Predator Influences on Behavioral Ecology of Dusky Dolphins
I developed a spatially explicit individual-based model (IBM) to capture the dynamic behavioral interaction between a fierce predator (killer whale, Orcinus orca) and a clever prey (dusky dolphin, Lagenorhynchus obscurus), and to answer the ultimate question of costs vs. benefits for dusky dolphins...
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fttexasamuniv:oai:oaktrust.library.tamu.edu:1969.1/ETD-TAMU-2009-05-329 2023-07-16T03:59:23+02:00 Predator Influences on Behavioral Ecology of Dusky Dolphins Srinivasan, Mridula Wursig, Bernd packard, jane grant, william wu, ben 2010-01-16 application/pdf https://hdl.handle.net/1969.1/ETD-TAMU-2009-05-329 en_US eng https://hdl.handle.net/1969.1/ETD-TAMU-2009-05-329 Behavioral Ecology Indirect Predation risk effects Fear Killer whales,dolphins Book Thesis Electronic Dissertation 2010 fttexasamuniv 2023-06-27T22:13:09Z I developed a spatially explicit individual-based model (IBM) to capture the dynamic behavioral interaction between a fierce predator (killer whale, Orcinus orca) and a clever prey (dusky dolphin, Lagenorhynchus obscurus), and to answer the ultimate question of costs vs. benefits for dusky dolphins when making anti-predator decisions. Specifically, I was interested in calculating time/distance budgets for dusky dolphins in the presence/absence of killer whales and the presence/absence of movement and behavioral rules, which presumably evolved in response to spatial and temporal variations in predation risk. Results reveal that dusky dolphins rest less, travel more and have reduced foraging time when killer whales are present. These effects are more pronounced with increased presence of killer whales. The model suggests that a strong reason favoring the adoption of short and long-term anti-predator mechanisms is increased survival resulting from decreased encounters with killer whales. Further, a mother with calf rests less and travels more when killer whales are present relative to a dolphin without calf. However, a mother with calf on average, flee shorter distances and have fewer encounters with killer whales than a dolphin without calf. Thus, despite ecological costs, it makes evolutionary sense for dusky dolphins to adopt anti-predator rules. Bioenergetic consequences for dusky dolphins with and without calf were estimated as total energetic costs and foraging calories lost due to low/high presence of killer whales. I calculated total energy costs as: Foraging costs (FC) Locomotor costs (LC) (Travel) or LC (Travel) LC (Flee) based on the absence, as well as low/high presence of killer whales. Foraging costs contributed significantly to total energetic costs estimated. Travel costs are minimal owing to proximity to deep waters. The total energy costs were not significantly higher from low or high presence of killer whales for mother with calf, but increases by about 90 kcal/day for a dusky without calf. ... Book Killer Whale Orca Orcinus orca Killer whale Texas A&M University Digital Repository |
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Texas A&M University Digital Repository |
op_collection_id |
fttexasamuniv |
language |
English |
topic |
Behavioral Ecology Indirect Predation risk effects Fear Killer whales,dolphins |
spellingShingle |
Behavioral Ecology Indirect Predation risk effects Fear Killer whales,dolphins Srinivasan, Mridula Predator Influences on Behavioral Ecology of Dusky Dolphins |
topic_facet |
Behavioral Ecology Indirect Predation risk effects Fear Killer whales,dolphins |
description |
I developed a spatially explicit individual-based model (IBM) to capture the dynamic behavioral interaction between a fierce predator (killer whale, Orcinus orca) and a clever prey (dusky dolphin, Lagenorhynchus obscurus), and to answer the ultimate question of costs vs. benefits for dusky dolphins when making anti-predator decisions. Specifically, I was interested in calculating time/distance budgets for dusky dolphins in the presence/absence of killer whales and the presence/absence of movement and behavioral rules, which presumably evolved in response to spatial and temporal variations in predation risk. Results reveal that dusky dolphins rest less, travel more and have reduced foraging time when killer whales are present. These effects are more pronounced with increased presence of killer whales. The model suggests that a strong reason favoring the adoption of short and long-term anti-predator mechanisms is increased survival resulting from decreased encounters with killer whales. Further, a mother with calf rests less and travels more when killer whales are present relative to a dolphin without calf. However, a mother with calf on average, flee shorter distances and have fewer encounters with killer whales than a dolphin without calf. Thus, despite ecological costs, it makes evolutionary sense for dusky dolphins to adopt anti-predator rules. Bioenergetic consequences for dusky dolphins with and without calf were estimated as total energetic costs and foraging calories lost due to low/high presence of killer whales. I calculated total energy costs as: Foraging costs (FC) Locomotor costs (LC) (Travel) or LC (Travel) LC (Flee) based on the absence, as well as low/high presence of killer whales. Foraging costs contributed significantly to total energetic costs estimated. Travel costs are minimal owing to proximity to deep waters. The total energy costs were not significantly higher from low or high presence of killer whales for mother with calf, but increases by about 90 kcal/day for a dusky without calf. ... |
author2 |
Wursig, Bernd packard, jane grant, william wu, ben |
format |
Book |
author |
Srinivasan, Mridula |
author_facet |
Srinivasan, Mridula |
author_sort |
Srinivasan, Mridula |
title |
Predator Influences on Behavioral Ecology of Dusky Dolphins |
title_short |
Predator Influences on Behavioral Ecology of Dusky Dolphins |
title_full |
Predator Influences on Behavioral Ecology of Dusky Dolphins |
title_fullStr |
Predator Influences on Behavioral Ecology of Dusky Dolphins |
title_full_unstemmed |
Predator Influences on Behavioral Ecology of Dusky Dolphins |
title_sort |
predator influences on behavioral ecology of dusky dolphins |
publishDate |
2010 |
url |
https://hdl.handle.net/1969.1/ETD-TAMU-2009-05-329 |
genre |
Killer Whale Orca Orcinus orca Killer whale |
genre_facet |
Killer Whale Orca Orcinus orca Killer whale |
op_relation |
https://hdl.handle.net/1969.1/ETD-TAMU-2009-05-329 |
_version_ |
1771547059808108544 |