the subspecies vlasowae have also been reassessed based on new knowledge on the variation within the nominate subspecies. Three new species to the Norwegian category A list are presented in this report. This brings the official Norwegian list to 477 species. Included in this list are accepted records in category A-C. The new species in 2006 were Masked Shrike Lanius nubicus (Utsira, Rogaland 2nd to 15 th October) and Blackpoll Warbler Dendroica striata (Reve, Rogaland 2nd to 12th November). In addition the first two Sykes’s Warblers Hippolais rama (Forus, Rogaland 11th September 1983 and Monstermyr, Vest-Agder 20th September 1997) were accepted during the reassessment of older records. A Red-necked Grebe Podiceps grisegena collected at Traena, Nordland 28th January 1949 has been accepted as the first Norwegian record of the holboellii subspecies. Two records of hybrid Blue-winged Teal Anas discors x Northern Shoveler A. clypeata (Aheim, More og Romsdal 7th – 9th June 2003 and Lista fyr, Vest-Agder 31 st July – 5th August 2006) have also been accepted as the national first and second records. General trends: Record numbers for Norway was recorded for the following species during 2006: Great Bittern Botaurus stellaris (eight records), Black Kite Milvus migrans (nine records), Mediterranean Gull Larus melanocephalus (ten records), Citrine Wagtail Motacilla citreola (nine records) and Lesser Grey Shrike Lanius minor (three records). Also, 2006 saw the highest number (six records of eleven birds) for Corn Bunting in recent times, including the first successful breeding since 1939. Six records involving ten birds of Arctic Redpoll Carduelis hornemanni of the nominate subspecies was also an all time high. Also published here are the 4th & 5th Egyptian Goose Alopochen aegyptiaca for Norway, 4 th American Black Duck Anas rubripes , 3rd Piedbilled Grebe Podilymbus podiceps , 2nd Little Shearwater Puffinus [assimilis] baroli , 3rd Swinhoe’s Storm-petrel Oceanodroma monorhis , 5th Collared Pratincole Glareola pratincola , 4 th American Golden Plover Pluvialis dominica , 8th & 9th Bonaparte’s Gull Larus philadelphia , 4th, 8th & 9th Yellow-legged Gull Larus michahellis , 10th & 11th Caspian Gull Larus cachinnans , 7 th Gull-billed Tern Sterna nilotica , 4th Isabelline Wheatear Oenanthe isabellina , 2nd Eastern Orphean Warbler Sylvia crassirostris and 2 nd Black-faced Bunting Emberiza spodocephala (cat. D).

Competition with Egyptian Geese Alopochen aegyptiaca overrides environmental factors in determining productivity of Black Sparrowhawks Accipiter melanoleucus

We studied a population of Black Sparrowhawks Accipiter melanoleucus that has recently colonized the Cape Peninsula, South Africa. Black Sparrowhawks are winter breeders: over most of their range winters are dry, but the Cape Peninsula has a Mediterranean climate, with most rain falling in winter. The birds bred at an average density of 38 pairs/100 km2. Monitoring of 70 breeding attempts by 26 pairs showed that the birds favoured large stands of trees for breeding. Birds breeding in smaller stands were more randomly spaced, dispersion being determined by habitat availability. Parameters related to climate, habitat and aspects of nest‐site selection failed to predict the birds’ productivity despite the fact that they had recently colonized a novel climatic window. Rather, productivity was best explained by the probability of nest usurpation by highly aggressive Egyptian Geese Alopochen aegyptiaca. Pairs encountering Goose usurpation problems raised an average of 0.76 chicks per breeding attempt, compared with 1.58 chicks for pairs without Geese. The only defence against nest usurpation by Geese appears to be the construction of multiple nests, an option most available to and most exploited by birds breeding in large stands of trees.

Waterbirds at the Theewaterskloof Dam, Western Cape, South Africa, 1993–2005

With a perimeter of 82km, the Theewaterskloof Dam is the largest dam in the Western Cape. This paper, based on mid-summer and mid-winter surveys between 1993 and 2005, assesses the importance of the dam for waterbirds. The median numbers of waterbirds in summer and winter were 3 086 and 1 321, respectively. Fifty-eight species were recorded, 35 of them on at least half of the summer or winter surveys. The proportion of Egyptian Geese Alopochen aegyptiaca in summer increased from 47% in the first four years to 88% in the final four years, and reached 94% in summer 2005. Numbers of most colonially-nesting waterbirds decreased over the period assessed; this is attributed to the ongoing decay of trees that were left standing when the dam was constructed. In 2005, 25 years after completion, Theewaterskloof Dam is considered not to have reached the 'mature lake' phase, because species composition patterns remain unstable. Despite its size, the dam is of minor conservation importance to waterbirds in the Western Cape.

British Ornithologists’ Union Records Committee: 31st Report (October 2004)

British Ornithologists’ Union Records Committee: 31st Report (October 2004)

Sjeldne fugler i Norge i 2002 - Rapport fra Norsk sjeldenhetskomité for fugl (NSKF)

This is the 27th annual report and the 28th announcement from the Norwegian Rarities Committee (NSKF). Most of the records treated here are from 2002, but older records are also included. The systematic list of accepted records is set out in the following system: (1) The birds Norwegian name, (2) scientific name, (3) the numbers in brackets, e.g. (30/32 - 1), refers respectively to the total number of records/total number of individuals up to and including 2001, and in 2002, (4) any limitations given of (3), (5) any breeding, (6) year, (7) county, (8) number of individuals, age (1K = first calendar year etc.), sex (if known) and sometimes circumstances (&laquo;ringmerket&raquo; means that the bird was ringed), (9) site and municipality, (10) date, (11) * indicates if the record was complemented by positive evidence, and type of the evidence (F = photo, V = video-recorded, L = tape-recorded, D = found dead), (12) observers names in brackets, main observer is specified first and emphasized with *, (13) roughly gives the species distribution and (14) comments concerning the records.General trends:Norway experienced a major influx of Rose-coloured Starlings Sturnus roseus in the summer and autumn of 2002. This influx included 26 records, which increased the total number of accepted records with 20 %. The year 2002 was also the first year with more than one accepted Balearic Shearwater Puffinus mauretanicus (three records). Five records of Bittern Botaurus stellaris and eight records of Little Egret Egretta garzetta were also year records. The number of accepted Water Pipits Anthus spinoletta was doubled with three new records. It was also a record year for Blyth&rsquo;s Pipit Anthus godlewskii (two records), Pechora Pipit Anthus gustavi (three records) and Citrine Wagtail Motacilla citreola (six records). Eight records of Great White Egret Ardea alba was a second best year ever. Other records of interest included a drake Blue-winged Teal Anas discors (5th record), three Spectacled EidersSomateria fischeri (4th record), Harlequin Duck Histronicus histronicus (7th record), Short-toed Eagle Circaetus gallicus (3rd record), Black-winged Pratincole Glareola nordmanni (3rd record), Greater Sand Plover Charadrius leschenaultii (3rd record), Semipalmated Sandpiper Calidris pusilla (4th record), Upland Sandpiper Bartramia longicauda (2nd record), Spotted Sandpiper Actitis macularia (5th record), Scops Owl Otus scops (2nd record), Lanceolated Warbler Locustella lanceolata (6th record) and Pallas&rsquo;s Grasshopper Warbler Locustella certhiola (7th record). Species and subspecies new to the Norwegian list:This report includes five additions to category A on the Norwegian list: Lesser Sand Plover Charadrius mongolus, American Golden Plover Pluvialis dominica, Eastern Crowned Warbler Phylloscopus coronatus, Eastern Bonelli&rsquo;s Warbler Phylloscopus orientalis and White-throated Sparrow Zonotrichia albicollis. A record of Egyptian Goose Alopochen aegyptiacus was also added to the Norwegian category C list. With these new records the official Norwegian birdlist consists of 464 species. A record of Ross&rsquo;s Goose Chen rossii migrating south with Barnacle Geese Branta leucopsis was probably the same individual as recorded in Northumberland,Great Britain a few days later, and is accepted as a new species in the Norwegian category D. The first breeding attempt of Pied-billed Grebe Podilymbus podiceps was also recorded in 2002, resulting in a hybrid chick with genes from Little Grebe Tachybabtus ruficollis.

Taxonomic recommendations for British birds: second report

Taxonomic recommendations for British birds: second report

Population dynamics and the physical and financial impacts to cereal crops of the Egyptian Goose Alopochenaegyptiacus on the Agulhas Plain, Western Cape, South Africa

Cereal crop farmers in the Western Cape province of South Africa regard the Egyptian Goose as a serious pest. The Agulhas Plain, in particular, attracts thousands of geese annually primarily because of the abundance and availability of nutritious crops such as wheat Triticum spp. and barley Hordeum spp. for food and permanent water bodies for roosting, moulting and breeding. Therefore, this paper investigates the population dynamics and physical and financial impacts to cereal crops of the Egyptian Goose on the Agulhas Plain, Western Cape. Egyptian Geese inflict damage during three main periods, viz. soon after sowing (surface seeds); young, developing plants (growing plants); and cut plants stacked in windrows (long, linear piles) to dry. The largest numbers of geese were recorded during June and July when they foraged on growing plants less than 25 cm tall. Overall, the mean yield loss was 65.6% in 1997 and 63.5% in 1998. Fields suffering greatest yield loss in 1997 and 1998 were generally those within 600 m of the roosting sites and had about 300 geese grazing on them on areas of around 2 ha in size for about 2 months. By August, geese moved from croplands on to pastures. During October and November, geese once again fed primarily on barley seeds in harvested crops stacked in windrows. Damage by geese to farmers was estimated to be >2.5 and 7% of annual revenue received from barley and wheat farming, in 1997 and 1998, respectively. There are many variables that need to be considered when attempting to quantify and explain damage to cereal crops by Egyptian Geese.

Controlling the flood in the Senegal Delta: do waterfowl populations adapt to their new environment?

Triplet, P. & Yésou, P. 2000. Controlling the flood in the Senegal Delta: do waterfowl populations adapt to their new environment? Ostrich 71 (1 & 2): 106–111. The delta of the Senegal river (320 000 ha) has been gradually dammed, mostly during the 1970–80s. From 1986, the Diama dam has stopped any backflow of salt water from the sea into most of the delta, and retains a large volume of fresh water which can be released into initially naturally flooded, but now embanked, areas, including the National Parks of Djoudj (Senegal) and Diawling (Mauritania) and other lowlands often used for agriculture, mainly rice-fields. Landscapes have been deeply modified (vegetation overgrowing in wetlands, desertification process around), sometimes in a provisionally positive way (creation or development of flooded areas through irrigation or hunting management). The Anatidae overwintering in the delta have been censused since 1972: we analyse these census data, with emphasis on the periods 1972–1976 and 1989–1996 (when census methodology and coverage were similar), in order to define how Anatidae have adapted to the new environmental conditions. Three Afrotropical and two Palearctic species are holding on, in spite of marked yearly variations and sometimes a loss of habitat quality (Fulvous Whistling Duck Dendrocygna bicolor. White-faced Whistling Duck D. viduata, Egyptian Goose Alopochen aegyptiacus. Northern Pintail Anas acuta, Garganey A. querquedula), two Palearctic species showed significant but not fully explained changes in numbers (Northern Shoveler Anas clypeata increasing, Common Teal A. crecca almost disappearing), and numbers of two Afrotropical species decreased following the environmental modifications (Spur-winged Goose Plectropterus gambensis, and Comb Duck Sarkidiornis melanotos even more markedly). In order to maintain or develop conditions favourable to these bird populations, it is necessary to supply the managers of protected areas with the resources needed to implement this aim. Also, the whole lower valley of the Senegal River (including the Lake of Aleg in Mauritania) must be taken into account in conservation measures, including non-protected areas potentially favourable to waterfowl. Such a conservation programme implies the co-operation of national and international bodies related to both nature conservation and wetland development.

Aspects of the biology of Egyptian Goose Alopochen aegyptiacus colonizing The Netherlands

Since 1967, the Egyptian Goose has established a feral breeding population of some 1350 pairs in the Netherlands and colonized large parts of the country. Aspects of the breeding cycle and the changes in winter numbers are analysed. The Dutch population has a six-month breeding season and overall breeding success in the Netherlands is higher than in Africa, or in the British population. The proportion of successful pairs and overall breeding success decreased a few years after colonization of new areas. Timing of the onset of incubation was positively related to winter severity. Density-dependent factors appeared to begin to operate soon after colonization. As soon as the population stabilized, environmental factors became of major importance. Although population size is reduced during severe winters, the delay in the onset of breeding and relatively high success after such winters, as well as the prolonged breeding season, can quickly compensate for these losses. This combination may explain the relatively greater breeding output of this tropical species in the moderate climate of Western Europe.

Avian Paramyxoviruses Serotype 3 Isolated from Captive Birds in Israel: Clinical Signs, Pathology, and Antigenic Characterization

Thirteen HA agents were isolated in Israel from captive flamingoes (Phoenicopterus ruber), Egyptian geese (Alopochen aegyptiacus) belonging to order Anseriformes, and ibis (Guara rubra) belonging to order Ciconiiformes. The isolation was done from postmortem materials in three cases of severe respiratory disease with high mortality. The isolates were examined serologically and identified as belonging to the serotype 3 of avian paramyxoviruses (APMV-3). The isolates were more close antigenically to the APMV-3b variety (prototype strain--APMV-3/Parakeet/Netherlands/449/75) than to the APMV-3a variety (prototype strain--APMV-3/Turkey/Wisconsin/68). This is the first isolation of APMV-3 from birds belonging to the orders Anseriformes and Ciconiiformes.

Temporal and spatial expansion of the Egyptian goose Alopochen aegyptiacus in The Netherlands, 1967–94

In this paper, the temporal and spatial expansion of the Egyptian goose in the Netherlands are described and analysed. The species bred near The Hague for the first time in 1967. In 1983 a second settlement developed in Drenthe. Both settlements expanded. Together, they contained about 1340 breeding pairs in 1994. For both settlements a linear relationship exists between the square root of the area occupied and time. In both cases, population growth is exponential. The bird behaves as a resident species. Thus, in winter numbers in The Netherlands also increase exponentially. The Egyptian goose seems to be sensitive to severe winters, which cause a high mortality. The observed velocity of range expansion is compared with the velocity as calculated with the expansion model of Van den Bosch et al. (1990). The observed velocity was about 3.0 km per year, which is about 20% lower than expected, but not significantly different. Population growth was estimated using a projection matrix. In the first 10 years after its settlement near The Hague, the actual population growth was larger than the calculated growth. There is evidence for good breeding success during the first years due to mild winters between 1972 and 1978. In the second settlement, Drenthe, the same rapid population growth occurred. Here, a low but regular influx of birds from a nearby city park was probably the main factor. In the near future, further temporal and spatial expansion can be expected, in the direction of Germany and Denmark in the east and Belgium and France in the south. Towards the east the severity of the winters might limit further range expansion, possibly coinciding with the 0o isotherm in January.