Egg predation and vertebrates associated with wild crocodilian nests in Mexico determined using camera-traps

2020 ◽  
Vol 54 (29-30) ◽  
pp. 1813-1826
Author(s):  
Giovany A. González-Desales ◽  
Luis A. Tello-Sahagún ◽  
Cynthia P. Cadena-Ramírez ◽  
Marco A. López-Luna ◽  
Alejandra Buenrostro-Silva ◽  
...  
Keyword(s):  
Camera Traps ◽  
Egg Predation

Out of sight but not out of mind: corvids prey extensively on eggs of burrow-nesting penguins

2015 ◽  
Vol 42 (6) ◽  
pp. 509 ◽  
Author(s):  
Kasun B. Ekanayake ◽  
Duncan R. Sutherland ◽  
Peter Dann ◽  
Michael A. Weston
Keyword(s):  
Population Viability Analysis ◽  
Camera Traps ◽  
Foraging Strategies ◽  
Population Declines ◽  
Egg Predation ◽  
Potential Threat ◽  
Predatory Behaviour ◽  
Population Growth Rates ◽  
Viability Analysis ◽  
Foraging Niche

Context Egg depredation is a major cause of reproductive failure among birds and can drive population declines. In this study we investigate predatory behaviour of a corvid (little raven; Corvus mellori) that has only recently emerged, leading to widespread and intense depredation of eggs of a burrow-nesting seabird (little penguin; Eudyptula minor). Aims The main objective of this study was to measure the rate of penguin egg depredation by ravens to determine potential threat severity. We also examined whether penguin burrow characteristics were associated with the risk of egg depredation. Ravens generally employ two modes of predatory behaviour when attacking penguin nests; thus we examined whether burrow characteristics were associated with these modes of attack. Methods Remote-sensing cameras were deployed on penguin burrows to determine egg predation rates. Burrow measurements, including burrow entrance and tunnel characteristics, were measured at the time of camera deployment. Key results Overall, clutches in 61% of monitored burrows (n = 203) were depredated by ravens, the only predator detected by camera traps. Analysis of burrow characteristics revealed two distinct types of burrows, only one of which was associated with egg depredation by ravens. Clutches depredated by ravens had burrows with wider and higher entrances, thinner soil or vegetation layer above the egg chamber, shorter and curved tunnels and greater areas of bare ground and whitewash near entrances. In addition, 86% were covered by bower spinach (Tetragonia implexicoma), through which ravens could excavate. Ravens used two modes to access the eggs: they attacked through the entrance (25% of burrow attacks, n = 124); or dug a hole through the burrow roof (75% of attacks, n = 124). Burrows that were subject to attack through the entrance had significantly shorter tunnels than burrows accessed through the roof. Conclusions The high rates of clutch loss recorded here highlight the need for population viability analysis of penguins to assess the effect of egg predation on population growth rates. Implications The subterranean foraging niche of a corvid described here may have implications for burrow-nesting species worldwide because many corvid populations are increasing, and they exhibit great capacity to adopt new foraging strategies to exploit novel prey.

Author response for "Conservation and people: Towards an ethical code of conduct for the use of camera traps in wildlife research"

2020 ◽  
Author(s):  
Koustubh Sharma ◽  
Matthias Fiechter ◽  
Todd George ◽  
Juliette Young ◽  
Justine Shanti Alexander ◽  
...  
Keyword(s):  
Code Of Conduct ◽  
Camera Traps ◽  
Author Response ◽  
Ethical Code

Monitoring activity rhythms ofEquus hemionusat watering holes by camera traps in Mount Kalamaili Ungulate Nature Reserve, Xinjiang

2014 ◽  
Vol 22 (6) ◽  
pp. 752
Author(s):  
Wu Hongpan ◽  
Chu Hongjun ◽  
Wang Yuan ◽  
Ma Jianwei ◽  
Ge Yan ◽  
...  
Keyword(s):  
Nature Reserve ◽  
Camera Traps ◽  
Activity Rhythms ◽  
Monitoring Activity

scholarly journals Impact of natural salt lick on the home range of Panthera tigris at the Royal Belum Rainforest, Malaysia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bryan Andrew Lazarus ◽  
Azlan Che-Amat ◽  
Muhammad Muzammil Abdul Halim Shah ◽  
Azwan Hamdan ◽  
Hasliza Abu Hassim ◽  
...  
Keyword(s):  
Home Range ◽  
Prey Availability ◽  
Nutritional Ecology ◽  
Camera Traps ◽  
Home Ranges ◽  
Panthera Tigris ◽  
Health Maintenance ◽  
Salt Lick ◽  
Save Energy ◽  
Salt Licks

AbstractNatural salt lick (sira) is a strategic localisation for ecological wildlife assemblage to exhibit geophagy which may act as a population dynamic buffer of prey and predators. Undoubtedly, many agree that geophagy at natural licks is linked to nutritional ecology, health and assembly places facilitating social interaction of its users. Overall, natural salt licks not only save energy of obtaining nutrient leading to health maintenance but also forms the basis of population persistence. The Royal Belum Rainforest, Malaysia (Royal Belum) is a typical tropical rainforest in Malaysia rich in wildlife which are mainly concentrated around the natural salt lick. Since this is one of the most stable fauna ecology forest in Malaysia, it is timely to assess its impact on the Malayan tiger (Panthera tigris) home range dynamics. The three-potential home ranges of the Malayan tiger in this rainforest were selected based on animal trails or foot prints surrounding the salt lick viz (e.g. Sira Kuak and Sira Batu; Sira Rambai and Sira Buluh and Sira Papan) as well as previous sightings of a Malayan tiger in the area, whose movement is dependent on the density and distribution of prey. Camera traps were placed at potential animal trails surrounding the salt lick to capture any encountered wildlife species within the area of the camera placements. Results showed that all home ranges of Malayan tiger were of no significance for large bodied prey availability such as sambar deer (Rusa unicolor), and smaller prey such as muntjacs (Muntiacus muntjac) and wild boar (Sus scrofa). Interestingly, all home range harbour the Malayan tiger as the only sole predator. The non-significance of prey availability at each home range is attributed to the decline of the Malayan tiger in the rainforest since tigers are dependant on the movement of its preferred prey surrounding natural salt licks. Thus, the information from this study offers fundamental knowledge on the importance of prey-predator interaction at salt lick which will help in designing strategy in rewilding or rehabilitation programs of the Malayan tiger at the Royal Belum Rainforest.

scholarly journals Occurrence and Activity of Roe Deer in Urban Forests of Warsaw

2020 ◽  
Vol 3 (1) ◽  
pp. 35
Author(s):  
Karolina D. Jasińska ◽  
Mateusz Jackowiak ◽  
Jakub Gryz ◽  
Szymon Bijak ◽  
Katarzyna Szyc ◽  
...  
Keyword(s):  
Predation Risk ◽  
Urban Area ◽  
Roe Deer ◽  
Urban Forests ◽  
Anthropogenic Disturbances ◽  
Camera Traps ◽  
Human Disturbances ◽  
Human Presence ◽  
Big Cities ◽  
High Level

Human presence or activities are perceived by animals as those associated with predation risk so activity and exploration patterns of animals should be shaped by indices of anthropogenic disturbances. The high level of human disturbances is noticed in big cities. Therefore, the aim of the study was to determine the occurrence of roe deer in Warsaw and its activity in the Warsaw urban forests. We used snow tracking on transect routes (winter seasons 2016, 2017, 2018; 115.1 km in total) to determine roe deer occurrence in four habitats: forests, open areas, parks, and built-up areas. The number of tracks was highest in forests (4.6 tracks/1 km/24 h), followed by open areas, built-up areas, and parks. We used camera traps to determine the activity of roe deer in selected urban forests. We collected 697 observations of roe deer in Warsaw forests in the years 2016–2019 (per 4826 trap-days in total). The peak of roe deer activity was noticed between 4:00 and 5:00 a.m. Animals were least active at 1:00–2:00 p.m. and between 11:00 p.m.–01:00 a.m. Our research showed that roe deer inhabiting the urban area avoided human presence by using well-covered habitats and being active in periods when humans’ disturbances’ level is lower.

scholarly journals Prey removal in cotton crops next to woodland reveals periodic diurnal and nocturnal invertebrate predation gradients from the crop edge by birds and bats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Heidi L. Kolkert ◽  
Rhiannon Smith ◽  
Romina Rader ◽  
Nick Reid
Keyword(s):  
Pest Control ◽  
Open Space ◽  
Optimal Foraging Theory ◽  
Time Of Day ◽  
Camera Traps ◽  
Generalist Predators ◽  
Crop Cover ◽  
Foraging Preferences ◽  
Experimental Feeding ◽  
Natural Pest Control

AbstractFactors influencing the efficacy of insectivorous vertebrates in providing natural pest control services inside crops at increasing distances from the crop edge are poorly understood. We investigated the identity of vertebrate predators (birds and bats) and removal of sentinel prey (mealworms and beetles) from experimental feeding trays in cotton crops using prey removal trials, camera traps and observations. More prey was removed during the day than at night, but prey removal was variable at the crop edge and dependent on the month (reflecting crop growth and cover) and time of day. Overall, the predation of mealworms and beetles was 1-times and 13-times greater during the day than night, respectively, with predation on mealworms 3–5 times greater during the day than night at the crop edge compared to 95 m inside the crop. Camera traps identified many insectivorous birds and bats over crops near the feeding trays, but there was no evidence of bats or small passerines removing experimental prey. A predation gradient from the crop edge was evident, but only in some months. This corresponded to the foraging preferences of open-space generalist predators (magpies) in low crop cover versus the shrubby habitat preferred by small passerines, likely facilitating foraging away from the crop edge later in the season. Our results are in line with Optimal Foraging Theory and suggest that predators trade-off foraging behaviour with predation risk at different distances from the crop edge and levels of crop cover. Understanding the optimal farm configuration to support insectivorous bird and bat populations can assist farmers to make informed decisions regarding in-crop natural pest control and maximise the predation services provided by farm biodiversity.

scholarly journals Understanding potential implications for non-trophic parasite transmission based on vertebrate behavior at mesocarnivore carcass sites

2021 ◽  
Author(s):  
Moisés Gonzálvez ◽  
Carlos Martínez-Carrasco ◽  
Marcos Moleón
Keyword(s):  
Red Fox ◽  
Close Contact ◽  
Infection Risk ◽  
Camera Traps ◽  
Emerging Pathogens ◽  
Domestic Species ◽  
Time Period ◽  
Wild Canids ◽  
Rubbing Behavior ◽  
Trophically Transmitted Parasites

AbstractHigh infection risk is often associated with aggregations of animals around attractive resources. Here, we explore the behavior of potential hosts of non-trophically transmitted parasites at mesocarnivore carcass sites. We used videos recorded by camera traps at 56 red fox (Vulpes vulpes) carcasses and 10 carcasses of other wild carnivore species in three areas of southeastern Spain. Scavenging species, especially wild canids, mustelids and viverrids, showed more frequent rubbing behavior at carcass sites than non-scavenging and domestic species, suggesting that they could be exposed to a higher potential infection risk. The red fox was the species that most frequently contacted carcasses and marked and rubbed carcass sites. Foxes contacted heterospecific carcasses more frequently and earlier than conspecific ones and, when close contact occurred, it was more likely to be observed at heterospecific carcasses. This suggests that foxes avoid contact with the type of carcass and time period that have the greatest risk as a source of parasites. Overall, non-trophic behaviors of higher infection risk were mainly associated with visitor-carcass contact and visitor contact with feces and urine, rather than direct contact between visitors. Moreover, contact events between scavengers and carnivore carcasses were far more frequent than consumption events, which suggests that scavenger behavior is more constrained by the risk of acquiring meat-borne parasites than non-trophically transmitted parasites. This study contributes to filling key gaps in understanding the role of carrion in the landscape of disgust, which may be especially relevant in the current global context of emerging and re-emerging pathogens. Graphical abstract

Sign in / Sign up

Export Citation Format

Share Document