Birds are key indicators of biological diversity (Gregory et al. 2003, Fraixedas et al. 2020) and habitat conditions (Smetzer et al. 2014, Whelan et al. 2015, BirdLife International 2018, Morelli et al. 2021). In mainland Africa, >2,000 bird species occur (Burgess et al. 2004), of which c.1,600 are endemic to sub-Saharan Africa (Jetz & Rahbek 2001). The largest number of these endemics is in the Albertine Rift, followed by the East African and Ethiopian Highlands (de Klerk et al. 2002). In Ethiopia, the region of Tigray has four Important Bird and Biodiversity Areas (IBAs), Lake Hashenge (sometimes incorrectly spelled Ashenge), Dessa'a forest, Hugumbirda and Gra-Kahsu (Hugumburda and Grat-Kahsu) forests, and Shire lowlands in the Tekeze Valley (Tilahun et al. 1996, Fishpool & Evans 2001, Ash & Atkins 2009, BirdLife International 2023a). Both Lake Hashenge and Hugumbirda and Gra-Kahsu forests are in southern Tigray, which region is characterised by a complex of mountains, a highland lake and plains, interspersed with a heterogeneous farmland mosaic that varies from relatively intact to substantially human-dominated. These characteristics also provide considerable potential to develop ecotourism in the region (Deribew et al. 2022).

Recently, both Hugumbirda and, especially, Gra-Kahsu forest have become increasingly fragmented and transformed into human-dominated landscapes. Raya Valley, though human dominated, remains a unique lowland habitat in Tigray, including agricultural fields, mixed plantations (coffee Coffea arabica, khat Catha edulis and fruits), Cactus pear Opuntia ficus-indica dominated habitat, Acacia woodland and wetlands. Lake Hashenge is also affected by farming, grazing, sedimentation and other human impacts (Yazew et al. 2013), yet is a unique aquatic habitat for resident and migratory bird species in the region (Alemayehu et al. 2017).

The avifauna of Tigray is sparsely known, although data from this region were included in the two benchmark publications on Ethiopian and Eritrean birds (Urban & Brown 1971, Ash & Atkins 2009). Taking data from Ash & Atkins (2009), we found the avifauna of Tigray and southern Tigray (i.e. the study area) to comprise 473 and 283 bird species, respectively.

Recent publications (Hering et al. 2015, Rannestad 2016, Dove et al. 2017, Gedeon et al. 2017, Buechley et al. 2019, 2022) have detailed new species and other notable records, as well as providing annotated checklists for poorly known parts of the Horn of Africa. Nevertheless, these studies were all the product of relatively short visits by a small number of researchers. Ongoing habitat change and human population growth have prompted us to document the avian diversity of Tigray. Here, we document new bird records for southern Tigray made during 2018–20. We also include information on habitat preferences and spatiotemporal patterns. Furthermore, we assessed land use and land cover (LULC) change using GIS and remote-sensing tools between 1985, 2000 and 2020, to examine trends in habitat modification due to anthropogenic activity.

Study area and Methods

Study area.—Located c.600 km north of Addis Ababa and 160 km south of Mekelle, capital of Tigray National Regional State, between 12°14′50″–12°52′11″N and 39°20′59″–39°52′30″E, at 949–3,699 m, the total area of southern Tigray is 10,139.3 km² and that of the study area is 2,328.24 km². With reference to Ash & Atkins (2009: 63) map squares, the study area lies mostly in half-degree squares 31b and 31d, with very small extensions into 31a and 31c (Figs. 1–2).

Hugumbirda and Gra-Kahsu State Forest is spread across Raya Azebo, Endamekoni, Ofla and Raya Alamata districts. The state forest is at 1,500–3,000 m and is part of the dry evergreen Afromontane forest and grassland complex (hereafter DAF). Dominant trees are African juniper Juniperus procera and African olive Olea europaea cuspidata (Woldemichael et al. 2010). The lowland area (Raya Valley) is at 949–1,600 m. The valley's vegetation comprises Acacia-Commiphora woodland and bushland (hereafter ACB) (Friis et al. 2010).

Figure 1.

Location of the study area in Ethiopia and of bird records in southern Tigray.

Due to human disturbance (including infrastructure development), the Raya Valley is currently characterised by fragmented Acacia woodland, settlements, farmland with scattered trees and mixed plantations (Table 1, Fig. 2), and is also affected by overgrazing and invasive plant species (e.g. Parthenium hysterophorus, Prosopis juliflora, Coleus sp.). The major land use land cover (LULC) categories in the study area are bare land, farmland, forest, grassland, settlements and water (Fig. 2). As the area covers both lowlands and highlands, mean annual min. temperature varies from 14–30°C in the lowlands (Raya Alamata and Raya Azebo districts) to 8–25°C in the highlands (Ofla district), respectively (Yemane et al. 2020).

Methods.—The study was conducted between 2018 and 2020. We used point counts (n = 134) to census birds along elevational gradients in Hugumbirda and Gra-Kahsu State Forest (relatively intact natural habitat). Other sites were surveyed using line transects (n = 22) in the human-dominated landscape at Raya Valley, and at Lake Hashenge and the surrounding grazing land and farmland (Fig. 3). Field visits were generally conducted 2–4 times a month in the morning (06.00–09.00 h) and evening (16.00–18.00 h) in the dry season (October–June). Birds were identified using the field guide by Redman et al. (2011).

TABLE 1

Description of habitat types at various localities, mostly human-dominated ecosystems, in southern Tigray, Ethiopia. Abbreviations: DAF = Dry evergreen Afromontane forest and grassland complex, and ACB = Acacia-Commiphora woodland and bushland proper (Friis et al. 2010).

Figure 2.

Land use land cover (LULC) change maps of the study area in southern Tigray from 1985 to 2020.

Figure 3.

Habitat types in southern Tigray from left to right: (top) farmland at Facha Hara and Acacia woodland at Sera Addi Ebo; (middle) Acacia-Commiphora woodland and bushland at Hada Alga and cactus pear Opuntia ficus-indica between Chekon and Facha Gama; and (bottom) Lake Hashenge and dry evergreen Afromontane forest and grassland complex at Hugumbirda, all December 2018 (Mulugeta Kiros)

We compared our new records with previously documented occurrence based on tetrad coverage by Ash & Atkins (2009). For inclusion herein, the criteria for new bird records were: (1) major range extension; (2) minor range extension, first report in Tigray; (3) discrepancy between distributions in different sources (Ash & Atkins 2009, Redman et al. 2011, BirdLife International 2023a, Gill et al. 2023); and (4) taxonomic questions. Some species met more than one criterion. A major extension is defined as previous occurrence only in remote tetrads, whereas a minor extension involves species previously recorded in directly adjoining tetrad/s but not those we surveyed. For taxonomy, we follow Gill et al. (2023).

Remote sensing data.—Land use and land cover (LULC) change maps were produced using Landsat Thematic mapper (TM 1985), Landsat Enhanced Thematic Mapper plus (ETM+ 2000) and Landsat Operational Land Imager (OLI 2020) captured in January and February during the dry season. Landsat images ( https://earthexplorer.usgs.gov), including TM, ETM+ and OLI were acquired for 2 January 1985, 5 February 2000 and 19 January 2020, respectively. We used bands 1–5 and 7 of TM and ETM+ and bands 1–7 of OLI for image analysis and classification. These Landsat images cover path 168 and rows 51–52 of TM and ETM+ and 51 of OLI. All bands used had 30 m resolution. Standard supervised classification was performed using ERDAS IMAGINE software and max. likelihood algorithm was applied. Overall accuracy and kappa coefficient were checked to assess the accuracy of the classified images.

Results

Species accounts.—We recorded 287 bird species in the study area during the period (2018–20) of which 55 were new for southern Tigray (  Supplementary Information (BBRC_143_4_03Abrha et al_Southern Tigray (Ethiopia) avifauna_Supplementary Info.docx)). Thirteen of the records were new for Tigray, of which eight involved major range extensions. Based on the criteria above, 13 new taxa for Tigray and four taxa new for southern Tigray are described below.

WHITE-BREASTED CORMORANT Phalacrocorax lucidus

First records for Tigray. Commonly encountered at Lake Hashenge (12°36′09″N, 39°30′14″E; 2,442 m) in association with other waterbirds in December 2018 and April 2019, including a non-breeding adult and a juvenile there on 17 April 2019 (Fig. 4).

Figure 4.

Non-breeding adult (left) and juvenile White-breasted Cormorants Phalacrocorax lucidus with Egyptian Geese Alopochen aegyptiaca, a Great White Pelican Pelecanus onocrotalus, African Sacred Ibis Threskiornis aethiopicus and Northern Shoveler Spatula clypeata, Lake Hashenge, Ofla, Ethiopia, April 2019 (Abadi Mehari Abrha)

EASTERN GREY WOODPECKER Dendropicos spodocephalus

First records for Tigray. A pair was constructing a nest cavity on 17 March 2018 at Facha Hara (12°25′44″N, 39°36′17″E; 1,457 m). A total of eight was recorded in Acacia woodland at St Rufael churchyard (Werrabbaye; 12°43′29″N, 39°38′20″E; 1,752 m) and Facha Hara on 26 May 2019 (Fig. 5). We also recorded a male and female at Alamata (12°24′57″N, 39°33′26″E; 1,563 m) on 28 May 2019, and a pair was found nesting in wooded grassland at Dessa'a Forest Reserve on 29 December 2019 (13°40′02″N, 39°46′25″E; 2,363 m). Another individual was seen feeding on the bark of the bamboo Yushania alpina in the Choke Mountains in Amhara National Regional State in 2019 (10°37′23″N, 37°46′42″E; 3,100 m). Ash & Atkins (2009) stated that the species is recorded only to 1,820 m in Ethiopia.

Figure 5.

Female (left) and male Eastern Grey Woodpecker Dendropicos spodocephalus with a nest cavity in a snag of umbrella thorn Vachellia tortilis, Facha Hara, Raya Alamata, Ethiopia, March 2018 (Abadi Mehari Abrha)

BLANFORD'S LARK Calandrella blanfordi erlangeri

First records for Tigray. C. b. erlangeri is endemic to the central highlands of Ethiopia (Ash & Atkins 2009). It was found over large areas of Tigray, but especially in highland habitats of southern Tigray (Hashenge; 12°35′33″N, 39°31′30″E; 2,453 m; Fig. 6). The first record was on 28 February 2018. The species was also identified at Alula Abba Nega International Airport (13°28′30″N, 39°31′56″E; 2,231 m, tetrad 23d) and at Mekelle University Endayesus campus (13°28′37″N, 39°29′06″E; 2,197 m, tetrad 23d). We also encountered C. b. blanfordi in the Atsbi highlands (13°38′37″N, 39°46′30″E; 2,727 m, tetrad 23d) and in Dessa'a Forest Reserve (13°56′51″N, 39°43′46″E; 2,430 m, tetrad 23d). In our study area, C. b. erlangeri is a farmland and grassland specialist. Breeding males in December 2018 climbed c.40–60 m above ground, singing for 2–5 minutes while circling.

Figure 6.

Blanford's Lark Calandrella blanfordi erlangeri, around Lake Hashenge, Ofla, Ethiopia, February 2018 (Abadi Mehari Abrha)

HORSFIELD'S BUSH LARK Mirafra javanica marginata

First record for Tigray. One was recorded on 7 January 2019 on unploughed farmland at Jihan Erra (12°25′39″N, 39°34′26″E; 1,523 m), feeding in carrot grass Parthenium hysterophorus, an invasive weed species (Fig. 7). The subspecies marginata, previously treated in Singing Bush Lark M. cantillans, is now considered part of Horsfield's Bush Lark M. javanica (Gill et al. 2023).

Figure 7.

Horsfield's Bush Lark Mirafra javanica marginata in harvested Eragrostis tef; the green weed is the invasive carrot grass Parthenium hysterophorus, Jihan Erra, Raya Alamata, Ethiopia, January 2019 (Abadi Mehari Abrha)

AFRICAN STONECHAT Saxicola torquatus albofasciatus

First records for Tigray. S. t. albofasciatus is nearly endemic to Ethiopia, reaching marginally into South Sudan and Uganda (Gill et al. 2023). An adult male and female were recorded on the highland plateau of Endodo (12°38′11″N, 39°32′02″E; 2,556 m), near Lake Hashenge on 18 November 2018 and 10 March 2019 (Fig. 8). Two were also recorded on 24 May 2017 in the Atsbi highlands in eastern Tigray (13°53′19″N, 39°43′38″E; 2,705 m). Only Siberian Stonechat S. maurus variegatus, a Palearctic winter visitor, has previously been recorded in much of northern and eastern Tigray (Ash & Atkins 2009).

Figure 8.

Male (above) and female African Stonechat Saxicola torquatus albofasciatus, Addibbo Mosa (Tabiya Hashenge), Ofla, Ethiopia, November 2018 (Abadi Mehari Abrha)

RÜPPELL'S STARLING Lamprotornis p. purpuroptera

First records for Tigray. Throughout the study period, L. p. purpuroptera was very common in Acacia woodland at Facha Hara (12°25′40″N, 39°36′17″E; 1,462 m) and Addis Kigni (12°24′46″N, 39°37′8″E; 1,441 m). Moreover, we encountered several adults with juveniles around the villages of Bora (12°26′30″N, 39°33′52″E; 1,606 m) and Harksa (12°26′04″N, 39°33′32″E; 1,584 m) at the foot of Mt. Gra-Kahsu in December 2018 and January 2019 (Fig. 9). The longer-tailed L. p. aeneocephalus has previously been recorded in north and west Tigray and in a small part of western Ethiopia bordering Sudan (Ash & Atkins 2009). Recently, L. p. aeneocephalus was also confirmed to occur in Kafta Shirao National Park (Buechley et al. 2022; AMA, KG & TT pers. obs.).

Figure 9.

Rüppell's Starling Lamprotornis p. purpuroptera, Addis Kigni, Raya Alamata, Ethiopia, December 2018 and January 2019 (Abadi Mehari Abrha)

CHESTNUT-CROWNED SPARROW-WEAVER Plocepasser superciliosus

First records for southern Tigray. Common in lowland Acacia woodland from Harksa (12°26′35″N, 39°33′10″E; 1,627 m), near Alamata, to Kukufto (12°37′13″N, 39°38′29″E; 1,646 m), at the foot of Hugumbirda and Gra-Kahsu forests. A male and female were recorded nestbuilding in the lower branches of a Vachellia xanthophloea on 25 January 2019 (Fig. 10). The most important nest materials were Eragrostis tef, Parthenium hysterophorus and other dry herbaceous species. The nest typically differs from other weavers because the dried plant material is interleaved into a complex structure without intertwining. Unlike the next species, individual nests are not in contact and the upper part of the structure includes non-thorny twigs and sticks (Fig. 10c).

Figure 10.

Chestnut-crowned Sparrow-Weaver Plocepasser superciliosus collecting carrot grass Parthenium hysterophorus (a), a grass stalk (b), bird inside the nest chamber (c) and perched on Vachellia xanthophloea (d), Bora, Raya Alamata, Ethiopia, January 2019 (Abadi Mehari Abrha)

RED-BILLED BUFFALO WEAVER Bubalornis niger

First record for Tigray. Fifteen observed nestbuilding on the lower branches of umbrella thorn trees on 2 March 2019 in Acacia woodland at Facha Hara (12°25′25″N, 39°34′16″E; 1,458 m). Nests were sited between 12 and 17 m (mean 14.3 m) above ground.

Figure 11.

Nests of White-headed Buffalo Weaver Dinemellia dinemelli showing (a) nest exterior largely constructed of thorny sticks, (b) egg chamber, (c) entrance, (d) a breeding bird, (e) nest in comparatively undisturbed Acacia-Commiphora woodland and bushland, and (f) nest close to a settlement, although note that there are no nests in the low Acacia trees nearest to the building (f'), Hada Alga, Raya Azebo, Ethiopia, January 2019 (Abadi Mehari Abrha)

BRONZE MANNIKIN Spermestes cucullata

First records for southern Tigray. On 24 November 2018 and 3 January 2019 several were found in coffee and khat plantations and farmland at Latie and Beyru (12°39′15″N, 39°35′5″E; 1,772 m). At Latie, the birds were using abandoned nests of Baglafecht Weaver Ploceus baglafecht to breed. We also observed a Bronze Mannikin nest being raided by a Baglafecht Weaver with the nestling being thrown out (Fig. 12). Elsewhere at Latie, an adult was observed feeding a fledged juvenile (Fig. 12).

Figure 12.

Bronze Mannikins Spermestes cucullata used deserted nests of Baglafecht Weaver Ploceus baglafecht, but the latter did not always accept the new occupants: (a) a female weaver enters a nest, (b), throws out a nestling mannikin, which (c) survived the c.4 m fall to the ground, and (d), an adult mannikin returned to the nest to feed the newly evicted young; (e) adult Bronze Mannikin feeding a fledged juvenile, Latie, Raya Azebo, Ethiopia, November 2018 and January 2019 (Abadi Mehari Abrha)

Land use and land cover (LULC) change.—Farmland cover in the study area increased from 51.0% (1,188.2 km²) in 1985 to 57.5% (1,339.1 km²) and 62.6% (1,458.5 km²) in 2000 and 2020, respectively. During 1985–2000, there was a decrease in forest cover from 26.5% (616.7 km²) to 22.4% (521.1 km²) and then to 16.9% (392.7 km²) in 2020. Similarly, bare land decreased from 9.6% (223.4 km²) to 9.3% (216.4 km²) during 1985–2000, reaching 5.5% (127.6 km²) in 2020. Human settlements increased in area from 7.0% (163.3 km²) to 8.9% (207.0 km²) between 1985 and 2000, and to 11.7% (271.8 km²) in 2020. Grassland cover abruptly decreased from 5.3% (123.2 km²) in 1985 to 1.3% (31.4 km²) in 2000, but increased to 2.8% (64.1 km²) in 2020. The relative size of water cover, mostly Lake Hashenge, has been similar since 1985 (Fig. 2). Overall, LULC changes from 1985 to 2020 demonstrated that settlement and farmland increased by 66.5% and 22.7% respectively. Contrastingly, grassland showed a 47.9% reduction, while bare land declined by 42.9% and forest cover by 36.3%.

Discussion

We documented range extensions for 55 bird taxa in the region, 13 (23.6%) of them first records for Tigray, suggesting that the geographic ranges of some species are broader than previously thought. For example, our House Sparrow records must be considered in the context of its recent expansion into the north-east and north-west, together with small pockets in central and southern Ethiopia (Gedeon et al. 2015, 2017, Buechley et al. 2022). Pygmy Falcon, Three-banded Courser, Eastern Grey Woodpecker, Horsfield's Bush Lark, African Stonechat, Rüppell's Starling, Chestnut Sparrow, and White-headed and Red-billed Buffalo Weavers were previously recorded in eastern Ethiopia and the Rift Valley (Ash & Atkins 2009, Redman et al. 2011, BirdLife International 2023), but hitherto not from Tigray.

White-breasted Cormorant was the only new record for Tigray at the highland lake. In contrast to Alemayehu et al. (2017), we detected no other congenerics there. Importantly, two endemics, Rouget's Rail Rougetius rougetii and Blue-winged Goose Cyanochen cyanoptera, previously recorded in the area (Tilahun et al. 1996, Ash & Atkins 2009) are now locally extinct, having been neither reported by Alemayehu et al. (2017) nor during our study in 2018–20. Grazing pressure (Alemayehu et al. 2017) could be a factor in their disappearance.

We confirmed that the Ethiopian endemic Calandrella blanfordi erlangeri is widely distributed from Hintalo and Enderta highlands to the southern Tigray highlands abutting the DAF plateaux belt of Hugumbirda and Gra-Kahsu State Forest and Lake Hashenge. Hitherto nominate C. b. blanfordi had been tentatively assumed to occur in the highlands of our study area (tetrad 31b), whilst tetrads 31a and 31c were thought to be occupied by erlangeri (Ash & Atkins 2009). However, we encountered C. b. erlangeri only in grazing land and farmland around Hashenge in tetrad 31b. According to our observations in 2017–18, C. b. erlangeri also occurs in plateau grassland of Dessa'a Forest Reserve, Atsbi (Kal Amin, Golgol Naele and Ruba Feleg) and Dera highlands, c.240 km north of our study area, in agreement with Ash & Atkins (2009). However, we did not investigate the potential co-occurrence of the taxa in Tigray.

In our three-year study, of the 17 newly recorded taxa, 14 (82.4%) were in the lowlands, three (17.6%) in highland areas. All of the new records were made in disturbed habitats, suggesting a degree of tolerance of at least some anthropogenic disturbance. Our results are thus in accord with other reports (Wang et al. 2022) that suggest human-dominated landscapes support high avifaunal diversity (Aerts et al. 2008), especially in structurally complex farmland (Otieno et al. 2011, Gove et al. 2013, Marcacci et al. 2022). As found by Gove et al. (2008) and Buechley et al. (2015) small-scale mixed plantations of coffee and khat also harbour high species diversity in our study area.

Based on LULC dynamics, key drivers of habitat modification at the expense of native grassland and intact forest habitats are settlements, farmland and bare land (79.8%). Moreover, the increase in grassland cover during 2000–20 may be due to replacement of native grass species with invasive weeds (e.g. Parthenium hysterophorus). Such changes could have a profound impact on the area's biodiversity. Thus, without serious conservation interventions, human-induced habitat modifications could gradually affect species diversity. The development of ecotourism in the region relies on speciose wildlife.

Recommendationsforfuturestudies.—Weprovidebaselinedatafromanornithologically poorly known area of Ethiopia. Our extended monitoring underscores the value of such work, as most of our ‘new’ species records were multiple, suggesting that they were not one-off sightings of ‘vagrants’ or ‘rarities’. Moreover, spatiotemporal documentation of bird species should avoid both false negatives as well as false positives, but does necessitate robust effort in terms of time, budget, field equipment and expertise, including trained field assistants.