21 research outputs found
Whales, dolphins, and porpoises of the eastern North Pacific and adjacent Arctic waters: a guide to their identification
This is an identification guide for cetaceans (whales, dolphins, and porpoises), that was designed to assist laymen in identifying cetaceans encountered in eastern North Pacific and Arctic waters. It was intended for use by ongoing cetacean observer programs. This is a revision of an earlier guide with the same title published in 1972 by the Naval Undersa Center and the National Marine Fisheries Service. It includes sections on identifying cetaceans at sea as well as stranded animals on shore. Species accounts are divided by body size and presence or lack of a dorsal fin. Appendices include illustrations of tags on whales, dolphins, and porpoises, by Larry Hobbs; how to record data from observed cetaceans at sea and for stranded cetaceans; and a list of cetacean names in Japanese and Russian. (Document contains 245 pages - file takes considerable time to open
Whales, dolphins, and porpoises of the western North Atlantic: a guide to their identification
This is an identification guide for cetaceans (whales, dolphins, and porpoises). It was designed to assist laypersons in identifying cetaceans encountered in the western North Atlantic Ocean and was intended for use by ongoing cetacean observer programs. This publication includes sections on identifying cetaceans at sea as well as stranded animals on shore. Species accounts are divided by body size and presence or lack of a dorsal fin. Appendices cover tags used on cetacean species; how to record and report cetacean observations at see and for stranded cetaceans; and a list of contacts for reporting cetacean strandings. (Document pdf contains 183 pages - file takes considerable time to open
Ballenas, delfines y marsopas del Pacifico nororiental y de las aguas árticas adyacentes
Esta guía de campo se ha diseñado para que los observadores puedan identificar los cetáceos (ballenas, delfines y marsopas) que vean en las aguas del Pacifico nororiental, incluyendo el Golfo de California, Hawaii y el Ártico occidental de Norteamérica. Los animales descritos no se agrupan por sus relaciones científicas sino por las similitudes de su apariencia en el campo. Las fotografías de los animales en su ambiente natural son la principal ayuda para su identificación. Los anexos describen como y a quienes se debe reportar la información sobre cetáceos vivos y muertos y proveen detalles para ayudar en la identificación de los cetáceos varados
CATCHES OF HUMPBACK AND OTHER WHALES FROM SHORE STATIONS AT MOSS LANDING AND TRINIDAD, CALIFORNIA, 1919–1926
Catches of Humpback and Other Whales from Shore Stations at Moss Landing and Trinidad, California, 1919-1926
Logbook data from California shore whaling stations at Moss Landing (1919-1922 and 1924) and Trinidad (1920 and 1922-1926) are analyzed. The logs for the two stations record the taking of 2,111 whales, including 1,871 humpbacks, 177 fin whales, 26 sei whales, 3 blue whales, 12 sperm whales, 7 gray whales, 1 right whale, 1 Baird’s beaked whale, and 13 whales of unspecified type (probably humpbacks). Most whales were taken from spring to autumn, but catches were made in all months of some years. The sex ratios of humpback, fin, and sei whales (the three species with sufficient sample sizes to test) did not differ from parity. Primary prey, determined from stomach contents, included sardines and euphausiids for both humpback and fin whales, and “plankton” (probably euphausiids) for sei whales. The prevalence of pregnancy was 0.46 among mature female humpbacks and 0.43 among mature female fin whales, although these values are reported with caution. Information on length distribution for all species is summarized. Analysis of the catch data for this and other areas supports the current view that humpback whales along the west coast of the continental United States comprise a single feeding stock and also suggests that the present population is well below pre-exploitation levels
Evidence of a Possible Decline since 1989 in False Killer Whales (Pseudorca crassidens) around the Main Hawaiian Islands.
v. ill. 23 cm.QuarterlyRecent evidence indicates that there is a small, demographically isolated, island-associated population of false killer whales (Pseudorca crassidens) around the main Hawaiian Islands. Although it is known that false killer whales in Hawai‘i are sometimes killed or seriously injured in the Hawai‘i-based longline fishery, it is not known whether such interactions have resulted in a reduction in population size or whether other factors have been negatively influencing population size. We report the results of an aerial survey in June and July 1989, the purpose of which was to obtain a minimum count of the number of false killer whales around the main Hawaiian Islands. The false killer whale was the third most commonly seen species of odontocete off the island of Hawai‘i during the survey, representing 17% of sightings. Groups of more than 300 individuals were seen on three different days, with minimum counts of 380, 460, and 470 individuals in these groups. The encounter rate, relative species ranking, and average group size from the 1989 survey were all substantially greater than those from more recent aerial and ship-based surveys. The largest group observed in 1989 (470) contained almost four times as many whales as estimated for the entire main Hawaiian Islands from recent aerial surveys (121 individuals, CV ¼ 0.47) or mark-recapture analyses (123 individuals, CV ¼ 0.72). Therefore, the population of false killer whales around the main Hawaiian Islands may have declined substantially since 1989. The cause or causes of such a decline are uncertain
Nesting Green Sea Turtles (Chelonia mydas) on Isla Clarion, Islas Revillagigedos, Mexico
Nesting green sea turtles (Chelonia mydas) on Isla Clarión, Islas Revillagigedos, Mexico by Frank T. Awbrey, Stephen Leatherwood, Edward D. Mitchell, and William Rogers. Bull. Southern California Acad. Sci., 83(2):69-75, 1984. Locations of green sea turtle (Chelonia mydas) nests were mapped and their density determined during beach surveys of Bahia Sulfur, Isla Clarion, Islas Revillagigedos, Mexico, conducted 9-1 1 October 1976. Based on 80 nests less than one year old in six sample quadrats, nest density was estimated as 0.027/m2. One old nest contained 76 spent eggs. At two other nests 89 and 92 hatchings were counted as they emerged. Possible annual turtle productivity in suitable areas of West Beach, Bahia Sulfur is estimated as 2.4 hatchlings/m-. Predation of hatchlings by ravens, various fishes, and possibly bottlenose dolphins was observed. At least 1 3 female turtles visited the beach during the three days. Several copulating pairs were observed and photographed