Friday, June 19, 2009

Orca Fathers - They Often Raise Each Other's Offspring

Among our southern resident whales, the dads don't participate directly in raising their offspring…but they help raise the calves sired by other males instead!

K26 travels tight with new sibling K42 on the west side of San Juan Island, July 6, 2008 (Photo by Holly Fernbach)

Killer whales are polygamous, so they mate with more than one partner, and in this case the males do not have any known defined role to play in raising the calves they produce.

Instead, the adult males stay with their own mothers and help care for their siblings, nieces and nephews, who were sired by a different male. Similarly, their own calves are raised in a different maternal group, and any males in that family will help with raising the calves sired by the other males.

By all accounts, mating is a free-for-all between different pods, yet it is extremely rare for two members of the same family to mate together. Periodically the different pods hang out together, and occasionally all three of the southern resident pods - J,K,and L - meet in what the researchers call a "super pod". Vigorous interaction and mating can occur at these gatherings, but apparently the females only select males from outside of their own family group.

Young males from three pods traveling together: L78, J27 and K26 (Photo by Ken Balcomb)

It all sounds like a pretty sweet deal for the males - they live with their moms and frolic freely, not responsible for outcomes. 15 to 17 months later when the calves are born, the females are living with their own families. And it is - but it is a sweet deal for the whole clan, and may be key to why the orcas coexist so peacefully.

In this situation, male rivalry is minimized, plus they would seem to have a vested interest in insuring the well being of all calves since most likely they don't know which ones they might have fathered.

Young male J26 (Photo by Katie Jones)

The members of J,K, and L pods are closely tied genetically, and as I looked through the Center's archived photos for this post, there was something that really struck me (not an original observation I am sure!) - which reminded me of my sixth grade biology class and introduction to genetics. Something about wrinkled versus smooth peas...

Creative Commons Photo

L73, also wavy. (Photo by Dave Ellifrit)

J1, known for his wavy dorsal fin. (Photo by Emma Foster)

The bottom line is that although the males don't mate within their birth families, they must wind up breeding with their own offspring at some point, and the population shows the expected low genetic diversity. Yet that appears to be true throughout their range, even among populations that are healthy.

To account for this, scientists speculate that the orca's low genetic diversity might be the result of having gone through a genetic "bottleneck" about 130,000 years ago, during which time their population was drastically reduced, and is not just do to their tendency to mate with related individuals.

It may turn out that the orcas' reproductive strategy - though it creates or maintains a limited gene pool - enhances the success of the population as a whole. Their population is controlled by factors we don't quite understand, but it is closely tied to food abundance, and it may turn out that birth defects as a result of close inbreeding are naturally weeded out.

However indirectly, the dads play a key role in ensuring the success of the whole southern resident clan of orcas. And although orcas are deemed apex predators and appear to have no natural enemies, what that really means is that there are no successful natural predators. I imagine that the males are active and vigilant in protecting their families along with their involvement in the rearing of other males' offspring.

In the big picture, it works beautifully.

L41 traveling north through Haro Strait, August 10, 2008 (Photo by Dave Ellifrit)

From: January 2008 II-124 NMFS

" Resident killer whales display some of the most advanced social behavior of any nonhuman mammal, as evidenced by their highly stable social groupings, complex vocalization patterns, the presence of long-lived post-reproductive females, and behaviors such as cooperative foraging, food sharing, alloparental care, matriarchal leadership, and innovative learning. Maintenance of minimal group sizes is therefore probably necessary in preserving beneficial social interactions and in raising young."

Thursday, June 18, 2009

Should Killer Whales Be Kept in Captivity?

"Lolita the Whale", taken from the Southern Resident Killer Whale clan (Creative Commons Photo).

The subject of keeping orcas in captivity is a big one, fraught with emotion and embedded in huge financial investment. We plan to tackle this thorny issue in detail once the summer season of research has been completed, but given the fact that The Seattle Aquarium is hosting what promises to be a rare opportunity to learn about the situation, now seems a good time to introduce it.

So far we have only begun to share with you how orcas live their lives - we talked about their family bonds, the challenges they face, and what it might mean to us to lose them. We have yet to talk about how they communicate, how intelligent they may be, or what their ocean environment is like.

In review, then:

They have strong, lifelong family bonds.
CWR 2009 Photo by Ken Balcomb

They almost never stop moving, and apparently the calves must stay in motion, in a term called 'obligate swimming'.

Photo by Astrid van Ginneken

They seem to be curious about us, and never intentionally cause harm.

Photo by Ken Balcomb

In light of that, plus the fact that although the Orcas have a global range they are not abundant anywhere, we need to think long and hard about why we need to see them like this:

Creative Commons Photo

When this is what it takes to capture them:

Photo Courtesy OrcaNetwork

And we can see them like this:
Sprouting male L89 off Mitchell Bay (Photo by Basil von Ah)

Orcas are bred in captivity, so capture is not always necessary, but their lives are far from ideal. Continued captivity is rationalized by those who love the whales as well as those who just profit from them - but when you distill the arguments what remains is a question of compassion, and how we treat the creatures that share our planet.

Sunday, June 14, 2009

J-pod update

J45. Photo by Erin Heydenreich, May 15 2009

Baby J45 and his family have disappeared for a while, most likely in search of food:

"The last encounter we had with J45 was on the 15th of May. He seemed just fine, and was acting like any normal young calf. He was last seen going by the Center on May 25th he was traveling with his mom J14 and his sister J37. He may have been seen from a whale watch boat since then. J pod left the area shortly after they were seen on the 25th by us, and there have been no reports of them since then."

Erin Heydenreich
Staff Assistant, Center for Whale Research

J45 traveling next to J30 with j2 in the back. Photo by Erin Heydenreich, May 15 2009

Although J-pod seems to have left the area for a while, members of the other southern resident killer whale pods have been seen more recently. It is not unusual for the pods to mix up from time to time, and two whales for K-pod have joined up with a family from L pod.

There has been concern expressed though, about what appears to be unusual behavior from the whales this year. Many people who know the whales and their typical movement patterns are worried by the changes, so over the coming weeks we will try to sort out for you what is happening. Please keep in mind though that the data won't be complete for a long time, maybe even years - but we will share what we know, and look at other populations of wildlife as a comparison.

Thursday, June 4, 2009

Baby J45, You Might Be One Lucky Orca Calf!

In previous posts we have touched a bit on the challenges that face our resident orca whales, specially the calves. About a third to a half of them don’t survive their first year, and those who do carry a toxic burden and face dire salmon shortages. So, in light of that, what could possibly be good news for this newest member of J-pod? He has some really good things going for him, but before discussing that I would like to digress a little.

As noted in an earlier post, the whales are named according to their ‘pod’, or group identity, followed by when they were first seen. So the baby Orca J-45 belongs to J-pod, and is the 45th member identified since records have been kept. The researchers find this a straightforward and logical way to keep track of the families and for the scientists these numbers are the most practical way to refer to the animals. Once the babies are a year old, The Whale Museum also gives them a name.

All of that can get a little bewildering because you will hear the same whales referred to by a variety of names in different media sources- so help you to keep the relationships sorted out and keep track of this special baby, I’ll refer to the family members as they relate to the calf, but will follow the scientific method. J-45 will be noted as “Baby J45”, etc.

So what makes little Baby J45 a lucky calf?

The first factor is his birth order. The lion’s share of a mother whale’s toxic load is transferred to her first calf, and fortunately Baby J45 is the sixth calf born to his mother J14. Also, there is evidence that older mothers are slightly more successful in raising a calf through it’s first year, although the researchers have not determined why this is so. It may be linked to experience, the reduced toxic load to the calf, the presence of siblings, or a combination of factors. His mother J14 is 35 years old, has four surviving offspring and only lost one calf.

This brings us to the next thing that makes Baby J45 lucky: he was born into a great extended family, known as the successful and long-lived “J-2 Matriline”. (A matriline is like a family tree where only the mother’s lineage is considered). Research shows that among our resident Orcas, young whales are known to stay with their moms throughout their lives.

Baby J45 and his mother J14 are surrounded, supported, and protected by a network of family members, and when he was born into the wintery cold Pacific water this year, Baby J45 most likely would have been helped to the surface by one or more of his three siblings; five year old sister J40, eight year old sister J37, and fourteen year old brother J30. Also present might have been his 98 year old Great-grandmother J2 and his Great-uncle J1, two of our more well known and beloved whales. There is no evidence as yet to support the idea that calf survivorship is related to the presence of older family members, but there is a link to the survivorship of the older siblings.

The final bit of luck? Baby J45 along with the other new calves had the good fortune to have been born in a time and place where people treasure and seek to protect, rather than capture or harm, the resident Orcas.

Next we’ll report on how BabyJ45 is doing, and where you might be able to see him, last I heard he is healthy, robust, and trying to catch fish!

Candace Calloway Whiting