Assessing Humpback Whale Body Condition Using Drones

Question 1

Describe humpback migration patterns

Answer 1

Humpbacks migrate from Winter breeding grounds (West Indies) to Summer feeding grounds (North Atlantic)

Question 2

What are some observations that have been made about the humpback whales in New York?

Answer 2

• Less understood habitat use
• Inshore sightings are predominantly juveniles
• Lunge feed on menhaden

Question 3

What are some challenges to studying marine mammals?

Answer 3

• Large
• Live underwater
• Free-swimming
• Often expensive to study
• Heavily migratory
• Need tons of permitting

Question 4

What are some methods for studying marine mammals?

Answer 4

• Photo-identification
• Focal observations
• Tagging & tracking
• Acoustics (passive / active)
• Biopsies / genetics
• Drones

Question 5

What are the advantages of using drones to study marine mammals?

Answer 5

• Low cost
• Adaptable to many research projects
• Increased perspective (“birds-eye view)
• Non-invasive
• Can be operated from land or boat

Question 6

What have drones been used to look at?

Answer 6

• Abundance
• Genetics
• Health metrics
• Body condition

Question 7

What was Chelsea Napoli’s research goal?

Answer 7

Assess the health of humpback whales in New York

Question 8

How did Chelsea conduct her research?

Answer 8

Measuring body condition

Question 9

Body condition

Answer 9

• General term for the energy reserves accumulated in an animal’s body
• Proxy for health
• Fat whales = successful whales / more energy
• More energy = increased foraging, reproduction, migration etc.

Question 10

Why does body condition matter for humpback whales?

Answer 10

• Migration
• Summer: forage in high latitudes (accumulating lots of energy)
• Winter: fasting, reproduction and calving in low latitudes (using a ton of energy)

Question 11

What methods did Chelsea use to conduct her research?

Answer 11

1. Fly drone over whales
2. Identify individuals from video
3. Screenshot for measurement
4. Measure with morphometrix
5. 3D model for body volume est.
6. Calculate body condition index

Question 12

Describe a day in the field for Chelsea Napoli

Answer 12

• 5am: arrive at Stony Brook Southampton Marine Station
• Pack cameras, drone, field gear & snacks onto R/V Parker
• Start searching for whales
• When found: focal follows for camera ID and drone flight
• Sightings data collection for all marine mammals

Question 13

What factors are important for a good day in the field?

Answer 13

• Weather: wind and we=well affect how long the day in the field is / how much data is collected
• Water condition: murky water is not good
• Whale location: closer to the surface = better footage

Question 14

How many whales are typically spotted in a day in the field?

Answer 14

1-2

Question 15

How does Chelsea utilize photo-ID in her research?

Answer 15

• Drone photos of the whales are taken in the field are matched to photos in a catalog
• Each humpback whale has a unique pattern on its tail that is as unique as a human fingerprint
• Thorne lab has ~200 collaborators

Question 16

How does Chelsea pick drone images for body condition research?

Answer 16

• Parallel to the surface of the water
• Clear image in focus
• Not bent, angled, or rolled
  These are wild animals and are often not in the perfect position for research images

Question 17

Allometry

Answer 17

Describes how the characteristics of living creatures change with size

Question 18

What information can be learned from using BCI values?

Answer 18

• Comparison: assess how the body condition of humpback whales varies across feeding grounds in the Western North Atlantic
  Mass: using density estimates from tagging studies to calculate the mass from body volume

Question 19

What was the main finding from Chelsea’s research?

Answer 19

In the gulf of main whales are accumulating more energy in the 40-60% range (metabolically active range) compared to the whales in the NY bight

Question 20

What are some potential reasons for the higher body condition index for whales in the gulf of Maine?

Answer 20

• Poleward movement of prey in the gulf of Maine is increasing
• Decline of prey species in Iceland, Greenland
• NY bight and Iceland whales may not be accumulating nervy over foraging season
• Regional variability in human threats (ex: entanglements / vessel strikes)

Question 21

Why are the findings from Chelsea’s research important?

Answer 21

• Energetically stressed animals = less resilient
• On-going UME events along the East Coast
• Many deaths occurring in the NYB

Question 22

What is some work that Chelsea hopes to conduct in the future?

Answer 22

• Continue collecting data to monitor body condition over time
• Lab pairing data with biopsy samples
• Study interannual and seasonal trends in body condition
• Modeling East Coast humpback whale mortality due to ship strikes using AIS data

Question 23

What are unusual mortality events (UME’s)

Answer 23

• Increase standings in Mid-Atlantic-states (NY, New Jersey, Virginia)

Question 24

Describe vessel strikes

Answer 24

• Collision between boat and marine life
• Global conservation issue
• Large ships: less maneuverability / harder to detect whales and collisions
• Increased risk with faster / larger vessels

Question 25

What are Chelsea’s research objectives in regards to whale mortality due to vessel strikes?

Answer 25

• How have vessel strike risk factors for East Coast humpbacks changed in both time and space
• Do existing vessel strike risk models correlate with known vessel strike stranding patterns
• What offshore regions present the highest vessel strike risk

Question 26

What has Chelsea done to study her research objectives regarding humpback whale mortality rates and vessel strikes?

Answer 26

Developed a model to assess the monthly risk of mortality due to vessel strikes (from cargo ships only)