Case Report: Short-Finned Pilot Whale

The purpose of this project is going to be focused on the well-being and enrichment of the Short-Finned Pilot Whale (Globicephala Macrorhynchus) in captive environments, specifically aquariums where the whale resides when they cannot be released back into the wild after rehabilitation. They are in the family Delphinidae along with Killer Whales and Dolphins and are typically found in tropical or subtropical waters in the Atlantic, Pacific, and Indian oceans. They can be found in deeper waters far out at sea or in close proximity to coastal areas, this is dependent on where in the world they reside and are able to find the most abundance of food. Their primary food source is cephalopods, which explains their deep diving habits (over 600 m in some cases; Dombrowski, 2012), but may also prey on small fish or mollusks occasionally. While it has been observed that Killer Whales may harass Short-Finned Pilot Whale pods, they have not been observed preying on them and tend to exist harmoniously (Dombrowski, 2012). Based on this information, the only known predator of Pilot Whales is humans. 

Short-finned Pilot Whales are toothed whales that appear almost black in color with white/gray markings on their throat and/or chest. They have been nicknamed “melon heads” much like the Beluga Whale for their bulbous foreheads that bulge out on top. Their snout is quite short, almost more like a beak, and their flippers are short and slender, which is what sets them apart from a very similar species, the Long-Finned Pilot Whale (Globicephala Melas). Males do tend to be larger than females, but the average size all encompassing of the species is 4-6 m in length (Dombrowski, 2012). 

While the Short-Finned Pilot Whale can breed year round, they typically do so between July and August, it’s rare to observe mating in the winter months. Females typically become sexually mature between 7-12 years with a 9 year average, while males typically mature between 7-17 years with an average of a little over 14 years (Dombrowski, 2012). Mating only occurs from outside of their pod for both males and females, and the females are the only ones who participate in the raising of the calf with the assistance of older females in their pods. It’s also worth noting that both males and females have multiple mates over the course of their lifetime. Gestation lasts around 15 months and calves are typically born in the winter months and are typically independent by the time they reach 3 years of age. It’s typical for females to remain with their mother’s pod throughout their lifetime, while it’s extremely uncommon for males to remain in the pods they were raised in, they typically travel between pods over the course of their lifetime. Short-finned pilot whale females are one of the only other species recorded to go through menopause, around the age of 40, and continue helping care for the calves/young in their pods after their own breeding period is over (Dombrowski, 2012).

Female short-finned pilot whales in the wild have an average lifespan of 63 years, while males only have about 46 years. Females tend to form “kinship pods” and remain together for most of their lives, while as mentioned above, males tend to travel from pod to pod over the course of their lives. These whales are extremely social, and are only observed alone a handful of times traveling to another pod. They are primarily nocturnal throughout their lives, so it’s normal for them to be resting and more docile/less social during the day than they are at night, which is when they typically hunt. They do travel, but typically remain within a few hundred miles of the same territory, simply migrating when food sources become scarce looking for more abundance elsewhere (Dombrowski, 2012).

These whales demonstrate high levels of communication visually, physically, and acoustically. Auditory communication consists of not only echo-location in search of prey or danger, but also whistles and clicks to their pod members either nearby or while searching/diving for food. It should be noted that they are rather sensitive to loud human sounds such as sonar and seismic exploration (Dombrowski, 2012). They communicate physically through breaching and tail slapping, and have incredible eyesight that adapts to the various ocean depths they are found in for hunting. They typically do the most diving and are most active around dawn and dusk in search of food, as previously mentioned diving upwards of 600 m at a time (Dombrowski, 2012). 

Link to video footage: https://www.youtube.com/watch?v=r5Wb4C_b1Fw

The time frame that behaviors were observed was 8 minutes and 4 seconds into the video until the end of the video for a total of 5 minutes. Behaviors observed include nursing of calves, standard pace locomotion, surfacing, affiliative behaviors with conspecifics, and out of sight (left the frame of footage for a period of time). The focal behavior that I have chosen is nursing. It should be noted that there are two calves and two mothers in this footage, so I conducted my research examination on the second calf and mother to come into frame at around the 45 second mark, the first pair is seen in the frame for less than one minute total at the beginning and the end. I measured the nursing behavior based on duration within the 5 minute footage timeframe, and found that the calf nursed for 2:05.55 minutes of that time. It should be noted that the calf/mother exited the frame in about the last 30 seconds of the video, so this is an estimate.  With that said, based on my observations, the calf was nursing approximately 41.2% of the time observed, so nearly half. Short-finned pilot whale calves nursing for around 24 months, however this calf did not appear to be a newborn, likely around 12 months of age.

Surfacing in short-finned pilot whales: (photo by Mark Carwardine)

Nursing of calves (screenshot from youtube video linked above):

Locomotion (photo from Science Photo Library):

Foraging; note that the whales are about to dive (photo taken by Tobias Bernhard):

Affiliative behaviors (older females will attend to the calf at the surface while the mother dives; photo taken by Danny Kessler):

So now that we’ve covered a few common behaviors for the short-finned pilot whales, we should note the significance of them. The most obvious is likely the surfacing behavior to breathe, the whales can hold their breath for up to 15 minutes at a time but will still need to come up for air and likely not take the full 15 minutes (Spencer, 2022). Nursing of the calves is of course of great importance, despite calves beginning to eat more solid food between 6-12 months of age, they continue to nurse for an average of two years, but sometimes even longer. At around 3 years of age, the whales are mature enough to go off on their own, but typically only the males leave while females remain with their mother’s pod many times for the rest of their lives. Locomotion is likely another one of the more obvious behaviors conducted by this species, as they are constantly on the move, even when resting. Given that they travel long distances in the wild, supplements for physical activity will need to be made for the animal’s welfare (Thorne, Lesley H., et al 2017). Foraging is one of the most important behaviors for pilot whales as their deep, swift dives are what they’re best known for. Having the ability to dive as deep as they do naturally, while difficult to achieve, could make a stark difference in the animals’ overall well-being (Aguilar Soto, Natacha, et al. 2008). Finally, affiliative behaviors with conspecifics can include older females often participating in the raising and taking care of the young calves in their pods while their mothers are observed hunting for themselves or conducting other behaviors that require being alone. Having older female pilot whales in captivity may be harmful if this natural role cannot be fulfilled, and could lead to more premature deaths than are typically observed in the wild due to lack of purpose (Heimlich-Boran, James Robert 1993). 

In regards to how short-finned pilot whales will fare in a captive setting, it would depend on a variety of factors including but not limited to previous human interaction (and if it was positive or negative), their age coming to the facility, what ailment has rendered them incapable of returning to the wild, what other whales or species they’ll be residing with, and much more. It seems safe to say that the younger the whale, the more adaptable they will likely be to captivity and bonding with humans. If they are found as an infant or are even born at the facility, they likely won’t be able to recall much of anything outside of where they reside in captivity. They may, however, miss out on vital teachings from older whales and may not exude the same behaviors due to the loss of the natural hierarchy, and older whales would have a much more difficult time with this adaptation to captivity. One of the most difficult behaviors to supplement for these animals would be the loss of their ability to forage/hunt deeply in the oceans and as a group, as this behavior is observed across all populations of short-finned pilot whales everywhere, and this may wind up detrimental to their well-being given that they cannot behave as they naturally would (Thorne, Lesley H., et al 2017).

The good news is that should a calf be born in captivity, nursing will be able to take place so long as the mother is capable of doing so. Not only will this bond be important for the mother and calf, with the mother being able to nurse for the normal 24 months if not more and teaching the young calf about their natural behaviors, but should there be another, older female pilot whale at the facility, it could bring purpose to that whale and allow them all to form a pod at the facility. This would be a simple behavior to replicate, but could end up vital for the animals’ welfare, having a sense of family and familiarity to a natural hierarchy. It has been observed that natural pilot whale pods can be intersex, so it should not cause issues should there be a male pilot whale in the pod. With that said, if breeding is forbidden or is not desired to take place, since there are no other pods to mate with the male and young females may attempt to mate within themselves, so precautions should be taken seriously (Heimlich-Boran, James Robert 1993).

In regards to the welfare of short-finned pilot whales, what is meant by this is that the whales’ biological, psychological, physical, and natural needs are being met through enrichment, proper environment, adequate nutrition, and the opportunity to behave naturally in their given space. This is of course easier said than done given that pilot whales swim hundreds of miles and dive deeper than 600 m in any given day, but behaviors can be supplemented in other ways. For example, While massive expansion of their habitat is likely unfeasible in most locations, what could be even more beneficial is simply making the environment more interesting. Simulating waves controlled by a machine, growing kelp or some other alternative plant, even artificial, acoustic absorbing tiles for more natural sounds, or even just different textures on the walls such as rubber could promote more movement/a more interesting environment. One could also promote an activity that the whales all have to complete together to supplement group hunting, such as they all have to complete a task like vocalizing at the same time to trigger an automatic feeder to release food. Something like this could also be completed as a solo activity, with one whale needing to complete a series of tasks, such as button presses or tail-fluke slaps to trigger an automatic feeder (Law, Graham, and Andrew C Kitchener, 2017).

There are many, many ideas out there that could be easily executed in order to promote short-finned pilot whales’ welfare in captivity. Of course great care is already taken in their cognitive activities and in their nutrition, but more could certainly be done to promote more active behavior and reduce depression/anxiety/lethargy that’s often observed in captive marine mammals. Ideally, all whales could just be released back to the wild after they are taken care of and their ailments are treated, but at this time that is just not always possible, and could end up more detrimental to their health. But, we can do so much to give them the best life possible at your facility, and with various enrichments such as a versatile environment to explore, cognitive lessons to learn from trainers, games to play with their fellow whales, and promoting as much natural behavior and hierarchy as possible, they can still live a wonderful life. 

 

Sources

Dombrowski, C. 2012. "Globicephala macrorhynchus" (On-line), Animal Diversity Web. Accessed February 12, 2023 at https://animaldiversity.org/accounts/Globicephala_macrorhynchus/

Heimlich-Boran, James Robert. “Social Organisation of the Short-Finned Pilot Whale, Globicephala Macrorhynchus, with Special Reference to the Comparative Social Ecology of Delphinids.” Welcome to AquaDocs, University of Cambridge, Department of Zoology, 1 Jan. 1993, https://aquadocs.org/bitstream/handle/1834/21661/Heimlich-BoranJR.pdf?sequence=1&isAllowed=y

Aguilar Soto, Natacha, et al. “Cheetahs of the Deep Sea: Deep Foraging Sprints in Short-Finned Pilot Whales off Tenerife (Canary Islands).” Journal of Animal Ecology, vol. 77, no. 5, 2008, pp. 936–947., https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2656.2008.01393.x

Thorne, Lesley H., et al. “Movement and Foraging Behavior of Short-Finned Pilot Whales in the Mid ...” MARINE ECOLOGY PROGRESS SERIES, 2017, https://www.int-res.com/articles/meps_oa/m584p245.pdf

Spencer, Joanne. “Short Finned Pilot Whale - Top Facts, Habitat & Information.” Animal Corner, 5 July 2022, https://animalcorner.org/animals/galapagos-pilot-whale/

 Law, Graham, and Andrew C Kitchener. “Environmental Enrichment for Killer Whales Orcinus Orca at Zoological ...” Researchgate, 2017, https://www.researchgate.net/publication/312107646_Environmental_enrichment _for_Killer_whales_Orcinus_orca_at_zoological_institutions_untried_and_untested