Bombus fervidus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Arthropoda Insecta Hymenoptera Apidae

Scientific Name: Bombus fervidus
Species Authority: (Fabricius, 1798)
Common Name(s):
English Yellow Bumblebee
Bombus californicus Smith, 1854
Bombus dumoucheli Radoszkowski, 1884
Taxonomic Notes: This species is synonymous with B. californicus, based on the lack of differentiation in DNA barcodes between individuals with this color pattern and those with the B. fervidus s. str. color pattern (Williams et al. 2014).

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2b ver 3.1
Year Published: 2015
Date Assessed: 2014-08-19
Assessor(s): Hatfield, R., Jepsen, S., Thorp, R., Richardson, L., Colla, S. & Foltz Jordan, S.
Reviewer(s): Ascher, J., Cannings, S., Inouye, D., Jha, S., Lozier, J., Vandame, R.V., Williams, P., Woodard, H. & Yanega, D.
Contributor(s): Antweiler, G., Arduser, M., Ascher, J., Bartomeus, N., Beauchemin, A., Beckham, J., Cromartie, J., Day, L., Droege, S., Evans, E., Fiscus, D., Fraser, D., Gadallah, Z., Gall, L., Gardner, J., Gill, D., Golick, D., Heinrich, B., Hinds, P., Hines, H., Irwin, R., Jean, R., Klymko, J., Koch, J., MacPhail, V., Martineau, R., Martins, K., Matteson, K., McFarland, K., Milam, J., Moisan-DeSerres, J., Morrison, F., Ogden, J., Packer, L., Pineda Diez de Bonilla, E.P., Richardson, L., Savard, M., Scott, V., Scully, C., Sheffield, C., Sikes, D., Strange, J., Surrette, S., Thomas, C, Thompson, J., Vandame, R.V., Veit, M., Wetherill, K., Williams, N., Williams, P., Winfree, R., Yanega, D. & Zahendra, S.
Facilitator/Compiler(s): Foltz Jordan, S., Hatfield, R., Colla, S. & MacPhail, V.
A number of studies have demonstrated abundance and persistence declines in this North American species (e.g. Colla et al. 2012, Colla and Packer 2008, Giles and Ascher 2006). Consistent with these studies, our analysis shows decline in relative abundance over the time period examined, as well as long term steady decline (Hatfield et al. 2014). If this species' relative abundance continues to decline at the same rate, we project that the species will go extinct in the next 70 to 80 years. The most recent time period shows the lowest relative abundance of all time periods. The relative abundance decline in the past decade has been nearly 50% from mean. Although the persistence value is relatively high and the extent of occurrence (EOO) loss has not been that great, the changes in relative abundance justify the Vulnerable category. Based on the calculations and trends shown in the Population section below (and see Supplementary Material), along with published reports of bumblebee decline and the Assessors' best professional judgement, we recommend this species for the Vulnerable Red List Category at this time.
For further information about this species, see 21215132_Bombus_fervidus.pdf.
A PDF viewer such as Adobe Reader is required.

Geographic Range [top]

Range Description:This is a widespread species across much of the mid-latitudes of the continent, from the Canadian Maritimes and eastern United States in the Eastern Temperate Forest and Boreal Forest regions, west through the central Great Plains of the United States and southern Canada to the Mountain West, Pacific Coast and Western Desert of California. This species is not abundant in the Boreal region. This species is also present in Mexico, where it is known from the following states: Baja California, Chihuahua, Coahuila, Distrito Federal, Durango, Guanajuato, Hidalgo, México, Michoacán, Nuevo León, Puebla, Tlaxcala and Zacatecas (ECOSUR database 2015).      

Countries occurrence:
Canada (Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince Edward I., Québec, Saskatchewan); Mexico (Baja California, Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, México Distrito Federal, México State, Michoacán, Nuevo León, Puebla, Tlaxcala, Zacatecas); United States (Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Minnesota, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming)
Additional data:
Continuing decline in extent of occurrence (EOO):Unknown
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species is synonymous with B. californicus, based on the lack of differentiation in DNA barcodes between individuals with this colour pattern and those with the B. fervidus s. str. colour pattern (Williams et al. 2014). The Mexican samples of this species are different from the US/Canada ones both morphologically (colour pattern of B. f. sonomae) and genetically (according to a preliminary DNA barcodes analysis), but further sampling is required to clarify their taxonomic status.

A number of published studies have demonstrated abundance and persistence declines in this species. A regional study of bumblebee community structure in Black Rock Forest, New York during the summer of 2003 found the current bumblebee community composition differed when compared to historical records; most notably, this survey of over 1,200 bumblebees failed to find B. affinis, B. pensylvanicus and B. fervidus despite their being noted as previously common in central New York (Giles and Ascher 2006). In another regional study in southern Ontario, Colla and Packer (2008) found B. fervidus (among others) had significantly and dramatically lower relative abundance in 2004-2006 than was exhibited during surveys at the same sites a few decades earlier (1971-1973). A larger study, considering over 69,000 bumblebee specimens of 21 eastern North America species collected from 1865-2010, assessed changes in relative abundance and occupancy of each species and ranked their conservation status throughout their entire United States and Canadian ranges (Colla et al. 2012). While most of the declining species exhibited declines between the last two time periods considered in the study, B. fervidus was found to be in chronic decline from earlier time periods to the present (Colla et al. 2012). Considering museum collections from the mid-1800s, this species was found to have declined by 70% in relative abundance since the 1930s (Colla et al. 2012).

We evaluated this species’ spatial distribution in North America (north of Mexico) over time using a measure of change in the extent of occurrence (EOO) and a measure of change in persistence (analytical methods described in Hatfield et al. 2014) (see Figure 1 in the Supplementary Material) . We also assessed changes in the species’ relative abundance (see Figure 2 in the Supplementary Material), which we consider to be an index of abundance relevant to the taxon, as specified by the IUCN Red List Categories and Criteria (IUCN 2012). For all three calculations we divided the database into historical (1805-2001, N=128,572) and current (2002-2012, N=74,682) records. This time frame was chosen to meet the IUCN criteria stipulation that species decline must have been observed over the longer of three generations or 10 years. Average decline for this species was calculated by averaging the change in abundance, persistence, and EOO. This analysis yielded the following results (see Supplementary Material for map of change in EOO over time (Figure 1) and graph of change in relative abundance (Figure 2)):

  • Current range size relative to historic range: 84.06%
  • Persistence in current range relative to historic occupancy: 85.84%
  • Current relative abundance relative to historic values: 38.04%
  • Average decline: 30.69%

This analysis suggests this species has suffered long term, steady decline. If this species' relative abundance continues to decline at the same rate, we project that it will reach zero in the next 70 to 80 years. The most recent time period shows the lowest relative abundance of all time periods. The relative abundance decline in the past decade has been nearly 50% from the mean. Note that this analysis includes records for B. californicus (a synonym of this species).

Mexican summary: The ECOSUR database (2015) includes 160 recent (2012-2014) records of this species from numerous Mexican states (Baja California, Chihuahua, Coahuila, Distrito Federal, Durango, Guanajuato, Hidalgo, México, Michoacán, Nuevo León, Puebla, Tlaxcala and Zacatecas).
For further information about this species, see 21215132_Bombus_fervidus.pdf.
A PDF viewer such as Adobe Reader is required.
Current Population Trend:Decreasing
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:

Bumblebees, as a whole, are eusocial insects that live in colonies composed of a queen, workers, and reproductives (males and new queens). Colonies are annual and only the new, mated queens overwinter. These queens emerge from hibernation in the early spring and immediately start foraging for pollen and nectar and begin to search for a nest site. Nests are often located underground in abandoned rodent nests, or above ground in tufts of grass, old bird nests, rock piles, or cavities in dead trees. Initially, the queen does all of the foraging and care for the colony until the first workers emerge and assist with these duties. Bumblebees collect both nectar and pollen of the plants that they pollinate. In general, bumblebees forage from a diversity of plants, although bumblebee species in a given area can vary greatly in their plant preferences, largely due to differences in tongue length. Bumblebees are well-known to engage in “buzz pollination,” a very effective foraging technique in which they sonicate the flowers to vibrate the pollen loose from the anthers.

Bombus fervidus is a long-tongued, later emerging species (Williams et al. 2014). It is found in open farmland and fields, urban parks, and gardens throughout its range and nests mostly on the surface of the ground, among long grass or in deserted mouse nests, but does occasionally nest underground.(Williams et al. 2014). This is one of the more aggressive bumblebee species, probably as an adaptation to protect more exposed above-ground nests (Williams et al. 2014).  Males congregate outside nest entrances in search of mates (Williams et al. 2014). Example food plants include Astragalus, Cirsium, Helianthus, Lonicera, Lythrum, MonardaPedicularisPenstemon, Trifolium, and Vicia (Williams et al. 2014).  This species is a known host to Bombus insularis; it is probably also host to B. suckleyi (Williams et al. 2014).

Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):1

Threats [top]

Major Threat(s):

This species occurs across a large range in Canada and the United States as well as parts of Mexico. It is unlikely that one threat explains the long-term decline trends observed. Regional studies give us some information about possible threats to this species. Gillespie (2010) found B. fervidus and B. pensylvanicus to be among the most uncommon species in Massachusetts but with significantly higher levels of Nosema bombi (but not other parasites) compared to the common species. Nosema bombi is known to spillover from managed bumblebees (Colla et al. 2006) and may be implicated in declines.

Open grassland habitats, old fields, and tallgrass habitats are likely the most suitable habitat types for this species in its range. This habitat type is of conservation concern and exists only in small remnants. In a survey performed in Iowa, Hines and Hendrix (2005) found higher abundance and diversity of bumblebees in high quality tallgrass prairie sites, depending on quality of the surrounding landscape. Landscape quality was assessed as the diversity and abundance of floral resources at various radii from the survey site. High quality sites with higher bumblebee diversity also contained B. fervidus, indicating this species may be more susceptible to environmental stressors, such as habitat loss (Hines and Hendrix 2005). Bumblebee diversity was found to be best predicted by high floral resource availability in surrounding grasslands (Hines and Hendrix 2005).

Agricultural intensification leads to loss of this habitat type. Pesticide use can also impact this species occurring on or near agriculture. Limited to above ground nesting in natural grasslands or agricultural fields, this species is susceptible to habitat loss or direct exposure to pesticides. In some cases, farmers may kill bumblebee colonies when they nest above ground (frequent among many species of the subgenus Thoracobombus) because they impact cattle and other domestic livestock. The long-tongue of this species restricts its foraging to certain flower types (e.g. legumes). Conversion in agricultural farmland from the use of nitrogen-fixing legumes to artificial fertilizers may further decrease available forage.

A meta-analysis across bumblebee faunas in three continents found species with late emergence (like B. fervidus) are more vulnerable to stressors (Williams et al. 2009). Natural wildfires and prescribed burning may benefit bees by creating open forage in otherwise unsuitable habitat. As such, the suppression of natural fires can result in habitat loss for bees and other grassland species, particularly in forested regions. In light of this, prescribed burning is frequently used as a conservation management tool to restore natural ecosystems (e.g. grasslands), increase biodiversity (particularly plant species), and control invasive species (e.g. Brockway et al. 2002, Hatch et al. 2002). However, depending on fire intensity, duration, season, frequency, and patchiness, prescribed fire may result in population loss for pollinators, particularly at sites where few individuals of a species exist (e.g. Swengel 1996). As such, both fire suppression and fire itself may threaten this species in some areas.

Reduced genetic diversity resulting from any of these threats can be particularly concerning for bumblebees, since their method of sex-determination can be disrupted by inbreeding, and since genetic diversity already tends to be low in this group due to the colonial life cycle (i.e. large numbers of bumble bees found locally may represent only one or a few queens) (Goulson 2010, Hatfield et al. 2012, but see Cameron et al. 2011 and Lozier et al. 2011).      

Conservation Actions [top]

Conservation Actions:

Conservation Needs: 

  • Restoration, creation and preservation of natural grassland habitats.
  • Restriction of harmful pesticide use on or near suitable habitat.
  • Promotion of farming practices that increase the abundance of nitrogen-fixing fallow (legumes).
  • Protection of species from diseases introduced by managed bees.

With the exception of the above, specific conservation and research needs for this species have not been identified. Research needs for North American bumblebees (as a whole) are summarized in Cameron et al. (2011), the final report for the 2010 North American Bumble Bee Species Conservation Planning Workshop.

More detailed information on the population trends and status of this species in Mexico is needed.

Citation: Hatfield, R., Jepsen, S., Thorp, R., Richardson, L., Colla, S. & Foltz Jordan, S. 2015. Bombus fervidus. The IUCN Red List of Threatened Species 2015: e.T21215132A21215225. . Downloaded on 20 February 2017.
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