Journal of Applied Life Sciences International 23(2): 36-48, 2020; Article no.JALSI.55646 ISSN: 2394-1103 Structure of the Woody Stands of the Future Pre-Release Site of North African Ostrich (Struthiocameluscamelus(Linnaeus, 1858)) in Koutous, Niger Maïmounatou Ibrahim Mamadou1,2*, Maman Kamal Abdou Habou1, Thomas Rabeil3, Habou Rabiou1, Marie Petretto4 and Ali Mahamane1,5 1Faculté des Sciences Agronomiques, Université de Diffa, BP : 78, Diffa, Niger. 2Sahara Conservation Fund, BP: 981, Niamey, Niger. 3Directeur Exécutif Wild Africa Conservation, Niger. 4Marwell Wildlife, Colden Common, Winchester, SO21 1JH, UK. 5Faculté des Sciences et Techniques, Université Abdou Moumouni, BP : 10662, Niamey, Niger. Authors’ contributions This work was carried out in collaboration among all authors. Author MIM the lead author of the article, developed the research protocol, collected field data and wrote the manuscript. Author MKAH participated in the data collection and revision of the manuscript. Author TR contributed in the choice of the theme and the revision of manuscript. Author HR gave methodological advice for carrying out this work and revised the manuscript. Authors MP and AM contributed in supervising the work and revised the final version of the manuscript. Article Information DOI:10.9734/JALSI/2020/v23i230145 Editor(s): (1) Vasil Simeonov, University of Sofia, Bulgaria. Reviewers: (1) Sandra Elizabeth Perez, Argentina. (2) M. Kiley-Worthington, France. Complete Peer review History: http://www.sdiarticle4.com/review-history/55646 Received 12 January 2020 Accepted 20 March 2020 Original Research Article Published 24 March 2020 ABSTRACT This study aims to investigate the composition and Important Value Index (IVI) of the woody stands of Tchillala, a 130-ha area selected for future North-African ostriches (Struthiocameluscamelus) prerelease in the Koutous region in Niger. The forest inventory method was implemented in 42 plots of 50 m x 20 m (1000 m²) for tree-level observation, using stratified random sampling. For each woody specimen, the trunk diameter, total height and crown diameter have been recorded; _____________________________________________________________________________________________________ *Corresponding author: E-mail: [email protected]; Ibrahim et al.; JALSI, 23(2): 36-48, 2020; Article no.JALSI.55646 thespecimens with a trunk diameter smaller than 5 cm are considered as regenerations. A total of 17 woody species distributed across 10 families have been identified and most of them belongs either to the Mimosaceae (4 species) or the Tiliaceae (3 species). The plants density, domination and frequency were used to determine the IVI: Acacia tortilis and Balanitesaegyptiaca are the species with the highest IVI(118.43 and 88.28 respectively). The woody plants condition assessment has emphasized that trees have been facing natural (uprooting) and anthropogenic (cutting, pruning) threats. Consequently, the diameter class structures within the whole woody species community of Tchilala, as well as of the Acacia tortilis and Balanitesaegyptiaca, are mainly small size trees. The results of this study inform silvicultural management actions that would benefit to the North-African ostrich’establishment in Tchilala and the data collected are considered as possible indicators for long-term monitoring of habitat. Keywords: Tree inventory; struthiocameluscamelus; prerelease; habitat; dendrometry; koutous; Niger. 1. INTRODUCTION governmental organizations (NGOs) or citizens. These slowly-growing captive populations The relationship between species and their constitute a hope for the sub-species’ possible habitat is one of the central themes in animal return to areas where it previously existed in population ecology [1]. The habitat assessment Niger. is therefore a key step in any reintroduction planning. In particular, plants fulfill the important However, captive-raised animals of many ecological function of producing organic species have had poor success after compounds for herbivores in the bottom of the reintroduction into their natural habitat [8,9, food web, but they can also play the roles of 10,11]. To maximize survival, reintroduction refuge for fauna or soil modifiers. Within the plant candidates must be able to procure food and community, the woody species are amongst the shelter, develop anti-predator skills, interact good indicators as they are persistent properly with conspecifics, and orient (navigate, components of the macro-habitat. migrate, and/or disperse) in a structurally complex environment [12,13]. According to GleléKakai et al. [2], a methodological approach of the tree diameter The prerelease phase may alter behaviors in distribution is a good alternative to the study of ways assumed to be beneficial to survival [14, the woody stands life history [3,4] and would 15,16,17,18]. During this preliminary phase, the allow to infer the needed landscaping actions to animals to be released can be actively trained, restore or protect the natural habitat [5] when as demonstrated with birds trained for physical long-term monitoring is not available. fitness and anti-predatory behaviors that survived better than untrained birds [19]. The soft-release Additionally, as the animal species respond to method is another strategy that allows to their environment features, the vegetation progressively expose the animals to the new characteristics such as taxonomic composition, challenges they will have to face to survive in the size, condition and distribution, influence the wild. This is particularly indicated for endangered occupation of the habitat [1]. The physical species of which the ecology is little known, conditions (e.g., altitude, substrate) also often because the project managers will be able to impact on the plant formations, and indirectly on monitor the animals’ behavior and implement ad- the animal density [6]. The North African ostrich hoc mitigation solutions when needed. (Struthiocameluscamelus) is a giant flightless bird that was formerly widely distributed in the The North-African ostriches exhibit low Sahelo-Saharan region: it was endemic in Niger population growth rates with high variance, are but has disappeared from its natural environment subject to high environmental variation (e.g., since 2004 when the last male located in the annual fluctuations in hatching or chicks AïrandTénéré Natural Reserve died [7]. mortality), and have little genetic variability relative to their population size. Thus, ostrich An ongoing national conservation program reintroduction presents many challenges. supports captive breeding of North-African Therefore, the two NGOs involved the ostriches in three locations, namely Kellé, speciesconservation program in Niger, the Iferouane and Mainé-soroa, managed by non- Sahara Conservation Fund (SCF) and the 37 Ibrahim et al.; JALSI, 23(2): 36-48, 2020; Article no.JALSI.55646 Cooperative of Exploitation of Natural Resources of the trunk (in cm) with a tape measure, of Koutous (CERNK), have agreed to prepare diameter of the crown on the two perpendicular and fence a 130-ha prerelease area, named axes with a tape measure, the total height (m) Tchillala, in the Koutous. with a graduated pole. The diameter (D) was then calculated by the formula D = circumference In accordance with the International Union for / π. These measurements were taken on Conservation of Nature (IUCN)’s individuals with a trunk diameter greater than or recommendations for reintroduction, any equal to 5 cm. The individuals thinner than 5cm conservation translocation must be justified, with have been considered as juveniles and counted development of clear objectives, identification for regeneration rate. and assessment of risks, and with measures of performance. This study is part of the broader The condition of the individuals encountered has preliminary assessment of a prerelease site, been also classified in the following categories: focusing on the woody species. Indeed, the trees cutting, pruning and heaving. represent an important component of the habitat features, particularly in the Sahel, where they 2.3 Data Analysis provide permanent source of food and shade benefiting to herbivores, small fauna (birds and 2.3.1 Dendrometric parameters arthropods) and annual plants. We aim to determine baseline data that will help to The following dendrometric parameters were implement a long-term monitoring program of the calculated: woody stands in Tchilala and inform the development of habitat management activities for - Importance value index (IVI): the return of the North-African ostrich in the The importance of the different woody species in Koutous. the site was assessed with the IVI [21]. This index is expressed according to the following 2. MATERIALS AND METHODS formula: 2.1 Study Site IVI = FR (%) + RBA (%) + DR (%) (1) The site of Tchilala belongs to the Municipality of With: Kéllé, department of Gouré, Region of Zinder (Fig. 1). It is a 132.4-ha area surrounded by hills FR: is the relative frequency of a species, it is the in the form of mounds of the Continental ratio of its specific frequency (number of plots in Terminal, located between N13°51’40’’ and which it is present) to the total of specific N14°53’40’’ and E9°51’40’’ and E11°14’20’’. As frequencies; described by Saadou [20], it is located in the North Sahelian oriental sector phytogeographic RBA: relative basal area, it is the quotient of its subdivision of Niger. The area is characterized basal area (basal area) by the total of