Disentangling direct and indirect effects of local temperature on abundance of mountain birds and implications for understanding global change impacts

Unravelling the environmental factors driving species distribution and abundance is crucial in ecology and conservation. Both climatic and land cover factors are often used to describe species distribution/abundance, but their interrelations have been scarcely investigated. Climatic factors may indeed affect species both directly and indirectly, e.g., by influencing vegetation structure and composition. We aimed to disentangle the direct and indirect effects (via vegetation) of local temperature on bird abundance across a wide elevational gradient in the European Alps, ranging from montane forests to high-elevation open areas. In 2018, we surveyed birds by using point counts and collected fine-scale land cover and temperature data from 109 sampling points. We used structural equation modelling to estimate direct and indirect effects of local climate on bird abundance. We obtained a sufficient sample for 15 species, characterized by a broad variety of ecological requirements. For all species we found a significant indirect effect of local temperatures via vegetation on bird abundance. Direct effects of temperature were less common and were observed in seven woodland/shrubland species, including only mountain generalists; in these cases, local temperatures showed a positive effect, suggesting that on average our study area is likely colder than the thermal optimum of those species. The generalized occurrence of indirect temperature effects within our species set demonstrates the importance of considering both climate and land cover changes to obtain more reliable predictions of future species distribution/abundance. In fact, many species may be largely tracking suitable habitat rather than thermal niches, especially among homeotherm organisms like birds.

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Direct and indirect effects of climate on bird abundance along elevation gradients in the Northern Appalachian mountains

Diversity and Distributions ◽

10.1111/ddi.12968 ◽

2019 ◽

Vol 25 (11) ◽

pp. 1670-1683 ◽

Cited By ~ 2

Author(s):

Timothy R. Duclos ◽

William V. DeLuca ◽

David I. King

Keyword(s):

Indirect Effects ◽

Appalachian Mountains ◽

Direct And Indirect Effects ◽

Bird Abundance ◽

Elevation Gradients

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Mapping the potential distribution of the Critically Endangered Himalayan Quail Ophrysia superciliosa using proxy species and species distribution modelling

Bird Conservation International ◽

10.1017/s095927091400046x ◽

2015 ◽

Vol 25 (4) ◽

pp. 466-478 ◽

Cited By ~ 7

Author(s):

JONATHON C. DUNN ◽

GRAEME M. BUCHANAN ◽

RICHARD J. CUTHBERT ◽

MARK J. WHITTINGHAM ◽

PHILIP J. K. MCGOWAN

Keyword(s):

Land Cover ◽

Species Distribution ◽

Climate Model ◽

Habitat Preferences ◽

Species Distribution Modelling ◽

Critically Endangered ◽

Suitable Habitat ◽

Distribution Models ◽

Extant Species ◽

Starting Point

SummaryThe Critically Endangered Himalayan Quail Ophrysia superciliosa has not been reliably recorded since 1876. Recent searches of historical sites have failed to detect the species, but we estimate an extinction year of 2023 giving us reason to believe that the species may still be extant. Species distribution models can act as a guide for survey efforts, but the current land cover in the historical specimen record locations is unlikely to reflect Himalayan Quail habitat preferences due to extensive modifications. Thus, we investigate the use of two proxy species: Cheer Pheasant Catreus wallechi and Himalayan Monal Lophophorus impejanus that taken together are thought to have macro-habitat requirements that encapsulate those of the Himalayan Quail. After modelling climate and topography space for the Himalayan Quail and these proxy species we find the models for the proxy species have moderate overlap with that of the Himalayan Quail. Models improved with the incorporation of land cover data and when these were overlaid with the Himalayan Quail climate model, we were able to identify suitable areas to target surveys. Using a measure of search effort from recent observations of other galliformes, we identify 923 km2 of suitable habitat surrounding Mussoorie in Northern India that requires further surveys. We conclude with a list of five priority survey sites as a starting point.

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Direct and indirect effects of regional and local climatic factors on trophic interactions in the Arctic tundra

Journal of Animal Ecology ◽

10.1111/1365-2656.13104 ◽

2019 ◽

Vol 89 (3) ◽

pp. 704-715 ◽

Cited By ~ 4

Author(s):

Claire‐Cécile Juhasz ◽

Bill Shipley ◽

Gilles Gauthier ◽

Dominique Berteaux ◽

Nicolas Lecomte

Keyword(s):

Trophic Interactions ◽

Indirect Effects ◽

Climatic Factors ◽

Arctic Tundra ◽

The Arctic ◽

Direct And Indirect Effects

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Direct and indirect effects of roads on space use by jaguars in Brazil

Scientific Reports ◽

10.1038/s41598-021-01936-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rafaela Cobucci Cerqueira ◽

Oscar Rodríguez de Rivera ◽

Jochen A. G. Jaeger ◽

Clara Grilo

Keyword(s):

Land Cover ◽

Indirect Effects ◽

Urban Areas ◽

Urban Expansion ◽

Space Use ◽

Wildlife Habitat ◽

Equation Modeling ◽

Direct And Indirect Effects ◽

Landscape Modification ◽

Species Response

AbstractRoads pose an imminent threat to wildlife directly through mortality and changes in individual behavior, and also indirectly through modification of the amount and configuration of wildlife habitat. However, few studies have addressed how these mechanisms interact to determine species response to roads. We used structural equation modeling to assess direct and indirect effects (via landscape modification) of roads on space use by jaguars in Brazil, using radio-tracking data available from the literature. We fit path models that directly link jaguars’ space use to roads and to land cover, and indirectly link jaguars’ space use to roads through the same land cover categories. Our findings show that space use by jaguars was not directly affected by roads, but indirect effects occurred through reductions in natural areas on which jaguars depend, and through urban sprawl. Males´ space use, however, was not negatively influenced by urban areas. Since jaguars seem to ignore roads, mitigation should be directed to road fencing and promoting safe crossings. We argue that planners and managers need to much more seriously take into account the deforestation and the unbridled urban expansion from roads to ensure jaguar conservation in Brazil.

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