Altitudinal Variation on The Distribution of Butterflies in The Tofala Hill Wildlife Sanctuary, South West Region Cameroon

Enokenwa Allen Tabi1* , Mfonkwet Njiaghait Younchahou1

1 Association for Biodiversity Conservation and Rural Development (ABCARD), Cameroon.

*Corresponding Author: Enokenwa Allen Tabi, Association for Biodiversity Conservation and Rural Development (ABCARD), Cameroon, Tel: +237 677 037 976; Fax: +237 677 037 976; E-mail: allen.tabi@abcard.org enokenwatabiallen@gmail.com

Citation: Enokenwa Allen Tabi, Manole Cojocaru, Mfonkwet Njiaghait Younchahou (2022) Altitudinal Variation on The Distribution of Butterflies in The Tofala Hill Wildlife Sanctuary, South West Region Cameroon. SciEnvironm 5: 156.

Received: October 06, 2022; Accepted: October 26, 2022; Published: October 31, 2022.

Copyright: © 2022 Enokenwa Allen Tabi, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Butterflies are one of the most abundant insects in the planet but their populations have decreased over the last decades. However, very little or nothing is known about butterflies in the tropical rainforest of Tofala Hill Wildlife Sanctuary. This study is to determine the altitudinal variation on the distribution of butterfly species and assess species diversity in this tropical rainforest area. Butterfly distribution along 3 different altitudinal levels was assessed by the use of baits of fruits, collection of dead butterflies and the use of digital camera to take pictures of butterflies along recce between February 2016 and October 2017. Twenty-seven (27) butterfly species representing 6 families were recorded. One-way ANOVA test reveals that, there is a significant difference between the mean proportion of butterflies observed in the 3 altitudes, F=13.19, P-value=0.0000. Habitat modification and vegetation types at the different elevations might have influenced their distribution. This study is an important first step in butterfly conservation in the sanctuary. Future research work should consider other habitat variable and environmental factors associated with butterflies in the Tofala Hill Wildlife Sanctuary.

Keywords

Keywords: Butterflies, Diversity, Tofala Hill Wildlife Sanctuary, Tropical Rainforest

Introduction

According to [31] and [25], tropical rainforests are well known as centers of biodiversity. These tropical rainforests are under enormous pressure. Around half of the tropical forest that was present at the start of the twentieth century has of now vanished with deforestation at the highest level within the 1980s and 1990s [32]. Forest degradation, in the form of deforestation, plantation or development, destroys the habitat of most forest-living species [7,13,18]. One of the group of animals with diverse species richness is insects which represent over 50% of terrestrial biodiversity. Butterflies, not at all like most other groups of insects, are well known, well recorded and simple to recognize. They are well adjusted to the landscape and respond rapidly to any modification in their habitat as a result of human-induced exercises such as farmland creations and logging [19]. Reference [9] affirmed that modified habitats and anthropogenic activities often influencing butterfly species and their dynamics. Butterfly population depends on interconnection of breeding habitats scattered over the landscape which makes butterflies especially vulnerable to environmental degradation [29]. Lepidoptera made up about 1% of all named insects [17] and are one of the most intensively studied groups [3]. However tropical forest is characterized by high but poorly inventoried insect diversity and absence of basic biological and ecological information [10,21]. Butterflies are particularly suitable for analyzing patterns of insect diversity and the effectiveness of conservation measures [6,11]. Hence butterflies have often been used as “flagship taxa” to quantify the conservation value of habitat types affected by human activities [1,2,22,30]. Butterflies have been frequently used as bio-indicators due to their high species diversity, in addition to their wellknown taxonomy and life cycle [12,24]. Some species of butterflies are prolific plant pollinators, and many of these creatures have relatively high economic value as they are used for entertainment, decorative art, and collections [14], [27]. Lepidoptera also provide raw materials such as silks in the textile industry and are indicators of good health and quality in plants, climatic change and a healthy environment [16]. Butterflies, in particular, are known to be an excellent group for investigating the loss of traditional pastures and the resulting effects of vegetation encroachment [15,28]. Reference [20], mentioned that many studies show the relationship between altitude and changes in the composition and variety of butterfly species. Although considered as one of the most intensively studied group, little is known about the butterflies in the tropical rainforest of the Tofala Hill Wildlife Sanctuary (THWS). This study has as objectives to document the diversity of butterfly species and determine altitudinal variation of species distribution in the Tofala Hill Wildlife Sanctuary.

Methodology

Study Site The study was carried out in Tofala Hill Wildlife Sanctuary located between longitudes 9o52’30” to 9o59’25” East and Latitude 5o34’18” to 5o44’19” North. The study site is situated next to the Forest Management Unit 11-002 and the Mone Forest Reserve, South West region with a total surface area of 80.87 Km². Tofala Hill Wildlife Sanctuary is made up of rolling landscape, with Betchati found in the lower altitude (365m) and Fossimondin at the higher altitude (2000m). The topography enables water to flows from north to south of the Sanctuary.

Reference [8], explained in his work that, the zones is located in the humid tropical climate and has an average rainfall of about 3,500mm with the peak in August. The dry seasons begins from November to February and the rainy months from March to October with daily temperature variation between 20°c and 35°c, with the peak in March. (Figure 1) Figure 1: Location of Tofala Hill Wildlife Sanctuary

Data Collection

The study was conducted from February 2016 to October 2017. The area was sampled using 1km by 1km grids with laid down transects (recces) of different lengths. These recces were walked by a team made up of a leader, one assistant and a guide. The leader was responsible for reading the bearing, taking photos, and collection of dead specimens were necessary. The assistant was responsible for recording the GPS coordinates and the guide was the pathfinder and cutter of vegetation when necessary to facilitate passage and identification of starting points. Thirty (30) km of recce were surveyed. Butterfly species were assessed quantitatively across the different habitat types and altitudinal levels (elevations) using a global positioning system (GPSmap 62 GARMIN) and a digital camera (Sony DSC-W800). Fruit baits were placed in different parts of the recce to attract the butterflies and a digital camera was used to take pictures of butterflies. Also, some dead but intact butterflies were collected from the forest floor and place in a labelled paper folders in a tight plastic bag to maintain their forms and avoid moisture. Butterflies were recorded at the following altitudinal levels (0-300m, 300m-500m, and 500m-100m) in both primary and secondary forest of the Sanctuary.

Data Analysis

Butterfly was identified with the use of International Institute of Agriculture guide [26]. Data collected on butterflies were classified following the altitudinal ranges. The butterfly diversity and abundance were measured based on the species and frequency encountered. STATISTICA 12 was used to perform one-way ANOVA to analyse effect of altitude on the number of species and identify differences between the means following a significant ANOVA (pvalue <0.05). The tukey’s HSD (Honesty Significant Difference) was used to perform single step-multiple comparison of pairs of means.

Altitudinal variation of butterfly species

Butterflies were recorded in different altitudinal levels, 0-300m, 300-500m and 500-1000m in the Tofala Hill Wildlife Sanctuary (Table HSD (Honesty Significant Difference) was used to perform single step-multiple comparison of pairs of means. 

Results and Discussions

Diversity of Butterfly species

A total of 27 species representing 6 families of butterflies identified from 601 specimens were recorded in the Tofala Hill Wildlife Sanctuary (Table 1).

Table 1: Butterfly families with the respective number of specimens in THWS

Family

 No. of specimens recorded

% Specimens

 No. of species 

% Species

Nymphalidae

478

80

18

67

Lycaenidae

20

3

3

11

Pieridae

17

3

1

4

Hesperiidae

22

4

2

7

Polyommatinae

9

1

1

4

Papilionidae

55

9

2

7

Total

601

100

27

100

80% of the specimens recorded were from the family Nymphalidae which made up the highest number of butterfly species (67%). Majority of the butterfly specimens (330) were recorded at the altitudinal level between 300-500m and less specimens (61) in 0-300m. The number of butterflies at altitude 0-300m is less than 300-500m (2.17 ± 2.96; 12.11 ± 29.14, p=0.0001). The number of butterflies in altitude 0-300m is less than that of altitude 500-1000m (2.17 ± 2.96; 7.40 ± 7.76, p=0179). There is no significant difference between the number of butterflies in altitudes 300-500m and 500-1000m (p=.0559). However, the One-way ANOVA test reveals that there is a significant difference between the mean proportion of butterflies observed in the 3 altitudes (F=13.19, P-value=0.0000). The disparity in the number of butterflies recorded at the different altitudinal levels might be the fact that majority of the degraded areas made up of farmlands lies within 0-300m altitude. There is a homogenous vegetation type of mostly primary forest within 300-500m and 500-1000m. Mexosantha ethosea was the highest butterfly recorded in the area. Though this butterfly was recorded in all the altitudinal levels but majority of the specimens (30) were recorded in altitude 300-500m. They were mostly recorded in secondary forest and abandon farmlands in the THWS. Meanwhile the least recorded butterfly is Neptis mettala recorded mostly in an undisturbed forest. Although several studies have demonstrated that butterfly diversity and abundance decline with increasing altitude or elevation [23], the study in Tofala Hill Wildlife Sanctuary revealed otherwise. At altitude of 300-500m and 500- 1000m high abundance of butterfly were recorded with no significant difference.

 Table 2: Butterfly families and species recorded in different altitudinal levels in THWS. 

     

0-300m

300-500m

500-1000m

 

Common Name

Family

Scientific Name

 

Altitude

 

Total specimens

Orange-streak Acraea

Nymphalidae

Acraea bonasia

2

8

10

20

Forest Amiral

Nymphalidae

Antanartia delius

0

6

11

17

 Forest glade nymph

Nymphalidae

Arterica galene

0

7

3

10

Light Bush Brown

Nymphalidae

Bicyclus dorothea

10

25

10

45

Oberthur’s Pathfinder

Nymphalidae

Catuna oberthueri

4

6

20

30

Plain Tiger

Nymphalidae

Dananus chrypsippus

2

12

16

30

Ceres Forester

Nymphalidae

Euphaedra ceres

1

11

2

14

Janetta Forester

Nymphalidae

Euphaedra janetta

5

6

9

20

Dark Blue Pansy

Nymphalidae

Junonia oenone

2

18

30

50

Little Commodore

Nymphalidae

Junonia Sophia

5

20

15

40

Soldier Commodore

Nymphalidae

Junonia terea

5

10

15

30

Drusy’s Delight

Nymphalidae

Mexosantha ethosea

10

30

15

55

Serene Sailor

Nymphalidae

Neptis serena

1

40

4

45

Yellow-Base Sailer

Nymphalidae

Neptis mettala

0

2

0

2

Gaudy Commodore

Nymphalidae

Precis Octavia

0

8

2

10

Western Blue Butterfly

Nymphalidae

Protogoniomorpha cytora

0

5

0

5

Mother of Pearl

Nymphalidae

Protogoniomorpha parhasus

3

25

12

40

Nymphalidae

Euphaedra temeraria

0

10

5

15

Common Brown playboy

Lycaenidae

Deutorix antalus

0

5

0

5

Large Fairy Hairstreak

Lycaenidae

Hypolycaena antifaunus

0

5

2

7

Chalkhill Blue

Lycaenidae

Lysandra coridon

0

8

0

8

Common Grass Yellow

Pieridae

Eurema hecabe

7

5

5

17

Blue-Dusted Elfin

Hesperiidae

Sarangesa tertullianus

0

16

0

16

Obsolete White-Spots

Hesperiidae

Osmodes omar

2

3

1

6

Common Chalk Blue

Polyommatinae

Thermoniphas mycilus

0

6

3

9

African Swallowtail

Papilionidae

Papilio phorcas

2

15

18

35

African Swallowtail

Papilionidae

Papilio lormieri

0

18

2

20

Total

    61 330 210 601

However, less butterflies were recorded in 0-300m altitude. This might be due to the high rate of forest degradation. References [4] and [5], explained that butterflies are very sensitive to environmental changes, which may be a barrier to their movement along the altitudinal gradient. Some species show strong specificity to wetter, cooler, and windy conditions at higher altitudes and are typical butterfly species from mountain environments.

Conclusion

This study represents an important step in butterfly conservation in the Tofala Hill Wildlife Sanctuary. It will contribute to a checklist of butterflies in the area as well as to monitor success of conservation measures that use butterflies as indicators. Butterflies’ diversity and richness is associated with various habitat variables and environmental factors. In this study only the altitudinal gradient (elevation) was assessed. Future research on butterflies in the THWS can be improved by considering other habitat variables such as climatic conditions, vegetation and habitat type. (Figure 2-9).

Figure 2: Dead butterflies collected from the forest floor of THWS         

        

 Figure 3: Hypolimnas anthedon


Figure 4: Orange-streak Acraea on the forest floor of THWS.       

 

  Figure 5: Flip flop butterfly on the knuckles of a researcher in THWS.     

                                                 

Figure 6: Junonia species                                                                         

                                                                                                                                                        Figure 7: Unidentified butterfly species in THWS. 

 

 Figure 8: Blue diadem butterfly basking on the rainforest floor          

                                                                                                                                                           Figure 9: Plain Tiger.               

   

Competing Interest

The authors declare no competing interests.

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