Of 163 fecal samples collected between March 1997 and February 1999 from the plains vizcacha, Lag... more Of 163 fecal samples collected between March 1997 and February 1999 from the plains vizcacha, Lagostomus maximus (Rodentia: Chinchillidae), 19 (12%) were found to be positive for coccidia. All species are from the genus Eimeria and 2 are described here as new. The third species is consistent with the description of Eimeria chinchillae De Vos and Van der Westhuizen, 1968. Sporulated oocysts of Eimeria lagostomi n. sp. are ellipsoidal to subspheroidal, 35.7 x 30.9 (26-36 x 30-41), with a length:width (L/W) ratio of 1.2 (1.0-1.3), without a micropyle (M) or polar granule (PG), but with an oocyst residuum (OR) comprised of a round, compact mass of many small granules. The sporocysts are lemon-shaped, 14.2 x 10.2 (9-11 x 11-16), with an L/W ratio of 1.4 (1.2-1.7) and have a Stieda body (SB) and sporocyst residuum (SR). Eimeria vizcacho n. sp. has sporulated oocysts that are subspheroidal, 26.4 x 23.4 (21-27 x 23-31), with an L/W ratio of 1.1 (1.1-1.2), lack an M and OR, but have 1-2 PGs. Sporocysts are elongate-ellipsoidal, 14.3-9.0 (8-10 x 13-15), with an L/W ratio of 1.6 (1.4-1.8), lack an SB, but have 2 SR; the first a small mass of granules lying between the sporozoites in the middle or at 1 end, and the second also of many small granules, always at the opposite end. Sporulated oocysts of the E. chinchillae-like organism are ellipsoidal to subspheroidal, 20.7 x 17.5 (15-22 x 17-24) with an L/W ratio of 1.2 (1.0-1.3), lack an M and OR, but have 0-3 PGs. Sporocysts are ellipsoidal, 10.7-6.9 (6-8 x 8-13) with an L/W ratio of 1.55 (1.3-1.8) and have an SB and SR.
ways that condition the outcome of the association. We examined interactions between burrowing ow... more ways that condition the outcome of the association. We examined interactions between burrowing owls (Athene cunicularia) and two burrowing mammals, hairy armadillos (Chaetophractus villosus) and plains vizcachas (Lagostomus maximus), and determined whether these ecosystem engineers are interchangeable for owls. We examined reproductive success for owls nesting in these mammal burrows, constructed a logistic regression model to identify habitat characteristics associated with owl nests, and examined the engineering activities of the mammals. Data on reproduction and habitat indicate that armadillos and vizcachas are not interchangeable for owls. Thirtyfive percent of the nests in vizcacha burrows produced fledglings; no fledglings were produced from nests outside vizcachas colonies, even though owls nest successfully in armadillo burrows in other parts of Argentina. Vizcachas facilitate burrowing owls by construction of burrows and by producing open understory vegetation through herbivory. In contrast, armadillos do not alter vegetation, and their burrows are
Shade coffee is among the most widespread and economically important crops in montane tropical re... more Shade coffee is among the most widespread and economically important crops in montane tropical regions and is considered more hospitable to wildlife than non‐shaded crops. Questions remain regarding the value of shade coffee as habitat for wildlife, however, given the historical research focus on small‐bodied and canopy species. Simultaneously, climate‐driven upslope migration of coffee crops represents an emerging threat to well‐conserved tropical montane forest at higher elevations. This study examined ground‐dwelling birds and medium‐large mammals in a shade coffee landscape of the Western Andes of Colombia. We asked the following questions: (1) How do bird and mammal occupancy, richness, and community composition change from continuous forest at higher elevations to middle‐elevation forest fragments and shade coffee? (2) Do birds and mammals differ in their response to shade coffee? (3) Do high‐elevation forests contribute to maintaining biodiversity in mid‐elevation shade coffee? We sampled birds and mammals with camera traps in middle‐elevation shade coffee plantations and forest fragments and in continuous forest further upslope. We then used a multi‐species occupancy model to correct for imperfect detection and to estimate occupancy, richness, and community composition. Shade coffee lacked ~50% of the bird and mammal species found in continuous forest, primarily large‐bodied and insectivorous birds and forest‐specialist and large‐bodied mammals. Forest fragment richness was closer to shade coffee than to continuous forest, but species composition significantly differed between coffee and both forest types. Birds in coffee plantations were generally a unique subset of disturbance‐adapted specialists, whereas mammals in coffee were mostly generalists. Distance from continuous forest was the most important landscape‐level predictor of occupancy for both taxa, suggesting that this forest plays a key role in maintaining biodiversity across the coffee landscape. Biodiversity conservation in shade coffee landscapes, therefore, will be ineffective unless linked to landscape‐level initiatives that conserve higher elevation tropical montane forest.
Context The spatial extent at which landscape variables most strongly influences wildlife populat... more Context The spatial extent at which landscape variables most strongly influences wildlife populations (i.e., scale of effect) is of key importance to ecology and conservation. Many factors can influence scales of effect, but these relationships are poorly understood. In particular, the way scales of effect vary with different landscape metrics has not been extensively tested. Objectives Our study examined whether metrics of landscape configuration have wider or narrower scales of effect than habitat composition. We also examined how a variety of factors (i.e., species traits and landscape context) influence the magnitude of these differences in scales of effect between metrics. Methods We calculated scales of effect for four metrics of habitat configuration and one metric of composition directly from species presence/absence data in online repositories. We did so for 102 species of mammals from 33 studies across the globe. Results Two metrics of configuration had significantly wider...
Of 163 fecal samples collected between March 1997 and February 1999 from the plains vizcacha, Lag... more Of 163 fecal samples collected between March 1997 and February 1999 from the plains vizcacha, Lagostomus maximus (Rodentia: Chinchillidae), 19 (12%) were found to be positive for coccidia. All species are from the genus Eimeria and 2 are described here as new. The third species is consistent with the description of Eimeria chinchillae De Vos and Van der Westhuizen, 1968. Sporulated oocysts of Eimeria lagostomi n. sp. are ellipsoidal to subspheroidal, 35.7 x 30.9 (26-36 x 30-41), with a length:width (L/W) ratio of 1.2 (1.0-1.3), without a micropyle (M) or polar granule (PG), but with an oocyst residuum (OR) comprised of a round, compact mass of many small granules. The sporocysts are lemon-shaped, 14.2 x 10.2 (9-11 x 11-16), with an L/W ratio of 1.4 (1.2-1.7) and have a Stieda body (SB) and sporocyst residuum (SR). Eimeria vizcacho n. sp. has sporulated oocysts that are subspheroidal, 26.4 x 23.4 (21-27 x 23-31), with an L/W ratio of 1.1 (1.1-1.2), lack an M and OR, but have 1-2 PGs. Sporocysts are elongate-ellipsoidal, 14.3-9.0 (8-10 x 13-15), with an L/W ratio of 1.6 (1.4-1.8), lack an SB, but have 2 SR; the first a small mass of granules lying between the sporozoites in the middle or at 1 end, and the second also of many small granules, always at the opposite end. Sporulated oocysts of the E. chinchillae-like organism are ellipsoidal to subspheroidal, 20.7 x 17.5 (15-22 x 17-24) with an L/W ratio of 1.2 (1.0-1.3), lack an M and OR, but have 0-3 PGs. Sporocysts are ellipsoidal, 10.7-6.9 (6-8 x 8-13) with an L/W ratio of 1.55 (1.3-1.8) and have an SB and SR.
ways that condition the outcome of the association. We examined interactions between burrowing ow... more ways that condition the outcome of the association. We examined interactions between burrowing owls (Athene cunicularia) and two burrowing mammals, hairy armadillos (Chaetophractus villosus) and plains vizcachas (Lagostomus maximus), and determined whether these ecosystem engineers are interchangeable for owls. We examined reproductive success for owls nesting in these mammal burrows, constructed a logistic regression model to identify habitat characteristics associated with owl nests, and examined the engineering activities of the mammals. Data on reproduction and habitat indicate that armadillos and vizcachas are not interchangeable for owls. Thirtyfive percent of the nests in vizcacha burrows produced fledglings; no fledglings were produced from nests outside vizcachas colonies, even though owls nest successfully in armadillo burrows in other parts of Argentina. Vizcachas facilitate burrowing owls by construction of burrows and by producing open understory vegetation through herbivory. In contrast, armadillos do not alter vegetation, and their burrows are
Shade coffee is among the most widespread and economically important crops in montane tropical re... more Shade coffee is among the most widespread and economically important crops in montane tropical regions and is considered more hospitable to wildlife than non‐shaded crops. Questions remain regarding the value of shade coffee as habitat for wildlife, however, given the historical research focus on small‐bodied and canopy species. Simultaneously, climate‐driven upslope migration of coffee crops represents an emerging threat to well‐conserved tropical montane forest at higher elevations. This study examined ground‐dwelling birds and medium‐large mammals in a shade coffee landscape of the Western Andes of Colombia. We asked the following questions: (1) How do bird and mammal occupancy, richness, and community composition change from continuous forest at higher elevations to middle‐elevation forest fragments and shade coffee? (2) Do birds and mammals differ in their response to shade coffee? (3) Do high‐elevation forests contribute to maintaining biodiversity in mid‐elevation shade coffee? We sampled birds and mammals with camera traps in middle‐elevation shade coffee plantations and forest fragments and in continuous forest further upslope. We then used a multi‐species occupancy model to correct for imperfect detection and to estimate occupancy, richness, and community composition. Shade coffee lacked ~50% of the bird and mammal species found in continuous forest, primarily large‐bodied and insectivorous birds and forest‐specialist and large‐bodied mammals. Forest fragment richness was closer to shade coffee than to continuous forest, but species composition significantly differed between coffee and both forest types. Birds in coffee plantations were generally a unique subset of disturbance‐adapted specialists, whereas mammals in coffee were mostly generalists. Distance from continuous forest was the most important landscape‐level predictor of occupancy for both taxa, suggesting that this forest plays a key role in maintaining biodiversity across the coffee landscape. Biodiversity conservation in shade coffee landscapes, therefore, will be ineffective unless linked to landscape‐level initiatives that conserve higher elevation tropical montane forest.
Context The spatial extent at which landscape variables most strongly influences wildlife populat... more Context The spatial extent at which landscape variables most strongly influences wildlife populations (i.e., scale of effect) is of key importance to ecology and conservation. Many factors can influence scales of effect, but these relationships are poorly understood. In particular, the way scales of effect vary with different landscape metrics has not been extensively tested. Objectives Our study examined whether metrics of landscape configuration have wider or narrower scales of effect than habitat composition. We also examined how a variety of factors (i.e., species traits and landscape context) influence the magnitude of these differences in scales of effect between metrics. Methods We calculated scales of effect for four metrics of habitat configuration and one metric of composition directly from species presence/absence data in online repositories. We did so for 102 species of mammals from 33 studies across the globe. Results Two metrics of configuration had significantly wider...
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