The Terrestrial Ecosystem

[BFG_9000]

I have an interesting question about the mythology in the Half-Life series.

When the portal storms started at the end of Half-Life, creatures from Xen started appearing across Earth, correct?

Well, obviously, creatures like headcrabs, bullsquids, and icthyosaurs would begin doing what they do best: surviving, by terminating (and consuming) the terrestrial competition.

With the food chain suddenly going to hell in a handbasket, what terrestrial critters could possibly survive?

I mean, Earth's greatest survivors: reptiles, mammals, birds, fishes. Would any of these native species manage to make it with alien species now in their habitat?

Discuss.

 

[ríomhaire]

Fish seem to have gone out the window in the Baltic/Black/Whatever Sea is in HL2 as they would probably all have been devoured by leeches. Of course the Ichy must live somewhere so all the waters of the world aren't full to bursting of leeches (though I think the Ichy might have been in the canals). I'd say not everything terrestrial is dead. Wolves, types of snakes etc and other tough stuff probably made it along with insects and rodents and other things that are small, fast and breed like mad.

And surly Xen didn't contain enough wildlife to fully consume Earth's (And it's not unreasonable to assume that an equal amout of Earth creatures made it to Xen)

 

[Vagrant]

Actually there was fish in the river thing with the Itchysaur that Gordon was accidentally teleported to.

Birds, of course, still survived too.


And I would imagine that quite a few of Earth's creatures could fend off Xen's. But certain animals like cows would probably die.

 

[ríomhaire]

Actually there was fish in the river thing with the Itchysaur that Gordon was accidentally teleported to.

Birds, of course, still survived too.


And I would imagine that quite a few of Earth's creatures could fend off Xen's. But certain animals like cows would probably die.

Fish? Are you sure? Do you have a screenshot?

 

[Vagrant]

Hmm, I can't seem to find a screenshot of it, oddly enough. But I'm pretty sure I remember seeing some fish around there. They seemed too big to be those leech things.

 

[Asknoone]

They were certainly leeches.

 

[Llama]

It is silly to asume none of Earth's native creatures survived. If cockroaches can suvive nuclear fallout, then alien invasion isnt going to be a problem

 

[Rizzo]

Well we se seaguls and crows. And i whould think some sharks and bottom feeders whould survive. I mean, Gordon can fend of alot of Xen creatures with a crowbar, so a Lion/Tiger/Rhino/etc. could probably too, (without the crowbar).

 

[Asknoone]

Well, I'm not sure how much ocean life would survive with countless Ichthyosaurs been ported in via constant portal storms (which, continue erratically to this day)...

I'm sure alot of our wildlife was simply overwhelmed, but at the same time - some number may have survived. But its doubtful...Earths a wasteland, ravaged by aliens...its going to be tricky for any species.

 

[jimmyjam]

birds got through that comet mess, they're just biding their time, waiting for an opportunity
an alien invasion fits the bill






HALF LIFE THREE: THE BIRDS

 

[DeusExMachina]

birds got through that comet mess, they're just biding their time, waiting for an opportunity
an alien invasion fits the bill






HALF LIFE THREE: THE BIRDS

:O

DUN DUN DUN.

 

[UltimaApocalypse]

Perhaps a few native creatures live in the Canal area?

 

[Asknoone]

Doubtful. Very doubtful. Not only is it populated by zombies and Barnacles (And most likely Bullsquids), awash with pollution and whatever else the Combine dumps in, but its also dotted with Combine outposts, and I'm sure trigger happy Metrocops would enjoy the free target practice.

The city 17 Canals are like everything else. Wasteland.

 

[Eejit]

I wonder what temperature ranges various Xen wildlife can survive in. Maybe the polar/sub-polar ecospheres are fine.

 

[UltimaApocalypse]

If they still exsist maybe....I mean from what the Combine have been doing theres probaly some global warming thing going on.

 

[Rizzo]

Well what is the tempreture on Xen?

 

[ríomhaire]

Well what is the tempreture on Xen?

Something livable to human.

 

[Lightice]

Something livable to human.

Or possibly not, considering that Gordon did wear a HEV-suit. There was pretty tropical feel in the place, though.

 

[ríomhaire]

Or possibly not, considering that Gordon did wear a HEV-suit. There was pretty tropical feel in the place, though.

Yeah, well Barney was wearing body armour, a shirt, pants, boots, a helmet and presumable socks and underwear.

 

[Darkside55]

I wonder what temperature ranges various Xen wildlife can survive in. Maybe the polar/sub-polar ecospheres are fine.

Xenians can easily survive in freezing temperatures; during the Black Mesa incident, when Gordon must go through the coolant reserve facility, he encounters headcrabs and vortigaunts that appear unaffected by the cold that is sapping Gordon's suit power and health.

If I were to hazard a guess on Xen's temperature, I would say it would be around 40-60 degrees fahrenheit on the "surface," and a little lower inside of the caves, perhaps going down to the 20s.

I'm sure that certain fish could survive the leeches, piranha being the most likely. Larger fish such as sharks could perhaps fend off leeches, but only a few types (the larger types, and/or the aggressors, like hammerheads) could withstand icthyosaurs. Dolphins and whales might stand a chance. And of course, creatures in the depths of the ocean would probably be safe, having adapted to the crushing temperatures that a Xenian aquatic animal could not survive.

On land, non-predators are probably all dead, or nearing extinction. The only things that could stand a chance would be predators like wolves, big cats, crocs, bears, wolverines...maybe tiny things like shrews that feed on insects and would be unnoticeable to Xen beasts. You've got to think though...what terrestrial animals could really stand up against a colony of antlions, or a garg?

 

[Lightice]

On land, non-predators are probably all dead, or nearing extinction. The only things that could stand a chance would be predators like wolves, big cats, crocs, bears, wolverines...maybe tiny things like shrews that feed on insects and would be unnoticeable to Xen beasts. You've got to think though...what terrestrial animals could really stand up against a colony of antlions, or a garg?

Animals generally don't fight an assault on their ecosystem. They run away or adapt. It seems to me, that the Xen wildlife has taken some ecological niches from Earth's ecosystem, but it has also adapted to their presence. I am certain that a great deal of original Earth wildlife exist outside the cities, even though some species have undoubtedly faced extinction.

 

[Darkside55]

I had considered that fact, but in the initial year(s) of the portal storms, I'd imagine the aliens hadn't developed an equilibrium with their environment, and went on a smorgasbord. Considering how numerous and voratious antlions are, especially during their mating season, it's not hard to see them taking out a large chunk of animals.

Then again, we don't know the distribution of alien species across the face of the earth, aside from the fact that they inhabit most of the wastes. But perhaps antlions are only scattered about in large, but isolated clusters, and gargs and icthyosaurs might be rare sights. Depending on all that, that affects which animals possibly remain.

 

[UltimaApocalypse]

You also have to consider where the portal storms occured. They didn't happen EVERYWHERE, theres still got to be some areas in the world that isn't wasteland. If the rebels get the Combine off Earth, they'd either rebuild in the wasteland or go live in those areas.

 

[Asknoone]

Yes, they pretty much did. They spread throughout the planet, and whilst some smalls areas may not have been hit by the constant flow of aliens (because whilst the storms may be weaker come HL2, they still continue), others would have been driven into those areas.

 

[Eejit]

I had considered that fact, but in the initial year(s) of the portal storms, I'd imagine the aliens hadn't developed an equilibrium with their environment, and went on a smorgasbord. Considering how numerous and voratious antlions are, especially during their mating season, it's not hard to see them taking out a large chunk of animals.

True, but when they initially arrived they were almost definitely less numerous. Antlions etc. have had what, 10 years? to breed on Earth.
Perhaps a slow buildup of numbers gave more terrestrial species a chance to adapt.

 

[Flyingdebris]

actually its not so much a matter of sharks or dolphins being able to fend off Xen leeches. its the fact that they HAVE to fend them off thats the problem.

They have no natural defense against them, plus the leeches are probably eating most of their food. It can be safe to assume that many larger aquatic creatures who are not eaten by xen wildlife simply starve to death. And thats not even taking into acount the fact that when you remove entire chunks out of an ecosystem, even more of the ecosystem gets screwed up before it can balance itself again. the same can apply to land.

However, considering that Xen creatures have no problems eating native wildlife. It may be possible that native wildlife can consume Xen wildlife. Who knows. Maybe dingos or wolves find that headcrabs taste really good.

 

[Darkside55]

We know that people can consume headcrabs and bullsquids without any adverse effects, so it's not hard to imagine our animals eating Xen creatures. Some creatures might have even adapted to eating them, or developed countermeasures to defend themselves against them.

And yes, Xenian creatures eating most of the food supply poses a big problem. However, in the case of leeches, they hang around closer to the shore so I doubt that animals further out into the sea (dolphins and sharks) would have to contend with them. Icthyosaurs, on the other hand...

About the initial number of creatures that arrived on Earth, I'd imagine that even a small colony of antlions teleported to an area inhabited by prey would cause a significant decrease in numbers. And the problem with antlions is that there really aren't many ways to "adapt" to them; they hunt by ground vibrations, and it isn't as if antelope will learn how to tiptoe, or wolves start climbing trees.

 

[ríomhaire]

We know that people can consume headcrabs and bullsquids without any adverse effects, so it's not hard to imagine our animals eating Xen creatures. Some creatures might have even adapted to eating them, or developed countermeasures to defend themselves against them.

And yes, Xenian creatures eating most of the food supply poses a big problem. However, in the case of leeches, they hang around closer to the shore so I doubt that animals further out into the sea (dolphins and sharks) would have to contend with them. Icthyosaurs, on the other hand...

About the initial number of creatures that arrived on Earth, I'd imagine that even a small colony of antlions teleported to an area inhabited by prey would cause a significant decrease in numbers. And the problem with antlions is that there really aren't many ways to "adapt" to them; they hunt by ground vibrations, and it isn't as if antelope will learn how to tiptoe, or wolves start climbing trees.

But they'd probably die out fast if a queen/king didn't wind up there too.

 

[Eejit]

And the problem with antlions is that there really aren't many ways to "adapt" to them; they hunt by ground vibrations, and it isn't as if antelope will learn how to tiptoe, or wolves start climbing trees.

Adapt the same way Gordon does. Stick to the rocks, i.e. move to rockier country/mountains.

As for icthyosaurs competing with terrestrial marine animals for food, well I don't see them eating Krill like whales do, so they should be ok.
Also since dolphins, orcas often travel in pods that should give them added protection from direct attack. Icthys could even be a new favourite food for orcas

 

[Flyingdebris]

In many cases I'd imagine that the new species would not immediately displace the native ones unless it its very dangerous, breeds like rabbits, and desires an area that another species needs.

For example. If there are wild Gargs running around the wastes, its doubtful that they are going to decimate any species since for all their deadliness, they are alot slower than their prey and incapable of stealth.

However antlions can easily decimate habitats. Perhaps not even through killing. All they have to do is infest a shore that a species of birds or sea mammals require for breeding and deny it from them, and BAM, goodbye local wildlife.

Leeches, it can thusly be assumed, that they bring about the ruin of fish like trout that have to travel to and from rivers throughout their lives since the leeches would eat anything entering or leaving the shallows. This in turn would cause animals that prey on such fish like bears or bigger fish to have a much harder time and possibly starve.

 

[_Z_Ryuken]

I wonder ho expansive the nubers of Xen's wildlife are exactly. Billions of creatures would have had to come through to make any difference.

I don't think they are as much of a threat outside the cities as within.

 

[Llama]

It didnt take billions of Europeans to wipe out the Aztecs, did it?

 

[Lightice]

It didnt take billions of Europeans to wipe out the Aztecs, did it?

A clash of cultures is a tad different from a clash of ecosystems. It (propably) didn't take billions of Combine to defeat the humanity.

In any case, it doesn't require billions of creatures to make a serious impact to Earth's ecosystem, but on the other hand, the same ecosystem has survived plenty of serious disasters, before. Most likely a great deal of species have extinct, especially the ones that were at risk, in the first place, but also plenty have almost certainly survived.

There are still forests on Earth and while some Xen-fauna may have settled to them, I'm certain that many of their original inhabitants have managed to keep at least parts of their ecological niches. Also, it should be noted that the Xen-creatures are out of their native enviroments. They are the ones with biggest problems to adjust to the current situation. Some, like the antlions have found enviroments that resemble their original habitats, but even they must eat and if they killed everything edible as soon as they got there, they'd starve to death. Personally, I don't think that the antlions are nearly as aggressive as seen in the game, outside their mating season, which was commented in the dialogue.

In whole, most of the Xen-monsters are just animals, that under everyday circumstances would most likely react like animals. The reason for their undue aggressivity in Half-Life 1 was most likely being teleported into an entirely unfamiliar enviroment with no place to run from potential attackers. The most hostile beings, like headcrabs propably weren't nearly as widespread in Xen, but in the resonance cascade an unusually large number ended up in the same place.