Monk Seal Monday #163: Pupping Time!

Last week, the Hawaii Department of Land and Natural Resources (DLNR) reported the fifth Hawaiian monk seal pup born on Oahu this year. Lesley Macpherson of the DLNR Division of State Parks captured the birth on video.

DLNR also reported new mom RH92 gave birth to her first-born pup, PO4, on or around April 14. RH92 was born to RK22 in May 2016. Shortly after weaning, a fisherman witnessed a dog attack her. Luckily, the puncture wounds weren’t deep; however, she was given antibiotics to stave off any possible infection. Then, she started feeding off scraps at a boat harbor, so she was translocated to a remote beach elsewhere on the island. Except that she returned to the boat harbor within a couple weeks. Luckily, an outreach campaign and regular law enforcement patrols reduced the amount of fishing scraps, and RH92 left the immediate area, foraging more widely. In November 2018, at the young age of two-and-a-half, RH92 made the open-ocean crossing to Oahu where she has been regularly sighted ever since.

On Kauai, there are several females who have pupped on the island in recent years:

• RB00: A recent regular “pupper” on Kauai, RB00’s due date is predicted to be May 1. She was born on Kauai but spends her days on/off Hawaii Island and typically rolls onto a Kauai beach on the north shore a day or two before giving birth.
  
• R400, also a regular pupper on Kauai. She pupped at Polihale last year in mid-June.
  
• The prolific RH58 took last year off and did not pup. At this point, she has not been confirmed to be pregnant.
  
• RK22 last known pupping event was 2017. She’s rarely sighted, presumably spending her days at Niihau.
  
• RK28, another traveler, she has not been sighted recently.

RB00

Read Full Post »

Monk Seal Monday #162: Bifurcated Tongues

Umami: It’s often called the fifth taste, completing the list that includes sweet, sour, salty, and bitter. The word comes from the Japanese, translating to “pleasant savory taste.” Umami has also been described as “brothy” or “meaty.” 

Humans have taste receptors that recognize various compounds as umami. Turns out, pinnipeds do not. It could be because pinnipeds—a group that includes Hawaiian monk seals–have a tendency to ingest food whole, bypassing the whole taste thing.

Hawaiian monk seals also have a bifurcated tongue. That is, it splits at the tip with the two folds slightly overlapping.

• 

• 

But why are the tongues of Hawaiian monk seals bifurcated? What biological advantage would such a tongue offer?

In general, the tongue has multiple functions: mastication, food gathering, prey processing, transport, swallowing, and taste.

Jamie Thomton, Kauai Marine Mammal Response Coordinator for NOAA says, “If I had to guess why pinnipeds tongues are bifurcated, [I would say,] to aid in creating suction for foraging, and to assist with manipulating prey items in their mouths. 

The pinniped tongue is thick and muscular. According to a recent scientific paper, “This morphology differs from the narrow, thin tongues found in many terrestrial carnivores.” That likely indicates the tongue is an important component in pinniped biology.

The study cited above supports Thomton’s well-educated guess. The study further states, “Aquatic mammals are often unable to pin down prey and cannot use inertial feeding effectively underwater. As a result, many aquatic mammals, like pinnipeds, grab prey with their teeth (biting) or use the tongue (and hyoid) to draw prey into the mouth (suction). The tongue is then used to manipulate prey and move prey to the back of the throat so that it can swallow prey whole with little to no processing. The tongue of many aquatic mammals has therefore been modified and plays a critical role in generating suction pressures for prey transport and intraoral prey transport.” 

Unfortunately, it’s hard to see the tip of a Hawaiian monk seal’s tongue in the wild. Here’s a clip from a captive monk seal—and it’s still almost impossible to see!

Read Full Post »

Field Report: March 2022

Monthly Update: 

The Kauai team logged 292 seal sightings this month. This included 33 individually identified seals.

• March: 292
• February: 233
• January: 233
• December: 267
• November: 168
• October: 229
• September: 251
• August: 213
• July: 286
• June: 218
• May: 209
• April: 155
• March: 137

New:

·       Monk seal activity in the Poipu area remains high with several seals hauled out daily on the very busy Poipu Beaches. 

·       New subadult male with bleach mark V11 (temporary ID of V11) is exhibiting concerning behavior by approaching people in the water with an obvious interest in humans and no signs of fear. Two displacements from Keiki Pool by staff also revealed the seal has no fear of humans, but instead boldly approaches crowding boards. Will continue to closely monitor this seal.

Molting: 1 seal completed a molt last month at Poipu, a challenging location to manage. The seal remained hauled-out overnight for 32 days and continues to remain in the Poipu area for much of the day.

Displacements: 3 seals were displaced from the Poipu Keiki Pool, per the management plan.

Volunteers

·       Held a new volunteer training for the first time since the pandemic began, trained 7 new volunteers.

·       The volunteer program has slowly transitioned from spot-checks to partial coverage of seals in busy areas, such as Poipu. This transition will continue to pre-pandemic style scheduled shifts in the Poipu area. However, outreach to the public is still a low priority and volunteers are instructed to monitor seals and the SRA from a moderate distance, rather than at the edge of the zone. In most other areas of the island, volunteers will respond to assess the seal, take photos, set signs, and then depart. 

·       The state requirement for volunteers to be vaccinated is no longer in effect, thus all volunteers are allowed to respond.

Read Full Post »

Whale Wednesday #1: Tail-Sailing.

A few weeks ago, a subadult Humpback whale was sighted off Na Pali Coast, floating stationary in the water, head down, the tip of its fluke visible above the waterline. At first, boat crews were concerned the whale was injured or entangled, however, no entangling gear was present, and no wounds were visible. During the ensuing weeks the same whale (confirmed by photographs of its fluke and various body scars) was seen in the same position–fluke just visible above the waterline–close to shore near Port Allen, Makahuena Point, Anahola, Kipu Kai, and in Hanamaulu a mere 30 yards from the pier. Dennis Fujimoto took photos and wrote this short piece in TGI.

Jamie Thomton, Kauai Marine Mammal Response Coordinator with NOAA, observed the whale and reported it was is in good body condition with no signs of injury. Its pattern of behavior was to pose in a vertical position for about 10 minutes, then back to normal logging/breathing position for 10 minutes, repeat. There have been no further sightings. 

Turns out, this behavior, while rarely seen in Humpback whales, is common in Southern right whales, according to this article in the UK’s Daily Mail, and it’s called “tail-sailing.” Scientists aren’t 100 percent certain why whales tail-sail, but it could have something to do with thermoregulation, suggests Ed Lyman Ed Lyman, Resource Protection Specialist for the Hawaiian Islands Humpback Whale National Marine Sanctuary, is quoted in the article. But, he says, it’s not necessarily a posture for navigation as the word, “sail” may indicate.

This is just a reminder that there’s much we don’t know about marine mammals. It’s always good to report unusual behavior. In this case, while unusual, it was normal.

• 

• 

Read Full Post »