scholarly journals Vocal recognition of a nest-predator in black grouse

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6533 ◽  
Author(s):  
Richard Policht ◽  
Vlastimil Hart ◽  
Denis Goncharov ◽  
Peter Surový ◽  
Vladimír Hanzal ◽  
...  
Keyword(s):  
Nest Predation ◽  
Red Fox ◽  
Warning Signal ◽  
Field Studies ◽  
Black Grouse ◽  
Common Raven ◽  
The Common ◽  
Altricial Birds ◽  
Precocial Birds ◽  
Nest Predator

Corvids count among the important predators of bird nests. They are vocal animals and one can expect that birds threatened by their predation, such as black grouse, are sensitive to and recognize their calls. Within the framework of field studies, we noticed that adult black grouse were alerted by raven calls during periods outside the breeding season. Since black grouse are large, extremely precocial birds, this reaction can hardly be explained by sensitization specifically to the threat of nest predation by ravens. This surprising observation prompted us to study the phenomenon more systematically. According to our knowledge, the response of birds to corvid vocalization has been studied in altricial birds only. We tested whether the black grouse distinguishes and responds specifically to playback calls of the common raven. Black grouse recognized raven calls and were alerted, displaying typical neck stretching, followed by head scanning, and eventual escape. Surprisingly, males tended to react faster and exhibited a longer duration of vigilance behavior compared to females. Although raven calls are recognized by adult black grouse out of the nesting period, they are not directly endangered by the raven. We speculate that the responsiveness of adult grouse to raven calls might be explained as a learned response in juveniles from nesting hens that is then preserved in adults, or by a known association between the raven and the red fox. In that case, calls of the raven would be rather interpreted as a warning signal of probable proximity of the red fox.

scholarly journals Evaluation of Spatio-Temporal Patterns of Predation Risk to Forest Grouse Nests in the Central European Mountain Regions

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 316
Author(s):  
Jan Cukor ◽  
Rostislav Linda ◽  
Oddgeir Andersen ◽  
Lasse Frost Eriksen ◽  
Zdeněk Vacek ◽  
...  
Keyword(s):  
Predation Risk ◽  
Red Fox ◽  
Predation Rate ◽  
Forest Edge ◽  
Camera Traps ◽  
Black Grouse ◽  
Mountain Areas ◽  
Artificial Nests ◽  
Common Raven ◽  
Nest Predator

We evaluated the spatiotemporal patterns of predation risk on black grouse nests using artificial nests that were monitored by camera traps in mountain areas with a small extant (Ore Mts.) and already extinct (Jeseníky Mts.) black grouse population. The overall predation rate of artificial nests was 56% and we found significant differences in survival rate courses over time between both study areas (68% Ore Mts. vs. 41%, Jeseníky Mts.). Within the time required for successful egg incubation (25 days), nest survival probability was 0.32 in the Ore Mts. and 0.59 in Jeseníky Mts. The stone marten (Martes foina) was the primary nest predator in both study areas (39% in total), followed by common raven (Corvus corax, 25%) and red fox (Vulpes vulpes, 22%). The proportion of depredated nests did not differ between habitat types (i.e., open forest interior, clearing, forest edge), but we recorded the effect of interaction of study area and habitat. In Ore Mts., the main nest predator was common raven with seven records (37%). The Eurasian jay (Garrulus glandarius) was responsible for most predation attempts in Jeseníky Mts. (five records, i.e., 83%), while in the Ore Mts., most predation attempts were done by red fox (six records, i.e., 38%).

scholarly journals Do small precocial birds enter torpor to conserve energy during development?

2020 ◽  
Vol 223 (21) ◽  
pp. jeb231761
Author(s):  
Yaara Aharon-Rotman ◽  
Gerhard Körtner ◽  
Chris B. Wacker ◽  
Fritz Geiser
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Surface Temperature ◽  
Heat Loss ◽  
Body Mass ◽  
Infrared Thermometer ◽  
Common Strategy ◽  
Energy Conserving ◽  
Altricial Birds ◽  
Precocial Birds

ABSTRACTPrecocial birds hatch feathered and mobile, but when they become fully endothermic soon after hatching, their heat loss is high and they may become energy depleted. These chicks could benefit from using energy-conserving torpor, which is characterised by controlled reductions of metabolism and body temperature (Tb). We investigated at what age the precocial king quail Coturnix chinensis can defend a high Tb under a mild thermal challenge and whether they can express torpor soon after achieving endothermy to overcome energetic and thermal challenges. Measurements of surface temperature (Ts) using an infrared thermometer showed that king quail chicks are partially endothermic at 2–10 days, but can defend high Tb at a body mass of ∼13 g. Two chicks expressed shallow nocturnal torpor at 14 and 17 days for 4–5 h with a reduction of metabolism by >40% and another approached the torpor threshold. Although chicks were able to rewarm endogenously from the first torpor bout, metabolism and Ts decreased again by the end of the night, but they rewarmed passively when removed from the chamber. The total metabolic rate increased with body mass. All chicks measured showed a greater reduction of nocturnal metabolism than previously reported in quails. Our data show that shallow torpor can be expressed during the early postnatal phase of quails, when thermoregulatory efficiency is still developing, but heat loss is high. We suggest that torpor may be a common strategy for overcoming challenging conditions during development in small precocial and not only altricial birds.

scholarly journals Nest-predator prevalence along a mountain birch - alpine tundra ecotone

2011 ◽  
Vol 38 (6) ◽  
pp. 525
Author(s):  
Åshild Ø. Pedersen ◽  
Lasse Asmyhr ◽  
Hans Christian Pedersen ◽  
Nina E. Eide
Keyword(s):  
Nest Predation ◽  
Alpine Tundra ◽  
Mountain Birch ◽  
Pine Marten ◽  
Willow Ptarmigan ◽  
Generalist Species ◽  
Management Actions ◽  
Nest Predator ◽  
Predation Rates ◽  
Birch Forests

Context Nest predation is a major factor influencing life history and population dynamics of ground-nesting birds. The transitions between the northern boreal mountain birch forests and the low-alpine tundra are important habitats for the willow ptarmigan, Lagopus lagopus (Linnaeus, 1758). During the past decades, these landscapes have been extensively developed with cabin resorts in southern Norway, which has led to an increased number of roads and foot paths in relatively undisturbed habitats. Aims The aim of the present study was to investigate relative nest-predation rates in elevation gradients (ecotones) spanning from northern boreal mountain birch forests to low-alpine tundra in three locations with contrasting willow ptarmigan densities. Methods We conducted an artificial nest study by using baited track boards (n = 108). Track boards were placed along transects (200 m) in the following three habitat types: birch forest, edge habitat and low-alpine tundra. Predator prevalence was analysed in relation to study-design variables (location, habitat, study period) and the load of human infrastructure (i.e. distance to foot paths and roads), using generalised linear mixed-effect models assuming binomial distribution for the response variable. Key results Prevalence of avian predators was consistently high (range 38.2–85.3%), in contrast to much lower prevalence of mammalian predators (range 2.8–22.9%). Raven (Corvus corax) was the dominant nest predator, followed by hooded crow (C. cornix) and pine marten (Martes martes). Location, as contrasted by differences in willow ptarmigan density, was not significantly related to total relative predation rates. Species-specific predator prevalence was habitat specific and related to human infrastructure, but with opposite relative predation patterns between pine marten and raven. Hooded crow predation was similar across the ecotone and not related to human infrastructure. Conclusions Predator prevalence was habitat specific and affected by human infrastructure (distance to human foot paths). Our study confirmed that human activity might alter the predation rates by generalist species in these low-alpine environments. Implications We recommend that attractive willow ptarmigan habitat should be avoided when planning human infrastructure in alpine ecosystems. To reduce predation pressure in this ecosystem, it appears that generalist predators should be considered for management actions. Further research is needed to explain the underlying mechanism driving expansion of generalist species into alpine habitats. Such knowledge is also important in developing alternative management actions with focus other than predator control.

scholarly journals Comparative Analysis of Nutrient Digestibility and Nitrogen Retention in Wild and Farmed Canids

2014 ◽  
Vol 14 (2) ◽  
pp. 307-314 ◽  
Author(s):  
Andrzej Gugołek ◽  
Janusz Strychalski ◽  
Małgorzata Konstantynowicz ◽  
Cezary Zwoliński
Keyword(s):  
Organic Matter ◽  
Vulpes Vulpes ◽  
Dry Matter ◽  
Red Fox ◽  
Nitrogen Retention ◽  
Nutrient Digestibility ◽  
Nyctereutes Procyonoides ◽  
Red Foxes ◽  
The Common ◽  
Raccoon Dogs

Abstract The aim of this study, conducted in November 2012, was to determine whether farming of common foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) leads to changes in nutrient digestibility and nitrogen retention in comparison with their wild counterparts. Wild and farmed animals were compared within and between species. Each group consisted of five males and five females aged around eight months. Farmed silver foxes - a variety of the common red fox (group FSF) and farmed raccoon dogs (group FRD) were purchased from a breeding farm in southeastern Poland. Wild red foxes (group WRF) and wild raccoon dogs (group WRD) were trapped in the hunting grounds of the Polish Hunting Association (Olsztyn Division). The animals were placed in metabolism cages. The coefficients of nutrient and energy digestibility, and daily nitrogen balance and retention values were compared between groups. Farmed animals tended to have higher digestibility coefficients than their wild counterparts. No significant differences were noted within species. The coefficients of dry matter (P≤0.01), organic matter (P≤0.05, P≤0.05) and protein (only FSF vs. WRD - P≤0.05) digestibility were higher in foxes. Raccoon dogs were characterized by higher digestibility of carbohydrates - N-free extracts (P≤0.01). Nitrogen retention was higher in farmed animals. The highest and lowest levels of retained nitrogen were observed in groups FSF and WRD, respectively

scholarly journals Experimentally induced antipredator responses are mediated by social and environmental factors

2019 ◽  
Vol 30 (4) ◽  
pp. 986-992 ◽  
Author(s):  
Frank Groenewoud ◽  
Sjouke A Kingma ◽  
Kat Bebbington ◽  
David S Richardson ◽  
Jan Komdeur
Keyword(s):  
Predation Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Ecological Factors ◽  
Antipredator Defense ◽  
Trade Offs ◽  
Future Reproduction ◽  
Female Investment ◽  
Predator Model ◽  
Nest Predator

AbstractNest predation is a common cause of reproductive failure for many bird species, and various antipredator defense behaviors have evolved to reduce the risk of nest predation. However, trade-offs between current reproductive duties and future reproduction often limit the parent’s ability to respond to nest predation risk. Individual responses to experimentally increased nest predation risk can give insights into these trade-offs. Here, we investigate whether social and ecological factors affect individual responses to predation risk by experimentally manipulating the risk of nest predation using taxidermic mounts in the cooperative breeding Seychelles warbler (Acrocephalus sechellensis). Our results show that dominant females, but not males, alarm called more often when they confront a nest predator model alone than when they do so with a partner, and that individuals that confront a predator together attacked more than those that did so alone. Dominant males increased their antipredator defense by spending more time nest guarding after a presentation with a nest predator, compared with a nonpredator control, but no such effect was found for females, who did not increase the time spent incubating. In contrast to incubation by females, nest guarding responses by dominant males depended on the presence of other group members and food availability. These results suggest that while female investment in incubation is always high and not dependent on social and ecological conditions, males have a lower initial investment, which allows them to respond to sudden changes in nest predation risk.

Tropic Croton (Croton glandulosus) Control in Peanut (Arachis hypogaea)

1991 ◽  
Vol 5 (4) ◽  
pp. 795-798 ◽  
Author(s):  
John W. Wilcut
Keyword(s):  
Arachis Hypogaea ◽  
Field Studies ◽  
Common Ragweed ◽  
Application Timing ◽  
Common Lambsquarters ◽  
Net Returns ◽  
Herbicide Treatments ◽  
The Common

Field studies in 1988 and 1989 evaluated POST herbicides alone and in tank-mixtures for tropic croton control in peanut. Acifluorfen + 2,4-DB, acifluorfen + bentazon, acifluorfen + bentazon + 2,4-DB controlled > 90% of tropic croton when applied at 2 or 4 wk after crop emergence. Paraquat + bentazon controlled 55% at 2 wk and 24% at 4 wk after crop emergence. Imazethapyr and imazethapyr + 2,4-DB controlled < 24% tropic croton at either 2 or 4 wk after crop emergence. Acifluorfen + 2,4-DB, acifluorfen + bentazon, and acifluorfen + bentazon + 2,4-DB controlled at least 90% of the common lambsquarters, common ragweed, and morningglory species. Greatest yields and net returns were obtained with acifluorfen + bentazon + 2,4-DB applied 2 wk after crop emergence. Yields were higher with acifluorfen + bentazon + 2,4-DB and imazethapyr applied at 2 wk after crop emergence than at 4 wk after crop emergence. All other herbicide treatments provided equivalent yields among application timings. Only acifluorfen + 2,4-DB provided equivalent net returns at either application timing. All other herbicide treatments provided lower net returns with applications made at 4 wk than at 2 wk after crop emergence.

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