Exploratory analysis reveals arthropod consumption in 10 lemur species using DNA metabarcoding.

Arthropods (insects, spiders, etc.) can fulfill major nutritional requirements for primates, particularly in terms of proteins, fats, vitamins, and minerals. Yet, for many primate species we know very little about the frequency and importance of arthropod consumption. Traditional methods for arthropod prey identification, such as behavioral observations and fecal dissections, offer limited taxonomic resolution and, as a result, underestimate true diversity. Metabarcoding arthropod DNA from primate fecal samples provides a promising but underused alternative. Here, we inventoried arthropod prey diversity in wild lemurs by sequencing two regions of the CO1 gene. Samples were collected opportunistically from 10 species of lemurs inhabiting three national parks in southern Madagascar using a combination of focal animal follows and live trapping. In total, we detected arthropod DNA in 98 of the 170 fecal samples analyzed. Although all lemur species included in these analyses showed evidence of arthropod consumption, those within the family Cheirogaleidae appeared to consume the highest frequency and diversity of arthropods. To our knowledge, this study presents the first evidence of arthropod consumption in Phaner pallescens, Avahi peyrierasi, and Propithecus verreauxi, and identifies 32 families of arthropods as probable food items that have not been published as lemur dietary items to date. Our study emphasizes the importance of arthropods as a nutritional source and the role DNA metabarcoding can play in elucidating an animal's diet.

Population Estimates of Hubbard's Sportive Lemur (Lepilemur hubbardorum) at Zombitse-Vohibasia National Park, Madagascar.

Estimates of population size are fundamental to setting conservation priorities for threatened primate species. Many taxa in the lemur genus Lepilemur remain understudied, and basic population statistics are often dated, incomplete, or absent. Hubbard's sportive lemur (Lepilemur hubbardorum) is known only from the Zombitse-Vohibasia National Park region in southwestern Madagascar. It is listed as Endangered by the IUCN owing to its fragmented, declining habitat and limited geographic range. However, this classification has not been confirmed through systematic population estimates. To address this issue, we undertook line transect surveys in the Zombitse parcel of the National Park. We applied geospatial analyses and data to quantify forest area as a proxy for L. hubbardorumhabitat. We recorded a total of 234 L. hubbardorum sightings over 18 survey nights, representing 47.2 km of survey effort. Our surveys revealed population densities of 145.6 L. hubbardorum individuals per km2 (95% CI: 97.2-218.1), for an extrapolated abundance estimate of ca. 16,500-18,000 L. hubbardorum individuals across the protected forests of the Zombitse parcel. This abundance estimate should be considered provisional, however, because our restricted sampling area did not include the more remote regions of the National Park where habitat disturbance and hunting practices have likely contributed to localized population declines.