A recent long-term stu­dy reports on the deve­lo­p­ment of the three brush-tail­ed pen­gu­ins: Adé­lie, Chin­strap and Gen­too pen­gu­ins on the South Ork­ney Islands. The stu­dy com­pa­res their situa­ti­on with the popu­la­ti­on deve­lo­p­ment around the Ant­ar­c­tic Pen­in­su­la. The sci­en­tists can look back on a con­ti­nuous cen­sus data set of 38 years, sin­ce 1978/79. Pre­vious­ly only spo­ra­dic counts were done. While the popu­la­ti­ons of Adé­lie and Gen­too pen­gu­ins were sub­ject to regu­lar fluc­tua­tions, the num­ber of Chin­strap pen­gu­ins decreased ste­adi­ly. Howe­ver, the Adé­lie pen­gu­in colo­nies were also decre­asing. The Gen­too pen­gu­ins did rela­tively well over the years, their num­bers were incre­asing – a trend that is also obser­ved at the Ant­ar­c­tic Pen­in­su­la. The rese­ar­chers explain the obser­ved fluc­tua­tions with a lively exch­an­ge of nes­t­ing birds bet­ween colo­nies of the archi­pe­la­go. At pre­sent, Adé­lie, Chin­strap and Gen­too pen­gu­in popu­la­ti­ons at the South Ork­neys are esti­ma­ted to be about 200,000, 600,000, and 5000-10,000 bree­ding pairs, respec­tively.

Today it is assu­med that a chan­ge in popu­la­ti­on size can be a good indi­ca­tor of chan­ges in the eco­sys­tem. This is rese­ar­ched in a num­ber of krill-eating spe­ci­es, e. g. also the brush-tail­ed pen­gu­ins. The Com­mis­si­on for the con­ser­va­ti­on of Ant­ar­c­tic mari­ne living resour­ces (CCAMLR) uses this data to moni­tor the mari­ne Eco­sys­tem. With that they can set catch limits for the krill and fish fishe­ries.

All three spe­ci­es are bree­ding tog­e­ther on Signy Island, South Ork­ney Islands. While the bree­ding suc­cess of all spe­ci­es is equal­ly good or bad over the years in the obser­ved peri­od, the popu­la­ti­on deve­lo­p­ment is dif­fe­rent. Sin­ce the begin­ning of the con­ti­nuous cen­sus Adé­lie pen­gu­ins decreased by 42% and Chin­strap pen­gu­ins by 68%. In the same peri­od, the ori­gi­nal­ly much smal­ler Gen­too pen­gu­in popu­la­ti­on increased by 255%! His­to­ri­cal data show a com­ple­te­ly dif­fe­rent trend bet­ween 1947 and 1978: the num­bers of the first two spe­ci­es increased enorm­ously during this ear­ly peri­od.

Accor­ding to some sci­en­tists, the popu­la­ti­on deve­lo­p­ment seems to be cor­re­la­ted to the regio­nal decli­ne in sea ice ext­ent and the long-term warm­ing of the regi­on. Howe­ver, the rese­ar­chers of the pre­sent stu­dy are loo­king a bit deeper into the con­text, becau­se ice-loving Adé­lie pen­gu­ins and ice-avo­i­ding chin­strap pen­gu­ins are sub­ject to the same decli­ne. They point out that the sur­vi­val rate of the young pen­gu­ins during their first win­ter, the access to krill stocks and the increase in fur seal num­bers and wha­les as food com­pe­ti­tors in the area, also seem to play a major role. Bet­ween 1977 and 1994, the num­ber of fur seals increased ten­fold at Signy Island.

In order to gain a bet­ter under­stan­ding for the decli­ne of one spe­ci­es and the suc­cess of ano­ther, rese­ar­chers have to look into the dyna­mics of the sys­tem even deeper. Their long-term data of the last deca­des and data from other field of sub­jects are important com­pon­ents for future models and under­stan­ding of the pro­ces­ses obser­ved.

Many ant­ar­c­tic visi­tors have enjoy­ed the hos­pi­ta­li­ty of the Ukrai­ni­an Ver­nad­sky Base. Now you can visit Ver­nad­sky wit­hout actual­ly tra­ve­ling to Ant­ar­c­ti­ca: the­re is now a new, com­ple­te pan­ora­ma tour of the base on this web­site, from sel­ec­ted sci­en­ti­fic working are­as to the famous Fara­day Bar. Click here and have fun!

North-West of the Ant­ar­c­tic Pen­in­su­la the South Shet­land Islands are situa­ted. Here rese­arch sta­ti­ons of many count­ries are gathe­ring, becau­se some of the islands are easy to reach by ship and the­re are rela­tively lar­ge ice free are­as. During the last deca­des the cli­ma­te has beco­me noti­ceable war­mer inWest-Ant­ar­c­ti­ca, par­ti­cu­lar­ly at the Pen­in­su­la. Some peo­p­le are com­pa­ring the sum­mer wea­ther of the South Shet­land Islands alre­a­dy with the sum­mer wea­ther at the Falk­land Islands.

The lar­gest island of the South Shet­lands is King Geor­ge Island. It is appro­xi­m­ate­ly situa­ted 1000 km South of Cape Horn. One-tenth of the island is free of ice and offers suf­fi­ci­ent space for 24 rese­arch sta­ti­ons and refu­ges of 12 nati­ons. 8 sta­ti­ons are ope­ra­ted all year long. Ger­man rese­ar­chers are regu­lar­ly in the area during sum­mer time. On King Geor­ge Island, many bio­lo­gists tend to work. They obser­ve the scar­ce plant life. Others ana­ly­se ter­restri­al-mari­ti­me food chain con­nec­tions or stu­dy mari­ne habi­tats. Orni­tho­lo­gists usual­ly work with pen­gu­ins or sku­as. But all sci­en­tists usual­ly also have an eye for unu­su­al occur­ren­ces.

Polish rese­ar­chers have been stu­dy­ing bird­life at the South Shet­land Islands for almost 40 years, sin­ce their sta­ti­on ope­ned for the first time in 1977. In 1981, White-rum­ped sand­pi­pers (Calid­ris fusci­col­lis) were obser­ved for the first time on Ard­ley Island, a small tidal island in Max­well Bay. Howe­ver, this does not mean that this spe­ci­es has not visi­ted the area befo­re. The obser­va­ti­on pro­gram only got star­ted in 1977. Sin­ce then small groups or sin­gle birds have appeared in the regi­on. Over an peri­od of 30 years, the­se small waders were obser­ved during twel­ve years. In eight of the­se cases spring was war­mer than usu­al.

White-rum­ped sand­pi­pers are migra­to­ry birds of super­la­ti­ves, like the Arc­tic tern. They breed in the Arc­tic tun­dra of North Ame­ri­ca. Within a month, the birds migra­te in big flocks to the South, almost wit­hout rest. Rea­ching the coast of Suri­na­me, they then turn in to the con­ti­nen­tal rou­te and cross the Bra­zi­li­an Ama­zon regi­on. In Octo­ber they arri­ve in their win­tering are­as in Argen­ti­na and Chi­le. The most rest­less indi­vi­du­als con­ti­nue fur­ther and spend the win­ter in Tier­ra del Fue­go or the Falk­land Islands. Why some indi­vi­du­als would head for islands in the cold Ant­ar­c­tic waters, such as South Geor­gia, South Ork­ney, or South Shet­lands, the rese­ar­chers begin to under­stand slow­ly.

In con­trast to other regi­ons of the Ant­ar­c­tic con­ti­nent, the Ant­ar­c­tic Pen­in­su­la expe­ri­en­ces a rapid, dra­ma­tic warm­ing. Mea­su­re­ments of avera­ge sum­mer tem­pe­ra­tures resul­ted in an increase of 2 degrees, the avera­ge tem­pe­ra­tures for the win­ter are yet 5-6 degrees hig­her than 50 years ago. Lower win­ter tem­pe­ra­tures and the exis­ting hole in the ozone lay­er are respon­si­ble for less fre­quent but stron­ger peri­odi­cal wes­ter­ly­cy­clo­ne sys­tems. They trans­fer warm, moist, mari­ti­me air to the coast of the Pen­in­su­la inclu­ding a num­ber of fea­the­red vagrants.

In addi­ti­on, the sea­son with sea-ice cover is about 90 dayss­horter than 4 deca­des ago. At the Ant­ar­c­tic Pen­in­su­la, the sea ice arri­ves later and dis­ap­pears ear­lier. All this are pre­con­di­ti­ons for fau­nal and flo­ral chan­ge over the coming deca­des. This is espe­ci­al­ly the case for the most nor­t­her­ly spur of the Ant­ar­c­tic: the South Shet­land Islands.

So it is no big sur­pri­se that even during in Janu­ary this year, atten­ti­ve gui­des and tou­rists at King Geor­ge Island have been spot­ting a small flock of White-rum­ped sand­pi­per. They report them “fora­ging on mud in the out­flow stream from a melt­wa­ter pond. The amount of time they spent res­t­ing calm­ly and pree­ning sug­gested that they were not despe­ra­te for food.” (Ste­phen F. Bai­ley auf M/V Aka­de­mik Ser­gey Vavil­ov, in: IAATO-News­let­ter)