African Small Mammals (Macroscelidea and Rodentia) Housed at the National Museum of Natural History and Science (University of Lisbon, Portugal)

Abstract

The National Museum of Natural History and Science holds a historical collection of 279 small African mammal specimens (Macroscelidea and Rodentia), representing 32 species, gathered during the Portuguese colonial period in Mozambique, Angola, and Guinea-Bissau. This study examines the collection, updates the small mammal species lists for each country, and highlights its importance as a historical baseline for biodiversity research. Rodents dominate the collection, reflecting their natural abundance and diversity, while Macroscelidea are less represented. The Angolan subset of the collection has the highest number of both specimens and species represented. Mozambique is underrepresented, and the Guinea-Bissau subset offers an extensive rodent representation of the country’s inventory. The most well-represented species are Gerbilliscus leucogaster, Lemniscomys striatus, Lemniscomys griselda (from Angola), and Heliosciurus gambianus (from Guinea-Bissau). Notably, the collection includes the neo-paratype of Dasymys nudipes (from Angola). Most species are common and not currently threatened, with geographic origin corresponding to savanna and forest habitats. These findings underscore the importance of integrating historical data and current biodiversity assessments to support multidisciplinary studies on target species, regions, or countries. In this context, the collection remains a valuable key resource for advanced research on African small mammals.

1. Introduction

Natural history museums serve as invaluable repositories of our cultural and natural heritage. By providing insights into global biodiversity, they play a crucial role in safeguarding collections of lesser-known species and poorly explored regions of the world [1,2]. This is particularly relevant for the largely understudied biological diversity across many African regions, as museums preserve vital records of species distributions, geographic locations, and historical time periods, ensuring their long-term accessibility for advanced research [3,4,5,6].

Although African fauna is renowned for its remarkable diversity, showcased for instance by a rich array of mammals ranging from iconic large species to lesser-known smaller ones, it remains poorly understood [7,8,9].

Most of the current knowledge on African mammals is derived from historical data gathered during organized expeditions, often focused on large game species, added by the studies of 19th century and early 20th century zoologists, who made significant contributions to the identification and description of many species across several taxa [10,11,12,13,14,15,16]. These early achievements have resulted in numerous specimens housed nowadays in museums, reflecting their critical role in documenting poorly known faunas.

Here, we describe the collection of sub-Saharan African small-sized mammals (represented by the orders Macroscelidea and Rodentia) housed at the National Museum of Natural History and Science (MUHNAC, University of Lisbon, Portugal), including specimens collected in Mozambique, Angola, and Guinea-Bissau. This collection was previously held by the Institute of Tropical Scientific Research (IICT) and was transferred to the MUHNAC in 2019, following the integration of the IICT into the University of Lisbon.

The primary mission of the IICT was to foster cooperation with countries in tropical regions, particularly the PALOPs (Portuguese-speaking African countries), by promoting access to their historical and scientific heritage. In alignment with this objective, the IICT developed a valuable collection of African mammals over the years, primarily assembled during various natural history expeditions and field surveys, as well as through donations and collaborative efforts [14,17,18,19]. In total, the IICT mammal collection includes approximately 950 records of 141 species, across 12 orders and five countries (including the three sub-Saharan African countries, referred above, plus São Tomé and Princípe and Cape Verde), covering the period 1945–1996.

The subset of sub-Saharan small mammals, from the above-mentioned countries, comprises 30% of the collection, most of which was established during Portugal’s colonial era, prior to Guinea-Bissau’s independence in 1973 and Mozambique’s and Angola’s independence in 1975.

The decades of social and political instability that followed the independence of these countries, marked by civil wars, coups, and guerrilla conflicts, severely hampered scientific research and limited the support of local authorities for conservation efforts, as priorities shifted toward addressing social inequalities and promoting economic development [9,20]. Over the years, the rapid growth of human populations, persistent poverty, wildlife exploitation, agricultural expansion, and the resulting habitat fragmentation and loss have significantly contributed to the population decline of many species [8,9,20,21], including some of the most iconic and threatened African large mammals such as the Black Rhino (Diceros bicornis), the African Forest Elephant (Loxodonta cyclotis), and the Lion (Panthera leo) (WWF https://www.worldwildlife.org/species/directory?direction=desc&page= 2&sort=extinction_status) (accessed on 8 April 2025).

However, due to limited research on smaller and less conspicuous species, the real impact of habitat loss and fragmentation on these species remains unclear [22,23,24,25]. As a result, current knowledge on small mammal diversity is mainly supported by studies conducted prior to the independence of Mozambique, Angola, and Guinea-Bissau. This has contributed to the predominance of historical records in the MUHNAC collection, a trend that is also observed in African natural history collections worldwide.

More recent knowledge has gradually expanded alongside growing conservation efforts by local authorities and NGOs to promote the sustainable use of mammal populations, which are aligned with their commitment to the principles of the Convention on Biological Diversity, the increasing establishment of protected areas, and the successful implementation of Action Plans for some rare species [26,27] (https://www.africanelephantfund.org/en/aeapobj1, accessed on 8 April 2025).

Comprehensive recent inventories of native terrestrial mammals in Mozambique and Angola were published in 2018 and 2019, respectively, estimating that more than 200 species occur in each of these countries, though this figure is likely an underestimate [23,25]. In Guinea-Bissau, knowledge of mammal diversity remains limited. The Strategy and National Action Plan for the Biodiversity 2015–2020 identifies approximately 130 mammal species in the country. However, this is presumed to represent only a fraction of the total mammal diversity, with many species yet to be discovered and documented [22].

The small mammal collection, housed at MUHNAC, here described and analysed, represents the most comprehensive collection of sub-Saharan African specimens in a Portuguese museum. We assessed the completeness of the collection in relation to each country’s updated species richness, making historical and geographical data available. By doing so we hope to emphasize the scientific and cultural significance of natural history museum collections as invaluable archives of global biodiversity, encouraging cooperative access and reinforcement of these repositories for future generations.

2. Material and Methods

• Brief geographical and ecological description and the mammal diversity in the sub-Saharan countries: Mozambique, Angola, and Guinea-Bissau

(i)

Mozambique

The Republic of Mozambique is located on the southeast coast of Africa and spans a total area of 801,590 km². Administratively, the country is divided in ten provinces and a capital city with provincial status.

According to the World Wildlife Fund for Nature (WWF) classification of priority ecoregions globally, Mozambique encompasses five major habitat types: (i) Tropical and subtropical moist broadleaf forests, found in southern Mozambique, (ii) Tropical and subtropical grasslands, savannas, and shrublands, covering extensive areas in the northern and central parts of the country, (iii) Flooded grasslands and savannas, including coastal floodplains in the deltas of the Zambezi, Pungwe, Buzi, and Save rivers, (iv) Montane grasslands and shrublands, extending over the western part of the country, and (v) Mangroves, which extends along the Indian Ocean coastline of Mozambique [20,28] (www.worldwildlife.org/publications/terrestrial-ecoregions-of-the-world, accessed on 18 April 2025).

This diversity of habitats sustains a rich fauna, including several threatened species. The most recent comprehensive inventory of native terrestrial mammals in Mozambique identifies 217 species, representing 14 orders, along with 23 species whose occurrence is uncertain [23]. Among the identified species, there is one Critically Endangered (CR) species, the Black Rhino (Diceros bicornis), whose trade is strictly regulated under Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Additionally, the list also includes three Endangered (EN) and seven Vulnerable (VU) species.

Carnivores represent the taxonomic group with the highest number of at-risk species, including the Endangered African Wild Dog (Lycaon pictus), and the Vulnerable Leopard (Panthera pardus), Lion (Panthera leo), and Cheetah (Acinonyx jubatus). In contrast, most of the small mammal species are classified as Least Concern (LC). The inventory refers as an exception within Macroscelidea the Dusky Sengi (Elephantulus fuscus) categorized as Data Deficient (DD) and within Rodentia the Vincent’s Squirrel (Paraxerus vincenti), an endemic species categorized as Endangered (EN).

In the years following the civil war, substantial efforts have been made to preserve natural resources that were severely depleted during the periods of social and political instability: Mozambique ratified the UN Convention on Biological Diversity (CBD) in 1995, and subsequently the Cartagena Protocol on Biosafety (hereinafter referred to as Cartagena Protocol) was ratified in 2003, and the Nagoya Protocol on Access and Benefit Sharing (hereinafter referred to as Nagoya Protocol) in 2014 (https://www.cbd.int/countries?country=mz, accessed on 18 April 2025).

(ii)

Angola

The Republic of Angola is situated on the west-central coast of Southern Africa, occupying an area of 1,246,700 km² administratively divided into 21 provinces. Approximately 50% of the country’s land area is covered by forests. The priority ecoregions identified by WWF highlight seven major habitat types in Angola: (i) Tropical and subtropical moist broadleaf forests, found along the Atlantic coast of the country, (ii) Tropical and subtropical dry broadleaf forests, occurring in a relatively small high-altitude area near the border with Zambia, (iii) Tropical and subtropical grasslands, savannas, and shrublands, covering most of central and southwestern Angolan plateau, (iv) Flooded grasslands and savannas, including seasonally or permanently flooded lowlands in the easternmost part of the country, (v) Montane grasslands and shrublands, located along the coast and on the inland slopes of the mountain range parallel to the coast, (vi) Desert and xeric shrublands, comprising a coastal desert and xeric region in southern Angola and (vii) Mangroves, found in the northern part of the country [20,28] (www.worldwildlife.org/publications/terrestrial-ecoregions-of-the-world, accessed on 18 April 2025).

Angola hosts a rich and diverse, though relatively understudied, mammalian fauna. A recent inventory of native terrestrial mammals documented 291 species across 13 orders [25]. Among these, two species are classified as Critically Endangered (CR), two as Endangered (EN), and 11 as Vulnerable (VU). The Critically Endangered species include the iconic Black Rhino (Diceros bicornis) and the Western Gorilla (Gorilla gorilla), both of which are listed under Appendix I of CITES. Also documented is the occurrence of the Critically Endangered Giant Sable (Hippotragus niger variani), a rare endemic subspecies of the Sable Antelope, that became the national symbol of Angola.

Carnivores and artiodactyls include some of the most charismatic at-risk species, such as the Endangered (EN) African Wild Dog (Lycaon pictus) and the Vulnerable (VU) African Golden Cat (Caracal aurata), Leopard (Panthera pardus), Giraffe (Giraffa camelopardalis) and Hippopotamus (Hippopotamus amphibius). The inventory also indicates that all Macroscelidea species are considered Least Concern (LC), along with most of the Rodentia species. However, several rodents are listed as Data Deficient (DD), while many others remain Not Evaluated (NE), together accounting for approximately 15% of the rodent species in the country.

Following the country’s independence, there was a prolonged decline in mammalian research, largely coinciding with the civil war from 1975 to 2002 [25]. However, during this period of instability, the Angolan government adhered to the principles of the Convention on Biological Diversity (CBD) and began its implementation in 1998. Moreover, in 2009, Angola signed the Cartagena protocol, and the Nagoya protocol in 2017. Most recently, a presidential decree established the National Biodiversity Strategy and Action plan for 2019–2025, outlining guidelines for conserving, preserving and protecting Angola’s rich diversity (https://www.cbd.int/countries?country=ao, accessed on 18 April 2025).

(iii)

Guinea-Bissau

The Republic of Guinea-Bissau, located on the West African Atlantic coast, spans an area of 36,125 km², and features a coastline extending 350 km. The country comprises a mainland territory and a group of islands, the Archipelago of Bijagós, a UNESCO Biosphere Reserve renowned for its exceptional biodiversity. Administratively, the country is divided into eight regions and one autonomous sector.

Accordingly to the WWF, two main habitat types are listed in the country: (i) Tropical and subtropical grasslands, savannas, and shrublands, stretching across the country, and (ii) Mangroves, predominantly found along the western coastal areas [20,28] (www.worldwildlife.org/publications/terrestrial-ecoregions-of-the-world, accessed on 18 April 2025).

The mammal fauna of Guinea-Bissau remains largely understudied. The Strategy and National Action Plan for Biodiversity 2015–2020 [22] reports the presence of 130 mammal species across 11 orders, including 20 rodent species—although these species are not described in detail (but see references therein). This figure updated data of a first comprehensive inventory of wild mammals, published more than two decades ago, listing 17 rodent species for the country [29]. It is estimated that approximately 19% of the mammal species in Guinea-Bissau are threatened, with the African Forest Elephant (Loxodonta cyclotis) being the only species currently classified as Critically Endangered (CR). Among small mammals, only the subspecies of Beecroft’s flying squirrel (Anomalurus beecrofti beecrofti) is considered rare and in need of protection.

The limited knowledge of biodiversity in Guinea-Bissau reflects the country’s repeated cycles of political and social instability, marked by numerous coups over several decades, dating back to the country’s independence from Portugal in 1973, that have also contributed to habitat fragmentation, soil erosion, and the depletion of water resources [30,31].

However, over the years, efforts have been made by local authorities to address and reverse this situation. Guinea-Bissau ratified the Convention on Biological Diversity (CBD) in 1996 and became a party to the Cartagena Protocol in 2010 (https://www.cbd.int/countries?contry=gw, accessed on 18 April 2025). In alignment with global commitments to preserving natural resources, the Strategic Plan mentioned above outlined several key goals, including improving biodiversity conservation, protecting ecosystems, species, and genetic diversity, halting the decline of the most threatened species, and raising public awareness about biodiversity and sustainable conservation practices.

2.

The Small Mammal Collection

The small mammal collection of MUHNAC consists of skulls and skins. Each specimen is labelled, and most are identified by a catalogue number, sex, locality, country, and date of collection. For many specimens body measurements are also available. The collection data can be made available upon request (www.museus.ulisboa.pt). Part of the collection has already been added to the GBIF network.

For the description of the three subsets of the collection, from Mozambique, Angola, and Guinea-Bissau, we followed several steps:

(i)

Each specimen was individually checked for labelling information, and corrections were made to the museum databases and digitized records when warranted;

(ii)

Specimens with missing information, particularly regarding species-level taxonomic identification, were discarded from the final description list and subsequent analyses unless this information could be completed;

(iii)

The retrieved specimens were organized following the taxonomic classification in Wilson et al. and Burgin et al. [32,33], and validated in agreement with the Mammal Diversity Database [34], which allowed to update the nomenclature of species to a currently valid scientific name;

(iv)

The species common names also align with those in Wilson et al. [32], with contributions from the AMS Database (MDD) [34];

(v)

Localities of occurrence were reviewed and, when needed, were updated to the current designation, using the GeoNames database (https://www.geonames.org/, accessed on 20 March 2025);

(vi)

To produce the final list, species were arranged alphabetically according to the hierarchy of taxonomic orders and families.

3.

Completeness of the Collection

To assess the completeness of the small mammal collection from each country, we employed two approaches.

First, for each country, we confirmed the current occurrence of all small mammal species (orders Macroscelidea and Rodentia) listed in the comprehensive inventories [22,23,25], using available mammal species compilation data by specifically reviewing the “Distribution” or “Geographic Range” sections [32,33,35]; this procedure also validated museum records and species common names, as referred above.

Second, recognizing that these inventories were published a few years ago, we conducted an additional extensive search for updates of the registered occurrences of small mammals in these countries using the GBIF, Web of Science, Scopus, and PubMed platforms. To ensure thorough confirmation, we extended our search to cover the past 10 years (2015–2025) for Mozambique and Angola, and 15 years (2010–2025) for Guinea-Bissau. The search strings were adjusted in accordance with the specifications of each database. The results were compiled into an Excel spreadsheet, and duplicate entries were removed. In the selected studies, we checked for the identification or description of new species for each country, excluding all records of species already listed.

The completeness of the collection was assessed by comparing the species richness in the museum (organized by order and family) with the updated reciprocal list for each country.

3. Results

3.1. The Sub-Saharan Mammal Collection

General Overview

The analysed small mammal collection consists of 279 specimens, representing 32 different species across ten families from the orders Macroscelidea and Rodentia—the only two small-sized mammal orders represented in the collection. Approximately three dozen additional specimens were excluded due to taxonomic inconsistencies, missing label information, or because they belonged to commensal species (e.g., the house mouse Mus musculus, and the brown rat Rattus norvegicus).

This collection is the most comprehensive of its kind in any Portuguese natural history museum and, despite its limited scope, is comparable in scale to several similar collections held by international institutions (see Supplementary Table S1).

The order Macroscelidea includes ten specimens from three different species within the family Macroscelididae, collected in Mozambique and Angola, while the order Rodentia has a better representation with 269 specimens from 29 different species across nine families out of the 15 families recorded for Africa [36], spanning the three target countries. The specimens were collected between 1948 to 1976, during the Portuguese colonial period in Africa.

The Macroscelidea subset from Mozambique is the most well-represented, comprising three species and eight specimens, compared to just one species and two specimens from Angola.

Among rodents, the family Muridae is the most dominant, with 184 specimens representing ten species from Angola (169 specimens) and four species from Guinea-Bissau (18 specimens), which accounts for more than half of the total specimens in the collection.

The family Sciuridae is also well-represented, with a total of 61 specimens spanning seven species from the three target countries: Mozambique (two species, six specimens), Angola (one species, one specimen), and Guinea-Bissau (four species, fifty-four specimens).

The remaining seven rodent families are less well-represented, comprising a total of 24 specimens from 12 species across all three countries (Figure 1).

Notably, the families Pedetidae and Gliridae are represented exclusively in the Mozambican subset, the Bathyergidae family is exclusively represented in the Angolan subset, and the Anomaluridae family is exclusively represented in the Guinea-Bissau subset (Figure 1).

Figure 1. Number of specimens and species per family and country included in MUHNAC collection.

Figure 1. Number of specimens and species per family and country included in MUHNAC collection.

3.2. Country Accounts

Below is a detailed description of the collection, including completeness rates at the family level, to better assess its intrinsic scientific value. These rates were determined by comparing the collection with updated inventories of Macroscelidea and Rodentia for the three countries, as mentioned above [22,23,25,29] (see Supplementary Tables S2–S4).

Notably, recent records have failed to confirm the continued presence of a few species that were previously reported based on limited historical data. However, none of these uncertain species are represented in the current collection. On the contrary, recent and ongoing studies—mainly conducted within protected areas—have documented the presence of new species in all three countries, thus expanding their respective species lists (

Table 1. Updated species numbers of Macroscelidea and Rodentia families for Mozambique, Angola, and Guinea-Bissau, in comparison with previous numbers, including number of species in MUHNAC and family completeness rate (N—total number of species per country in the updated lists); commensal species were excluded from both previous and final lists.

Order	Family	Previous Lists *	Final List #	MUHNAC Species	Completeness (%)
Mozambique
Macroscelidea N = 5	Macroscelididae	5	5	3	60
Rodentia N = 53	Nesomyidae	8	9	1	11.1
	Muridae	27	29	0	0
	Anomaluridae	1	1	0	0
	Pedetidae	1	1	1	100
	Hystricidae	1	1	1	100
	Thryonomyidae	2	1	1	100
	Bathyergidae	3	3	0	0
	Sciuridae	5	5	2	40
	Gliridae	3	3	1	33.3
Angola
Macroscelidea N = 2	Macroscelididae	3	2	1	50
Rodentia N = 89	Nesomyidae	15	15	2	13
	Muridae	48	52	10	19
	Anomaluridae	2	2	0	0
	Pedetidae	1	1	0	0
	Hystricidae	1	1	0	0
	Thryonomyidae	1	1	0	0
	Bathyergidae	2	2	1	50
	Petromuridae	1	1	0	0
	Sciuridae	9	8	1	12.5
	Gliridae	5	6	0	0
Guinea-Bissau
Rodentia N = 28	Anomaluridae	1	1	1	100
	Nesomyidae	1	1	1	100
	Muridae	7	17	3	18
	Hystricidae	1	2	1	50
	Thryonomyidae	1	1	1	100
	Sciuridae	4	4	4	100
	Gliridae	1	2	0	0

* Mozambique [23], Angola [25], Guinea-Bissau [22,29]. # This study.

, Supplementary Table S4).

(i)

Mozambique

The subset from Mozambique includes only ten species, three from the order Macroscelidea and seven from the order Rodentia. However, the representation of different taxonomic families within the collection varies significantly between the two groups, as detailed below (Table 1 and

Table 2. List of African small mammal species in MUHNAC collection, including common name, IUCN global categorization (DD—Data Deficient, LC—Least Concern; NK—Unknown), population trend (I—Increasing, S—Stable, D—Decreasing), and geographic location (Province or Region, Localities and Coordinates; LNK—location not known).

Order/Family	Species	Common Name	IUCN	Trend	Location Province/Region	Location Locality and Coordinates
Mozambique
MACROSCELIDEA	Elephantulus brachyrhynchus (Smith 1836)	Short-snouted sengi	LC	NK	LNK (3)
Macroscelididae	Rhynchocyon cirnei (Peters 1847)	Chequered sengi	LC	D	Niassa (1)	LNK (1)
	Petrodromus tetradactylus (Peters 1846)	Four-toed sengi	LC	NK	Sofala (4)	Gorongosa (4) 18°40′32″ S/34°4′22″ E
RODENTIA Pedetidae	Pedetes capensis (Forster 1778)	Spring hare	LC	NK	LNK (4)
Nesomyidae	Saccostomus cf.campestris (Peters 1846)	South African pouched mouse	LC	S	Sofala (1)	Gorongosa (1) 18°40′32″ S/34°4′22″ E
Hystricidae	Hystrix africaeaustralis (Peters 1852)	Cape porcupine	LC	S	LNK (1)
Thryonomyidae	Thryonomys swinderianus (Temminck 1827)	Greater cane rat	LC	NK	Maputo (2)	Maputo (2) 25°57′55″ S/32°34′59″ E
Sciuridae	Heliosciurus gambianus (Ogilby 1835)	Gambian sun squirrel	LC	NK	Sofala (1)	Gorongosa (1) 18°40′32″ S/34°4′22″ E
	Paraxerus cepapi (A. Smith 1836)	Smith’s bush squirrel	LC	S	LNK (2)
	Paraxerus palliates (Peters 1852)	Red bush squirrel	LC	NK	LNK (4)
Gliridae	Graphiurus murinus (Desmarest 1822)	Woodland dormouse	LC	S	Maputo (1)	Maputo (1) 25°57′55″ S/32°34′59″ E
Angola
MACROSCELIDEA Macroscelididae	Elephantulus brachyrhynchus (Smith 1836)	Short-snouted sengi	LC	NK	Moxico (2)	Cameia (2) 11°41′26″ S/20°50′21″ E
RODENTIA Nesomyidae	Saccostomus cf. campestris (Peters 1846)	Southern african pouched mouse	LC	S	Huambo (1)	Calombe (1) 11°50′16″ S/19°55′3″ E
	Steatomys pratensis (Peters 1846)	Fat mouse	LC	S	Moxico (4)	Cameia (4) 11°41′26″ S/20°50′21″ E
					Lunda Norte (1)	LNK(1)
Muridae	Aethomys kaiseri (Noak 1887)	Kaiser’s rock rat	LC	NK	Malanje (2)	Quimbango (1) 10°57′49″ S/17°34′28″ E Mulundo (1) 11°23′18″ S/17°43′47″ E
	Aethomys thomasi (de Winton 1897)	Thomas’s rock rat	LC	NK	Huíla (3)	Humpata (3) 15°4′21″ S/13°22′3″ E
					Cuando Cubango (10)	Cuchi (10) 14°38′14″ S/16°57′39″ E
	Dasymys cf. incomtus (Sundevall 1847)	African marsh rat	LC	NK	Malanje (5)	Quimbango (5) 10°57′49″ S/17°34′28″ E
					Cuanza Sul (6)	Mussende (6) 10°12′46″ S/15°58′34″ E
					Huambo (2)	Massano de Amorim (2) 12°21′13″ S/15°6′8″ E
					Cuando Cubango (1)	Dirico (1) 17°30′0″ S/20°50′0″ E
	Dasymys nudipes (Peters 1870)	Angolan shaggy rat	DD	NK	Cuando Cubango (4)	Dirico (1) 17°30′0″ S/20°50′0″ E Cuchi (3) 14°38′14″ S/16°57′39″ E
					Huíla (7)	LNK (1) Cuvango (1) 14°27′56″ S/16°17′32″ E Humpata (5) 15°4′21″ S/13°22′3″ E
					Huambo (1)	Massano de amorim (1) 12°21′13″ S/15°6′8″ E
	Gerbilliscus leucogaster (Peters 1852)	Bushveld gerbil	LC	S	Huíla (19)	Humpata (8) 15°4′21″ S/13°22′3″ E Quiteve (11) 16°1′4″ S/15°11′6″ E
					Malanje (11)	Quimbango (2) 10°57′49″ S/17°34′28″ E Mulundo (9) 11°23′18″ S/17°43′47″ E
					Cunene (10)	Naulila (10) 17°12′6″ S/14°40′50″ E
					Namibe (9)	Moçamedes (9) 15°11′46″ S/12°9′8″ E
					Benguela (1)	Farta (1) 13°8′54″ S/13°6′16″ E
					Moxico (3)	Cameia (1) 11°41′26″ S/20°50′21″ E Lago Dilolo (2) 11°30′15″ S/22°0′52″ E
	Gerbilliscus validus (Bocage 1890)	Savanna gerbil	LC	S	Malanje (14)	Luando (2) 11°0′51″ S/17°39′9″ E Quimbango (13) 10°57′49″ S/17°34′28″ E
	Lemniscomys griselda (Thomas 1904)	Griselda’s striped grass mouse	LC	S	Cunene (1)	Nehome (1)
					Huila (6)	LNK (2) Quiteve (4) 16°1′4″ S/15°11′6″ E
					Malanje (8)	Quimbango (4) 10°57′49″ S/17°34′28″ E Mulundo (2) 11°23′18″ S/17°43′47″ E Xandel (2) 9°23′11″ S/17°11′39″ E
					Cuanza Sul (7)	LNK (1) Cariango (2) 10°34′50″ S/15°19′46″ E Carilahongo (1) 10°45′45″ S/14°15′27″ E Ebo (1) 10°55′45″ S/14°44′41″ E Ipumba (1) 10°45′16″ S/14°12′6″ E Seles (1) 11°29′54″ S/14°29′23″ E
					Benguela (1)	Chongoroi (1) 13°35′21″ S/13°48′44″ E
					Moxico (3)	Calombe (1) 11°50′16″ S/19°55′3″ E Cameia (2) 11°41′26″ S/20°50′21″ E
	Lemniscomys striatus (Linnaeus 1758)	Typical striped grass mouse	LC	I	Uíge (20)	LNK (2) 31 de Janeiro (1) 6°53′53″ S/15°19′26″ E Banza Tumba(1) 6°28′28″ S/14°59′50″ E Cabinda (7) 7°19′20″ S/15°5′19″ E Lucunga (1) 7°34′0″ S/15°17′0″ E Negage (6) 7°45′33″ S/15°16′19″ E Quitexe (1) 7°56′24″ S/15°2′26″ E Songo (1) 7°8′0″ S/14°47′21″ E
					Malanje (4)	Xandel (2) 9°23′11″ S/17°11′39″ E Quizenga (2) 6°47′40″ S/15°31′49″ E
					Cabinda (5)	Cabinda (5) 5°33′43″ S/12°11′41″ E
					Moxico (4)	Calombe (1) 11°50′16″ S/19°55′3″ E Cameia (3) 11°41′26″ S/20°50′21″ E
	Pelomys fallax (Peters 1852)	Creek groove-toothed swamp rat	LC	NK	Moxico (1)	Cameia (3) 11°41′26″S/20°50′21″ E
Bathyergidae	Fukomys mechowii (Peters 1881)	Mechow’s mole-rat	LC	S	Moxico (1)	Calombe (1) 11°50′16″ S/19°55′3″ E
Sciuridae	Funisciurus congicus (Kuhl 1820)	Congo rope squirrel	LC	S	LNK (1)
Guinea-Bissau
RODENTIA Anomaluridae	Anomalurus beecrofti (Fraser 1853)	Beecroft’s scaly-tailed squirrel	LC	NK	LNK (1)
Nesomyidae	Cricetomys gambianus (Waterhouse 1840)	Northern giant pouched rat	LC	S	Tombali (1)	Cacine (1) 11°7′0″ N/15°1′0″ W
					LNK (2)
Muridae	Arvicanthis ansorgei (Thomas 1910)	Sudanian grass rat	LC	NK	Biombo (4)	Tor (4) 11°51′0″ N/15°54′0″ W
					Cacheu (1)	Canchungo (1) 12°26′0″ N/16°5′0″ W
	Mastomys natalensis (Smith 1834)	Natal multimammate mouse			Biombo (1)	Tor (1) 11°51′0″ N/15°54′0″ W
					Bafatá (1)	Chitole (1) 11°44′0″ N/14°49′0″ W
					Cacheu (4)	Canchungo (4) 12°26′0″ N/16°5′0″ W
					Tombali (1)	Cacine (1) 11°7′0″ N/15°1′0″ W
					LNK (2)
	Uranomys ruddi (Dollman 1909)	Rudd’s mouse	LC	D	Oio (1)	Bissorã (1) 12°13′23″ N/15°26′51″ W
Hystricidae	Hystrix cristata (Linnaeus 1758)	Crested porcupine	LC	NK	Bissau (2)	Bissau (2) 11°51′48″ N/15°35′51″ W
Thryonomyidae	Thryonomys swinderianus (Temminck 1827)	Greater cane rat	LC	NK	LNK (2)
Sciuridae	Funisciurus pyrropus (F. Cuvier 1833)	Fire-footed rope squirrel	LC	S	LNK (4)
	Heliosciurus gambianus (Ogilby 1835)	Gambian sun squirrel	LC	NK	Bafatá (2)	LNK (2)
					LNK (23)
	Heliosciurus rufobrachium (Waterhouse 1842)	Red-legged sun squirrel	LC	NK	LNK (7)
					Bafatá (1)	LNK (1)
					Oio (1)	LNK (1)
	Xerus erythropus (Desmarest 1817)	Striped ground squirrel	LC	NK	Biombo (1)	Tor (1) 11°51′0″ N/15°54′0″ W
					LNK (15)

, Figure 2, Figure 3 and Figure 4).

Order Macroscelidea

The three species in this order represented in the Mozambican collection include the Short-snouted Sengi (Elephantulus brachyrhynchus, locality unknown), the Chequered Sengi (Rhynchocyon cirnei, from Niassa Province), and the Four-toed Sengi (Petrodromus tetradactylus, from Sofala province), represented by three, one, and four specimens respectively.

E. brachyrhynchus is considered the most widespread species of sengi in the grasslands and savannas of central and southeastern Africa [37,38]. The distribution of the other two species, R. cirnei and P. tetradactylus, is associated with forests, montane habitats, and woodlands [39,40,41]. All three species are currently classified as Least Concern (LC) [35].

Order Rodentia

The rodent subset includes representatives from six of the nine families recorded in the country (Table 1), comprising seven species, with one to four species represented per family. No specimens from the families Muridae, Anomaluridae, or Bathyergidae are included in this subset. In total, the rodent subset from Mozambique includes 15 specimens.

The data compiled from online and literature search indicate that a single species from each of the families Pedetidae, Hystricidae, and Thryonomyidae occurs in Mozambique, respectively the Spring Hare (Pedetes capensis), the Cape Porcupine (Hystrix africaeaustralis), and the Greater Cane Rat (Thryonomys swinderianus). The Nesomyidae family is also represented in the collection by a single specimen of the South African Pouched Mouse (Saccostomus cf. campestris) [42].

Both the Spring Hare and the Greater Cane Rat are found throughout the country, favouring shrubland and grassland habitats. In comparison, the Cape Porcupine, is mostly found in the southern regions, tending to avoid forested areas [43,44,45,46,47]. The South African Pouched Mouse is primarily associated with savanna woodland habitats across almost the entire country [42].

The subset of the Sciuridae family in MUHNAC is represented by only two of the most widespread species in the country: Smith’s Bush Squirrel (Paraxerus cepapi) and the Red Bush Squirrel (P. palliatus), by two and four specimens, respectively. Both species are arboreal and diurnal. The Red Bush Squirrel is typically solitary and inhabits a variety of habitats, including moist forests and woodlands [48]. In contrast, Smith’s Bush Squirrel is a savanna woodland species that primarily lives in groups [49].

The Gliridae family is represented by a single species and a single specimen in the collection, the Woodland Dormouse (Graphiurus murinus), corresponding to 33% family completeness rate. The Woodland Dormouse has a scattered distribution throughout Mozambique and inhabits a range of environments, including woodlands, savannas, grasslands, and rocky areas [33,50].

The populations of most species in this subset are considered stable in the wild and in addition to their widespread distribution across the country all have been classified as Least Concern (LC) [35]. Except for the South African Pouched Mouse, represented by a single specimen from Sofala Province, and the Greater Cane Rat and Woodland Dormouse, whose specimens originated from Maputo Province, no precise collection locality is recorded for the remaining specimens in the rodent subset.

(ii)

Angola

A total of fifteen species is included in the collection, one from the order Macroscelidea and fourteen from the order Rodentia (Table 1 and Table 2, Figure 2, Figure 3 and Figure 4).

Order Macroscelidea

Two species of this order and the single Macroscelididae family are confirmed to occur in Angola; however, recent reports suggest the possible presence of two additional species, whose occurrence remains uncertain and requires further field surveys for confirmation [26,41]. The only Macroscelidea species represented in the MUHNAC collection from Angola is the Short-snouted Sengi (Elephantulus brachyrhynchus), with two specimens collected from Moxico Province. The Short-snouted Sengi is widely distributed across sub-Saharan Africa. In Angola, it inhabits grasslands and miombo woodlands [37,41]. As previously noted, the MUHNAC collection also includes specimens of this species from Mozambique.

Order Rodentia

This taxonomic group is represented by 179 specimens across four families: Nesomyidae, Muridae, Bathyergidae, and Sciuridae, each comprising between one and 53 specimens. The Nesomyidae family is represented by two species while the Muridae family includes 10 species. The Bathyergidae family is represented by a single species, and the Sciuridae family by just one species.

The two Nesomyidae species, the Southern African Pouched Mouse (Saccostomus cf.campestris), and the Fat Mouse (Steatomys pratensis) are classified as Least Concern, with their populations considered stable globally [42,51]. Both species inhabit savanna, woodlands, and cultivated fields. The Southern African Pouched Mouse complex has a widespread distribution in Angola and Central Africa [33] but is represented in the collection by just a single specimen collected in Huambo Province. The Fat Mouse, with five specimens in the collection, appears to have comparatively a more restricted range, mainly in the northern part of the country [33]. Samples in the collection were collected in Lunda Norte and Moxico Provinces.

Most of the ten Muridae species from the collection are categorized as Least Concern. An exception is the Angolan Shaggy Rat (Dasymys nudipes), classified as Data Deficient [52]. This species is native to the central highlands of Angola and is included in the collection by 12 specimens collected in Huambo, Huila, and Cuando Cubango Provinces. One of these specimens, a male from the Huila province is the neo-paratype of the species. The original type specimen housed in “Museu Bocage” in Lisbon [53], was destroyed in a devastating fire in 1978. Verheyen et al. [54] created a neo-paratype (collection reference 0701987) and neotype, housed in the American Museum of Natural History.

Notably, around half of the ten species, including the Angolan Shaggy Rat, have an uncertain global population trend, underscoring the need for more comprehensive ecological and biological studies. In addition, targeted taxonomic studies are also required to clarify the taxonomic composition of species complexes such as Dasymys cf. incomtus, included in the Angolan subset with 14 specimens collected in Malanje, Cuanza Sul, Huambo, and Cuando Cubango Provinces.

The most widely distributed murid species in Angola are the two Gerbilliscus species [55]: the Bushveld Gerbil (Gerbilliscus leucogaster), represented by 53 specimens in the collection, and the Savanna Gerbil (G. validus), represented by 15 specimens, all together collected in Malanje, Lunda Norte, Benguela, Huila, Namibe, Cunene, and Moxico Provinces, as well as the Natal Multimammate Mouse (Mastomys natalensis), with four specimens that originated from the Huambo and Moxico Provinces. All three species inhabit savanna, soft soils in grassland areas and are associated with agricultural fields [33]. The populations of the Multimammate Mouse are locally extremely common, being considered major agricultural pests [32,56,57].

Another species with a distribution range, spanning much of central and southern Africa as well as large parts of Angola, is the Creek Groove-toothed Swamp Rat (Pelomys fallax) [55]. Its distribution is likely partly associated with the occupation of cultivated areas [32]. This species is represented in the collection by a single specimen, which was collected in Moxico Province.

The Kaiser’s Rock Rat (Aethomys kaiseri) and the Thomas’s Rock Rat (A. thomasi) have relatively restricted distributions in Angola [32,33,55]. The two specimens of A. kaiseri in the collection originated from Malanje Province, while the thirteen specimens of A. thomasi were collected from Huila and Cuando Cubango Provinces. A few specimens in the collection belonging in Aethomys sp. were excluded from analysis due to uncertain taxonomic identification, highlighting the need for advanced methodologies to achieve a definitive classification.

Two other murid species in the collection have relatively restricted distributions in Angola. The Typical Striped Grass Mouse (Lemniscomys striatus) mostly occurs in grasslands, secondary and open dry forests [32,33,55,58]. The other Lemniscomys species in the collection, the Griselda’s Striped Grass Mouse (L. griselda) has also a restricted distribution in Angola occupying preferentially savanna-type habitats, but its populations are considered stable although the scarcity of ecological reported studies [32,33,55,59]. These species all together are represented in the collection by a total of 55 specimens collected in Cabinda, Uíge, Malanje, Cuanza Sul, Benguela, Huambo, Huila, and Moxico Provinces (see Table 2 for more details).

A single Bathyergidae species, is included in the collection, Mechow’s Mole Rat (Fukomys mechowii), categorized as Least Concern (LC). This is a highly adaptable colonial subterranean species with a wide distribution across the central and northeastern part of the country [33,60]. The single specimen in the collection originated from Huambo Province.

Similarly, only one Sciuridae species from Angola is represented in the collection—the non-threatened Congo Rope Squirrel (Funisciurus congicus)—with just a single specimen, lacking a precise collection location. However, this species is among the most widespread and population-stable rope squirrels in sub-Saharan Africa, occurring across nearly half of Angola and inhabiting the country’s westernmost provinces [33,61].

Figure 2. Maps of Mozambique (A), Angola (B), and Guinea-Bissau (C) showing provinces or regions from which MUHNAC samples were collected (see main text for further details).

Figure 2. Maps of Mozambique (A), Angola (B), and Guinea-Bissau (C) showing provinces or regions from which MUHNAC samples were collected (see main text for further details).

(iii)

Guinea-Bissau

The subset from Guinea-Bissau includes 11 rodent species, representing a taxonomic completeness of 41% (Table 1 and Table 2, Figure 2, Figure 3 and Figure 4).

This taxonomic group is represented in the collection by six rodent families: Anomaluridae, Nasomyidae, Muridae, Hystricidae, Thryonomyidae, and Sciuridae, each represented by one to four species, with between one and 25 specimens per species. In total, this subset comprises 77 specimens.

The families Muridae and Sciuridae are the most well-represented, each with four species, corresponding to 23% and 100% completeness rates, respectively. All three murid species included in the collection are widely distributed across Guinea-Bissau, the Sudanian Grass Rat (Arvicanthis ansorgei), the Natal Multimammate Mouse (Mastomys natalensis), and Rudd’s Mouse (Uranomys ruddi) [32,62]. The Sudanian Grass Rat typically inhabits grasslands and shrublands and is often regarded as an agricultural pest. The three specimens in the collection were obtained from Cacheu, Biombo, and Bissau Regions. The nine specimens of the Natal Multimammate Mouse were sampled across a larger area compared to the previous two species, including the Regions of Cacheu, Biombo, Bissau, and Tombali. This species is commonly found in areas associated with human activity. No global population trends for these two species [56,63], a situation mirrored in Guinea-Bissau due to limited ecological data. These species are found throughout the country.

Rudd’s Mouse (Uranomys ruddi), also widely distributed, is represented in the collection by a single specimen from the Oio Region. It preferentially inhabits grassland and shrubland habitats. Similarly, no population trends are known for Guinea-Bissau, although its populations are decreasing at a global level [32,62,64].

Within the Guinea-Bissau subset, sciurid specimens are the most dominant. The most well-represented species are the Gambian Sun Squirrel (Heliosciurus gambianus) and the Striped Ground Squirrel (Xerus erythropus) with 25 and 16 specimens, respectively. The Gambian Sun Squirrel is a common and widespread species found in savanna and woodland habitats [62]. However, only two specimens in the collection are recorded as originating from the Oio Region. The Striped Ground Squirrel is also widely distributed and exhibits a broad habitat preference, ranging from forests and drier woodlands to cultivated fields [62,65]. Only one specimen in the collection is recorded as having been collected from the Biombo Region. No data on population dynamics are available in Guinea-Bissau for either of these species.

The other two sciurid species in the collection are less well-represented, the Fire-footed Rope Squirrel (Funisciurus pyrropus) and the Red-legged Sun Squirrel (Heliosciurus rufobrachium), with four and nine specimens, respectively. Both species are common throughout their ranges inhabiting tropical moist forests and savannas [66,67]. More detailed ecological and population data are missing from Guinea-Bissau. There are no indications in the collection data where the specimens were collected.

The remaining four families, Anomaluridae, Nesomyidae, Hystricidae and Thryonomyidae, are each represented by one species, respectively Beecroft’s scaly-tailed squirrel (Anomalurus beecrofti), with one specimen, the Northern Giant Pouched Rat (Cricetomys gambianus), with three specimens, and the Crested Porcupine (Hystrix cristata) and the Greater Cane Rat (Thryonomys swinderianus) both with two specimens, corresponding to 100%, 100%, 50% and 100%, family completeness rates, respectively. The latter species is also represented in the Mozambican subset, confirming its wide range in sub-Saharan Africa [46,68].

All these species mostly occur in rainforest-savanna mosaics, woodlands, or agricultural areas [36,46,68]. No precise information is available regarding the collection sites of the specimens mentioned above, except for a single Northern Giant Pouched Rat specimen, which originated from the Tombali Region.

All species in the Guinea-Bissau subset are classified as Least concern (LC) [35].

Figure 3. Skull and skin of a neo-paratype specimen of Dasymys nudipes (Peters 1870) from Angola, including labelled data.

Figure 3. Skull and skin of a neo-paratype specimen of Dasymys nudipes (Peters 1870) from Angola, including labelled data.

Figure 4. Representatives of the most prominent families in the collection: (A): Petrodromus tetradactylus: (A1)—museum specimen (Mozambique); (A2)—Live specimen (Photo by Marc Henrion; https://www.inaturalist.org/observations/20260443, accessed on 2 June 2025); (B): Gerbilliscus leucogaster: (B1)—museum specimens (Angola); (B2)—Live specimen (Photo by Mike Richardson; https://www.inaturalist.org/observations/257799174, accessed on 2 June 2025); (C): Lemniscomys striatus: (C1)—museum specimens (Angola); (C2)—Live specimen (Photo by Alex R; https://www.inaturalist.org/observations/115185550, accessed on 2 June 2025); (D): Heliosciurus gambianus: (D1)—museum specimen (Guinea-Bissau); (D2)—Live specimen (Photo by marynvdlaarse; https://www.inaturalist.org/observations/194422419, accessed on 2 June 2025).

Figure 4. Representatives of the most prominent families in the collection: (A): Petrodromus tetradactylus: (A1)—museum specimen (Mozambique); (A2)—Live specimen (Photo by Marc Henrion; https://www.inaturalist.org/observations/20260443, accessed on 2 June 2025); (B): Gerbilliscus leucogaster: (B1)—museum specimens (Angola); (B2)—Live specimen (Photo by Mike Richardson; https://www.inaturalist.org/observations/257799174, accessed on 2 June 2025); (C): Lemniscomys striatus: (C1)—museum specimens (Angola); (C2)—Live specimen (Photo by Alex R; https://www.inaturalist.org/observations/115185550, accessed on 2 June 2025); (D): Heliosciurus gambianus: (D1)—museum specimen (Guinea-Bissau); (D2)—Live specimen (Photo by marynvdlaarse; https://www.inaturalist.org/observations/194422419, accessed on 2 June 2025).

4. Discussion

Sub-Saharan Africa is an environmentally diverse region, encompassing various ecoregions and habitats such as tropical and subtropical savannas and grasslands, tropical moist forests, dry forests, and mangroves [9,28]. This diversity, coupled with climatic variability, supports an extraordinary richness of mammalian species, including some of the world’s most iconic and threatened large mammals [9,69]. Small mammals are also notable for their taxonomic diversity and endemism [70].

However, not only have larger species been insufficiently studied but smaller ones are also among the least understood components of many ecosystems, considered underrepresented in existing checklists [22,23,24,25]. This knowledge gap can be largely attributed to decades of political and social instability across many African countries. These conditions have been further exacerbated by continuous human population growth, in conjunction with a range of environmental challenges, such as deforestation, soil erosion, desertification, and wetland degradation, which have constrained sustained investment in biodiversity research and conservation initiatives [9,71].

Mozambique, Angola, and Guinea-Bissau, like many other countries in Africa, have struggled for decades to gain independence and have a historical legacy of instability, which is reflected in the current limited understanding of their mammalian diversity. However, in recent years, authorities’ increased efforts, along with a stronger commitment to international regulations and conventions, have significantly improved current knowledge and the definition of legal conditions for biodiversity conservation.

One of the most significant contributions of local authorities to the advancement of research and conservation efforts has been the increased establishment of protected areas, which Hu et al. [72] regarded as a critical step toward enhancing biological knowledge.

The African small mammal collection at MUHNAC, consisting of specimens from the orders Macroscelidea and Rodentia, represents a regional collection as defined by Monfils et al. [6]. It includes a total of 279 specimens across 32 species, collected between 1946 and 1976. Specimens were collected during the Portuguese colonial era, highlighting the collection’s significance as a valuable baseline reference for more recent inventories. It is also part of the most comprehensive and well-preserved collection of African mammals housed in a Portuguese Natural History Museum, comparable in scope to many international collections.

Regarding the collection completeness, Macroscelidea species from both Mozambique and Angola exhibit a completeness rate of 60% and 50%, whereas rodents from these countries show considerably lower rates of 13% and 16%, respectively. In contrast, the rodent subset from Guinea-Bissau, with a completeness rate of 41%, represents a comparatively more thorough coverage of the country’s rodent taxa within the collection. However, when the completeness rate is assessed at the family level, values range from 11 to 100%. These completeness rates are influenced by the inclusion of several species in current mammalian inventories that were only recognized after the colonial period, particularly in recent decades. At the time the collection was originally assembled, it likely offered a more comprehensive representation of the small mammal diversity known in each country [15,17,23,73,74].

Moreover, despite their lower completeness rates compared to macroscelids, rodents are the most represented taxonomic group in the collection in terms of specimen numbers, though the majority of these specimens belong to just a few species. This pattern suggests that the collection may have been assembled opportunistically. The fact that nearly all represented species (with only one exception, the Angolan Shaggy Rat Dasymys nudipes, classified as DD) are considered non-threatened, with most showing stable global population trends, implies that the sampled species were likely the most abundant and easily trapped at the time and location of capture [75]. However, there is no data available to support this assumption, either in the museum archives or in published reports from organized expeditions. Additionally, biological and ecological data on small mammals remain also very scarce at the national levels, as already referred above.

In terms of geographic coverage, the Mozambican subset of the collection, unlike those from Angola and Guinea-Bissau, contains only a limited number of specimens with precise locality information on their labels. A few of these refer specifically to Gorongosa National Park in Sofala Province, one of the most extensively studied protected areas in Africa with respect to biodiversity (https://gorongosa.org/exploracao-da-biodiversidade/?lang=pt-pt, accessed on 20 April 2025). It is noteworthy that, in general, the distribution of small mammal species in Mozambique remains poorly documented, reflecting the broader pattern observed for mammals in general. Neves et al. [24] identified several provinces in the northern part of the country—namely Niassa, Cabo Delgado, Nampula, and Tete—as particularly lacking comprehensive data on terrestrial mammals. These provinces are also characterized by rapid human population growth and expanding agricultural development, both of which pose significant challenges to biodiversity conservation [24,76]. However, recent research efforts have been preferentially concentrated in certain areas, particularly within protected regions [77,78].

In Angola, the collection primarily covers the western part of the country, ranging from Cabinda and Uíge Provinces in the north to Cunene and Cuando Cubango in the south. This part of the country corresponds to the Angolan Escarpment zone, which extends from the forests of Cabinda to the Cunene River and is known to harbour a high number of vertebrate endemics, including mammals [9,79,80]. However, the populations of several species are today highly depleted due to hunting pressure during and after the civil war and persist only in reduced and fragmented areas [25]. Nevertheless, for small mammals, significant geographic gaps in knowledge regarding their distribution and persistence have not been identified across Angola. As in Mozambique, recent studies have focused on selected areas or protected parks [81], suggesting that small mammal occurrences in many regions remain relatively less investigated.

The small mammal collection from Guinea-Bissau predominantly originates from the westernmost regions of the country. The collection geographically covers five Regions, Oio, Cacheu, Biombo, Bissau, and Tombali, the latter located in the southernmost part of the country. The Bissau Region, which includes the capital city, is the most urbanized. The urban expansion which also affects also the Biombo Region has led to habitat degradation and increased hunting pressure, with direct negative impacts in faunal diversity. In contrast, the Tombali Region is one of Guinea-Bissau’s most biodiverse and least disturbed regions. Recent studies conducted in Guinea-Bissau’s protected areas have produced inventories of small mammal species [82,83,84]. Nevertheless, research on small mammals remains limited on other parts of the country, leading to significant geographic gaps in knowledge regarding their presence and distribution.

Most of the small mammals represented in the collection are species that predominantly inhabit savanna and forested habitats. This pattern is consistent with the geographic origin of the MUHNAC samples, from western Angola and Guinea-Bissau, and as well as the few Mozambican specimens with documented provenance, including those from Gorongosa National Park, an area predominantly covered by savanna (approximately 76%) with about 14% consisting of forested areas.

Africa’s savanna and forest ecosystems are among the most biologically diverse and ecologically significant landscapes on the planet [28,85]. While these ecosystems are renowned for their large and iconic mammal populations, it is relevant to recognize that small mammals also play vital roles within these ecological communities, contributing to key processes and the overall health of the entire system [32,62,85].

In summary, it is important to emphasize that a substantial part of current knowledge on small mammals, and mammals in general, in Mozambique, Angola, and Guinea-Bissau is still derived from studies conducted prior to the independence of these countries. Many of the more recently added species in national inventories have been identified through ongoing research projects supported by local authorities, primarily within protected areas, but reflecting a remarkable national commitment to conservation efforts and planning. Examples of such initiatives, along with their expected outcomes, are outlined in each country’s Strategic Plans, which are periodically submitted to the CBD as part of partner obligations. The knowledge gained from these efforts is expected to contribute in the near future to more detailed national assessments of species population dynamics and conservation status, with particular emphasis on small mammals.

However, significant taxonomic uncertainties still persist regarding many African species. As ecological, taxonomic and molecular studies progress, it is likely that alongside the identification of new species, others may be reclassified or cryptic species uncovered, further expanding current species inventories in each country. This perspective reinforces the urgent need for sustained investment in scientific research, particularly in areas beyond formally protected areas. It also highlights the importance of strengthening species representation in natural history museums [86], considering the critical role of museum collections as vital biodiversity archives for supporting multidisciplinary research over time.