Package Name: aschettino_strata_HI_RES_p_electra

Population size and structure of melon-headed whales (Peponocephala electra) around the main Hawaiian Islands: Evidence of multiple populations based on photographic data

Metadata:

• Identification_Information
• Spatial_Data_Organization_Information
• Entity_and_Attribute_Information

Identification_Information:

Citation:

Citation_Information:

Originator:

Jessica Aschettino, Hawai‘i Pacific University (Hawaii) and Cascadia Research Collective (Olympia, Washington)

Publication_Date: May, 2010

Title:

Population size and structure of melon-headed whales (Peponocephala electra) around the main Hawaiian Islands: Evidence of multiple populations based on photographic data

Online_Linkage: https://cascadiaresearch.org/wp-content/uploads/2018/01/Aschettino_et_al_2011.pdf

Description:

Abstract:

To assess population size and movements of melon-headed whales (Peponocephala electra) in Hawai‘i, more than 40,000 photos were collected from 47 encounters around the Main Hawaiian Islands between 2002 and 2009, and additional photos were obtained from collaborators from 1986 – 2001. Using only good quality photographs, there were 1,433 unique individuals in the photoidentification catalog, of which 1,046 were distinctive. Of these, 330 (31.5%) were seen on more than one occasion. Re-sighting data combined with social network analyses showed evidence of two distinct populations – a smaller, resident population, seen exclusively off the northwest region of the island of Hawai‘i, and a much larger Main Hawaiian Islands population, seen throughout the entire range of the Main Hawaiian Islands. Depth of encounters with the resident population were significantly shallower (median = 381 m) than those with the Main Hawaiian Island population (median = 1,844 m). Re-sightings of individuals have occurred up to 22 years apart for the Hawai‘i resident population and up to 13 years apart for the Main Hawaiian Islands population, suggesting long-term residency for both populations. Abundance estimated through mark-recapture analyses (corrected for the non-distinctive individuals), was 447 (CV = 0.12) for the Hawai‘i residents and 5,794 (CV = 0.20) for the Main Hawaiian Islands population.

Purpose:

"Despite the presence of melon-headed whales in tropical and sub-tropical waters worldwide, little is known about this species. Melon-headed whales frequent offshore waters surrounding the Main Hawaiian Islands where aerial surveys by Mobley and colleagues suggest a relatively small population (154 individuals (CV=0.88)). A 2004 near mass-stranding in Hanalei Bay, Kaua‘i occurred when an embayment of 150 – 200 animals coincided with naval mid-frequency sonar use. Photo-identification studies were conducted to assess population size and movements in the main Hawai‘ian Islands"

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 1986-2009

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: Unknown

Keywords:

Theme:

Theme_Keyword: melon-headed whale

Theme_Keyword: Peponocephala electra

Theme_Keyword: distribution

Theme_Keyword: abundance

Theme_Keyword: density

Theme_Keyword: population structure

Theme_Keyword: mark-recapture estimates

Place:

Place_Keyword: Hawaii

Stratum:

Stratum_Keyword: main Hawaiian Islands

Data_Set_Credit:

Aschettino, J.M. 2010. Population size and structure of melon-headed whales (Peponocephala electra) around the main Hawaiian Islands: evidence of multiple populations based on photographic data. M.Sc. Thesis, Hawai‘i Pacific University. 117 pp.

Spatial_Data_Organization_Information:

Point_and_Vector_Object_Information:

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: aschettino_strata_HI_RES_p_electra

Attribute:

Attribute_Label: FID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: Name

Attribute_Definition: Area Name

Attribute_Definition_Source: Jesse Cleary

Attribute:

Attribute_Label: N

Attribute_Definition: abundance

Attribute_Definition_Source: Jesse Cleary

Attribute:

Attribute_Label: CV

Attribute_Definition: coefficient of variation

Attribute_Definition_Source: Jesse Cleary

Attribute:

Attribute_Label: D

Attribute_Definition: Animal density

Attribute_Definition_Source: Jesse Cleary

Attribute:

Attribute_Label: L90

Attribute_Definition: lower bound 90% confidence interval

Attribute_Definition_Source: Jesse Cleary

Attribute:

Attribute_Label: U90

Attribute_Definition: upper bound 90% confidence interval

Attribute_Definition_Source: Jesse Cleary

Attribute:

Attribute_Label: Dens_n_km2

Attribute_Definition: column used for internal cetmap symbology generation

Attribute_Definition_Source: Jesse Cleary