Maximising camera trap data: Using attractants to improve detection of elusive species in multi-species surveys

Abstract

Camera traps are a key tool in ecological studies, and are increasingly being used to understand entire communities. However, robust inferences continue to be hampered by low detection of rare and elusive species. Attractants can be used to increase detection rates, but may also alter behaviour, and little research has evaluated short-term, localized response to the presence of attractants. We conducted three camera trap surveys in Kibale National Park, Uganda, using food baits and scent lures (“attractants”) at each camera station to entice small carnivores to pass in front of camera stations. To examine the interrelationship between scavenging and response to attractants, we also placed camera traps at five food refuse pits. We modelled the effect of attractant and duration of trap placement on the detection probability of small carnivores and selected African golden cat Caracal aurata prey items. We examine transient site response of each species, by comparing our observed likelihood of detection in each 24 h period from 1–7 d following refreshing of attractants to randomly generated capture histories. African civet Civettictis civetta , rusty-spotted genet Genetta maculata , African palm civet Nandinia binotata , and marsh mongoose Atilax paludinosus detection probabilities were highest and Weyns’s red duiker Cephalophus wenysi detection probability was lowest immediately after attractants were placed. Within 24 h after attractant was placed, rusty-spotted genet and African palm civet were more likely to be detected and African golden cat, red duiker, and blue duiker Philantomba monticola were less likely to be detected. Our results suggest that attractants can increase detection of small-bodied species and include some arboreal species in terrestrial camera trap sampling. However, attractants may also alter short-term visitation rates of some species, with potentially cascading effects on others. Community level and intraguild interaction studies should control for the potentially confounding effects of attractants on spatial activity patterns.

Competition and specialization in an African forest carnivore community

“…Stations were operational for 76.6 ( SD 13.8) days, with some variation due to trap failure and elephant Loxodonta africana damage. An attractant comprising a combination of meat, fruit and cologne (Calvin Klein Obsession for Men) was used at every station (Mills Fattebert, Hunter, & Slotow, ). We serviced cameras and refreshed attractants every 7–10 days.…”

“…Between January 2013 and February 2014, we conducted three sys- (Mills Fattebert, Hunter, & Slotow, 2019). We serviced cameras and refreshed attractants every 7-10 days.…”

A review of factors to consider when using camera traps to study animal behavior to inform wildlife ecology and conservation

“…This influence may be exacerbated by clearing immediate vegetation to reduce false triggers, potentially leaving behind additional cues of recent human presence. Many CT studies use bait or lure to bring animals into the camera's detection zone, thus increasing the probability of detecting particular species, typically carnivores, and have the potential to alter species behavior (Braczkowski et al, 2015(Braczkowski et al, , 2016Burton et al, 2015;Holinda, Burgar, & Burton, 2020;Mills, Fattebert, Hunter, & Slotow, 2019). Bait designed to attract carnivores can also result in the avoidance of the camera location by prey species, resulting in fewer detections (Rocha, Ramalho, & Magnusson, 2016).…”

“…Bait designed to attract carnivores can also result in the avoidance of the camera location by prey species, resulting in fewer detections (Rocha, Ramalho, & Magnusson, 2016). Hence, both baited and unbaited cameras could have particular implications for observations of species that use odor for communication, navigation, or to detect predators and/or prey (Mills et al, 2019). Moreover, we consider it possible that the use of attractants could increase local potential for human-wildlife conflicts if animals come to associate the attractant and camera system with humans (sensu Newsome, & Van Eeden, 2017).…”

Natural Selection of Melanism in Costa Rican Jaguar and Oncilla: A Test of Gloger’s Rule and the Temporal Segregation Hypothesis

“…Scent stations are widely used to increase photo quality for studies aimed at species and individual identification ( Barea-Azc on et al, 2007;Conner et al, 1983;Randel & Peace, 2010;Thorn et al, 2009;Travaini et al, 1996;Weaver et al, 2005). In an experimental study, Mills et al (2019) concluded that attractants are an effective tool for increasing the detection of elusive carnivores, although responses are species-specific. Each station consisted of a free-standing polyvinyl chloride pipe (sometimes a strap attached to a tree) with a piece of sponge scented with Calvin Klein's "Obsession for Men" cologne (Calvin Klein Inc., New York, NY, USA) inside a clear plastic tube.…”