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Senior co-administrator of the Norcoast Salmon Research Facility, Dr. Mackenzie Connor was a biologist who studied the spawning habits of salmon. Then, last season, just as she and Dr. Emily Mamani were starting their research, they were interrupted by the arrival of Brymm, the first Dhryn to set foot on Earth.

And suddenly everything changed for Mac, Emily, Brymn, the human race, and all the member races of the Interspecies Union. Base was attacked, Em was kidnapped by the mysterious Ro, and Mac and brymn had to flee for their lives to the Dhryn home world.

What should have been Earth's best hope - an attempt to forge an alliance with the Dhyrn against the Ro - went horribly wrong. Mac nearly lost her life, and the peaceful, isolationist Dhyrn abandoned their world, hurtling out on an unfathomable path of destruction through civilized space.

Now the members of the IU feel the only hope of stopping the Dhryn is to contact the Ro and ask for help. But no one knows how to accomplish that.

As the enemy destroys life on planet after planet, the IU organizes a secret Gathering of every being with information on the Dhryn. With the data available there, Mac begins to suspect that the Dhyrn may not be ruthless destroyers. Their actions may be a response to something simpler and more deadly - the imperative to migrate. But even if Mac is right, can she and her team discover why this is happening and how to halt the Dhryn? 

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First published April 4, 2005

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About the author

Julie E. Czerneda

103 books754 followers
Having written 25 novels (and counting) published by DAW Books, as well as numerous short stories, and editing several anthologies, in 2022, Julie E. Czerneda was inducted in the Canadian Science Fiction and Fantasy Hall of Fame. Her science fiction and fantasy combines her training and love of biology with a boundless curiosity and optimism, winning multiple awards. Julie's recent releases include the standalone novel To Each This World, her first collection Imaginings, and A Shift of Time, part of her Night's Edge fantasy series. For more visit czerneda.com Julie is represented by Sara Megibow of Megibow Literary Agency LLC.

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Displaying 1 - 30 of 67 reviews
177 reviews64 followers
April 22, 2013
Part 2 of the series following biologist Mackenzie Connor, who gets caught up in a crisis involving a creepy biological threat to tons of alien worlds and races. Compared to the first book in the trilogy, this was slower, and had far less action or adventure (it takes place entirely on Earth, for instance); but it was better in other respects.

For one, the previous book only hinted at a universe teeming with intelligent life, but mostly confined itself to featuring one alien species, alongside humans, in speaking roles. This time however we get a whole slew of interesting species — which are, design-wise, at least a few steps above lazy Star-Trek-style species thanks to the author's background in biology. They're well thought out biologically, and full of personality. The alien characters are some of the best parts of the book. Also hilarious: the running joke amongst non-human species that humans are the sexual deviants of the galaxy.

I mentioned it's a slow read, and it is, to the point where it might turn off some readers. A good way I can think to describe it is this: You know in the Mass Effect games how you, as Commander Shepard, often come across research bases full of scientists (often made up of multiple species) and you briefly converse with them about their research, before charging off to battle somewhere else? This book is like it's told from the perspective of those scientists. They're aware of the galaxy-scale threats out there, but they spend most of their time working away at their research and meetings. The character Nik in this book is a bit like Shepard, in that he's the man of action, but we don't follow him when he steps out of frame to go do his dashing spy work.

The thing is, this worked for me because as a biologist and a fan of optimistic SF, I love reading about how scientific research is conducted in the future. I love the hi-tech bases and gadgets they get to use on a daily basis. I also enjoyed reading about the politics and diplomacy of a (mostly) peaceful multi-species future.

The series is rather like Mass Effect, if you subtract the endless shooting at things (also if you replace the big bad machine threat with a big bad organic one). Low on action, heavy on conversation and politics, but just a nice absorbing read set in a bright, bustling SF future.
Profile Image for Angela.
Author 6 books67 followers
December 23, 2008
The Species Imperative series continues to be a solid example of what Czerneda does best--create vivid and memorable alien species. The two major alien characters in Migration weren't quite as cool as Brymn in Survival, but they definitely had their moments. I really liked Fourteen in particular, and how he developed through the course of this installment of the ongoing story. I also liked the lead alien character at the conference Mac attends--since she is a collective consciousness, and written very well.

Slightly disappointingly, however, the human characters this time around don't quite match up to the alien ones. Our hero Mac mostly alternates between angsting over the capture of her best friend Emily by the Ro and angsting over her budding attraction to Nik, the spy-type we saw show up in the first book. The one disappointing quirk in Czerneda's writing from the first book carries over into this one, too--when Mac addresses her thoughts at Emily, Czerneda is inconsistent in making those thoughts first person vs. third person. I wouldn't ordinarily find this a problem, except that she also keeps working Em's name into these thoughts, and it reads really weird when you try to write out someone's thoughts in third person and you're also still trying to address them to an imagined audience.

For example: She didn't mean to do that, Em. Bits like this kept showing up in Mac's thought patterns, italicized to clearly show that they're thoughts, and yet they're in third person. People don't think in third person, and they don't address third-person thoughts to imaginary listeners, either. This comes across as the author addressing Em somehow rather than Mac. I didn't mind Mac constantly talking to Em when she was alone or constantly directing her thoughts at her--coping mechanism for the character, I can deal with that. I just wish that Czerneda would have been more consistent in writing out the actual thoughts. I'm wondering why this got past her editor; it's a quirk that's only shown up in this series. She hasn't done it before.

Meanwhile, Mac also spends a lot of time angsting about the aforementioned Nik, as mentioned. One reviewer on Amazon.com took this as an excuse to slam this book as a thinly veiled romance novel, which isn't fair--yes, Mac and Nik do have a budding romance going, but that's not the main point of this plot. And I do like Nik's periodic appearances, suitably sparse through the book to account for the fact that the man is a spy, and he has plenty to do that Mac doesn't get to witness. The thing that actually knocked me out of the story a bit, oddly enough, was Mac's propensity for regularly thinking of Nik as "yummy". That particular word choice just seemed weird to me--a bit too frivolous a word choice for this woman who's been set up as a hard-headed, no-nonsense kind of scientist who regularly rolled her eyes at Em's attempts to get her paired up with someone. Especially in this book, where Mac's fighting off the nightmares about what happened to Brymn in the first book and how his transformation led to her having to get an artificial arm, and where she's worried as all hell about whether Em is alive or dead. Yet every time Nik shows up in her thoughts, it's "ooh, yummy". Just doesn't fit.

Not that I take issue necessarily with describing Nik as yummy, 'cause, well, he is. I especially like the bits where he shows up to watch over Mac when she has nightmares and winds up holding her during one--very sweet. But "yummy" is a word I'd expect out of a much fluffier heroine in a much fluffier book.

What else... I do have to take issue with the fact that when you get down to it, at least in Mac's part of this plot, not much actually happens. All the interesting stuff is happening away from her, out where the Dhryn are hitting various worlds on their migration. Things don't start getting really interesting until Mac reaches the gathering of delegates in New Zealand and convinces everybody there that a) the Dhryn are obeying a species imperative to migrate, and b) that imperative is actually getting enforced on them by an external source. It would have been nice, though, to see what the hell everybody else at that conference was doing while Mac and her group were doing their research--we barely glimpse the other attendees.

And oh yes--there's a really neat piece of art on the cover of this book, which is described by Czerneda in the book's acknowledgements as Vancouver being destroyed while Mac looks on. However, nothing of the sort actually happens anywhere in the book. Hrmph. :) False advertising!

Now for stuff I really did like.

As I mentioned, the major alien characters--very cool. I liked Fourteen a lot, especially his banter with Kay when the two of them first show up and weasel their way into interrupting Mac's vacation. I also liked the gathering leader--Anchen, that was her name. And the Vessel showing up at the Gathering was a suitably gripping plot development, and helped continue Mac's connection with the Dhryn.

I really, really liked the development of Mudge as a character as well. He got a lot more participation in this book than he had in the first one--and to be honest, I almost expected him to start being set up as a competing romantic interest to Nik, especially when we got a lot of emphasis about Mudge's and Mac's long history. And Mudge lamenting, "Who will I have to argue with?" when he is faced with the prospect of Mac never being around any more. And all of the things that Mudge takes on during the course of the plot to help Mac out. Part of me thinks the poor guy really needs to have something neat happen to him since he started being so useful to Mac all throughout this plot--and although I would habitually vote for the yummy guy, I have to admit I'd be oddly satisfied if Mac wound up realizing Mudge was more important to her.

(Though I don't think that's where this is going, now that I've finished the book. I think it's telling that I was almost disappointed that Mudge and Mac remained entirely platonic through the course of this plot. ;) )

And I liked the ending, where Mac finally convinces the gathering that they have to turn off the signal that they'd been set up to activate, saving Earth in the nick of time.

All in all--not the best work Czerneda's done, but a mostly good, solid read despite its flaws. I'm looking forward to seeing how this wraps up in Book 3!
This entire review has been hidden because of spoilers.
Profile Image for Efka.
551 reviews324 followers
December 1, 2015
Just don't have determination and devotion and time to read mediocre books. "Migration" isn't terribly crappy or criminally bad written, but it is dull and boring, and I don't care about anything or anyone in it. Guess it was a mistake to read this book, despite not really liking #1 of the series, Survival. Off to look for greener pastures, then. And one thing I can't understand, is How the hell can this book have a rating of 4,05?. I just can't grasp it.
Profile Image for Cheryl.
355 reviews1 follower
July 30, 2021
I love the science woven into the story, the various aliens and people are well fleshed out, I'm just REALLY! tired of the internal monologues to Em, stop it, just stop it. Mac can think inside her head all she wants, just stop "conversing" with Em.
Profile Image for PhilomathicJ.
166 reviews3 followers
August 11, 2020
While I enjoyed the first book in this series, I found the second far more engrossing. Unlike the first book, which had a few oddly perfunctory "action" scenes, this book largely sticks to what appear to be her strengths: biology and research.

That might sound boring, but I found it fascinating, and ended up reading about 80% of the book in three days. Once it got rolling, I didn't want to put it down.

She introduces a slew of alien species, each with idiosyncratic biologies and cultural quirks. This made for some unique moments that elicited genuine laughter (often due to a certain numbered character).

Definitely looking forward to the final book in the trilogy.
Profile Image for Synful.
229 reviews
September 20, 2020
Book 2 of this trilogy spent a good chunk of its time dealing with fall out from book 1 and trying to figure out what exactly is going on with the deadly Dhryn. Most of it read more like a mystery or a bottle episode, if this was tv. Not that there weren't some twisty parts and small surprises. I mentioned in my review of book 1 that I liked the time and emphasis spent on not having an easy time communicating with other species and this book multiplied that by several times. The amount of detail on that was pretty good. I also liked, in relation to fall out from book 1, that the main character, Mac, is definitely not ok. The sadness and most definite PTSD isn't used too frequently, I feel, or at least not as just a stiff upper lip or what have you. The hero/ine usually just jumps up and goes full speed ahead even when some crazy or painful or nightmarish things might happen to them. Granted, Mac isn't exactly hopping on a psych couch either, but her scrambled brain is at least a real addressed thing. I did feel, though, that the story could've almost stopped at the end of this book because it has a fairly satisfying close, but I know there's still a couple of big loose ends to deal with so moving on to book 3...
Profile Image for Nyssa.
896 reviews71 followers
April 24, 2025
Rating 4.5

The shoe continues to drop, but this time it wasn't as shocking. I think, instinctively, we readers were a bit more prepared and less trusting. There are even more threats than we previously believed... so, what happens now?
Profile Image for Rebecca.
672 reviews29 followers
November 23, 2008
Normally the second book in a trilogy is the best; you don't have to spend a lot of time with either set up or typing up loose ends, and you can devote most of the book to action and moving the plot. While this book definitely moves the plot arc forward, it seemed like it took too long to get there. The opening chapters contain some important set up, and it is true that life doesn't always move at a breakneck pace, so it was realistic, but I found myself at times going "Oh come on, get to the action!"

This was a solid installment in the series and definitely had some good parts, but I am somewhat ambivalent to it; I'll have to see how the third book goes to really process this one. It pains me to not be able to give a ringing review to one of her books, and I suspect it will go better on repeated reading when I know the pace and won't try to get ahead of myself.
Profile Image for Andrew.
233 reviews81 followers
March 20, 2013
Fish biologist goes to a conference. This is still a spy story, but now it's a spy story happening in an academic study group. To be fair, the group is studying the same problem as the spies -- the imminent sterilization of all nearby planets -- so it's not a tonal clash, just an excuse to change gears frequently.

I like that the aliens have senses of humor, and agendas, and do not regard humans as either yokels or incomprehensible marvels. (In the last book, the Dhryn were worrisomely ignorant of biology and how to deal with other species. As expected, this turns out to be a relevant peculiarity of their culture. Everyone else has good interspecies manners. When we see another alien get all offended about some Earth thing and run off, we're supposed to read it as *strange* -- and, indeed, it is.)
1 review
February 28, 2014
i had a lot of trouble finishing the first book "survival" and the same problem is happening with "migration" . I don't like the main character , she is so focused on her little world that she doesn't pay attention to some clues. when reading i kept thinking that it would be better if she could stay with her salmons and if the reader was provided with someone else as the main character.
Profile Image for Dee.
23 reviews
February 19, 2020
Czerneda sure does love her sloooowwwww pacing. That's perfectly alright, though; every moment feels crisp and thoughtful. While there was pretty heavy drag in the middle-third of this book (I was pretty sure I was going to rate it 3/5 through much of it), I was won back when the plot kicked into gear once again.

I was worried at first that the NorCoast salmon research facility we spend so much of book 1 on would be left behind completely; luckily, that wasn't so, as Migration begins there once again. We bid it (a final?) farewell before venturing off to... Mac's family's vacation home. Here, the book grinds to a halt. I was enjoying Mac's antics for a time, especially as we're given a few interesting new characters for her to play off of, but the grand return of His Esteemed Spylyness, Mr. Nikolai Piotr Trojanowski swings in to kick things back up a notch. Which is unfortunate, because for whatever reason I just do not like this character one bit. As stated in my review of Survival, Trojanowski feels like he's been brought in from a completely different genre. In contrast to this, the most curmudgeonly minor character from the first book returns in a big way, seemingly out of nowhere, and quite instantly became one of my favorites. I'm a damn sucker for the "enemies to begrudging allies to genuine good friends" dynamic, and this book has it in spades. He's an excellent foil to Mac and benefits from being a part of "her world," as it were. Hugely pleasant surprise.

As the drama unfolds, so does the saga of the Dhryn, the mysterious alien race we delved deep into in Survival. Unlike that book, though, aside from the interludes, we (and by extension, Mac) never leave Earth. It's a little odd, given how far we traveled in the first book, but we make up for it by meeting a whole slew of new alien species, some of which were mentioned in the first book, and most of whom are captivating. The Interspecies Union Consulate in New Zealand is full of new and old faces, strange beings, and a ton of little conflicts and mysteries. By the third act, the pacing once again picks up exponentially as all of the dominoes line themselves up to be knocked down.

It's hard to talk about this one without spoilers as so much happens only toward the end, but as someone who loved the first book and who is generally a fan of slower pacing (when done well), I came away from this book pleased. Not to mention, Czerneda's prose is a treat that I can't get enough of reading. It's so rare to find thoughtfully built, impressively-scaled, galactic-community scifi written this way -- the protagonist is a biologist and she damn well feels like one, I love reading about a scientist facing scientific problems within their field in an interstellar setting -- and while I was already sick to death of military scifi, I now feel like I can never go back.
Profile Image for Dominick.
Author 16 books31 followers
November 5, 2021
Enjoyable enough but unexceptional space opera. This second volume (of three) shares the strengths and weaknesses of the first volume, so I suspect volume three will be more or less comparable. The key strength: quite plausible creation of myriad alien species; Czerneda's aliens have not only physical but also intellectual and cultural differences that are clearly differentiated. (The detachable genitalia is a nice touch.) She does a good job of acknowledging the challenges inherent in bridging cultural gaps. On the other hand, though the plot includes some nice twists and unexpected developments, it is also somewhat dilatory, and the big twist at the end of this book is essentially just a reversal of the big twist at the end of the first book. First time out, we learn near the end that the apparently victimized species is really the threat. Here, we discover that tis now apparently dangerous species is actually still the victim of the original apparent enemy, having been genetically engineered by said first alien group as an interstellar genocide force. I will be curious to see whether we get a reverse reverse in book three. More problematic for me is the depiction of the protagonist, though, who does a bunch of the sorts of things I tend not to like. She has conversations inside her head with a missing friend, a device I just find jarring (Maybe people really do this, but it never strikes me as convincing as a narrative device). Worse, she seems wiling to allow the fate of all intelligent life in the universe to take a back seat to her own personal needs when she withholds vital information. That sort of plot device is one I always really dislike. Nevertheless, the world-building and overall plot are engaging enough to make this a pleasant enough read.
Profile Image for Catherine Fitzsimmons.
Author 9 books16 followers
May 19, 2025
These books are the first of Julie's science fiction titles that I've read, having previously enjoyed a couple of her fantasy books. Now, I just need to be sure to read other authors as well.

Both Survival and Migration started off as fun hard SF with charming characters and humour, and with both, the knowldege of what type of book it really is doesn't truly set in until the book's well and truly gotten its hooks in, and it does a masterful job at all of it. That this absolutely fantastic writer has said kind things about some of the books I've published is incredible. I am stoked for the finale.
Profile Image for Rebecca A..
106 reviews8 followers
August 23, 2020
Julie Czerneda is a world-builder par excellence. In this series, Species Imperative, she is also a world-destroyer. Rather, one species of her creation has become an unstoppable destroyer of worlds, and is heading for Earth.

Utilizing multiple knowledge-streams, Czerneda also gives her readers a template into what it might take to save life here on our own Earth; here and now.

With enticing plots of multiple layers, characters you want to read about, Czerneda never disappoints.

Profile Image for Darceylaine.
541 reviews3 followers
September 5, 2019
An entertaining and enjoyable read. Czerneda creates such imaginative and unusual worlds and species. I’m inclined to forgive her for her use of well worn tropes. The romance in the series is hastily developed, and I don’t really believe it. But the relationships between Mac and the non-humans are compelling. I care about those relationships.
Profile Image for Katie Foth.
Author 3 books19 followers
May 8, 2021
A friend recommended this author and series, and I had trouble finding the titles on Hoopla and Libby. I finally purchased the series on Kindle and thoroughly enjoyed them. I found the characters well-rounded, interesting, and thoroughly believable. The author's imagination and world-building are top-notch. I read the whole series within two weeks--really enjoyed this author's work.
652 reviews
Read
October 26, 2025
Why you might like it: Biology-led contact with rigorous cultural logic. Rubric match: not yet scored. Uses your engineering/rigor/first-contact/world-building rubric. Tags: biology, first-contact, culture
Profile Image for Takiyah Dudley.
428 reviews1 follower
May 22, 2017
A bit slow going at first, but it picks up. a good continuation of the series.
Profile Image for Judi.
34 reviews2 followers
December 2, 2019
I liked this one better than the first one.
Profile Image for Kim.
17 reviews
May 18, 2020
I enjoyed this one more than the first. I read it slowly to make it last! The aliens are fabulous - “idiot” !!!
312 reviews3 followers
November 30, 2023
Another slow start, but still an enjoyable book. Now, onto the last of the trilogy!
Profile Image for Britt K.
21 reviews
July 4, 2024
Throughout most of the book, nothing happens. It felt like the author just really wanted it to be the same length as the first one :(
Profile Image for Michelle.
1,125 reviews15 followers
January 21, 2025
Not sure how I missed these SF novels when they came out, because they have a major focus on the PNW and salmon, but I'm glad I found them eventually.
403 reviews1 follower
June 3, 2025
Another solid 4 stars. Great idea and good writing. Little romance. Will probably pick up book 3
Profile Image for Jim.
Author 95 books2,386 followers
June 10, 2007
Dr. Mackenzie Winifred Elizabeth Wright Conner (Mac), salmon researcher extraordinaire, has returned to the Norcoast research facility after barely surviving her discovery of the "true" nature of the Dhryn. Her friend, Dr. Emily Mamani, is still working with the mysterious Ro, who may be the key to stopping the Dhryn's murderous attacks. And Mac is struggling with a bit of post-traumatic stress as she tries to adapt to her former life.

In the first book, Mac wanted nothing more than to study her salmon, but the universe simply refused to leave her alone. The same holds true in book two. An earthquake devastates Norcoast, and Mac finds herself drawn back into Interstellar Union issues once again. This time, she is brought to an I.U. gathering to help research how to contact the Ro and stop the Dhryn. But are the Dhryn truly evil, or simply responding to the demands of biology? And are the Ro really the saviors some believe them to be?

There is a lot to love about this book. Czerneda's aliens are delightful as always, particularly the acerbic & lovable Myg, Fourteen. The author's own background in biology serves her well as she designs one species after another, from the terrifying metamorphoses of the Dhryn to the unique offensive capabilities of the Trisulians. Her talent for writing fully-developed, fascinating species makes the book worth reading all by itself.

In terms of plot, Migration suffers a bit from second-book syndrome. At the end of book one, the Dhryn have been loosed upon the galaxy. Planets have been scourged of life. Mac lost her hand to a Dhryn and barely escaped with her life. Yet in the beginning of book two, we see very little about these events. As a result, the pacing feels slow. It takes a while to get Mac out of Norcoast and back into the midst of things. In book one, when we didn't know what was happening, the author had more leeway to develop the characters and build suspense. This time, I was a bit impatient. Likewise, with the Species Imperative books being a single ambitious story, things are left unfinished at the end.

And yet I found the ending of Migration more satisfying than the ending of Survival. The threat to humanity and the I.U. is revealed to be even worse than before, but another, more personal plot point is brought to resolution.

Migration is a good book by itself. Having also read the third book in the series, I can say that the trilogy is a both a highly satisfying story and a very impressive feat by the author.
Profile Image for astaliegurec.
984 reviews
June 20, 2021
3.0 out of 5 stars
About the Same as the First Book
September 10, 2007

This book, "Migration," is the 2nd in Czerneda's "Species Imperative" trilogy (the first book is Survival: Species Imperative #1 (Species Imperative) , the 3rd is Regeneration: Species Imperative #3 (Species Imperative) ). I had hoped that this book would be an improvement over the first. On one hand, some things did get better (the main character actually uses some of her personal knowledge to further the plot (though it's mostly as the chairperson of a committee)). But, on the other hand, some things got worse (her "gaga" infatuation with Nik is just jarring, and now she's continually talking to Em in her head). Overall, my review for "Survival" applies equally well to this book. Like the 1st book, the biggest problem here is that Czerneda does nothing to further the plot until about half-way through. Instead of doing ANYTHING related to the situation at hand, Czerneda treats us to 250 pages of personal problems at Mac's lab/base, a vacation with aliens in the Canadian outback, eating "poodle" with said aliens, looking at owls for her Dad, and finally, just like in the first book, when pushed, she gets shipped somewhere and starts doing something. But, even that activity is unnecessarily drawn out since every time something starts to click, Mac gets drawn aside into some side difficulty. It's just frustrating to read.

Again, since the idea behind the story is so interesting, I was hoping this book would read better than the previous one. Unfortunately, I can give it no better than an OK 3 stars out of 5. Get it from the library before spending your own money on it.
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