Dear colleagues,
I am pleased to announce the publication of 2 papers:
Community structure and cluster definition of Atlantic spotted dolphins, Stenella frontalis, in the Bahamas. MARINE MAMMAL SCIENCE, 00(0): 1–17 (2012)
DOI: 10.1111/j.1748-7692.2012.00576.x
And
Replacement dolphins? Social restructuring of a resident pod of Atlantic bottlenose dolphins, Tursiops truncatus, after two major hurricanes. 2011 MARINE MAMMAL SCIENCE 27:39–59, online early publication 2010: DOI: 10.1111/j.1748-7692.2010.00403.x
Find the abstracts below.
Please email me at cindy.elliser@gmail.com for pdf copies.
Thanks for your interest,
Cindy Elliser PhD
Community structure and cluster definition of Atlantic spotted dolphins, Stenella frontalis, in the Bahamas
Abstract:
Fission-fusion dynamics typical of many delphinid populations allow for a variety
of social grouping patterns. Identifying these groupings is crucial before conducting
a detailed social structure analysis. This study analyzed the structure of a population
of Bahamian spotted dolphins, Stenella frontalis. Through long-term observations
and preliminary analysis, three clusters were defined: Northern, Central, and Southern.
To quantitatively investigate these delineations, we conducted analysis on 12 yr
of sighting data using SOCPROG 2.3. Coefficients of association (CoA) were calculated
using the half-weight index, with individuals sighted six or more times per
pooled period (3 yr each). Nonmetric multidimensional scaling (MD), hierarchical
agglomerative cluster analysis and Mantel tests were conducted to determine if any
divisions were present. Mantel tests and MD plots analysis supported the delineations
into the three clusters. Cluster analysis showed cluster groupings, but with
less clear distinctions between the clusters. The amount and strength of associations
were significantly higher within clusters than between clusters. Based on behavioral
and geographic overlap, these clusters did not meet the definition of separate communities
and thus were termed social clusters. These fine scale, within community
divisions, are biologically and socially important aspects of their community and
are crucial in understanding the dolphins’ social structure.
Replacement dolphins? Social restructuring of a resident pod of
Atlantic bottlenose dolphins, Tursiops truncatus, after two major
hurricanes
Abstract:
Environmental variations can influence the structure of ecological communities
that in turn alter the grouping and association patterns of social communities. This
study compares the social structure of bottlenose dolphins in the Bahamas before
and after two major hurricanes. Approximately 30% of regularly seen individuals
disappeared after the hurricanes, with an equal number of immigrants arriving
afterwards. The primary goal of this study was to quantitatively describe social
structure changes occurring after this large-scale emigration (or death) and subsequent
immigration of individuals using the social analysis program, SOCPROG
2.3. The pre-hurricane results revealed one community with association patterns
that were consistent with previous work on this population as well as other welldocumented
populations. Post-hurricane associations revealed that the community
split into two distinct units, whose members associated highly within, but rarely
between units. Association patterns varied between units. Immigrants assimilated
well into the population, especially males. Over half of the post-hurricane associations
involved immigrants, the majority between residents and immigrants, and
primarily involving immigrant males. The costs/benefits of choosing to associate
with an immigrant individual differ between males and females and may have been
the driving force for the changes in social structure that occurred.