2.2 Threat: Agriculture
p. 72-79
Texte intégral
2.2.1 All farming systems

Likely to be beneficial
Retain or plant native trees and shrubs amongst crops (agroforestry)
1Seven studies evaluated the effects of retaining or planting native trees and shrubs amongst crops on bat populations. Two studies were in South America, four were in Mexico, and one was in Tanzania.
2COMMUNITY RESPONSE (7 STUDIES)
3Community composition (1 study): One replicated, site comparison study in Tanzania found different compositions of bat species in coffee plantations with different amounts and types of shade cover.
4Richness/diversity (7 studies): Four of six replicated, site comparison studies in Colombia, Mexico and Costa Rica found a similar number of bat species in shaded and unshaded coffee plantations, and in coffee plantations with different amounts and types of shade cover. The two other studies found more bat species and higher bat diversity in coffee, cacao and banana plantations with varied shade cover, than in plantations with a single shade species or no shade. One replicated, site comparison study in Tanzania found more bat species in shaded coffee plantations than in traditional mixed agroforestry systems with natural forest vegetation.
5POPULATION RESPONSE (5 STUDIES)
6Abundance (5 studies): Two replicated, site comparison studies in Mexico captured more bats in coffee plantations with varied shade cover than in plantations with a single shade species. One replicated, site comparison study in Mexico found higher activity (relative abundance) of forest bat species in plantations with a varied shade cover than in plantations with a single shade species, but the opposite was true for open habitat bat species. One replicated, site comparison study in Costa Rica found no difference in the number of bats captured between cacao and banana shade plantations and unshaded monocultures. One replicated, site comparison study in Tanzania found greater bat occurrence in shaded coffee plantations than in traditional mixed agroforestry systems with natural forest vegetation.
7BEHAVIOUR (0 STUDIES)
8Assessment: likely to be beneficial (effectiveness 55 %; certainty 50 %; harms 0 %).
9https://www.conservationevidence.com/actions/963
Use organic farming instead of conventional farming
10Twelve studies evaluated the effects of using organic farming instead of conventional farming on bat populations. Eight studies were in Europe, two in the USA, one in Canada and one in Chile.
11COMMUNITY RESPONSE (7 STUDIES)
12Community composition (1 study): One replicated, paired sites study in the USA found that the composition of bat species did not differ between organic and non-organic farms.
13Richness/diversity (7 studies): Five of seven replicated, paired sites or site comparison studies in Europe, the USA, Canada and Chile found that the number of bat species did not differ between organic and non-organic farms. The other two studies found more bat species on organic farms than non-organic farms.
14POPULATION RESPONSE (12 STUDIES)
15Abundance (12 studies): Five of nine replicated, paired sites or site comparison studies in Europe, the USA, Canada and Chile found that overall bat activity (relative abundance) and common pipistrelle activity did not differ between organic and non-organic farms. The other four studies found higher overall bat activity, bat feeding activity, Brazilian free-tailed bat activity, and activity of four of seven bat species on organic farms than non-organic farms. Two replicated, paired sites and site comparison studies in the UK found higher activity of Myotis species over water and rivers on organic farms than non-organic farms, but no differences were found for other species or habitats. One replicated, site comparison study in France found higher activity for two of three bat species over organic fields than two of three types of conventionally managed fields.
16BEHAVIOUR (0 STUDIES)
17Assessment: likely to be beneficial (effectiveness 60 %; certainty 60 %; harms 0 %).
18https://www.conservationevidence.com/actions/961
Unknown effectiveness
Create tree plantations on agricultural land to provide roosting and foraging habitat for bats
19Three studies evaluated the effects of creating tree plantations on agricultural land to provide roosting and foraging habitat for bats on bat populations. The three studies were in Australia.
20COMMUNITY RESPONSE (3 STUDIES)
21Richness/diversity (3 studies): Three replicated, site comparison studies in Australia found no difference in the number of bat species in agricultural areas with and without plantations of native trees.
22POPULATION RESPONSE (3 STUDIES)
23Abundance (3 studies): Two of three replicated, site comparison studies in Australia found no difference in bat activity (relative abundance) in agricultural areas with and without plantations of native trees. The other study found higher bat activity in plantations next to remnant native vegetation than in isolated plantations or over grazing land. In all three studies, bat activity was lower in plantations compared to original forest and woodland remnants. BEHAVIOUR (0 STUDIES)
24Assessment: unknown effectiveness (effectiveness 30 %; certainty 30 %; harms 0 %).
25https://www.conservationevidence.com/actions/958
Engage farmers and landowners to manage land for bats
26One study evaluated the effects of engaging farmers and landowners to manage land for bats on bat populations. The study was in the UK.
27COMMUNITY RESPONSE (0 STUDIES)
28POPULATION RESPONSE (1 STUDY)
29Abundance (1 study): One study in the UK found that during a five-year project to engage farmers and landowners to manage land for bats, the overall population of greater horseshoe bats at four maternity roosts in the area increased (but see summary below).
30BEHAVIOUR (1 STUDY)
31Change in human behaviour (1 study): One study in the UK found that a landowner engagement project resulted in 77 bat-related management agreements covering approximately 6,536 ha of land.
32Assessment: unknown effectiveness (effectiveness 55 %; certainty 20 %; harms 0 %).
33https://www.conservationevidence.com/actions/1936
Introduce agri-environment schemes
34Three studies evaluated the effects of agri-environment schemes on bat populations. The three studies were in the UK.
35COMMUNITY RESPONSE (0 STUDIES)
36POPULATION RESPONSE (3 STUDIES)
37Abundance (3 studies): Two of three replicated, paired sites study in the UK found that total bat activity (relative abundance) and the activity of six bat species did not differ significantly between farms managed under agri-environment schemes and those managed conventionally. The other study found significantly lower overall bat activity and activity of pipistrelle species on agri-environment scheme farms than conventional farms.
38BEHAVIOUR (0 STUDIES)
39Assessment: unknown effectiveness (effectiveness 35 %; certainty 30 %; harms 10 %).
40https://www.conservationevidence.com/actions/962
Manage hedges to benefit bats
41One study evaluated the effects of managing hedges to benefit bat populations. The study was in the UK.
42COMMUNITY RESPONSE (0 STUDIES)
43POPULATION RESPONSE (1 STUDY)
44Abundance (1 study): One replicated, paired sites study in the UK found that pipistrelle activity (relative abundance) did not differ between hedges managed for wildlife on agri-environment scheme farms and hedges on conventional farms.
45BEHAVIOUR (0 STUDIES)
46Assessment: unknown effectiveness (effectiveness 0 %; certainty 20 %; harms 0 %).
47https://www.conservationevidence.com/actions/1943
Reduce field size (or maintain small fields)
48One study evaluated the effects of maintaining small fields on bat populations. The study was in Canada.
49COMMUNITY RESPONSE (0 STUDIES)
50POPULATION RESPONSE (1 STUDY)
51Abundance (1 study): One study in Canada found that agricultural landscapes with smaller fields had higher activity (relative abundance) of six of seven bat species than landscapes with larger fields.
52BEHAVIOUR (0 STUDIES)
53Assessment: unknown effectiveness (effectiveness 60 %; certainty 30 %; harms 0 %).
54https://www.conservationevidence.com/actions/1939
Retain riparian buffers on agricultural land
55One study evaluated the effects of retaining riparian buffers on agricultural land on bat populations. The study was in the UK.
56COMMUNITY RESPONSE (0 STUDIES)
57POPULATION RESPONSE (1 STUDY)
58Abundance (1 study): One replicated, paired sites study in the UK found that pipistrelle activity (relative abundance) did not differ along waterways with buffers of vegetation on agri-environment scheme farms and waterways on conventional farms.
59BEHAVIOUR (0 STUDIES)
60Assessment: unknown effectiveness (effectiveness 40 %; certainty 20 %; harms 0 %).
61https://www.conservationevidence.com/actions/2284
Retain unmown field margins
62One study evaluated the effects of retaining unmown field margins on bats populations. The study was in the UK.
63COMMUNITY RESPONSE (0 STUDIES)
64POPULATION RESPONSE (1 STUDY)
65Abundance (1 study): One replicated, paired sites study in the UK found that pipistrelle activity (relative abundance) did not differ between unmown field margins managed for wildlife on agri-environment scheme farms and field margins on conventional farms.
66BEHAVIOUR (0 STUDIES)
67Assessment: unknown effectiveness (effectiveness 0 %; certainty 10 %; harms 0 %).
68https://www.conservationevidence.com/actions/1940
No evidence found (no assessment)
69We have captured no evidence for the following interventions:
- Increase the proportion of semi-natural habitat in the farmed landscape
- Manage ditches to benefit bats
- Plant field margins with a diverse mix of plant species
- Plant in-field trees
- Plant new hedges
- Provide or retain set-aside areas in farmland
- Retain existing in-field trees
- Retain remnant forest or woodland on agricultural land.
2.2.2 Livestock farming

Unknown effectiveness
Remove livestock modifications from water troughs
70One study evaluated the effects of removing livestock modifications from water troughs on bat populations. The study was in the USA.
71COMMUNITY RESPONSE (0 STUDIES)
72POPULATION RESPONSE (0 STUDIES)
73BEHAVIOUR (1 STUDY)
74Use (1 study): One replicated, paired sites study in the USA found that removing livestock modifications from water troughs resulted in bats drinking from them more frequently.
75Behaviour change (1 study): One replicated, paired sites study in the USA found that when livestock modifications were removed from water troughs, bats approached troughs fewer times before successfully drinking from them. Assessment: unknown effectiveness (effectiveness 60 %; certainty 30 %; harms 0 %).
76https://www.conservationevidence.com/actions/1951
No evidence found (no assessment)
77We have captured no evidence for the following interventions:
- Avoid the use of antiparasitic drugs for livestock
- Manage grazing regimes to increase invertebrate prey
- Replace culling of bats with non-lethal methods of preventing vampire bats from spreading rabies to livestock.
2.2.3 Perennial, non-timber crops

No evidence found (no assessment)
78We have captured no evidence for the following interventions:
- Introduce certification for bat-friendly crop harvesting regimes
- Prevent culling of bats around fruit orchards
- Replace netting with non-lethal measures to prevent bats from accessing fruit in orchards
- Restore and manage abandoned orchards for bats.
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