What Works in Conservation 2021
| , , ,15. Terrestrial mammal conservation
15.12 Habitat restoration and creation
Texte intégral
Beneficial
Provide artificial dens or nest boxes on trees
1Thirty studies evaluated the effects on mammals of providing artificial dens or nest boxes on trees. Fourteen studies were in Australia, nine were in the USA, three were in the UK, one was in each of Canada, Lithuania, South Africa and Japan.
2COMMUNITY RESPONSE (0 STUDIES)
3POPULATION RESPONSE (6 STUDIES)
4Abundance (5 studies): Three of five controlled studies (three also replicated) in the USA, the UK, Canada and Lithuania, found that provision of artificial dens or nest boxes increased abundances of gray squirrels and common dormice. The other two studies found that northern flying squirrel and Douglas squirrel abundances did not increase.
5Condition (1 study): A replicated, randomized, paired sites, controlled, before-and-after study in Canada found that nest boxes provision did not increase body masses of northern flying squirrel or Douglas squirrel.
6BEHAVIOUR (27 STUDIES)
7Use (27 studies): Twenty-seven studies, in Australia, the USA, the UK, Canada, South Africa and Japan found that artificial dens or nest boxes were used by a range of mammal species for roosting and breeding.
8Assessment: beneficial (effectiveness 65 %; certainty 70 %; harms 0 %).
https://www.conservationevidence.com/actions/2584
Likely to be beneficial
Create or maintain corridors between habitat patches
9Four studies evaluated the effects on mammals of creating or maintaining corridors between habitat patches. One study was in each of Canada, the USA, Norway and the Czech Republic.
10COMMUNITY RESPONSE (0 STUDIES)
11POPULATION RESPONSE (0 STUDIES)
12BEHAVIOUR (4 STUDIES)
13Use (4 studies): Four studies (three replicated) in Canada, the USA, Norway and the Czech Republic found that corridors between habitat patches were used by small mammals. Additionally, North American deermice moved further through corridors with increased corridor width and connectivity and root voles moved further in corridors of intermediate width.
14Assessment: likely to be beneficial (effectiveness 70 %; certainty 50 %; harms 0 %).
https://www.conservationevidence.com/actions/2576
Manage vegetation using livestock grazing
15Six studies evaluated the effects on mammals of managing vegetation using livestock grazing. Four studies were in the USA, one was in Norway and one was in Mexico.
16COMMUNITY RESPONSE (0 STUDIES)
17POPULATION RESPONSE (1 STUDY)
18Abundance (1 study): A replicated, controlled, before-and-after study in the USA found that introduction of livestock grazing increased the abundance of Stephens’ kangaroo rat after two years.
19BEHAVIOUR (5 STUDIES)
20Use (4 studies): One of four studies (three replicated controlled studies and a before-and-after study), in the USA and Norway, found that sheep-grazed pasture was used by feeding reindeer more than was ungrazed pasture. One found mixed effects on Rocky Mountain elk use of grazed plots and another found no response of Rocky Mountain elk to spring cattle grazing. The forth study found cattle grazing to increase the proportion of rough fescue biomass utilized by elk in the first, but not second winter after grazing.
21Behaviour change (1 study): A replicated, paired sites study in Mexico found that in pastures grazed by cattle, Tehuantepec jackrabbits spent more time feeding than they did in pastures not grazed by cattle.
22Assessment: likely to be beneficial (effectiveness 50 %; certainty 50 %; harms 0 %).
https://www.conservationevidence.com/actions/2545
Provide artificial refuges/breeding sites
23Eight studies evaluated the effects on mammals of providing artificial refuges/ breeding sites. Two studies were in each of the USA, Spain and Portugal and one was in each of Argentina and Australia.
24COMMUNITY RESPONSE (0 STUDIES)
25POPULATION RESPONSE (4 STUDIES)
26Abundance (3 studies): Two studies (one controlled), in Spain and Portugal, found that artificial warrens increased European rabbit abundance. A replicated, randomized, controlled, before-and-after study in Argentina found that artificial refuges did not increase abundances of small vesper mice or Azara’s grass mice.
27Survival (1 study): A study in USA found that artificial escape dens increased swift fox survival rates.
28BEHAVIOUR (4 STUDIES)
29Use (4 studies): Four studies (two replicated), in Australia, Spain, Portugal and the USA, found that artificial refuges, warrens or nest structures were used by fat-tailed dunnarts, European rabbits, and Key Largo woodrats and Key Largo cotton mice.
30Assessment: likely to be beneficial (effectiveness 65 %; certainty 55 %; harms 0 %).
https://www.conservationevidence.com/actions/2583
Remove vegetation by hand/machine
31Twenty studies evaluated the effects on mammals of removing vegetation by hand or machine. Eleven studies were in the USA, and one each was in Canada, South Africa, Israel, Norway, Portugal, France, Spain, the Netherlands and Thailand.
32COMMUNITY RESPONSE (1 STUDY)
33Richness/diversity (1 study): A site comparison study in the USA found that mechanically clearing trees within woodland reduced small mammal diversity. POPULATION RESPONSE (12 STUDIES)
34Abundance (11 studies): Eight of 11 site comparison or controlled studies (nine of which were replicated), in the USA, Israel, Portugal, Spain and the Netherlands, found that clearing woody vegetation or herbaceous and grassland vegetation benefitted target mammals. Population or density increases were recorded for small mammals, European rabbits and Stephens’ kangaroo rat while black-tailed prairie dog and California ground squirrel colonies were larger or denser and Utah prairie dog colonies established better than in uncleared areas. Two studies found mixed results of clearing woody vegetation, with hazel dormouse abundance declining, then increasing and small mammal abundance increasing, then declining in both cleared and uncleared plots alike. One study found no effect of scrub clearance from sand dunes on habitat specialist small mammals.
35Survival (1 study): A replicated, site comparison study in the USA found that mechanical disturbance of woody vegetation within forest (combined with reseeding, follow-up herbicide application and further seeding) increased overwinter survival of mule deer fawns.
36BEHAVIOUR (8 STUDIES)
37Use (8 studies): Four of seven studies (of which six were site comparisons or controlled), in the USA, Canada, Norway, France and Thailand, found that areas cleared of woody vegetation or herbaceous and grassland vegetation were utilized more by mule deer, reindeer, mouflon and gaur. One study found that clearing woody vegetation promoted increased use by white-tailed deer in some but not all plots, one found that it did not increase use by mule deer and one found that carrying out a second clearance on previously cleared plots did not increase use by white-tailed deer. A before-and-after study in South Africa found that clearing woody vegetation from shrubland increased wildebeest and zebra abundance following subsequent burning but not when carried out without burning whilst other mammals did not show consistent responses.
38Assessment: likely to be beneficial (effectiveness 65 %; certainty 60 %; harms 0 %).
https://www.conservationevidence.com/actions/2550
Restore or create forest
39Five studies evaluated the effects on mammals of restoring or creating forest. Two studies were in the USA and one each were in Colombia, Italy and Australia.
40COMMUNITY RESPONSE (2 STUDIES)
41Richness/diversity (2 studies): Two site comparison studies (one replicated) in the USA and Colombia found that mammal species richness in restored forest was similar to that in established forest.
42POPULATION RESPONSE (2 STUDIES)
43Abundance (2 studies): One of two replicated studies (one a site comparison) in Australia and Italy found that replanted or regrowing forest supported a higher abundance of hazel dormice than did coppiced forest. The other study found only low numbers of common brushtail possums or common ringtail possums by 7–30 years after planting.
44BEHAVIOUR (1 STUDY)
45Usage (1 study): A replicated, site comparison study in the USA found that restored riparian forest areas were visited more by carnivores than were remnant forests when restored areas were newly established, but not subsequently, whilst restored areas were not visited more frequently by black-tailed deer.
46Assessment: likely to be beneficial (effectiveness 55 %; certainty 42 %; harms 0 %).
https://www.conservationevidence.com/actions/2570
Restore or create grassland
47Three studies evaluated the effects on mammals of restoring or creating grassland. One study each was in Portugal, the USA and Hungary.
48COMMUNITY RESPONSE (1 STUDY)
49Richness/diversity (1 study): A replicated, site comparison study in Hungary found that grassland restored on former cropland hosted a similar small mammal species richness compared to native grassland.
50POPULATION RESPONSE (3 STUDIES)
51Abundance (2 studies): A controlled, before-and-after study in Portugal found that sowing pasture grasses into areas cleared of scrub did not increase European rabbit densities. A replicated, site comparison study in Hungary found that grassland restored on former cropland hosted a similar abundance of small mammals compared to native grassland.
52Survival (1 study): A replicated, site comparison study in the USA found that seeding with grassland species as part of a suite of actions including mechanical disturbance and herbicide application increased overwinter survival of mule deer fawns.
53BEHAVIOUR (0 STUDIES)
54Assessment: likely to be beneficial (effectiveness 40 %; certainty 40 %; harms 0 %).
https://www.conservationevidence.com/actions/2566
Restore or create savannas
55Two studies evaluated the effects on mammals of restoring or creating savannas. One study was in Senegal and one was in the USA.
56COMMUNITY RESPONSE (1 STUDY)
57Richness/diversity (1 study): A replicated, randomized, paired sites, controlled study in the USA found that restoring savannas by removing trees increased small mammal diversity.
58POPULATION RESPONSE (2 STUDIES)
59Abundance (2 studies): A study in Senegal found that in a population of dorcas gazelle translocated into a fenced enclosure where vegetation had been restored, births outnumbered deaths. A replicated, randomized, paired sites, controlled study in the USA found that restoring savannas by removing trees did not, in most cases, change small mammal abundance.
60BEHAVIOUR (0 STUDIES)
61Assessment: likely to be beneficial (effectiveness 59 %; certainty 50 %; harms 0 %).
https://www.conservationevidence.com/actions/2568
Restore or create shrubland
62Three studies evaluated the effects on mammals of restoring or creating shrubland. Two studies were in the USA and one was in Mexico.
63COMMUNITY RESPONSE (2 STUDIES)
64Richness/diversity (2 studies): Two site comparison studies, in the USA and Mexico, found that following desert scrub or shrubland restoration, mammal species richness was similar to that in undisturbed areas.
65POPULATION RESPONSE (1 STUDY)
66Abundance (1 study): A site comparison study in the USA found that restored desert scrub hosted similar small mammal abundance compared to undisturbed desert scrub.
67BEHAVIOUR (1 STUDY)
68Use (1 study): A replicated, site comparison study in the USA found that restoring shrubland following tree clearance did not increase usage of areas by mule deer compared to tree clearance alone.
69Assessment: likely to be beneficial (effectiveness 45 %; certainty 40 %; harms 0 %).
https://www.conservationevidence.com/actions/2569
Unknown effectiveness
Apply fertilizer to vegetation to increase food availability
70Two studies evaluated the effects on mammals of applying fertilizer to vegetation to increase food availability. One study was in Canada and one was in the USA.
71COMMUNITY RESPONSE (0 STUDIES)
72POPULATION RESPONSE (0 STUDIES)
73BEHAVIOUR (2 STUDIES)
74Use (2 studies): Two replicated, controlled studies, in Canada and the USA, found that applying fertilizer increased the use of vegetation by pronghorns and Rocky Mountain elk.
75Assessment: unknown effectiveness (effectiveness 60 %; certainty 30 %; harms 0 %).
https://www.conservationevidence.com/actions/2577
Manage vegetation using grazing by wild herbivores
76Two studies evaluated the effects on mammals of managing vegetation using grazing by wild herbivores. One study was in the USA and one was in South Africa.
77COMMUNITY RESPONSE (0 STUDIES)
78POPULATION RESPONSE (2 STUDIES)
79Abundance (2 studies): A site comparison study in the USA found that areas with higher numbers of wild herbivore grazers hosted more small mammals than did areas grazed by fewer wild herbivores. A study in South Africa found that grazing by Cape mountain zebras did not lead to a higher population of bontebok.
80BEHAVIOUR (0 STUDIES)
81Assessment: unknown effectiveness (effectiveness 43 %; certainty 30 %; harms 0 %).
https://www.conservationevidence.com/actions/2548
Manage wetland water levels for mammal species
82One study evaluated the effects of managing wetland water levels for mammal species. This study was in the USA.
83COMMUNITY RESPONSE (0 STUDIES)
84POPULATION RESPONSE (1 STUDY)
85Abundance (1 study): A replicated, site comparison study in the USA found that managing wetland water levels to be higher in winter increased the abundance of muskrat houses.
86BEHAVIOUR (0 STUDIES)
87Assessment: unknown effectiveness (effectiveness 60 %; certainty 21 %; harms 0 %).
https://www.conservationevidence.com/actions/2574
Provide more small artificial breeding sites rather than fewer large sites
88One study evaluated the effects on mammals of providing more small artificial breeding sites rather than fewer larger sites. This study was in Spain.
89COMMUNITY RESPONSE (0 STUDIES)
90POPULATION RESPONSE (1 STUDY)
91Abundance (1 study): A replicated, controlled study in Spain found that smaller artificial warrens supported higher rabbit densities than did larger artificial warrens.
92BEHAVIOUR (0 STUDIES)
93Assessment: unknown effectiveness (effectiveness 60 %; certainty 30 %; harms 0 %).
https://www.conservationevidence.com/actions/2595
Restore or create wetlands
94Four studies evaluated the effects on mammals of restoring or creating wetlands. Three studies were in the USA and one was in the UK.
95COMMUNITY RESPONSE (2 STUDIES)
96Community composition (1 study): A site comparison study in the USA found that the composition of mammal species present differed between a created and a natural wetland.
97Richness/diversity (2 studies): Two site comparison studies (one replicated) in the USA, found that mammal species richness did not differ between created and natural wetlands.
98POPULATION RESPONSE (2 STUDIES)
99Abundance (1 study): A before-and-after study in the USA found that following marshland restoration, muskrat abundance increased.
100Survival (1 study): A replicated, controlled, before-and-after study in the UK, found that water voles persisted better in wetlands that were partially restored using mechanical or manual methods than they did in wetlands undergoing complete mechanical restoration.
101BEHAVIOUR (0 STUDIES)
102Assessment: unknown effectiveness (effectiveness 59 %; certainty 30 %; harms 0 %).
https://www.conservationevidence.com/actions/2572
Unlikely to be beneficial
Remove vegetation using herbicides
103Six studies evaluated the effects on mammals of removing vegetation using herbicides. All six studies were in the USA.
104COMMUNITY RESPONSE (0 STUDIES)
105POPULATION RESPONSE (4 STUDIES)
106Abundance (2 studies): Two controlled studies (one replicated) in the USA found that applying herbicide did not increase numbers of translocated Utah prairie dogs or alter mule deer densities in areas of tree clearance.
107Survival (1 study): A replicated, site comparison study in the USA found that applying herbicide, along with mechanical disturbance and seeding, increased overwinter survival of mule deer fawns.
108Condition (1 study): A replicated, controlled study in the USA found that applying herbicide did not reduce bot fly infestation rates of rodents and cottontail rabbits.
109BEHAVIOUR (2 STUDIES)
110Use (2 studies): Two replicated, controlled studies in the USA found that applying herbicide increased forest use by female, but not male, white-tailed deer and increased pasture use by cottontail rabbits in some, but not all, sampling seasons.
111Assessment: unlikely to be beneficial (effectiveness 30 %; certainty 42 %; harms 19 %).
https://www.conservationevidence.com/actions/2565
No evidence found (no assessment)
112We have captured no evidence for the following interventions:
-
Remove topsoil that has had fertilizer added to mimic low nutrient soil
-
Replant vegetation.
Table des illustrations
![]() | |
---|---|
URL | http://books.openedition.org/obp/docannexe/image/25460/img-1.jpg |
Fichier | image/jpeg, 80k |
© Open Book Publishers, 2021
Creative Commons - Attribution 4.0 International - CC BY 4.0