There are at least 3,000 species of mites (Arachnida: Acari) living in close association with birds (Aves). The influence of mites on host survival and reproduction ranges from severely detrimental to mildly beneficial. Four orders of mites include species that are blood or tissue feeders on birds. While surveying mites from birds in Alberta, we became aware of the need for an inclusive illustrated key to identify the families and genera of blood and tissue feeding mites. We collected mites by washing birds and examining the filtrate. In total, 328 individual birds representing 123 species were examined. We used a camera-mounted compound microscope, Adobe Photoshop, and a drawing tablet to acquire and edit images. The resulting key covers 13 families and 14 genera of parasitic mites. It was created with non-acarologists in mind and can be easily used by anyone interested in identifying bird-associated mites.

Ptilonyssus bombycillae (Rhinonyssidae)
ex. Bohemian Waxwing (Bombycilla garrulus).

We collected approximately 600 Albertan birds contributed by the Alberta Fish & Wildlife Forensic Laboratory, the Royal Alberta Museum, waterfowl hunters, and colleagues at the University of Alberta. Our key is based on examination of washings from about 328 individual birds representing 123 species from 16 orders. There are 402 species of birds in Alberta, thus our sample represents 31% of Alberta’s avian fauna (Royal Alberta Museum 2005).
Birds were maintained at -20ºC until processing. Frozen birds were first thawed and then washed using the following method. The bird was placed in a suitably sized container, ranging from 4-18L, with a drop of dish detergent, enough 95% ethanol to soak the plumage of the bird, and enough water to submerge it. The sealed container was then shaken vigorously for five minutes. Particularly large birds were washed in a basin and thoroughly massaged while in the solution. Each bird was then removed from the container and rinsed thoroughly over a Fisher Scientific 53 µm mesh filter; large birds were rinsed over the washing basin. The washing liquid was filtered through the same 53 µm filter. The container and lid were rinsed thoroughly over the same filter as well. The filtrate was stored in 30 ml scintillation and snap cap vials. For approximately half of the birds that were washed, no particular attention was paid to flushing the respiratory passages to remove nasal mites. For the remainder we ensured that the nasal passages were flushed with 95% ethanol.
Washings were examined using Leica MZ16 and MZ6 dissection microscopes at 20-25x magnification. Blood and tissue feeding mites were removed, and most were cleared in 85% lactic acid for one to twenty four hours depending on the degree of original transparency. Mites were mounted in a polyvinyl alcohol medium (PVA) from Bioquip Products Inc. (6371A). Slides were cured on a slide warmer at about 40ºC for three to four days.
We made our identifications using a combination of synoptic literature (Krantz 1978; McDaniel 1979) and primary literature (Fain and Elsen 1967; Moss 1978; Pence 1975; Smiley 1970). Images of selected slide-mounted mites were taken with a Canon Powershot S40 digital camera mounted on a Leica DMLB compound microscope with DIC, at 200-400x magnification. Images were captured in the Canon Utilities Remote Capture program, version 2.2.0.11. We edited images using Adobe Photoshop CS version 8.0, Adobe Systems Inc. For a generalized representative of each of the four orders collected, selected mites were drawn using an Intuos 2 Graphics Tablet from WACOM Co., Ltd. and Adobe Photoshop CS version 8.0. Two representative mites were drawn from images taken as described above and the other two mites were redrawn from published literature, one from Smiley (1970) and the second from Moss (1968).

The key covers 14 genera from 13 families of blood and tissue feeding mites (Table 1). All taxa, with one exception (soft ticks, Argasidae), were collected from our specimens of Albertan bird specimens (Table 2). We collected blood and tissue feeding mites, from 38% of 328 individual bird specimens and 58% of 91 genera examined. Mites of the family Rhinonyssidae were collected from the most bird genera (25), followed by Harpirhynchidae (23 host genera) (Table 2). Harpirhynchids were not identified to genus due to time constraints. Host association records presented here are not intended to be exhaustive since examination of more bird specimens and taxa will undoubtedly reveal additional records.
Our key to parasitic mites associated with Albertan birds begins with brief section on feather mites, whose families are not covered in the key since feather mites are largely benign (Proctor and Owens 2000). Gaud and Atyeo (1996) developed synoptic keys to feather mite genera of the world. The body of our key has two main parts, the first to families and the second to genera, and is based primarily on adult females. Within the key there are links to labeled diagrams illustrating important morphological characteristics of the four orders of mites collected.

We particularly thank Bob McClymont and the Alberta Fish and Wildlife Forensic Laboratory, as well as the Royal Alberta Museum for providing us with numerous specimens. Dr. David Walter provided information and helpful criticism and Dr. Bruce Heming advice and editing. S. Grundke and S. Wojtkiw washed birds during the summer of 2003, and N. Romaniuk and M. Pedruski did the same during the summer of 2004. G. Williams and H. Shannon allowed us to use a few of their images in the key. We thank Dr. Al Shostak for his assistance in identifying ticks, as well as the use of his facilities. Lastly, we thank Wayne Roberts for providing us with some unique specimens.
We conducted this research with a scientific salvage permit to take migratory birds from Environment Canada (permit no. CWS03-A009), and a permit to salvage found dead wildlife (excluding endangered species) from Alberta Environment (permit no. 428 CN). This project was funded by an NSERC Discovery grant to HCP and an NSERC USRA to W. Knee.

Table 2. The taxa of blood and tissue feeding mites associated with Albertan birds, with the families and genera of hosts from which they were collected.

Benign Mites Commonly Associated with Birds:
There are approximately 2000 described species of feather mites (Astigmata) worldwide; most birds have feather mites. Feather mites belong to the superfamilies Analgoidea, Freyanoidea and Pterolichoidea. These mites are benign; hence they are excluded from this key. Not all astigmatans are feather mites; some are blood and tissue feeders. Here are a few species of feather mites collected from a Sora Rail, Porzana carolina Linnaeus.

To discriminate feather mites from other mites, feather mites always lack tarsal claws on at least legs 1 and 2, instead they have an elaborate ambulacrum on the end of the tarsi. For comparison, here is the ambulacrum and tarsal claws of legs 1 and 2 of a tissue feeding astigmatan nasal mite.

Key to the Families of Blood and Tissue Feeding Mites Known from Birds in Alberta (primarily based on females)
The identification of some mites, especially members of the order Mesostigmata, requires an identifier to discriminate between males and females. All mesostigmatan males have a prominent gonopore (Fig 68.) located anteriorly on the sternal shield, and spermadactyl (Fig 69.) fused to the moveable cheliceral digits. All mesostigmatan females have a genital shield (Fig 70.), they do not have a gonopore on the sternal shield, and do not have a spermadactyl on the chelicera (Fig 71). Body length measurements included the gnathosoma and were made primarily on females.

Key to the Genera of Blood and Tissue Feeding Mites of Ereynetidae, Cheyletiellidae, and Rhinonyssidae, Known from Albertan Birds.

Ereynetidae (Prostigmata):

Cheyletiellidae (Prostigmata) (females only):

Rhinonyssidae (Mesostigmata) (females only):

Figure Captions:

1, Ixodida representative: Dorsal and ventral features present in figure. Image drawn from image taken on compound microscope. 2, Astigmata representative: Dorsal and ventral features present in figure. Image drawn from image taken on compound microscope. 3 & 4, Prostigmata representative: Image redrawn from Fig. 18 Ornithocheyletia gersoni Smiley, from Smiley (1970). 5, 6 & 7, Mesostigmata representative: Image redrawn from Fig. 7, Dermanyssus hirundinis (Hermann), from Moss (1968). 8, Ixodida hypostome. 9, Ixodida Haller’s organ on tarsus 1. 10, Ixodidae prodorsal shield. 11, Mesostigmatan stigmata. 12, Prostigmatan peritreme. Image by G. Williams and W. Knee. 13, Trombiculid trichobothria and prodorsal shield. 14, Syringophilid whole mount. 15, Syringophilid empodium on tarsus 1. 16, Ereynetid barbed leg setae. 17, Ereynetid ereynetal organ in tibia 1. 18, Ereynetid reticulate cuticle on leg. 19, Harpirhynchid whole mount with asymmetrically short legs 3 and 4. 20, Harpirhynchid gnathosoma showing serrate setae distally on palp. 21, Turbinoptid tarsal claws legs 1-4. 22, Knemidokoptid propodosomal shield and pattern of cuticle on dorsum. 23, Cheyletiellid whole mount showing epimerites. 24, Cheyletiellid gnathosoma showing palpal segmentation. 25, Harpirhynchid gnathosoma showing palpal segmentation (below). Harpirhynchid whole mount (above). 26, Macronyssid showing sternal shield, peritreme and stigma. 27, Macronyssid female genital shield. 28, Laelapid female showing genital and sternal shields. 29, Rhinonyssid female genital shield. 30, Rhinonyssid peritreme. 31, Laelapid sternal shield. 32, Laelapid chelicerae. 33 Androlaelaps (Laelapidae) female chelicerae. 34, Dermanyssus (Dermanyssidae) sternal shield. 35, Ptilonyssus (Rhinonyssidae) cheliceral digits. 36, Dermanyssus (Dermanyssidae) peritreme and stigma. 37,  Mesostigmatan gnathosoma showing the tritosternum. 38, Dermanyssus (Dermanyssidae) chelicerae. 39, Rhinonyssid peritreme. 40, Rhinonyssid stigma without a peritreme. 41, Boydaia (Ereynetidae) tarsus showing barbed setae. 42, Neoboydaia (Ereynetidae) leg 2 (above) and leg 3 (below) showing setiform setae. 43, Ornithocheyletia (Cheyletiellidae) dorsal opisthosoma showing hysterosomal shield. 44, Bakericheyla (Cheyletiellidae) showing tarsal claws on the palp, and legs 1 and 2. 45, Bakericheyla (Cheyletiellidae) propodosomal shield. 46, Neocheyletiella (Cheyletielldae) showing tarsal claws on the palps and legs. 47, Neocheyletiella (Cheyletiellidae) propodosomal shield. 48, Rhinonyssid stigma with a peritreme. 49, Rhinonyssid stigma without a peritreme. 50, Ptilonyssus (Rhinonyssidae) cheliceral digits. 51, Ptilonyssus (Rhinonyssidae) cheliceral shaft. 52, Rhinoecius (Rhinonyssidae) chelicerae. 53, Sternostoma (Rhinonyssidae) chelicerae. 54, Rhinonyssus (Rhinonyssidae) chelicerae. 55, Dermanyssid whole mount. 56, Laelapid whole mount. 57, Macronyssid whole mount. 58, Rhinonyssid whole mount. 59, Knemidokoptid whole mount. 60, Turbinoptid whole mount. 61, Cheyletiellid whole mount. 62, Ereynetid whole mount. 63, Harpirhynchid whole mount. 64. Trombiculidae whole mount. 65, Feather mite (Astigmata) tarsus and ambulacrum. 66, Nasal mite (Turbinoptidae: Astigmata) legs 1 and 2. 67, Metanalges (Analgidae) male, Psilobrephosceles (Alloptidae) male, and Grallobia (Pterolichidae) female, feather mites. Images by H. Shannon, and W. Knee. 68, Mesostigmatan male, showing gonopore located anteriorly on the sternal shield. 69, Mesostigmatan male showing the spermadactyl fused to the moveable digit. 70, Mesostigmatan female genital shield. 71, Mesostigmatan female chelicerae.