AN APPROACH TO CHARACTERIZE THE MAJOR HISTOCOMPATIBILITY COMPLEX DQB IN ORCINUS ORCA
Dzhikiya E.L., (1) Burdin, A. M. (2), Kolesnikov A. A., (3) and Tsidulko G. A. (4)

This study is part of the Far East Research Orca Project studying Orcinus orca in the waters of Kamchatka, Russia. Here we report on the results of an investigation of variation at the MHC class II DQB locus in killer whales. This research was initiated to explore the fitness of Kamchatka killer whales and evaluate their level of DQB polymorphism in relation to other cetaceans. A 172 bp fragment of the DQB gene was amplified and cloned for 2 killer whales. Analysis of ten clones from each animal (Oror11 and Oror17) revealed two unique sequences. While a single sequence was obtained from the Oror11 clones, the Oror17 clones contained two distinct sequences, including one identical to that obtained from Oror11. Alignment of the two DQB sequences revealed 10 variable sites. All substitutions between sequences were nonsynonymous, suggesting that positive selection is acting on the killer whale DQB gene as indicated in other cetacean MHC studies. A neighbor-joining tree was constructed using our sequences and an additional 33 sequences collected from GenBank and representing 18 cetacean species. In the tree, our killer whale sequences clustered with those of small to medium-sized North Pacific delphinids, including Risso’s dolphin, short-beaked common dolphin, Pacific white-sided dolphin and short-finned pilot whale. These results lead to two hypotheses to be tested: 1) These sequences arose before speciation (Hayashi et al., 2003) in delphinids and have been maintained since then. 2) These sequences formed in each species within the group independently in the evolutionary process due to exposure to the same pathogens or other selective forces. Given their worldwide distribution and the existence of sympatric, ecologically different populations killer whales could serve as the model species in cetacean MHC studies.

VARIATION IN SADDLE PATCH PIGMENTATION IN THE KILLER WHALE (ORCINUS ORCA) FROM NORTHWEST (KAMCHATKA, RUSSIA) AND THE NORTH-EAST OF PACIFIC OCEAN
Ivkovich, T. (1), Burdin, A. (2), Sato, H. (3) and Hoyt, E. (4)

An analysis of variation of saddle patch pigmentation was made to compare ecological types of killer whales from the Northeast and Northwest Pacific. Photos taken 1999-2005 of the Avachinsky Bay, Kamchatka, resident fish-eating community (AVR, n=147) and killer whales we called transient (AVT, n=13) were compared to published catalogues of Northeast Pacific killer whales including northern (NR, n=190) and southern (SR, n=79) Vancouver Island resident communities; Alaskan resident (AR, n=202) and transient (AT, n=47) communities; and the Northeast Pacific transient community (T, n=155). Two features were selected in the saddle patch pigmentation, "notch" and "saddle patch length", and classification of variations was worked out (six variations for notch and two variations for length). No differences in saddle patch pigmentation were found between AVR and AR, AVR and NR, AR and NR (p>0.1). Comparisons between SR and other resident populations showed a significant difference (p<0.001). Saddle patch types for transients were similar between AT and T (p>0.1). The resident populations were significantly different from AT and T (p<0.001). Five notch variations were typical for residents but never found in transients. One variation in saddle patch length, typical for transients, was never found in residents. The number of identified animals from AVT was too small for statistical analysis. AVT had one notch variation typical both for residents and transients, one variation in saddle patch length typical only for transients was not encountered in AVR and other resident populations. The variations in saddle patch patterns are consistent with acoustic and association data showing that two genetically distinct populations might visit Avachinsky Bay. We suppose that AVR killer whales are not only ecologically but also genetically closer to residents than to transients from the Northeast Pacific, and killer whales from AVR, AR, NR are closer to each other than to killer whales

THE ECHOLOCATION OF KILLER WHALES DURING HUNTING BEHAVIOR
Lazareva, E. (1), Burdin, A.(2) and Hoyt, E. (3)

The purpose of our work was to measure and analyze the parameters of resident killer whale’s echolocation from the Kamchatka Peninsula. Our data was collected around Starichkov Island in the Central Avacha Gulf of Kamchatka Peninsula. Underwater sound recording was conducted from an inflatable boat using a Sony TCD-D100 DAT recorder with a mono-hydrophone (Offshore Acoustics, Canada; frequency range 10Hz-40kHz) and a mobile hydrophone stereosystem (two hydrophones with a frequency range 300Hz-40kHz). Recordings were made with a sampling frequency 48 kHz. Spectrographic analysis was carried out by Cool Edit Pro 1.2. For all trains we measured: length of the train, number of clicks in the train, interclick intervals and repetition rate (clicks/second). Also we measured regularity of the trains using a coefficient of variation (SD/mean interclick interval). We divided the hunting behavior into “hunting on a salmon” and “hunting on an Atka mackerel”. During the “hunting on an Atka mackerel”  12% of the echolocation trains are buzzes which had such characteristics: the mean interclick interval of this trains is 3,85ms±0,11; these are short trains (length: 0,27±0,02ms) with a fast repetition rate (229,51±5 clicks/sec). We suppose that animals use them only when they are going to catch the fish. Also there are 33% of the trains that are from 0,125ms up to 1 second length: their repetition rate is 89,4±12,4 clicks/sec; the mean interclick interval is 38,16ms±4,33; probably these trains can be used during the fishing pursuit. 62% of the trains were from 1 to 10 sec length (repetition rate 10,49±1,41 clicks/sec) and only 4,6% from all the trains were greater than 10 seconds (length: 16,91±0,88ms), such trains had a lot of clicks (103±14,74) and the average repetition rate was very slow(6,39±0,75), it is possible that these trains are used to detect a fish at the bottom.

VOCAL DIALECTS AND POPULATION STRUCTURE IN KILLER WHALES OF EASTERN KAMCHATKA
O.A.Filatova, A.M.Burdin, E.Hoyt

Investigations of killer whale behaviour in the Eastern North Pacific showed the existence of two ecotypes of killer whales: fish-eating (resident) and mammal-eating (transient). Each resident pod has its own unique repertoire of discrete calls. Pods that share calls belong to the same acoustic clan. Resident and transient whales share no calls and differ greatly by vocal activity, as well as by ecology, social organization and genetics.

Until recently, the vocal repertoire of the Western North Pacific population remained completely unstudied. We now present a description of vocal dialects of killer whales from Eastern Kamchatka (Far East Russia). Materials and data being used for this study were collected in 2000-2005 in Avacha Gulf . Whales were individually recognized through photographic identificatio n. We classified 25 discrete call types and 24 more subtypes - a total of 49 calls. We identified individual group repertoires and measured the similarity of call repertoires between pods by calculating an index of the degree of call sharing. The index values were then used to calculate a dendrogram of the hierarchical structure of acoustic similarity. Most of the groups shared at least one call type with another group, which means that all are members of one clan. One group shared no calls with other groups, and their appearance and behaviour looked like mammal-eating (transient) killer whales from the Eastern North Pacific. These results enable us to suggest the existence of two sympatric populations of killer whales in the Western North Pacific. Through this work, we believe it will be possible to make important comparisons to the well-studied Eastern North Pacific killer whales, which will help to illuminate the function of vocal dialects and unlock the evolutionary mechanisms and the role of social learning or cultural transmission, in dialect formation and development.

CAN KILLER WHALES CALL FOR HELP?
I.D.Fedutin, M.Nagailik, O.A.Filatova, A.M.Burdin, E.Hoyt

Many species of dolphins use cooperative hunting on schooling fish. It is known that some dolphins (for example, dusky dolphins Lagenorhynchus obscurus) call for conspecifics if the number of animals in a group is not large enough to herd the school of fish. For other members of the Delphinidae including the killer whale (Orcinus orca), such behaviour is anecdotal but not well documented although killer whales are known to be cooperative hunters. During our 2005 field season in Avacha Gulf, Kamchatka (Russian Far East) we noted that slowly travelling killer whales started to move very quickly, even porpoising, and then joined some other group which was foraging. On five occasions we made acoustic recordings of vocal exchanges between quickly travelling and foraging animals. We compared the number of different categories of acoustic signals per minute in these recordings with the number of different categories of acoustic signals per minute during the slow-travelling and foraging alone. The number of discrete calls per minute during fast travelling/foraging was significantly higher than during the slow-travelling and foraging alone. The number of whistles and variable calls per minute during fast travelling/foraging was fewer than during the slow-travelling and foraging. Since discrete calls are believed to be long-range communicative signals and whistles and variable calls are usually used during close-range activities, our results indicate that vocal exchanges during fast travelling/foraging may be used for long-range communication. Together with behavioural observations these data could be explained in several ways. One suggested hypothesis is that foraging killer whales can be calling for other members of the group to join them. Another explanation is that traveling killer whales could announce their presence to foraging ones by calling.