Wolf researcher Kira Cassidy likes to say that when Rudyard Kipling wrote 'The Jungle Book' in 1894 and included the famous line “For the strength of the Wolf is the Pack and the strength of the Pack is the Wolf,” he would have had no idea that over a century later, scientific research would back up his poetic phrase. In this episode, Kira takes us inside the world of the wolf and pulls back the curtain on what it means to be the leader of the pack.
Music by Chad Crouch, Victrola Dog/Podington Bear Music
For Yellowstone National Park and the Acoustic Atlas at Montana State University, this is "Telemetry." (sounds of spring bird calls) Narrator: There’s nothing like this time of year in Yellowstone. (sounds of spring birds) Narrator: And while most creatures in Yellowstone are busily singing their hearts out this time of year, there’s one animal that actually gets a little quieter in the spring and summer. (sounds of wolf howls) Narrator: And that’s the wolf. You see, there’s a seasonal cycle to wolf howling. Howling ramps up through the fall and peaks in late winter as wolves enter the breeding season. Then, come springtime, (wolf howls out) Kira: Howling abruptly drops off. This is caused by the female choosing a place to den that they really want to keep secret if at all possible. Narrator: That’s Kira Cassidy, research associate with the Yellowstone Wolf Project. Kira: Choosing a den site is extremely important for a wolf pack. It's going to be their hub for the entire summer. It's the house of the entire next generation ... and it has to be protected of course because the tiny helpless pups are going to be there for several months. We've had cases where a pack has attacked another wolves' den and even killed the pups in some cases. They don't really want to let other packs know where they are and what they're doing…and in order to avoid that they keep quiet. Narrator: It’s not only the frequency of howling that changes throughout the year, but the type of howling shifts, too. Kira: Wolves howl for a couple of different reasons. Some of that would be within the pack so to keep track of each other, say if they’ve been separated. Narrator: Even though they’re doing a lot less of it, this is the kind of howling that tends to dominate in the spring and summer: Wolves communicating with their own packmates. Kira: They also howl to let other packs know where they are and to establish a territory. Narrator: Wolves will often have these howling bouts with other packs. The two packs will howl back and forth as if to say this is our turf—our territory. And it’s that howling for territoriality—--that grows in the months leading up to the winter breeding season. Kira: Howling really tracks the hormones as the wolves are getting ready for the breeding season. (wolf howls) The testosterone will start to spike and howling starts to increase. It's a stressful time in some ways. They do a lot of howling during the breeding season. (wolf howls) Kira: I think they use howling as a way to advertise the number of wolves they have in the pack, the type of wolves they have in the pack. If they have a lot of big male fighters, that's going to come across in a howling bout with another pack. And in some ways, wolves may be able to use it to avoid a fight with another pack too. They can create that space between each other…They can do that and let the other pack know where they are but also let them know who they are. Narrator: Kira’s specialty is looking at territoriality in wolves and inter-pack aggression, basically when two rival packs come into contact with each other and fight. Sometimes wolves fight until one pack or one animal displaces another. Sometimes they fight to the death. Kira: This stuff , this running into other packs is so vastly important to a wolf pack. Of all the wolves that live in Yellowstone that we’ve radiocollared. By the time they live their entire lives, some of them disperse outside of Yellowstone of course, but if they live their whole life in Yellowstone, two thirds of them end up being killed by other wolves. (music) Kira: I really became interested in territoriality when I saw a couple of these things play out… I saw a handful of times the Druid Peak pack ran into some of their neighbors. It was pretty fascinating the way it happened. They were intruding in other pack's territories. They were sometimes outnumbered but still winning…. I wanted to know why they’re winning or who’s winning. (music) Kira: So when two packs run into each other, we always like to think of it as team one versus team two and in some cases that works, but that's really kind of a human way looking at it. A pack of wolves is made up of--it's often a family--but it's made up of all of these different individuals who are driven by different things going on in their life, and some of those things we can measure. Kira: Of all the packs we measured, one of the things that was most important was just being in a larger pack. Which wasn’t really surprising. It was kind of cool to figure out the value of one wolf. Just having one wolf more than your rival ups your chances of winning quite a bit. (music) Kira: Yeah so, If you live in a pack of say six wolves and you run into a pack of five, your odds of winning…are a 2.4 to 1. The value of just having one extra wolf is extremely important. Narrator: And if you live in a pack with more males? That also ups your chances of a win during inter-pack aggression--by about 65%
Kira: But the most important factor was having a single old wolf in your pack. (music) Kira: If you live in a pack of, say, five and one of your pack mates is old, you're better off living in that pack than just having another sixth wolf, that old wolf is more important than having the numbers. And that shocked me at first because I really thought that these prime aged animals would be best…. If there is any age that mattered at all, then it would be the big fighters that are strong. But the old wolves have years and years of experience. The older wolves have been through these aggressive interactions before. They've probably seen pack mates die. They may have participated in killing a rival or at least chasing and attacking a rival. They know what to do. They don't panic. Kira: After learning that, it really drove home this connection back to other animals but also humans. There's an oldest animal in the pack that's bringing leadership and knowledge and experience to the group that once they die is gone. Narrator: “old” for Kira’s research is six years old. That’s the median age of death for wolves in Yellowstone. Kira: We've had wolves live up to 12 and a half. That was our oldest. We've had only a handful--eight or so--live to be more than 10 years old. Three of them are still alive. The Canyon alpha pair is a great example: We know that the alpha male was born in 2006. We know that the alpha female was born in 2005 and we followed them throughout their entire lives. Not only are they both pretty old for wolves, two of the oldest that we've been able to follow, but they've been a pair now together for nine years which is pretty special. I don't know if anyone has recorded a pair living so long together. (music) Narrator: So, Kira and I first talked back in April 2017. And a few days after we did this interview, the Canyon alpha female was mortally wounded. But not by other wolves. She had been shot. (music) Hikers found her near a trail on the north side of the park and, due to the severity of her injuries, park staff had to euthanize her. (music) Kira: So, after the canyon alpha female was poached, it got me really thinking about what was going on with the rest of her pack and certainly the loss of her was a pretty big blow to them. And also, what a lot of people don’t know is that her mate disappeared. We’re not sure if he left to go find another mate now that she was gone or if he died for some other different reason around that same time. …and so with the loss of the two of them together, they had over two decades worth of knowledge--on how to avoid other packs, how to find food in this ecosystem, how to pick an appropriate den site and raise their pups--and so that knowledge that they had accumulated over all this time was gone. Now hopefully, the rest of the pack--and we think there may be three, four, maybe five of them left--hopefully they’ve been taught well enough. (wolf howls and music) Narrator: But Kira says it’s important to remember that for wolves, life goes on. That these animals have a sovereignty and self-determination that can’t be stripped away. That hopefully, the Canyon wolves will take this challenge, like they take all challenges, in long, steady stride. (wolf howls and music) Narrator: For Yellowstone National Park, I’m Jennifer Jerrett. This podcast is supported in part by Yellowstone Forever and the "Eyes on Yellowstone" program. "Eyes on Yellowstone" is made possible by Canon, USA. This program represents the largest corporate donation for wildlife conservation in the park. This is "Telemetry." Thanks for listening.