Distribution and Local Movement of Humpback Whales in Okinawan Waters Depend on Sex and Reproductive Status
| Autor: | Keisuke Kato, Hirokazu Miyahara, Isao Kawazu, Senzo Uchida, Hidehiro Kato, Gen Nakamura, Nozomi Kobayashi, Naoto Higashi, Haruna Okabe |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Male
0106 biological sciences Aging Time Factors Distribution (economics) Biology 010603 evolutionary biology 01 natural sciences Humpback whale Animals West coast Reproductive ecology Transect Ecosystem Humpback Whale Pacific Ocean business.industry 010604 marine biology & hydrobiology biology.organism_classification Fishery Habitat Animal Migration Female Animal Science and Zoology Seasons business Animal Distribution |
| Zdroj: | Zoological Science. 34:58-63 |
| ISSN: | 0289-0003 |
| DOI: | 10.2108/zs160012 |
| Popis: | The distribution and local movement patterns of humpback whales in waters off the west coast of Okinawa Island, southwest Japan, were investigated using line transect and photo-identification methodologies. Line transect surveys were conducted from 2011 to 2014 and photo-identification survey from 2006 to 2012. During the surveys, humpback whales aggregated in the areas around Ie and Kerama Islands, and tended to travel along the inshore coast of Okinawa Island when they move locally between those two sites. A total of 496 humpback whales of the known sex were photo-identified (322 males, 75 females and 99 females with a calf). Of these, 24.8% were confirmed moving locally between the sites of Ie and Kerama Islands within the same season. Frequency rates of the local movement for males, females and females with a calf were 41.9, 25.0, and 15.1%, respectively; the frequency of local movement for males was significantly higher than that for females and females with a calf. These results indicate that male humpback whales tend to move more actively between the local breeding sites as compared to females and females with a calf. We speculate that the males search for more opportunities to mate, whereas females with a calf tend to remain in the same areas to nurse their calves. These findings extend our knowledge of the habitat use and reproductive ecology of humpback whales in Okinawan waters, which remain poorly understood. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|