scholarly journals Predation of nesting Thick-billed Parrots Rhychopsitta pachyrhyncha by bobcats in northwestern Mexico

2020 ◽  
pp. 1-9
Author(s):  
JAMES KENDAL SHEPPARD ◽  
JOSÉ IGNACIO GONZÁLEZ ROJAS ◽  
JAVIER CRUZ ◽  
LUZ FRANCELIA TORRES GONZÁLEZ ◽  
MIGUEL ÁNGEL CRUZ NIETO ◽  
...  
Keyword(s):  
High Elevation ◽  
Lynx Rufus ◽  
Reproductive Value ◽  
Conifer Forest ◽  
Western Mexico ◽  
Mixed Conifer Forest ◽  
Sierra Madre ◽  
Northwestern Mexico ◽  
Breeding Seasons ◽  
North Western

Summary We report on what appear to be increasing predation events on nesting Thick-billed Parrots Rhychopsitta pachyrhyncha. Thick-billed Parrots are classified as ‘Endangered’ and their seasonal breeding range is restricted to increasingly fragmented and degraded high elevation mixed conifer forest habitat within the Sierra Madre Occidental region of north-western Mexico. Predation of established breeding pairs has recently contributed to the ongoing decline of Thick-billed Parrot populations by removing mature birds with high reproductive value, which has associated consequences for future recruitment. We observed increasing predation events on nesting Thick-billed Parrots by bobcats Lynx rufus accompanied by kittens throughout the 2018–2019 breeding seasons, and we speculate that recent reductions in bobcat habitat have pushed them into new ranges where they are supplementing their diet with nontraditional prey items.

A survey of ecotourism on islands in northwestern México

1999 ◽  
Vol 26 (3) ◽  
pp. 212-217 ◽  
Author(s):  
B.R. TERSHY ◽  
L. BOURILLÓN ◽  
L. METZLER ◽  
J. BARNES
Keyword(s):  
Government Regulation ◽  
Costs And Benefits ◽  
Management Options ◽  
Western Mexico ◽  
Human Use ◽  
Northwestern Mexico ◽  
Negative Impacts ◽  
North Western

The >150 islands in north-western México are relatively pristine, but may easily be damaged by unregulated human use. Tourists visit many of these islands, but their numbers and impact are unknown. To examine some of the costs and benefits of ecotourism we sent a questionnaire to 42 ecotourism companies that visit islands in north-western México; 29 respondents reported that tourist days on these islands had increased at >7% yr-1, from <15 000 in 1986 to about 47 000 in 1993. Neither government regulation nor cost of trips were reported to be important impediments to tourism growth. In 1993, ecotourist organizations visiting islands reported spending US$3.7 million, none of which went directly to the protection and management of the islands. We provide several management options to increase the conservation benefits of ecotourism and minimize the negative impacts.

scholarly journals Effect of clear cutting on snow accumulation and water outflow at Fraser, Colorado

1997 ◽  
Vol 1 (2) ◽  
pp. 325-332 ◽  
Author(s):  
C. A. Troendle ◽  
J. O. Reuss
Keyword(s):  
High Elevation ◽  
Snow Accumulation ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Post Harvest ◽  
Clear Cutting ◽  
Mixed Conifer Forest ◽  
The Mean ◽  
Zero Discharge ◽  
Water Outflow

Abstract. This paper compares of snowpack accumulation and ablation, evapotranspiration, and water outflow from clearcut and forested plots within a high elevation (2900 m) mixed conifer forest at the Fraser Experimental Forest near Fraser, Colorado, USA. Also presented is a method for defining contributing area where outflow is measured from unbounded plots. Plots were monitored from 1980 to 1990 and again in 1993. The clearcut plot was harvested in late 1984. Evapotranspiration (ET) of the forested plot at zero discharge (ETo) was estimated at 426 mm while the ET was 500 mm at the mean precipitation of 596 mm. ET was dependent on precipitation with about 28% of precipitation input in excess of 426 mm contributing to increased ET, while the remainder contributed to increased outflow. During the six monitored post-harvest years, Peak Water Equivalent of the snowpack averaged 36% higher on the cut plot than on the control, and the mean discharge increased from 85 mm to 356 mm. Area estimates were obtained from the slopes of the regression of outflow on precipitation inputs. Hydrologic parameters corresponded closely to those previously determined at Fraser Experimental Forest using other methods, lending credence to the validity of the area estimates.

Holocene vegetation and fire regimes in subalpine and mixed conifer forests, southern Rocky Mountains, USA

2008 ◽  
Vol 17 (1) ◽  
pp. 96 ◽  
Author(s):  
R. S. Anderson ◽  
C. D. Allen ◽  
J. L. Toney ◽  
R. B. Jass ◽  
A. N. Bair
Keyword(s):  
Rocky Mountains ◽  
High Elevation ◽  
Picea Engelmannii ◽  
Abies Lasiocarpa ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
The Holocene ◽  
Southern Rocky Mountains ◽  
Sedimentary Records ◽  
Mixed Conifer Forest

Our understanding of the present forest structure of western North America hinges on our ability to determine antecedent forest conditions. Sedimentary records from lakes and bogs in the southern Rocky Mountains of Colorado and New Mexico provide information on the relationships between climate and vegetation change, and fire history since deglaciation. We present a new pollen record from Hunters Lake (Colorado) as an example of a high-elevation vegetation history from the southern Rockies. We then present a series of six sedimentary records from ~2600 to 3500-m elevation, including sites presently at the alpine–subalpine boundary, within the Picea engelmannii–Abies lasiocarpa forest and within the mixed conifer forest, to determine the history of fire in high-elevation forests there. High Artemisia and low but increasing percentages of Picea and Pinus suggest vegetation prior to 13 500 calendar years before present (cal yr BP) was tundra or steppe, with open spruce woodland to ~11 900 cal yr BP. Subalpine forest (Picea engelmannii, Abies lasiocarpa) existed around the lake for the remainder of the Holocene. At lower elevations, Pinus ponderosa and/or contorta expanded 11 900 to 10 200 cal yr BP; mixed conifer forest expanded ~8600 to 4700 cal yr BP; and Pinus edulis expanded after ~4700 cal yr BP. Sediments from lake sites near the alpine–subalpine transition contained five times less charcoal than those entirely within subalpine forests, and 40 times less than bog sites within mixed conifer forest. Higher fire episode frequencies occurred between ~12 000 and 9000 cal yr BP (associated with the initiation or expansion of south-west monsoon and abundant lightning, and significant biomass during vegetation turnover) and at ~2000–1000 cal yr BP (related to periodic droughts during the long-term trend towards wetter conditions and greater biomass). Fire episode frequencies for subalpine–alpine transition and subalpine sites were on average 5 to 10 fire events/1000 years over the Holocene, corresponding to one fire event every ~100 to 200 years. (5) Our Holocene-length sedimentary charcoal records provide additional evidence for the anomalous nature of the 20th-century fire regime, where fires were largely suppressed as a national policy.

scholarly journals On some new species of Stenheliinae Brady, 1880 (Copepoda, Harpacticoida, Miraciidae) from north-western Mexico, with the proposal of Lonchoeidestenhelia gen. nov.

ZooKeys ◽  
2020 ◽  
Vol 987 ◽  
pp. 41-79
Author(s):  
Samuel Gómez
Keyword(s):  
New Species ◽  
Sister Group ◽  
The Other ◽  
Sister Group Relationship ◽  
Monotypic Genus ◽  
Outer Spine ◽  
Western Mexico ◽  
Outer Seta ◽  
Northwestern Mexico ◽  
North Western

Quarterly sampling campaigns during 2019 to study the diversity of meiofauna in a polluted estuary in northwestern Mexico revealed the subfamily Stenheliinae Brady, 1880 as one of the most important contributors to the diversity of benthic harpacticoids. Two new stenheliin species are described here. One of them was assigned to the, so far, monotypic genus Lonchoeidestenheliagen. nov. defined by the autapomorphic modified proximal outer spinules on the sigmoid process of the male P2ENP2. The other species was assigned to Willenstenhelia Karanovic and Kim, 2014. Lonchoeidestenheliagen. nov. shares the armature formula of the P1 EXP2 with Stenhelia, Anisostenhelia, and Beatricella, but seems to bear a sister-group relationship with the former two genera by the loss of one inner seta on the P2–P3 EXP3, the presence of two outer spine-like elements on the male P5EXP, and the displacement of the outer spine and medial and inner distal setae of P2ENP3, to an apical and subapical inner position, respectively, but is more closely related to Anisostenhelia by the overall shape of the male P2ENP2. Willenstenhelia reductasp. nov. is attributed to a group of species composed of Wi. minuta, Wi. urania, and Wi. terpsichore characterized by the strongly reduced inner seta of the female P5 baseoendopod, but differs in the discrete female P5 baseoendopods and in the presence of one outer seta only on that segment. Willenstenhelia reductasp. nov. is defined here by the autapomorphic loss of the outermost seta of the female P5 baseoendopod.

Spatial variability in microclimate in a mixed-conifer forest before and after thinning and burning treatments

2010 ◽  
Vol 259 (5) ◽  
pp. 904-915 ◽  
Author(s):  
Siyan Ma ◽  
Amy Concilio ◽  
Brian Oakley ◽  
Malcolm North ◽  
Jiquan Chen
Keyword(s):  
Spatial Variability ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Mixed Conifer Forest ◽  
Before And After
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