Surveys, distribution and current status of the Madagascar Harrier Circus macrosceles in Madagascar

Abstract

We conducted a 16-month country-wide survey to determine the status of the threatened Madagascar (Marsh) Harrier Circus macrosceles from 2005 to 2006. We searched for harriers in varying habitat types, focusing on marshes, grasslands and savannas, secondary forests and the edge of primary forests. We surveyed 68% of the districts of Madagascar which contain 71% of the potential harrier habitat throughout the country. We recorded 80 individuals of this sexually dimorphic raptor; 48 males and 32 females of which 71 were observed during the breeding season (June to December) and nine outside the breeding season (January to May). The Madagascar Harrier has a broad distribution of about 1,000 km north to south (Madagascar is about 1,500 km in length) and east to west, but at extremely low density. Fifty-three (69%) harriers were observed in high elevation marshes and grasslands above 1,100 m in the provinces of Mahajanga and Antananarivo during the breeding season. Three major threats to harriers, all human caused, were identified: the transformation of marshes to rice fields (all nests in lower elevation natural marshes), uncontrolled fires destroying nests (n 5 7 nests lost in 2005 to fires), and human persecution by taking young from nests for a food source and killing adults due to their predatory nature. From our surveys in Madagascar and information from Comoro Islands, we estimate the global population to be 250-500 individuals suggesting the current Madagascar Harrier population is heading towards endangerment. The survival of the Madagascar Harrier in Madagascar is critically dependent on protecting the remaining natural marshes, which are an extremely limited and critically endangered habitat in Madagascar, with bordering grasslands.

Birds of Ambondrolava mangrove complex, southwest Madagascar

“…Circus macrosceles A. Newton, 1863 -This globally Vulnerable (IUCN 2011) endemic to the Madagascar region has an estimated global population size of 250-500 pairs, restricted in Madagascar to marshes and grassland in the centre and north-west of the island (René de Roland et al 2009). We observed a pair in courtship -pair-formation flights as described by René de Roland et al (2004) -during August 2010 and September 2011, but breeding was not confirmed.…”

Distribution, density, and important hotspots of Krüper’s Nuthatch Sitta krueperi in Turkey and Lesvos Island, Greece

“…Population density and distribution should be taken into account when developing conservation and management plans for species (Lopes et al, 2008;de Roland et al, 2009;Mattos et al, 2009). In this regard, some hotspot areas for Krüper's Nuthatch should be identified for conservation purposes.…”

A molecular phylogeny of the harriers (Circus, Accipitridae) indicate the role of long distance dispersal and migration in diversification

“…Three harrier taxa (C. m. macrosceles, C. m. maillardi and C. maurus) are currently listed as either Vulnerable or Endangered (IUCN Red List 2014), while a fourth (C. macrourus) is listed as near threatened due to steep population declines (BirdLife International, 2004). In Madagascar and Reunion, habitat transformation and human disturbance are listed as one of the main threats to C. m. macrosceles (De Roland et al, 2009) and C. m. maillardi (Bretagnolle et al, 2000). The southern African endemic C. maurus is estimated to have fewer than 1000 mature individuals (Curtis et al, 2004), and in addition, their primary nesting habitat is threatened by agriculture (Curtis et al, 2004).…”