MATRIARCHAL SOCIETY - THE WISDOM OF MENOPAUSE ORCAS HELP SURVIVE THE YOUNGER
Classic life-history theory predicts that menopause should not occur because there should be no selection for survival after the cessation of reproduction. Yet, human females routinely live 30 years after they have stopped reproducing. Only two other species—orcas (Orcinus orca) and short-finned pilot whales (Globicephala macrorhynchus) — have comparable postreproductive lifespans. In theory, menopause can evolve via inclusive fitness benefits, but the mechanisms by which postreproductive females help their kin remain enigmatic. however, a study about orca behavior, published in Current Biology, suggests that older females provide valuable information for the survival of the group. According to the study’s authors, female orca, who are mothers between 12 and 40 years can get to fulfill 90. But, What is the evolutionary point of living so long without being able to reproduce? Until now it was known that the longevity of mothers increases the chances of survival of their sons. According to the authors, females led their groups especially in times of shortage of salmon. Information on how and where to find fish, it can be vital for survive. The wisdom they bring older females “may help explain why female orca and women continue to live long after they have ceased to reproduce,” said Brent, who lead the study
Photo: A postreproductively aged female, J16, leads her adult son and two adult daughters. credit: Dave Ellifrit, Center for Whale Research.
Reference: Brent et al. 2015. Ecological Knowledge, Leadership, and the Evolution of Menopause in Killer Whales. Cell
JAAN, AnimalsIndonesia, Centre for Orangutan Protection, and Airlangga vets investigating
Morphometric and external examination before necropsy
Two volunteers measuring Whale total length.
Photos: Benvika, Rifqi Ajier, Lubis KKHL (MMAF)
15th June 2016, 19:53
A total of at least 29 Whales (possibly Pilots, possibly more than 30) are currently stranded at Desa Randupitu, Kecamatan Gending, Kabupaten Probolinggo: 23 mature individuals of 4 meters long and 6 calves or juveniles of 2 m long. Please spread news. BPSPL Denpasar are coordinating the rescue effort. News by Rifqi Ajier, Jakarta Animal Aid Network
16th June 2016, 06:31
Three Pilots were refloated back to sea up to last night. Two individuals positive dead. More photos soon. Team are discussing next steps with incoming tides
16th June 2016, 07:54
Last update this morning… four additional Pilots found in mangrove area; three of them positive dead. The team are trying to release the one individual. That brings it to total 3 released, 5 dead, 1 still on rescue effort.
16th June 2016, 11:45
Rescue wrap up: 29 Pilots stranded, 7 dead, 4 refloated back to sea by rescuers, 18 returned to the sea on their own. Field team is now preparing necropsy. News from Rifqi Ajier JAAN.
16th June 2016, 12:34
They found more Pilot Whale carcasses at the adjacent Bentar and Gending beaches. Total 32 stranded, 10-11 died (for the whole event). Exact dead count TBA.
16th June 2016, 16:49
Necropsy in still ongoing. Just to reiterate that BPSPL Denpasar is the coordinator of this rescue effort. A team from the central MMAF (Ministry of Marine and Fisheries Affairs) in Jakarta has arrived on site. A scientist from LIPI (Indonesia’s scientific institute) is arriving in an hour. Necropsy is led by Arie DVM from Udayana Uni, aided by vets from Airlangga Uni and Gajah Mada Uni.
16th June 2016, 20:18
Two Pilot Whales were seen near shore by two local fishers just now. Amank and Rifqi Ajier from JAAN are checking the scene again. It has been advised to just conduct observation without herding, for the two Whales might just be saying goodbye to the deceased, as has been observed during a Pilot Whale mass stranding in Banyuwangi East Java on 22 May 2004 (database ID 68).
17th June 2016, 12:44
From Rifqi Ajier at 10:35 am local time: “Local fishers reported two more stranded Pilot Whales found last night. This morning, the team combed the area but found no carcasses. Possibly they have moved due to high tide. A necropsy is done this morning, led by the R&D team of the MMAF and LIPI. Next is burying the carcasses and monitoring/combing the adjacent waters. At the moment, we have 10 dead Whales ready for burial.”
21st June 2016, 12:40
News from Sekar Mira (LIPI) and Rifqi Ajier (JAAN) has it that the death count is now 15 Pilot Whales. With total 32 Pilot Whales stranding (assuming the new deaths were part of the original group), it makes quite a high mortality rate with more than 50% animals dead. Still kudos to all BPSPL Denpasar-led team who have worked so hard during the Holy Month of Ramadhan to make the rescue and post mortem investigation happen.
Marine animals that undertake breath-hold dives to access underwater niches must balance their access to two vital, but spatially separated resources: oxygen at the surface and food at depth and thus, Short-finned pilot whale use the same, highly specialised hunting strategy that cheetahs use, scientists report in a recently study. They say it gives the lie to our perception that deep sea whales are slow, energy-saving creatures. No other whale has been recorded to swim nearly as fast at depth.
Were tagged and studied 23 short-finned pilot whales (Globicephala macrorhynchus) living off the coast of the Canary Islands, one of only three places in the world that these whales permanently reside.
During the day, they look lazy the surface, often in social groups. That led scientists to previously think the whales only hunt at night. But the tags demonstrate the whales also hunt during the day. And when they do, they dive deep, and they dive fast. Tags showed the whales take just 15 minutes to dive to depths of 800m to 1,000m (0.6 mile), and more.
Okay, before anyone says anything, yes I am aware that these pictures do not show the full reality of cetacean captivity. However, I was looking through my 2009 San Diego photo album and ran across pictures like these. Keep in mind, when I took these pictures I was a pro-cap. I saw nothing wrong with these. Yes, I wanted them to have bigger tanks, but I was mostly elated to be seeing these whales again in person (the last time I went was 4 years prior). I was so moved by these just now that I needed to share.
First picture: one of the pilot whales after a show. Can anyone ID them? Second picture: Ulises waiting for Believe to start.
**You do not have permission to use these images elsewhere without my approval.**
Photo of Short Finned Pilot Whales (Globicephala macrorhynchus) & Melon-headed Whales (Peponocephala electra) by Deron Verbeck:
We came across a very rare sight today on WHOA. This large pod of Melon-headed Whales were seemingly mugging these Short Finned Pilot Whales. There was lots of commotion on the surface between the larger Pilots Whales and the much smaller Melon-headed Whales. There was tail slapping by the Pilots Whales towards the Melon-headed Whales and lots of chasing back and forth. Very amazing to watch. I was able to slide in and capture this image right in the middle of the fiasco!