Papers by Juan Manuel Grande
PLOS ONE, Oct 1, 2012
Bookmarks Related papers MentionsView impact
Ecological Indicators, Jun 1, 2020
Bookmarks Related papers MentionsView impact
Behavioral Ecology, 2015
Bookmarks Related papers MentionsView impact
Oikos, Apr 1, 2009
Bookmarks Related papers MentionsView impact
Biological Conservation, 2020
Bookmarks Related papers MentionsView impact
Bird Conservation International, 2017
SummaryHigh mortality by electrocution has been suggested to be the main factor behind the reduct... more SummaryHigh mortality by electrocution has been suggested to be the main factor behind the reduction of several birds of prey populations across the world. Almost nothing is known, however, about the impact of power lines on this group of birds in the Neotropical Region. Here we estimate electrocution rates for birds on power lines covering both arid and semiarid biomes of central Argentina. We conducted six bi-monthly power line and raptor surveys throughout 355 km of lines and roads covering an area of approximately 12,000 km2. We described the structural design of 3,118 surveyed electricity pylons. We found 34 electrocuted individuals of four bird families that constitute an annual bird electrocution rate of 0.011 bird/pylon/year. Bird electrocution occurred mostly on concrete pylons with jumpers above the cross-arm. Larger birds of prey had a higher electrocution rate than smaller species. The Crowned Solitary Eagle Buteogallus coronatus was disproportionately affected by this m...
Bookmarks Related papers MentionsView impact
Ecology and Evolution, Jul 29, 2023
Variation in offspring sex ratio, particularly in birds, has been frequently studied over the las... more Variation in offspring sex ratio, particularly in birds, has been frequently studied over the last century, although seldom using long‐term monitoring data. In raptors, the cost of raising males and females is not equal, and several variables have been found to have significant effects on sex ratio, including food availability, parental age, and hatching order. Sex ratio differences between island populations and their mainland counterparts have been poorly documented, despite broad scientific literature on the island syndrome reporting substantial differences in population demography and ecology. Here, we assessed individual and environmental factors potentially affecting the secondary sex ratio of the long‐lived Egyptian vulture Neophron percnopterus. We used data collected from Spanish mainland and island populations over a ca. 30‐year period (1995–2021) to assess the effects of insularity, parental age, breeding phenology, brood size, hatching order, type of breeding unit (pairs vs. trios), and spatial and temporal variability on offspring sex ratio. No sex bias was found at the population level, but two opposite trends were observed between mainland and island populations consistent with the island syndrome. Offspring sex ratio was nonsignificantly female‐biased in mainland Spain (0.47, n = 1112) but significantly male‐biased in the Canary Islands (0.55, n = 499), where a male‐biased mortality among immatures could be compensating for offspring biases and maintaining a paired adult sex ratio. Temporal and spatial variation in food availability might also have some influence on sex ratio, although the difficulties in quantifying them preclude us from determining the magnitude of such influence. This study shows that insularity influences the offspring sex ratio of the Egyptian vulture through several processes that can affect island and mainland populations differentially. Our research contributes to improving our understanding of sex allocation theory by investigating whether sex ratio deviations from parity are possible as a response to changing environments comprised by multiple and complexly interrelated factors.
Bookmarks Related papers MentionsView impact
El Hornero, Dec 1, 2019
Bookmarks Related papers MentionsView impact
El Hornero, Aug 1, 2019
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Journal of Arid Environments, May 1, 2023
Bookmarks Related papers MentionsView impact
Emu, Apr 3, 2022
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Biological Conservation, Oct 1, 2020
Bookmarks Related papers MentionsView impact
Ornitología Neotropical
Bookmarks Related papers MentionsView impact
Global Ecology and Conservation
Bookmarks Related papers MentionsView impact
Oecologia, Apr 4, 2015
Bookmarks Related papers MentionsView impact
Waterbirds, Sep 1, 2002
Bookmarks Related papers MentionsView impact
Authorea (Authorea), Mar 31, 2021
Bookmarks Related papers MentionsView impact
Ornitología Neotropical
∙ The Burrowing Parrot Cyanoliseus patagonus is known to breed in burrows mostly on cliffs and ra... more ∙ The Burrowing Parrot Cyanoliseus patagonus is known to breed in burrows mostly on cliffs and ravines in arid or semi‐arid regions of Argentina and Chile. However, during a tree cavity monitoring project we confirmed at least two active nests in tree cavities. Cavity entrances were located between 3.1 and 5.3 m above the ground in live caldén (Prosopis caldenia) trees, Parque Luro, province of La Pampa, Argentina. One nest failed while the other one successfully produced three fledglings. The absence of cliffs and scarcity of ravines in the region, and the presence of a nesting colony of the Blue‐crowned Parakeet (Thectocercus acuticaudatus) in the site may have promoted the adoption of this new nesting substrate for the species. Resumen ∙ Nidificación inusual del Loro Barranquero (Cyanoliseus patagonus) en cavidades naturales de árboles El Loro Barranquero (Cyanoliseus patagonus) nidifica mayoritariamente en cavidades en barrancos y acantilados en regiones áridas y semiáridas de A...
Bookmarks Related papers MentionsView impact
Uploads
Papers by Juan Manuel Grande