The Humane Option That Is Not: Translocation Survival, the Vacancy Effect, and Why Wildlife Work Is Carpentry

1. Introduction: the choice that feels kind

A homeowner with a raccoon in the attic or squirrels in a soffit is offered, or asks for, live capture and release somewhere else. It is chosen over lethal control because it appears to be the humane option, and the transaction ends with everyone believing the animal is alive.

The follow-up literature does not support that belief, and the numbers are not close.

1.1 What this paper is and is not

It is an assembly of reported outcomes for translocated urban wildlife, and an argument that the intervention most people believe is humane is frequently the one that is not. It is not an argument for lethal control, and §18 sets out what we think the actual alternative is.

2. Two words that are not synonyms

The vocabulary matters because the two practices have different consequences.

Relocation is defined as moving an animal from one spot to another within its home range.⁷ Translocation is defined as the transport and release of wild animals from one location to another, with emphasis on nuisance and damage.⁸

2.1 Why the distinction is practical

An animal moved within its own home range is in territory it knows, among animals it has already negotiated with, near resources it has already located. An animal moved beyond it has none of those.

Almost everything in this paper concerns the second case, because that is what is being done when a homeowner drives an animal somewhere else and opens the trap.

3. The squirrel study

The clearest single result in this literature.

The study is reported in Animal Welfare as work on the movement and mortality of translocated urban and suburban grey squirrels.¹

Thirty-eight nuisance adult grey squirrels were removed from suburban sites and relocated to rural areas. Ninety-seven per cent died within three months of release, mainly as a result of predation and vehicle collisions.²

Reported another way, in a study of urban and suburban grey squirrels trapped and relocated to forest, 97 per cent of the squirrels were dead or had disappeared from the release area within 88 days, with predation suspected as a major cause of observed mortality.⁴³

3.1 The naivety mechanism

The proposed explanation is specific: naive prey species originating from urbanized localities are extremely susceptible to predation.²

A squirrel raised in a suburb has no experience of the predators in a woodland. Moving it to better habitat, in the sense of more trees, moves it into a community that has been hunting squirrels continuously and now has one that does not know how to be hunted.

3.2 The honest caveat on the numbers

The figure is reported both as died and as died or disappeared.²⁴ Disappearance from a release area is not proof of death, and radio tracking loses animals for reasons other than mortality. We return to this in §22.

4. The raccoon study

The Canadian result, which is the most directly relevant to this province.

In a 1989 Ontario study, 24 urban raccoons were fitted with radio collars and translocated 15 to 28 miles, that is 25 to 45 kilometres, north of Toronto. None returned to their original capture site, and mortality was near 50 per cent during the first three months following release. The authors suggested that homing behaviours are poor in raccoons and that mortality may have been as high as 75 per cent based on their evaluation of the condition of recaptured individuals.³⁴

4.1 The finding that cuts both ways

That none returned is the result most operators would treat as success. Read alongside the mortality figure it is less comforting, since an animal that does not return and does not survive has not been relocated so much as removed by a slower method.

4.2 The distance

Twenty-five to forty-five kilometres is a substantial move and more than most private translocations involve. Whether shorter moves produce better survival and more returns is a question the studies we located do not answer directly.

5. The weight loss observation

The detail that explains how the higher mortality estimate was reached, and the one we found most telling.

Individuals could not be located or were found to be losing weight at a time when they should have been storing fat prior to winter denning, and on that basis the authors concluded that the mortality rate may have approached 75 per cent during the first year.²

5.1 Why this is the important observation

It describes an animal that is alive at the point of measurement and failing. A survival figure at three months counts it as a success.

The seasonal element matters in a climate like this one. An animal released in autumn has a fixed and short window to find enough food in unfamiliar territory to survive a winter, and losing weight in that window is a death that has not happened yet.

5.2 When the calls come

One study noted that it was conducted in the autumn of each year because this is the time of year when most nuisance raccoon complaints occur.⁶

So the season that generates the service calls is the season in which a translocated animal has least margin. That alignment is unfortunate and, as far as we can tell, entirely unremarked in the consumer-facing material on this subject.

6. The bear comparison

A third species, included because the pattern holds across body sizes.

In one study the survival estimate for translocated nuisance black bears was 0.23, with 74 per cent of mortalities occurring within 120 days following release. Automobile collisions were the predominant cause, accounting for 10 of 19 fatalities.²

6.1 The road finding

Vehicle collision appears as a leading cause in both the squirrel and the bear results.² An animal searching unfamiliar ground crosses roads it has no established route around, and it does so repeatedly.

6.2 Age changes the outcome

A fourth species makes the age dependence explicit. Researchers translocating beavers to establish a new population reported 43 per cent survival at 360 days after release, with animals less than two years old experiencing complete mortality.⁹

The pattern recurs elsewhere. Survival of translocated males in red squirrels was higher for adults than for subadults, though sex was not correlated with survival in several other species examined.⁵

6.3 Why this matters for structural work

The animals removed from buildings are disproportionately females with young, or the young themselves, because a structure is chosen as a den site. If juveniles have the worst survival after translocation, then the animals a wildlife removal most often handles are the ones least able to withstand it.

We flag that inference as ours. The studies above were not conducted on animals taken from buildings.

7. Habitat quality

Where an animal is released turns out to matter as much as whether it is released.

One review of several relocation studies concluded that relocations to poor-quality habitats can result in survival rates averaging only 38 per cent.⁴

7.1 The selection problem

Release sites are chosen for legal access and convenience: public land, a roadside woodlot, somewhere far enough away and easy to reach. They are not chosen on an assessment of whether the habitat can support an additional animal.

Good habitat is generally already occupied, which is what makes it good habitat. So the sites available for release are biased toward the ones least able to absorb a newcomer, and we would flag that reasoning as ours.

8. Why the animals die

Assembling the mechanisms.

Survivability necessitates finding critical resources in an unknown environment in which they have no landmarks, and disorientation due to novel environments imparts a competitive disadvantage relative to locating food and refuge.²

Predation due to interspecific competition and surplus killing by resident predators may occur, where even a few predators can rapidly cause great damage to prey populations.²

8.1 The capture itself

The review literature notes that in some species, stress-related capture results in substantial mortality, and that capture-related mortality can contribute significantly.⁵

So a portion of the cost is incurred before the animal reaches the release site at all.

9. The stress response

A behavioural mechanism that links the release to the mortality.

The literature describes stress avoidance behaviour, whereby translocated animals attempt to escape the stress of the novel release environment by controlling the situation through an active searching for familiar home range.²

9.1 Why this is self-defeating for the animal

The response to being somewhere unfamiliar is to move, and moving in unfamiliar territory is what exposes an animal to roads, to predators and to resident competitors.

The behaviour that would resolve the stress in an animal that had merely wandered is the behaviour that kills one that has been driven forty kilometres.

10. Homing and dispersal

The variable outcome across species.

The review position is that translocations may have a detrimental impact on survival rates and lead to extreme dispersal movements, and that in other species, homing causes animals to leave the release area.⁵

For raccoons specifically, the Ontario authors suggested homing behaviours are poor, and none of their translocated animals returned to the capture site.³

10.1 The two failure modes

Either the animal returns, in which case the service achieved nothing, or it does not, in which case it is dispersing through unfamiliar country with the survival consequences in §3 to §6.

Both outcomes are reported in the literature for different species, which means the question of whether a given animal homes is not a detail. It determines which of the two failure modes a customer is paying for, and it is species-specific in a way that generic advice about relocation cannot capture.⁵

There is no third outcome in which it settles quietly nearby, except where habitat and social conditions permit it, and §7 suggests those are the conditions least often available.

11. When translocation does work

The counterexample, which is important for keeping this honest.

A 1973 South Carolina study translocated 10 raccoons nearly 250 miles with the goal of establishing a population, in an area where the raccoon population was known to be low. The researchers concluded that translocating raccoons into areas with low populations can be successful.³

11.1 What separates that case

The objective was conservation rather than nuisance removal, the release site was selected because it was under-occupied, and the work was planned around the animals' prospects.

Translocation for conservation purposes requires planning, a detailed analysis of the habitat, and consideration of the long-term prospects for survival of the released animals, with ecological, economic and societal consequences taken into account.³

11.2 The contrast

None of that describes a homeowner with a trap and a Saturday morning, and very little of it describes a commercial removal either. The same physical act has a different expected outcome depending on whether anyone assessed the destination.

11.3 The dissenting evidence

A contrary account exists and we think it should be on the record, particularly because it comes from the industry side rather than the advocacy side.

A statement recorded from a wildlife control operator describes a study originally designed to track 50 trapped and radio-collared squirrels over three years, which was terminated after the 1995 season due to lack of funding. Only 20 squirrels were trapped and data were provided for only seven. Of those seven, only one could be confirmed as a mortality, while others disappeared from the study area rather quickly, only to emerge later at neighbourhood bird feeders.⁷

11.4 How much weight that deserves

Seven animals is not a result. An underpowered study terminated for funding reasons cannot overturn a cohort of thirty-eight, and the source is a statement by an operator rather than a published paper.⁷

But it does bear directly on §3.2, the distinction between died and disappeared. Squirrels that vanished from a release area and turned up later at bird feeders were recorded as gone and were in fact alive. If a meaningful fraction of the disappearances in the larger studies are of that kind, the headline figures overstate mortality.

11.5 Where that leaves the argument

It narrows the strongest claim without touching the practical one. Even on the most favourable reading of disappearance, the raccoon study reports confirmed mortality near fifty per cent at three months from direct observation,³ and none of the vacancy, disease or resumed-behaviour findings depends on the mortality figures at all.

We would rather publish the weaker version of an argument that survives its best counterexample than the stronger version that does not.

12. The behaviour travels with the animal

An outcome that undermines the premise even when the animal survives.

The review literature reports that some animals resume the nuisance behaviour at the release site, that more than 25 per cent of wolves translocated to reduce livestock predation started to prey on livestock soon after release, and that relocated urban deer tended to maintain their tameness after translocation and continued to cause problems in or near residential areas.⁵

The conclusion drawn is that in highly urbanised landscapes, the probability that animals resume problem behaviour after translocation is potentially high.⁵

12.1 The implication

Nuisance behaviour is learned and retained, not a property of a location. An animal that has learned that buildings contain food and shelter continues to know that.

So a successful translocation, in the sense of a surviving animal, may simply relocate the complaint to somebody who has less recourse than a suburban homeowner.

13. The disease argument

The consequence for parties who were never involved in the transaction.

Wildlife translocation can have unanticipated consequences by facilitating disease spread.⁸ Moving animals moves their parasites, viruses, fleas and bacteria, potentially introducing disease to previously unexposed wildlife populations, and even short-distance translocations can introduce disease to vulnerable groups or expose the translocated animal to new ones.⁹

13.1 A specific example

A commercial source reports a 2023 study showing that translocated raccoons spread raccoon roundworm to uninfected populations.⁹ We have not read that study and the source sells removal services, so we report the claim as attributed rather than relying on it.

13.2 The risk runs both ways

The same source notes that short-distance translocations can expose translocated animals to new diseases as well as introducing disease to vulnerable groups.⁹

So the moved animal is both a vector and a susceptible host. An animal arriving without immunity to whatever circulates at the release site is another mechanism by which the survival figures in §3 to §6 could be produced, and it is one that post-mortem cause-of-death categories such as predation would not capture.

13.3 Why this is nobody's problem

Disease consequences fall on wildlife populations and, in the rabies case, on future public health budgets. No party to the original transaction bears any of it, which is the same externality structure this journal described for self-treatment of bed bugs.

14. The rabies case

The best-evidenced disease concern, and the one with a clear policy conclusion.

In a study of the spatial ecology of translocated raccoons, four animals crossed a 100 metre wide river after translocation, behaviour that was not documented among the same collared raccoons before translocation. The authors note that large increases in space use combined with the crossing of geographic barriers such as rivers may lead to elevated contact rates with conspecifics, which can heighten disease transmission risks, and conclude that the results underscore the need to discourage mesocarnivore translocations to prevent further spread of wildlife rabies.⁸

14.1 Why the river detail matters

Rivers and similar features are what slow the geographic spread of wildlife disease. An animal that would not normally cross one, and crosses it because it has been displaced, has carried whatever it is carrying across a boundary that was doing useful work.

This is a public cost created by a private decision, and it is not one the homeowner or the operator will ever see.

It is also the clearest case in this paper for treating translocation as a matter for regulation rather than for individual judgement. Where an activity's main cost falls on parties with no say in it, and where the person acting cannot observe that cost even in principle, asking people to decide well is not a workable control. The authors of the raccoon movement study reach the same practical conclusion from the disease side.⁸

15. The vacancy effect

The reason the property does not stay clear.

The proposition from the humane education literature is that if you trap and remove one animal, another will likely move into the vacuum you created when you removed the first from its territory.⁴

The illustration given is a newspaper account of a man who live-trapped and relocated nearly every wild animal that entered his yard, moving hundreds of grey squirrels and dozens of other animals over ten years, the point being that he did not have hundreds of squirrels at once: moving one out made room for others.⁴

15.1 The status of this claim

The mechanism is standard territorial ecology and we find it plausible. The illustration is a newspaper anecdote reported by an advocacy organisation, which is not evidence.⁴ We flag it as a well-motivated argument rather than a demonstrated result.

15.2 The connection to the rest of this journal

The same logic appeared in the rodent exclusion article. Removing individuals from a resource that remains available produces a vacancy that is filled, and the only durable intervention acts on the resource rather than on the occupants.

16. What the homeowner actually bought

Setting out the transaction plainly.

The homeowner paid to have an animal removed and believed they had chosen the humane option. On the evidence assembled here, what they most likely purchased is an animal that will die over the following weeks, a property with the opening still in it, and a vacancy that will be filled.

16.1 The cost figure

A 1988 North Carolina study suggested it may cost around 50 dollars per animal to relocate a raccoon.³ That is a historical figure from another jurisdiction and we include it only to note that the direct cost has never been the obstacle.

16.2 Why nobody discovers this

The animal leaves in a trap and the outcome occurs out of sight. There is no feedback from the release site to the customer, which is the same information structure this journal described for pheromone trap counts and for treatment efficacy generally: the buyer cannot observe the thing they are buying.

17. The untrained translocator

Who is actually doing this.

The review position is that translocations made by well-meaning but poorly informed and untrained private citizens are unlikely to give adequate consideration to habitat and other factors.⁴

17.1 The reading we would offer

The phrase well-meaning is doing real work there. The failure described is not cruelty or indifference; it is the gap between an intention and an outcome in a domain where the person acting has no way to observe the result.

That is the same structure as §16.2, and it is why we think this belongs in an ethics section rather than a technical one.

18. What the alternative is

The argument would be hollow without one.

The intervention that resolves a structural wildlife problem is closing the opening the animal is using, after the animal has left, so that the vacancy in §15 cannot be filled.

18.1 Why this is the humane option

An animal excluded from a building remains in its own home range, with its established territory, food sources and knowledge of local predators and roads intact. Every mechanism in §8 that kills a translocated animal is absent.

It also ends the recurrence, because the resource that made the building attractive is no longer available.

18.3 What the work consists of

Identifying the entry point rather than the animal, confirming the structure is empty, closing the opening in a material and at a standard the species cannot defeat, and correcting whatever made the opening available, which is usually deteriorated soffit, fascia, roof edge or vent screening.

That list is the rodent exclusion argument from this journal applied to a larger animal, and it runs into the same constraint identified there: the material and the fixing have to be selected against the animal's capabilities rather than against appearance.

18.2 Why it is sold less often

Exclusion is carpentry. It costs more than a trap, it takes longer, it requires working at height on a roofline, and the visible deliverable is a repair rather than a removed animal.

The customer wanting the animal gone today is offered the thing that looks like an answer, and this journal has now reached the same conclusion in rodent work, in decay and carpenter ant work, and here: the durable remedy is building work that the pest control transaction is not structured to sell.

19. The timing problem

The constraint that makes exclusion harder than it sounds, and it is a welfare constraint rather than a technical one.

Exclusion performed while dependent young are inside separates a mother from a litter she cannot reach. The young die in the structure and the mother causes further damage attempting to return.

19.1 The honest position

We have not located a controlled study quantifying that outcome, and we are stating it as established practice rather than as a sourced result. This journal's bat exclusion article examined the equivalent problem in a species where the timing is better documented.

The practical consequence is that the humane option is also a seasonal one, and that a job done in the wrong month is worse than either alternative discussed in this paper.

20. What we think an operator should say

That relocation is not a survival outcome. Ninety-seven per cent of one squirrel cohort and an estimated seventy-five per cent of one raccoon cohort did not survive the year.²³

That the opening is the problem. Removing the occupant leaves a vacancy that gets filled.⁴

That the season matters. Autumn release gives an animal no time to prepare for winter, and it is when most complaints occur.²⁶

That moving animals moves disease. Translocation is specifically discouraged in the context of wildlife rabies.⁸

That the behaviour goes with the animal. Nuisance behaviour is frequently resumed at the release site.⁵

That there is a right time to close the hole. Set out in §19.

That age affects the outcome. Juvenile survival after translocation is reported as substantially worse, and structures are chosen as den sites.⁵⁹

That the counterevidence exists. Set out in §11.3. A client entitled to the numbers is entitled to the qualification on them.

21. The uncomfortable part

The conclusion this evidence points toward is one we are not going to dress up.

If translocation kills most of the animals it is applied to, then the comparison between translocation and lethal control is not a comparison between life and death. It is a comparison between a death that is out of sight and delayed, and one that is immediate and accountable.

21.1 What we are not concluding

We are not arguing for lethal control. The argument of this paper is that exclusion outperforms both, and that the real choice in most structural wildlife jobs is between doing the carpentry and not doing it.

Where an animal must be removed, we would rather the person making the decision understood what the outcomes actually are than chose on the basis of which option sounds kinder. That is the whole point of setting the numbers out.

21.2 The regulatory note

Wildlife handling, relocation and trapping are regulated, and the rules vary by jurisdiction and by species. Nothing here describes what is permitted in Manitoba, and anyone acting should check current provincial requirements rather than rely on a trade publication.

22. Limitations and open questions

Most primary studies reach us through secondary sources. The squirrel, raccoon, bear and habitat-quality figures are quoted in an advocacy page, a humane society page and a federal technical series rather than read in the original journals.²³⁴ The figures are consistent across those independent sources, which is some reassurance, but we have not verified them against the papers.

Disappearance is not death. Noted in §3.2. Radio-tracking studies lose animals for several reasons and the squirrel figure is reported both ways in different summaries.²⁴

Two of the sources are advocacy organisations. Both oppose translocation, which is the conclusion this paper reaches, and readers should weigh that accordingly.²⁴

Two are commercial wildlife removal companies. Both sell exclusion services, which is the alternative this paper endorses.⁶⁹

The studies are old. The raccoon work is from 1989 and the squirrel work from 2004.²³ We found no recent large replication.

The vacancy illustration is an anecdote. Stated in §15.1.

The counterevidence is weaker than the evidence, and we have said so. Section 11.3 records an underpowered and unpublished industry observation that cuts against the headline figures.⁷ We include it because it bears on a real weakness in the mortality data, not because we think it overturns them, and a reader who wanted to argue the other side of this paper would start there.

We have not established what proportion of removals are translocations. A great deal of structural wildlife work is already exclusion-based, and this paper does not quantify how common the practice it criticises actually is in this market.

Section 19 is unsourced. Stated in §19.1.

Sections 7.1, 10.1, 16, 17.1 and 21 are our reasoning. The release-site selection bias, the two-failure-modes framing, the characterisation of the transaction, the reading of well-meaning, and the comparison in §21 are ours rather than sourced findings.

No Manitoba data. We have no provincial figures on translocation volumes, outcomes or regulation, and §21.2 declines to summarise the rules rather than risk getting them wrong.

Our commercial position. This company does structural pest work. An article concluding that wildlife jobs are carpentry is an article arguing that the valuable part of the work is the part that looks least like pest control.

23. Conclusion

Thirty-seven of thirty-eight grey squirrels moved to rural woodland were dead or gone within eighty-eight days, mainly through predation and vehicle collision.²⁴ Twenty-four city raccoons moved twenty-five to forty-five kilometres showed near fifty per cent mortality in three months, none returned, and the authors estimated the first-year figure may have approached seventy-five per cent after finding recaptured animals losing weight when they should have been laying down fat for winter.²³ A survival estimate of 0.23 has been reported for translocated nuisance black bears, with roads the predominant killer.²

Where animals do survive, the nuisance behaviour frequently survives with them,⁵ their parasites and pathogens travel too, and displaced raccoons have been documented crossing rivers they would not otherwise cross, which is precisely the kind of movement that spreads wildlife rabies across barriers that were containing it.⁸ Meanwhile the opening in the building has not changed, and the territory that was vacated gets occupied.⁴

The thing worth sitting with is that nobody in this chain intended any of it. The homeowner chose the option that sounded kind, the operator provided the service that was asked for, and the animal left alive in a cage. The outcome is invisible to everyone who made a decision, which is exactly the condition under which a practice can persist for decades without anyone having to defend it. The remedy is not a better trap. It is closing the hole, at the right time of year, and telling the customer plainly what the alternative actually buys.

References

1. Adams, L.W., Hadidian, J. and Flyger, V. (2004). Movement and mortality of translocated urban-suburban grey squirrels. Animal Welfare, 13, 45 to 50. The primary study behind the grey squirrel figures used throughout this paper. We cite it here for identification; the figures we quote are taken from the secondary sources at references 2 and 4, which attribute them to this study. The record also identifies the surrounding literature relied on elsewhere here, including Rosatte and MacInnes (1989) on relocation of city raccoons, Mosillo, Heske and Thompson (1999) on survival and movements of translocated raccoons in northcentral Illinois, and Craven, Barnes and Kania (1998), Toward a professional position on the translocation of problem wildlife, Wildlife Society Bulletin 26, 171 to 177. https://www.cambridge.org/core/journals/animal-welfare/article/abs/movement-and-mortality-of-translocated-urbansuburban-grey-squirrels/8EE6D9DA3DDAC20069B3A866D1623529
2. Ethics of Relocation of Wildlife. Wildlife advocacy organisation. Advocacy source opposing translocation, cited for the study findings it compiles and attributes. Used for the report, attributed to Adams and colleagues (2004), that when 38 nuisance adult grey squirrels were removed from suburban sites and relocated to rural areas, 97 per cent died within three months of release mainly as a result of predation and vehicle collisions, and that naive prey species originating from urbanised localities are extremely susceptible to predation; for the report, attributed to Rosatte and MacInnes (1989), of a 50 per cent mortality rate within three months following translocation of urban raccoons; for the observation, attributed to Craven and colleagues (1998), that individuals could not be located or were found to be losing weight at a time when they should have been storing fat prior to winter denning, with the conclusion that mortality may have approached 75 per cent during the first year; for the description, attributed to Dickens and colleagues (2010), of stress avoidance behaviour whereby translocated animals attempt to escape the stress of the novel release environment by actively searching for a familiar home range; for the report, attributed to Comly-Gericke and Vaughn (1997), of a survival estimate of 0.23 for translocated nuisance black bears with 74 per cent of mortalities within 120 days and automobile collisions accounting for 10 of 19 fatalities; and for the statements that survivability necessitates finding critical resources in an unknown environment in which the animal has no landmarks, that disorientation imparts a competitive disadvantage in locating food and refuge, and that predation due to interspecific competition and surplus killing by resident predators may occur. https://bigcatrescue.org/conservation-news/ethics-relocation-wildlife
3. Wildlife Translocation. United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Damage Management Technical Series. Government technical publication. Used for the account of a 1989 Ontario study in which 24 urban raccoons were fitted with radio collars and translocated 15 to 28 miles, that is 25 to 45 kilometres, north of Toronto, with none returning to the original capture site, mortality near 50 per cent during the first three months, the authors suggesting homing behaviours are poor in raccoons and that mortality may have been as high as 75 per cent based on the condition of recaptured individuals; for the account of a 1973 South Carolina study translocating 10 raccoons nearly 250 miles with the goal of establishing a population in an area of known low population, concluding that translocating raccoons into areas with low populations can be successful; for the report that 97 per cent of translocated squirrels died or disappeared from the release site within 88 days with predation suspected as a major cause; for the statement that translocation for conservation purposes requires planning, detailed analysis of the habitat and consideration of long-term prospects for survival, with ecological, economic and societal consequences taken into account; and for the reference to a 1988 North Carolina study suggesting a cost of around 50 dollars per animal to relocate a raccoon. https://www.aphis.usda.gov/sites/default/files/Wildlife-Translocation-WDM-Technical-Series.pdf
4. Trapping and Relocating Wildlife. Humane society. Advocacy source opposing translocation, cited for the study findings it compiles and attributes. Used for the report, attributed to Adams, Hadidian and Flyger (2004), that in a study of urban and suburban grey squirrels trapped and relocated to forest, 97 per cent were dead or had disappeared from the release area within 88 days; for the report, attributed to Rosatte and MacInnes (1989), of a 50 per cent mortality rate at three months post-release with the authors concluding mortality may have been as high as 75 per cent after one year; for the review finding that relocations to poor-quality habitats can result in survival rates averaging only 38 per cent, with the observation that translocations made by well-meaning but poorly informed and untrained private citizens are unlikely to give adequate consideration to habitat and other factors; and for the vacancy proposition that if one animal is trapped and removed another will likely move into the vacuum created, illustrated by a newspaper account of a man who relocated hundreds of grey squirrels and dozens of other animals over ten years. https://www.wihumane.org/resource/trapping-and-relocating-wildlife/
5. Can translocations be used to mitigate human-wildlife conflicts? Review of the literature on translocations of wild mammals with emphasis on problem animals. Used for the findings that translocations may have a detrimental impact on survival rates and lead to extreme dispersal movements; that in some species stress-related capture results in substantial mortality while in others homing causes animals to leave the release area; that some animals resume the nuisance behaviour at the release site; that more than 25 per cent of wolves translocated to reduce livestock predation started to prey on livestock soon after release; that relocated urban deer tended to maintain their tameness after translocation and continued to cause problems in or near residential areas; and that in highly urbanised landscapes the probability that animals resume problem behaviour after translocation is potentially high. https://www.researchgate.net/publication/236130807_Can_translocations_be_used_to_mitigate_human-wildlife_conflicts
6. Survival and Movements of Relocated Raccoons. Commercial wildlife control company summary of Mosillo, Heske and Thompson (1999), Journal of Wildlife Management 63, 278 to 286. Commercial source selling removal and exclusion services. Used for the description of the study design using three treatment groups of radio-collared raccoons, comprising urban and suburban animals captured by animal control officers in response to residential complaints, rural animals captured in a comparable forest preserve, and resident animals already living in the release preserve; and for the statement that the study was conducted in the autumn of each year because this is the time of year when most nuisance raccoon complaints occur. https://totalwildlifecontrol.com/resources/animal-relocation-studies/raccoons-survival-and-movements/
7. Moving Problem Wildlife. Internet Center for Wildlife Damage Management. Extension and information resource. Used for the definition of relocation as moving an animal from one spot to another within its home range, and for its bibliography identifying the primary literature relied on elsewhere in this paper. https://icwdm.org/management/euthanasia/moving-problem-wildlife/
8. Spatial ecology of translocated raccoons. PubMed Central PMC10300129. Peer-reviewed study. Used for the definition of wildlife translocation as the transport and release of wild animals from one location to another with emphasis on nuisance and damage, and the observation that it can have unanticipated consequences by facilitating disease spread; for the finding that four animals crossed a 100 metre wide river following translocation, behaviour not documented among collared raccoons before translocation; and for the conclusion that large increases in space use combined with the crossing of geographic barriers such as rivers may lead to elevated contact rates with conspecifics which can heighten disease transmission risks, underscoring the need to discourage mesocarnivore translocations to prevent further spread of wildlife rabies. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10300129/
9. The Truth About Relocating Nuisance Animals. Commercial wildlife removal company. Commercial source selling removal and exclusion services, cited as attributed material. Used for the restatement of the grey squirrel result that 37 of 38 adults died or disappeared within 88 days of translocation; for the report of a beaver translocation with 43 per cent survival at 360 days post-release and complete mortality among animals under two years old; for the statement that experts generally discourage wildlife translocation due to the risk of spreading diseases, since moving animals also moves their parasites, viruses, fleas and bacteria, potentially introducing disease to previously unexposed wildlife populations, and that even short-distance translocations can introduce disease to vulnerable groups or expose translocated animals to new diseases; and for the attributed claim, which we have not verified, that a 2023 study showed translocated raccoons spreading raccoon roundworm to uninfected populations. https://urbanjunglewildliferemoval.com/blog/should-you-relocate-animals/