Second report on research on the Great Knot tenuirostris on the breeding grounds

Pavel Tomkovich

Tomkovitch,P.S. 1995. Second reporton researchon the Great Knot Caliddstenuirostds on the breedinggroundsø Study Group Bullo78: 50-52. [Reprinted,with acknowledgement, from The Stilt 26: 58-60; 1995]. P. So Tomkovich,Curator of ,Department of Ornithology,Zoological Museum of Moscow State University,Moscow, Russia.

INTRODUCTION It was necessaryto use a helicopterto reach base camp from Markovo village as no other transport method was Reproducedbelow is the edited reportof Pavel Tomkovich possibleat the time. It was possibleto travel up the river on his continuingresearch on breeding Great Knots (for by motor boat (a much cheaperform of transport)just one first reportsee St/It24)• This studyhas again been funded week later, by that time the majorityof Great Knots had by the AustralianNature ConservationAgency (ANCA)o begun breeding.

PROJECT PARTICIPANTS RESULTS

Pavel S. Tomkovichand Dmitry EoTe (Assistant),student Site faithfulness and mate fidelity of the Zoology Department,Moscow Pedalogical Museum. The individualcolour-marking of 12 adult breedingGreat Knots(one knownfemale and 11 supposedmales) from STUDY AREA the study area in 1993 made it possibleto recorda degree of their site faithfulness. Nine of these birds (75%) were found back in the study area; and individuallywithin the Studiescontinued in the same are where the projectwas same parts of the area, with a presumed relationshipto initiated in 1993; on the eastern spur of the Shchuchy defended pre-breedingareas. It is inferredfrom this that MountainRange, north-eastern Siberia (64 ø 55'N,168 ø most, if not all, survivingadult males returnannually to 35'E). their former breeding sites.

Both adults of a colour-marked pair returned to their LOGISTICS former territory,nesting some 125 metres from the nest site of the previousseason. As only one knownfemale It was plannedto reachthe base camp at the mouth of the was marked it is not possibleto draw any definite BalaganchickRiver, a tributary of the Anadyr River, on or conclusions about female site faithfulness from this. about 20 May 1994 - before or at the time of arrival of Additionalbirds, includingfemales, were marked in 1994, Great Knots, in orderto obtain data on the ecologyof thus it may be possibleto obtain more reliable results in these birds beforethe commencementof breeding,as this 1995. has not previouslybeen studied. However,because bad weather conditionsprevented plane and helicopterflights, As would be expectedto a species which is presumed not it was not possibleto reachthe base camp until31 May. to breed until at least the age two, none of the 29 Great As a result it took a total of 20 days to travel from Moscow Knot chicks banded in 1993 were seen in the natal area in to the base camp, thus reducingthe time availablefor 1994. However, one chick banded in 1993 was recovered studiesduring the pre-breedingperiod and restrictingthe on 3 June 1994 from Aniva Bay in SouthernSakhalin, general Great Knot studiesto the period 1 June to therefore at least some one year old Great Knots 2 August. With travel time includedthe expeditionlasted undertakea northwardmigration and probablyover- from 11 May to 8 August 1994. summer on the shores of the Sea of Okhotsk.

50 Breeding density departedin the lastthird of July, after accompanyingtheir chicksfor 24 to 30 days. It would appear that the slower Thesame study area as that of 1993of 9.5 - 10 km2 of growth rate of chicks in 1994 resulted in the departureof montane lichentundra was used for densitycalculations. young both separatelyfrom parent males, and somewhat In 1993 the area was occupiedby 13 broodsand in 1994 later than in 1993 (33 days was the maximumage of a twenty-fourbroods, and two unsuccessfulnests were young in 1994 comparedwith 30 days in 1993). found. The most intensivelystudied area, a plateauof circa1 km2 nearthe basecamp, was inhabited by three Breedingsuccess broodsin 1993, and by six pairs and three unpaired territorialmales in 1994. Flocks of feeding birdswere also In 1994 chicks hatched in three of five nests under noted to be larger through-outthe 1994 season. observation.One nestwas deserted(the female may have perished,the colour marked male was observedlater Taking into accountthe knownstrong site-faithfulness of in pre-departingflocks), and one was predated. It would this speciesit is presumedthat the dramatic increasein appear howeverthat the majority of clutcheshatched densityof breedingbirds was due to immigrationof first- successfullybut this was not the case with broods. Eight year breedersinto the local population.Such an of the 20 broods under more or less regular observation immigrationcannot howeverby explainedby a good chick disappeared,most probablythese chicksdied. At the productionyear two years previously,on the contrary same time mean broodsize at fiedgingor a few days later 1992 was a poor breedingseason, and thereforethese did not differ much betweenyears (2.5 young per brood numbersmust be attributedto local conditions. High falls (n=8) in 1993, and 2.3 (n=12) in 1994). In total at least 29 of snow in the upperand middlereaches of the Anadyr juveniles fledged of the 62 chicks banded in 1994. These River in 1994 probablyled to a lack of suitablebreeding resultsshow a slightlyhigher mortality rate of chicksin habitatsin that area, however,by luck,the mountain 1994, neverthelessthe overall breedingsuccess was fairly range withinthe studyarea was uniquelyfree from large good. The higherlosses of eggs and chicksin 1994 can areas of snow in early June 1994 and thereforeprobably be at least partlyexplained by the greater numberof attractiveto first-yearbreeders. It is of interestto note mammalian predators( Mustellaerrninea and Martes that one marked male which had raised a brood in 1993 zibeilina)following the increasein the rodentpopulation in was left unpairedin 1994. 1993 and 1994, however,this can not explainall brood losses. It is presumedthat the increasedbreeding density of Great Knots in 1994 will continuein 1995, thus making Food and food resources further studies in 1995 even more attractive. Several adult and fledgedyoung Great Knotwere Phenology collected(under permitfrom the Russianauthorities) outsidethe study area from mid June to early August It is knownthat egg laying began in early June however 1994. Preliminaryanalysis of the stomachcontents of data on hatchingdates are more precise and allow for these birds and of casualtiesof downyyoung and comparisonsto be made with the previousseason and for collecteddroppings has given an unexpectedresult. It is accuratelydefining the breedingseason. Hatchingtook apparent that to a large extent these birds were feeding on place from about25 June to 9 July, with most broods plants. Only small chicksfeed exclusivelyon hatchedin very early July. This is similarto the timing of (Carabid beetles),while the food of chicksafter one week hatchingin 1993. More precise hatchingdates will be of age and adultsconsisted of berries(Arctous alpina, obtainedby back calculationsfrom measurementsof Empetrumnigrum, Vacciniumuliginosum), old ones in chicks from 21 broods. June and new green ones in July/August. This appearsto be uniqueamong Calidridspecies. Three nests were found with incompleteclutches, allowing intervalsbetween the laying of successiveeggs to be On the basis of this findingwe can assume that (1) determinedabout five days to completea clutchof four distributionand/or densitiesof Great Knotsin alpine eggs. Unfortunatelyonly one of these nests survivedto habitatscan be directlyrelated to the distributionof berry hatching,and this had an incubationperiod of 21 days for producingplants, and (2) fledgingsuccess of the species the last egg. dependson the availabilityof surface-activeinsects and on the crop of berries. Repeated measurementsof chicksrevealed slower developmentin 1994 in comparisonwith 1993. In at least If the latter suppositionis correct,it providesan some broodsfiedging took 23 to 25 days in 1994, explanationfor the reducedgrowth rate and increased comparedwith 20 to 21 days in 1993. chick mortalityin 1994. It was hot in June and cool in July with rain periodsfor several days in 1994 in the study Large scale movementsof Great Knots began in late June area, just the oppositeto the situationthere in 1993. As a 1994, however,the majorityof the populationdeparted on result the pitfalltraps set in 1994 revealed a peak in 1 and 2 July. The first wave of migrationconsisted of arthropodnumbers, especially of beetles, in the second birdswhich were recognisedfailed-breeders, unmated half of June and a markeddecrease in early July. males, and females which had deserted their mates at the Therefore the hatchingof the chicks in 1994 did not time of hatching. Successfulbreeding males mainly coincidewith the peak numbersof beetles- the main

51 chick food. A lack of proteincould result in the reduced Materials of the Working Group on of the growth rate of chicks. Measuringof arthropodabundance CIS. Two papers on the breedingrange and throughthe next season (1995) in the same place will help migrationof Great Knot in Russia are in preparation to check this hypothesis. for possiblepublication in an international ornithologicaljournal and a set of slides with a note Crops of berrieswere not large in the alpine tundra of the about breedingdistribution and biologyof the Great study area in 1994, but this have been differenton other Knot was submittedto Dutch B•)'ding. mountains. We can only speculatethat the disappearanceof broods in the study area was due to the low numbers of berries there in addition to the low FURTHER PLANS FOR STUDIES abundanceof beetles• No surveysof berrieswere undertaken in other areas in 1994 but it would be useful to A unique knowledgeof various aspects of the distribution do so in 1995. and breedingbiology of the Great Knot has been built up over the last two years of the project. It has become clear that the mountainsof the upper Anadyr River are ideal as OTHER ACTIVITIES an area for studiesof the Great Knot at the breeding grounds. The speciesis a difficultone to study, primarily a• At least 270 adult waders of 18 species, mostly becausethe birdsare scatteredacross many mountain Great Knot, Common SandpiperActitis hypoleucos, tops or plateaux. Therefore it is necessaryto undertake Terek SandpiperXenus cinereusand Pacific Golden studiesover severalseasons in orderto obtain meaningful Plover Pluvialisfulva, were checkedfor colour-flags results. or bands near Anadyr airport;in Markovo; and in the vicinity of the base camp. One Great Knot Some aspectsof the breedingbiology of the speciesare wearing a foreignband (probablyan Australianone) now fairly well understood(breeding and departure on the righttarsus was detected. The bird was an phonology,mating and parental care systems,growth of unmated male, holdinga territoryon the study area chicks,etc.), but others need furtherstudy. The main gap plateau. Observations of this bird revealed concernsthe arrival dates and pre-breedingperiod, information on the local movements and behaviour althoughother aspects of missing informationhave been of an unmated male Great Knot. It was last raised in this report. Data on year to year variations in observedon 1 July, in a large flock beforedeparture breedingphonology, distribution, density, and breeding to the southø successare such aspectswhich are of interestand importance. A total of 224 birds of 26 species, mainly waders (122 birds of nine species)and passerineswas Because of the above it is consideredimportant that at banded. The waders banded were: 82 Great Knot least a third year of these studies be undertaken. (20 adults, 62 chicks), 12 PacificGolden Plover, Knowledgeof the area and of the speciesrequirements eight Ringed Plover Charadriushiaticula, five Terek will lead to a greaterunderstanding of what is necessary , four Temminck'sStint Calidris to ensure its continued survival. temminickii, four Red-necked Stint Co ruficollis,three CommonSandpiper, three SolitarySnipe solitaria,and one Wood Sandpiper Tringaglareola. Most of these birds were fitted with red and white "Darvic"flags or colour pendantsattached to the metal bands.

The study of the poorly known local bird fauna was continued;77 species were recorded in 1994, including11 previouslyunrecorded. Breedingby three new specieswas also recorded. Of particular interestwas the breedingrecord of a Red-necked Stint, on the edge of its known breedingrange. Records of the Western Sandpiper Calidrismauri in May and August near the Anadyr airport are new for that area, and are outsidethe knownbreeding range of this nearcticspecies. d. Data on the distribution,numbers, and some aspects of the breedingbiology of the Pacific Golden Plover and SolitarySnipe were obtainedin the alpine tundra and adjacent habitats. e. A note on the breedingrecord of SolitarySnipe in north-easternSiberia was publishedin 'Information •rcat Knot

52