Effectiveness of camera traps for quantifying daytime and nighttime visitation by vertebrate pollinators

Abstract

Identification of pollen vectors is a fundamental objective of pollination biology. The foraging and social behavior of these pollinators has profound effects on plant mating, making quantification of their behavior critical for understanding the ecological and evolutionary consequences of different pollinators for the plants they visit. However, accurate quantification of visitation may be problematic, especially for shy animals and/or when the temporal and spatial scale of observation desired is large. Sophisticated heat‐ and movement‐triggered motion‐sensor cameras (“camera trapping”) provide new, underutilized tools to address these challenges. However, to date, there has been no rigorous evaluation of the sampling considerations needed for using camera trapping in pollination research.We measured the effectiveness of camera trapping for identifying vertebrate visitors and quantifying their visitation rates and foraging behavior on Banksia menziesii (Proteaceae). Multiple still cameras (Reconyx HC 500) and a video camera (Little Acorn LTL5210A) were deployed.From 2,753 recorded visits by vertebrates, we identified five species of nectarivorous honeyeater (Meliphagidae) and the honey possum (Tarsipedidae), with significant variation in the species composition of visitors among inflorescences. Species of floral visitor showed significant variation in their time of peak activity, duration of visits, and numbers of flowers probed per visit. Where multiple cameras were deployed on individual inflorescences, effectiveness of individual still cameras varied from 15% to 86% of all recorded visits. Methodological issues and solutions, and the future uses of camera traps in pollination biology, are discussed. Conclusions and wider implications: Motion‐triggered cameras are promising tools for the quantification of vertebrate visitation and some aspects of behavior on flowers. However, researchers need to be mindful of the variation in effectiveness of individual camera traps in detecting animals. Pollinator studies using camera traps are in their infancy, and the full potential of this developing technology is yet to be realized.

How reliable are motion‐triggered camera traps for detecting small mammals and birds in ecological studies?

“…2) suggested some differences in the efficiency of two popular camera models, but given that some studies (e.g. Krauss et al ., 2018) have identified the possibility of variation in performance of individual cameras from the same manufacturer, greater replication of individual cameras would be required to confirm whether the poor performance of the Moultrie camera for detecting rodents at 2 m is an intrinsic feature of this particular camera model. In this study, we found no statistically significant differences in performance among the individual Bushnell cameras used in the experiments (see Materials and methods).…”

“…However, there are serious limitations on the ability of humans to make direct sightings. Humans lack visual acuity and the stamina needed for long observation periods, particularly at night (Steen, 2012; Krauss et al ., 2018). In addition, human presence can alter natural animal behaviour or deter animals from an area.…”

“…The overwhelming majority of studies making use of camera traps have focused on larger mammals (Kucera & Barrett, 2011; Swanson et al ., 2015). However, there is an increasing realization that modern camera traps with close‐focusing lenses and flashes that do not overexpose subjects at close range can be useful for studying smaller animals such as birds, rodents, reptiles and even some insects (Wester et al ., 2009; Rowcliffe et al ., 2011; McCallum, 2013; Burton et al ., 2015; Van der Niet et al ., 2015; Zoeller et al ., 2016; Krauss et al ., 2018; Randler & Kalb, 2018; Cozien et al ., 2019; Johnson et al ., 2020).…”

“…PIR camera traps can detect animals regardless of light availability, are relatively inexpensive, available commercially and can be left at remote sites for longer periods (ranging from days to months). Concerns have been raised about limited sensitivity of PIR cameras, particularly in the case of studies of smaller animals (Swann et al ., 2004; Pirie et al ., 2016; Krauss et al ., 2018; Randler & Kalb, 2018; Glover‐Kapfer et al ., 2019). Objective testing of PIR cameras requires quantification of the proportion of actual events that are captured by cameras which is a non‐trivial undertaking, particularly under field conditions, given that the limitations of recording actual events are usually the reason for using cameras in the first place.…”

Application of Environmental DNA: Honey Bee behavior and Ecosystems for Sustainable Beekeeping

“…In the times when there are flowers in abundance, there can be nectar in excess of what the users can consume, but at other times, competition over limited nectar sources usually prevails. The potential competitors for honeybees include other types of honeybees, bumble bees, insects such as butterflies, bird species such as hummingbirds, and mammals like bats [39][40][41].…”