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Abstract Leaf litter inputs can influence the structure and function of both terrestrial and adjacent aquatic ecosystems. Dioecy and herbivory are two factors that together have received little attention, yet have the potential to affect the quantity, quality, and timing of riparian litterfall, litter chemistry, and litter decomposition processes. Here, we explore litter chemistry differences for the dioecious Sitka willow ( Salix sitchensis Sanson ex. Bong), which is establishing on primary successional habitats at Mount St. Helens (WA, USA) and is heavily infested with a stem‐boring weevil ( Cryptorhynchus lapathi ). Weevil‐attacked branches produced summer senesced litter that had significantly higher %N, lower C:N ratios, and lower condensed tannins than litter from branches that were unattacked by the weevil and senesced naturally in the autumn. Weevils more often attack female willows; however, these common litter chemicals did not significantly differ between males and females within the weevil‐attacked and ‐unattacked groups. High‐resolution mass spectrometry was used to isolate compounds in litter from 10 Sitka willow individuals with approximately 1500–1600 individual compounds isolated from each sample. There were differences between weevil‐attacked litter and green leaf samples, but at this level, there was no clustering of male and female samples. However, further exploration of the isolated compounds determined a suite of compounds present only in either males or females. These findings suggest some variation in more complex litter chemistry between the sexes, and that significant differences in weevil‐attacked litter chemistry, coupled with the shift in seasonality of litter inputs to streams, could significantly affect in‐stream ecological processes, such as decomposition and detritivore activity.
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Using ultrasonography to compare uterine litter size with litter size at weaning for Gunnison's prairie dogs.
Accurate estimates of population dynamics play a major role in formulating conservation strategies for Gunnison’s prairie dogs (Cynomys gunnisoni) and other keystone species. Over five years (2014-2018) at Valles Caldera National Preserve in New Mexico USA, we used a portable ultrasound machine (PUM) to investigate the presence or absence of pregnancy, and to determine uterine litter size for 238 pregnant female Gunnison’s prairie dogs from two colonies. We compared litter size at weaning for 168 of these 238 females and we found no significant difference between uterine litter size and litter size at weaning. For 76 of these 168 females (45%), estimates of uterine litter size and litter size at weaning were identical. We detected no significant variation among years for uterine litter size versus litter size at weaning. To our knowledge, our research is the first to compare uterine litter size to litter size at weaning for the same group of females living under natural conditions.
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- Award ID(s):
- 1753829
- PAR ID:
- 10295786
- Date Published:
- Journal Name:
- Mammal research
- Volume:
- 65
- ISSN:
- 2199-2401
- Page Range / eLocation ID:
- 869-874
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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