How rare is rare? Quantifying and assessing the rarity of the bush dog Speothos venaticus across the Amazon and other biomes

Abstract

The bush dog Speothos venaticus is a mediumsized Neotropical canid. It is considered to be rare and its biology and population parameters are still poorly understood. The Amazon is one of the main strongholds of this species and is important for maintaining viable populations, as the region still holds extensive tracts of pristine habitat. We gathered field data from camera-trap studies throughout the Brazilian Amazon to estimate the relative abundance of the species and gain an understanding of its rarity, and how this compares with estimates from other vegetative formations and for sympatric hypercarnivores. We focused on three pristine or partially disturbed sites and one fragmented site. The estimated relative abundance of the species was .-. individuals per  trap-days, confirming that the species is rare. The bush dog's abundance in the Amazon is equivalent to that in all other areas outside the Basin. The mean group size recorded was c. . individuals. There were no differences in group sizes between forests in the Amazon and in other regions of Central America; however, there were significant differences between forests and open habitats. A combination of competition/predation, habitat structure/integrity, and disease may be acting synergistically in determining the abundance and rarity of bush dogs.

First records and abundance of margay Leopardus wiedii from semi-arid thorny scrub habitat of the Brazilian Caatinga

“…Abundance in the specific caatinga scrub habitat was even lower, at 0.081 records/100 trap-days. Thus, it is possible to conclude that, given the relatively low relative abundance, this felid is rare in both the biome and specific habitat of the Brazilian Caatinga (see Oliveira et al, 2018). In the tropical deciduous forest of southern Puebla, Mexico, margay abundance was found to be 0.112 records/100 trap-days (Farías et al, 2015), similar to that found in this study.…”

Assessment of Attractants for Neotropical Mammals

“…We used the R language with environment for statistical computing (R Development Core Team, 2018) to generate figures and analysis presented in this study. We also used the package Igraph (Csardi & Nepusz, 2006) in R (R Development Core Team, 2018) to graphically display the interactions among single or mixed, edible or inedible substances and families of mammals that were attracted by substances.…”

“…Despite the importance of monitoring and evaluating the distribution and abundance of mammals in ecosystems, there remains a lack of consistency and standardization in the methods used in studies in tropical regions (Ahumada, Hurtado, & Lizcano, 2013; Munari, Keller, & Venticinque, 2011). This is particularly the case of mammal species that may have low densities, large home ranges, are discrete and elusive, coupled with the logistical difficulties encountered in most tropical regions, often limiting the approach of studies that can be used (de Oliveira et al., 2018; du Preez, Loveridge, & Macdonald, 2014; Laurance, 1992; Michalski, 2010).…”

Water availability not fruitfall modulates the dry season distribution of frugivorous terrestrial vertebrates in a lowland Amazon forest

“…This minimum 30-min interval reduces the temporal dependence between camera trap detections [45] and has been widely used in studies with camera traps [47–49]. Vertebrates were identified using field guides of mammals and birds [50–52].…”

“…In order to estimate the relative abundance of vertebrates, we considered as independent, videos with over a 30 min interval, when the same species was recorded during the same day on the same camera [ 7 , 45 , 46 ]. This minimum 30-min interval reduces the temporal dependence between camera trap detections [ 45 ] and has been widely used in studies with camera traps [ 47 – 49 ]. Vertebrates were identified using field guides of mammals and birds [ 50 – 52 ].…”