Notes on the Breeding Biology of the Kentish Plover in the Nile Delta

Notes on the breeding biology of the Kentish Plover in the Nile Delta

Olivier Pineau

Pineau,O. 1993. Noteson the breedingbiology of the KentishPlover in the Nile Delta.Wader Study GroupBull. 67:63 - 66.

OlivierPineau, Station Bioiogique de la Tourdu Valet,La Sambuc, 13200Aries, France

INTRODUCTION

In winter 1989/90 and spring1990, an extensive ornithologicalproject was carriedout to assess the carryingcapacity of Egyptianwetlands (Meininger et ai. 1991; Meininger& Atta in prep.).As a side activity duringthe surveysof Lake Manzala in spring1990, data were collectedon breedingKentish Plovers haradriusalexandrinus. Northern Egypt is an important breedingarea for KentishPlovers, with probablyover 1,000 pairs in the Nile Delta lakes (Meiningeret ai.1986) (the largestconcentrations in Lake Manzala) and about 1,900 pairs in Lake Bardawil(Dunnet eta/. 1986). In the areas of Lake Manzala studied in 1990 approximately100 pairswere breeding.Because little informationis availableon the breedingbiology of the KentishPlover for the Mediterraneanregion (Banner- man & Bannerman 1971, 1983; Brosset 1961; Lessells Study area 1984), and especiallyfor the south-easterncorner, these observationsmay increasethe knowledgeof this species.They are also a contributionto the Wader consuming,and when nests were found the incubation StudyGroup KentishPlover Project (J•)nsson eta/. stage of the eggs was not checked.In contrast,adults 1990). were systematicallywatched to determinewhether and howmany chicks they accompanied. Where possible, STUDY SITES at leastone chickfrom any broodwas captured, measured(tarsus with calipers in mm),weighed (with a Data were collectedalong Lake Manzala (c. 31ø15' N, springbalance to the nearestg) and ringed.Weight can 32ø00'E),in the north-easternpart of the Nile Delta, be usedto makean accurateestimate of chickage Egypt.The first site is on the the eastem shore of the (Pineauin prep.).If no chickswere caught,the age of lake,along the roadfrom Ismailiyato PortSaid. Kentish broodswas estimatedfrom their plumage development Ploversbred in disusedsalt pansconverted into fish (Lessells1984). Layingdates were then estimated farms.The secondsite, the mostimportant for Kentish assuminga 30-dayegg laying/incubationperiod Plovers on the northernshore of the lake, is in a com- (Cramp& Simmons1983). plexof ancientlagoons and salt pansbordering the Mediterranean,east of the Damiettalighthouse. The RESULTS AND DISCUSSION latter site was a militaryarea with restrictedaccess. Hatching dates METHODS Fifty-oneKentish Plover broods were foundbetween 23 Observationswere madeon 23 April,from 30 Aprilto Apriland 25 May and at leastone chickcaught from 43 11 May and from 18 to 25 May. Systematicnest of these broods.The estimatedhatching dates of these searcheswere not made becausethey were too time broodsare shownin Figure1. The earliestestimated

63 Table 1. Size of Kentish Plover brood observed in the Nile Delta, Egypt,between 23 Apriland 25 May 1990(Brood size in parentheses).

Esfi mated fro m Hatching dates Brood sizes

[] plurnegedeYelopment of chicks 1 week old 2 weeks old 3 weeks old 4 weeks old [] weightof chicks 1-7 April (•)x•

8-14 April (1)xl (2) x 1 (2) x 2 z (3) x 1

15-21 April (1)xl (1)x4 (2) x 2 (2) x 4 (2) x 1 (3) x 1 mean 1.66 n=9 o 4 11 18 25 2 9 16 2;• ;50 22-28 April (1)x3 (1) x2 March April (2) x 1 (2) x 1 Laying dates (3) x 2 (3) x 1 mean 1.83 mean 1.75 n=6 n=4

Figure1. Hatchingdates of KentishPlover chicks found in the Nile 29 April-5 May (1) x 1 (1) x2 Delta, Egypt, between 23 April and 23 May 1990. (2) x 2 (2) x 2 (3) x 1 (3) x 1 hatchingdate was 7 April.These chickswere already mean 2.0 mean 1.8 13=4 n=5 more than two weeks old at the start of the study period.Because broods of this age tendto be spread 6-12 May (2) x 4 out, it is possiblethat familieswith olderchicks were (3) x 2 missed,and hencethat layingstarted earlier than the mean 2.33 n=6 beginningof March. 13-19 May (2) x 1 The claim of Urban et ai. (1986) that the layingperiod of (3) x I KentishPlover in Egyptcovers only March and April is surprisingfor a birdthat regularlyproduces second and/ 20-23 May (1) x 1 (3) x 1 or replacementclutches (Cramp & Simmons1983). The decrease in the numberof broodshatching during the Total mean: 2.10 1.75 1.70 1.83 secondpart of May in the presentstudy site is more s.d.: 0.78 0.75 0.67 0.75 n: 20 12 10 6 likelythe resultof a lack of time spentsearching for chicksrather than the end of the breedingseason. In Iraq (Marchant1963) and Mediterraneanareas suchas Becauseof the smallsample size, statisticalanalysis is southernFrance (Blondel& Isemann 1981), the inconclusive,but two trends can be suggested: Balearics(Bannerman & Bannerman 1983) and eastern Morocco(Brosset 1961 ), breedingcontinues until early ß there is a slightincrease in broodsize with time of July and August. breeding;

Breeding success ß there is not a pronounceddecrease in broodsize with chicksage (Newman-Keuls,F=0.893, p>O.05), Breedingsuccess could only be estimatedfor the implyingthat chickmortality is low duringthis rearing periodpost-hatching. An unknownproportion of pairs period. failedduring incubation. However, egg collectingdoes not seem to be a common practicein this part of the Broodsize close to fledging (mean 1.83, n=6) is similar Delta, in contrast to Lake Bardawil where it is said to be to that observed elsewhere, at sites where there is a widespreadhabit (Mulli• 1989). much destruction and disturbance of nests and chicks by man (SouthernFrance: mean 1.84, n=45, pers.obs.; Broodsize varied with both hatchingdate and chickage California,USA: mean 1.64, n=21, Page eta/. 1983; (Table 1). NW-Europe:mean 1.5-2.0, Rittinghaus1975).

64 With littlehuman disturbance (military area) and few the WesternPalearctic, Vol. 3. OxfordUniversity Press, naturalpredators (there are no corvidsand few mam- Oxford. malianpredators except Red Fox Vuipesvuipes and SwampCat Fellschaus (Maininger & Serensenin Dunnet,G.M., Cdck, H.Q.P. & Baha el Din, S.M. 1986. prep.),only adverse weather could be responsiblefor BardawilLagoon baseline environmental study and this relativelylow fledgingsuccess. vulnerabilityto oil-pollution.In: Medmaravis& X. Monbaillu(eds.): Mediterranean madne avifauna, pp. CONCLUSION 335-338. SpringerVerlag, Berlin.

The startof the KentishPlover breeding season in J6nsson,P.E., Meininger,P.L., Schulz, R. & Szbkely,T. northernEgypt has beendetermined but its lengthis 1990.The WSG KentishPlover Project. Wader Study not yet known.No informationon successwas obtained GroupBull. 60:1-3. duringthe incubationperiod but fledging success is no better than elsewhere where chicks have to face Lessells,C.M. 1984. The matingsystem of Kentish additionalhazards. Possible threats to this population Plover Charadrius alexandrinus. Ibis 126: 474-483. includehunting (an estimated1,750-1,850 Kentish Ploversare shot annuallyin Lake Manzala, Mulli• Marchant,S. 1963.The breedingof someIraqi birds. 1989) especiallyif the breedingpopulation is the main Ibis 105:516-557. target,and habitatloss due to landclaim (agriculture and fish-farming)(Meininger & Mulli• 1981) and coastal Meininger,P.L. & Atta,G.A.M. (eds.). 1992. Ornithologi- erosion(Sestini 1991 ). cal studiesin Egyptianwetlands 1989/90. WlWO Report,FORE Report,Zeist/Middelburg. ACKNOWLEDGEMENTS Meininger,P.L. & Mullib,W.C. 1981. Thesignificance of The EgyptianWetland Project 1989/90 was a joint Egyptianwetlands for wintering waterbirds. Holy Land projectof the Foundationfor OmithologicalResearch in Conservation Fund, New York. Egypt,the InternationalWaterfowl and Wetlands ResearchBureau and the EgyptianWildlife Service. It Meininger,P.L. & Sorensen,U.G. in prep.Notes on wouldnot have beenpossible without the grantsof the reptiles,amphibians, land mammalsand cetaceansin NationalGeographic Society (grant 4031-89), the Swiss Egypt,1989/90. In: P.L. Meininger & G.A.M.Atta (eds.). "OfficeF•deral de I'Environment,des For•ts et du 1992. Ornithologicalstudies in Egyptianwetlands 1989/ Paysage"through the RamsarBureau, and the Founda- 90. WIWOReport, FORE Report, Zeist/Middelburg. tionTour de Valat.Our colleagues of the Egyptian Wildlife Service were instrumental in the success of the Meiniger,P.L., Sorensen,U.G. & Atta, G.A.M. 1986. project.Rienk Geene, Hans Schekkerman,Frans Thebreeding birds of the lakesin the NileDelta, Egypt. Schepersand Robvan Westrienenhelped to locate Sandgrouse7:1-20. and catchbroods. Peter L. Meiningercommented on an earlierdraft of the manuscript.Finally, I thankKate Meininger,P.L., Sorensen, U.G., Petersen,I.K. & Atta, Lessellsfor critical comments and constructive sugges- G.A.1990. Egyptian wetlands on the verge. IWRB tionsto the presentpaper. News 4:1-2.

REFERENCES Mulli•,W.C. 1989.Bird hunting in Egypt.In: S.M. Goodman& P.L.Meininger (eds.) The Birds of Egypt. Bannerman,D.A. & Bannerman,W.M. 1971. Handbook OxfordUniversity Press, Oxford. to the Birdsof Cyprus.Oliver & Boyd,Edinburgh. Page, G.W., Stenzel,L.E., Winkler,D.W. & Swarth, Bannerman,D.A. & Bannerman,W.M. 1983. The Birds C.W.1983. Spacing out at MonoLake: breeding of the Balearics.Croom Helm, London. success,nest density and predationin the Snowy Plover. Auk 100:13-24. Blondel,J. & Isenmann, P. 1981. Guide des oiseaux de Camargue.Delachaux & Niestl•, Neuchatel. Pineau,O. in prep. Biometricsof KentishPlovers Charadrius alexandrinus in Southern France. Brosset,A. 1961. Ecologiedes oiseauxdu Maroc oriental.Trav. inst. Sci. Ch•rif.(Zoo/.). 22:1-55. Rittinghaus,H. 1975. Seeregenpfeifer,Charadrius a. alexandrinus.In: Glutzvon BlotzheimU.N., Bauer,K.M. Cramp,S. & Simmons,K.E.L. (eds.) 1983. TheBirds of & Bezzel,E. Handbuchder V•gei MitteleuropasBand 6