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A Survey of Conditions seen in Wildlife Admitted for Wildlife Rehabilitation

Shirley J. Casey and Allan M. Casey
WildAgain Wildlife Rehabilitation Inc.
Presented at the 18th Annual Symposium of NWRA in Milwaukee, WI, March, 2000; and previously published as Casey A. M. III and Casey S. J. 2000. A Survey of Conditions Seen in Wildlife Admitted for Wildlife Rehabilitation, Pp. 143-160 in Wildlife Rehabilitation, Volume 18 (D. R. Ludwig, ed.). St. Cloud, MN: National Wildlife Rehabilitators Association.


From time to time, many wildlife rehabilitation facilities and rehabilitators have compiled statistics about the wildlife they treated during the previous year.  Many incorporated this analysis as a routine annual activity.  Special projects and studies have compiled statistics about wildlife conditions seen by all wildlife rehabilitators throughout an entire state for a given year. 

Since time is usually limited for such recordkeeping and analysis, many of these compilations were fairly general in nature recording reasons animals were brought in for rehabilitation.  General descriptions included HBC (hit by car), or “fell out of tree, or nest”, or “found on front porch”, or even “rescuers’s cat was playing with it”.  While these categories described the circumstances of a situation, they provided little information as to the condition of the animal when presented for rehabilitation.

The statistics and analysis presented in this paper resulted from an informal survey conducted by the authors to compile a closer look at the types of conditions seen most often in wildlife admitted for rehabilitation. The data are drawn from a representative sample of rehabilitators throughout the United States.  The data originate from the observations and records of more than 140,000 wild animals (an average of more than 47,000 wild animals treated annually during 1995, 1996 and 1997) by 43 survey respondents from 28 states across the United States (Figure 1).


Survey Methodology

The primary survey instrument was an eight-page questionnaire mailed by WildAgain Wildlife Rehabilitation, Inc. during November 1997.  The survey was mailed to approximately 200 wildlife rehabilitators within the United States, including large facilities and home-based rehabilitators.  Survey recipients were selected from the 1997 membership directories from the International Wildlife Rehabilitation Council (IWRC) and the National Wildlife Rehabilitators Association (NWRA).  Recipients were selected to provide a desired coverage of 3 to 4 rehabilitators per state; a range of small to large facilities; and a wide range of wildlife species admitted as indicated by the membership directories.  Additionally, announcements were concurrently published in Wildlife Rehabilitation Today and the IWRC Newsletter describing the survey, and asking individuals interested in participating to contact the authors. The forty three surveys that were returned represented a response rate of just over 20 percent.

A one-page cover sheet explained the nature and objective of the survey and provided guidance on completing the questionnaire.  The first section of the survey requested general demographic profile information of the respondent, including the types and numbers of native wildlife admitted annually for rehabilitation. The second section was a six and one-half page questionnaire that asked each respondent to indicate the relative frequency of each of 204 possible individual conditions seen in wildlife admitted for rehabilitation.  Respondents estimated the frequency of occurrence for each condition, with an indication of “High” (Hi), “Medium” (Med), “Low” (Lo), or leave “blank” for none, for eight major categories of wildlife species (Table 1). 

The list of the individual 204 conditions was developed with the assistance of many experienced wildlife rehabilitators and several veterinarians from across the United States.  For purposes of constructing the questionnaire, the 204 conditions were grouped into 28 major categories of conditions (Figure 2).  The respondents were encouraged to use estimates when completing the questionnaire rather than to take the time to go back to detailed, individual treatment records for the three year period.  The authors felt that since this was meant to be an informal survey these estimates would be reliable for indicating major trends, and that asking for more detailed analysis on the part of the respondent would discourage completion and return of the survey.

The third and last section of the survey asked the respondents to review 28 major categories of conditions seen in wildlife admitted and rank those categories that resulted in the highest incidence of non-releaseable wildlife (i.e., euthanasia, death, permanent incapacity, etc.). Respondents also ranked the 28 categories regarding the categories they felt a rehabilitator should be skilled in handling.


Tabulation of Results

The results of the first section of the survey (demographic data) are summarized in Tables 1 and 2.  The results of the second section, or the questionnaire (Tables 3 through 11) were tabulated by first assigning the numerical values of 3, 2, 1 and 0 to the responses of Hi, Med, Lo and (blank), respectively.  A weighted average was then calculated using the following formula:

  ( s1 )( i1) + (s2 )( i2) + . . . + (sµ )( iµ)  
     s = number of wild animals for a species/species group admitted annually by a respondent
     i = incident rate of condition seen by that respondent (either 1, 2, 3 or 0)
     µ = total number of respondents admitting the species or species group

     n = total number of wild animals for that species or species group admitted annually by all respondents.

This approach was used to provide appropriate weighting to those rehabilitators with a larger database of observations for each condition as a result of admitting more animals. 

The formula used to arrive at the “weighted average” for all respondents is illustrated in this simple example.  Respondent A indicates a “Hi” incidence of head trauma in 1,000 raptors admitted annually.  Respondent B indicates a “Med” incidence of head trauma in 500 raptors admitted annually.  A simple average arrived at by assigning a “3” to respondent A and a “2” to respondent B yields a score of 2.5.  However this approach does not recognize the higher incidence of head trauma seen by respondent A who admits twice the number of raptors annually than does respondent B.  Using the previously described formula, the weighted average approach assigns a higher value to the respondent that admits more animals and yields a score for this example of head trauma seen in raptors of 2.7.

The relative order in which major categories of conditions, or the individual conditions themselves, are presented or ranked do not represent or imply severity of injury, disease or condition.  Neither do any numerical values assigned to any condition.  The values merely represent the relative frequency with which they were observed by the rehabilitators.


The Major Conditions

The study identified the top 20 individual conditions seen most frequently across all species groups (Figure 3).  The top 20 conditions represents the top 10 percent of the entire list of 204 individual conditions. It is probably not surprising to most rehabilitators to find that the most frequently seen conditions across the United States consistently involved fractures, head trauma, bruising, shock, dehydration, emaciation, wounds and problem conditions involving the skin, fur or feathers.  This data is derived from the combined data set of almost 141,000 animals and represents an average across all groups of wildlife, weighted more heavily towards avian species. Birds comprised 78 percent of the wildlife seen by the survey respondents.  The more meaningful data are those views of the top 10 percent of conditions seen in the major groups of wildlife (Figures 4 through 13).

The scores shown in Figures 4 through 13 represent a weighted average of the respondents calculated using the formula described earlier, such that a respondent that saw a large number of animals influenced the final score more than a rehabilitator that saw a much smaller number of animals.  The scoring implies only the relative frequency with which the condition was observed and not the severity of the condition.  The data do not suggest or explain why or how the conditions developed in the animals in the wild, but only the relative frequency these conditions were seen by wildlife rehabilitators.












The Major Categories

Figure 2 shows the relative frequency of observation of the 28 categories of individual conditions.  These categories contain from 2 to 13 individual conditions. The one-third most frequently observed of the categories are profiled below in decreasing order.  The name of the category and the individual conditions that were grouped in the category are given.  The tabulated frequency from the survey is given for each condition.

Shock and dehydration were observed most frequently across all major groupings of wildlife.  Presumeably, regardless of the condition which resulted in an animal being brought to a rehabilitator, many were either in a state of shock from an injury, or in some state of dehydration from a weakened state (perhaps from injury or disease) or orphaned wildlife were dehydrated from being separated from their mother.


  Head trauma was the second most frequently observed condition with concussion, bruising, and swelling seen most frequently.  These conditions were seen most often in raptors, the all other bird species group, and in mid-size mammals.  Head trauma conditions were not included in the top 10 percent of most frequently seen conditions in marine mammals and herptiles.


Wounds, most notably punctures, lacerations and bites, was the third most frequently seen set of conditions.  Conditions in this category were most often noticed in waterfowl, seabirds and shorebirds, all other birds, small mammals and herptiles. Air sac injuries were also prominent in the all other birds group.   Head or body tilt were the most frequently seen neurological conditions.  Other nerve injuries included paralysis, damaged nerves, weakness, circling and impaired reflex.

Within the diet and nutrition category emaciation was seen very frequently in all groups of birds and in mid-size, large and marine mammals.  The conditions refuses food and ravenous were both seen with about equal frequency.  Refusing food was seen most frequently in herptiles.


  Within musculoskeletal conditions fractures was the single most frequently seen condition across all groups of wild animals. Fractures was the highest ranking condition in each individual group of bird species.  It was in the top four or five conditions observed in mammals and in the top fifteen to twenty conditions in marine mammals and herptiles.  Sprains and strains, deep bruising and muscle tears were noted frequently in this category.  For obvious reasons the condition of cracked shell was number one in the herptiles group.  Comments from respondents tended to indicate that when metabolic bone disease was observed, it was usually a result of wildlife being in the hands of the public and generally from being fed an incorrect diet.


The most frequent occurrences of blood related concerns were severe bruising, blood loss, bleeding from orifices, and anemia.




  Ectoparasites (fleas, ticks, maggots, mites, etc.) received top rankings for parasites on or in the skin, maggots, parasites on or in wounds, and parasites observed in or around body orificies.
The most frequently seen emotional states were fear of others (harm, touch, strangers, etc.), general fear, and aggression.  Fear of others was noted as the most frequently seen condition in all mammals.  Other states of emotion, generally fear, were noted in the top 10 percent of all conditions seen in each of the individual groups of species of wildlife.  While most respondents provided observations for this category, a few indicated that it was probably inappropriate to try to assess what emotional conditions, if any, may be existing in the wildlife.  

While the discussion has focused on the top one-third of the most frequently seen categories, it seems appropriate to also comment on the categories that make up the last one third (Figure 2).  The fact that these categories were seen less frequently does not suggest a lower severity or impact of the category, but only that they were observed less often.  Some of these categories appear to comprise conditions that may not be severe enough to cause an animal to be admitted for rehabilitation, such as problems with ears or dental conditions.  Perhaps these conditions were noted more as secondary and tertiary conditions of animals admitted for a more severe, life threatening condition.  Alternatively, some of the categories (poisoning, electrical shock and disease) may in fact be much more severe and would cause an animal’s death in the wild more quickly. Many of these animals might never make it to rehabilitation.  Disease agents and conditions received a low score, perhaps because as noted by several respondents that many animals were not formally tested to assess such conditions.


Survey Part III Responses

The answer to the first question was compared to the overall survey results to see if there was a correlation between the most frequently seen categories and the categories that result in the highest incidence of non-release (death, euthansia, permanent impairment, etc.).  From the answer to the second question there appears to be a match between the most frequently seen conditions and the respondent’s view of the skills that should be possessed by both experienced and novice rehabilitators in handling those categories of conditions (Table 12).  The five categories listed in Table 12 matched categories within the top six categories listed in Figure 2. 


Potential Uses of the Data

The authors feel there are several potential uses of the survey data and results.  The uses suggested below are founded on the belief that this informal survey reflects general trends and relative frequency of the various conditions seen in wildlife treated by wildlife rehabilitators across the U.S.  As a national survey, the data do not necessarily reflect local or regional differences, nor do they take into account the effects of localized events, such as extreme weather occurrences, sudden disease outbreaks or human caused disasters such as oil spills.

Training.  Wildlife rehabilitators working with a specific group of species, such as raptors, or mid-sized mammals, could use the data to design and tailor both introductory training and continuing education to emphasize the recognition and proper treatment of the conditions seen most frequently.  This could be done at a facility level or at local, regional or national conferences.  Priority could be given to the top one third of the categories seen most often (Figure 2). with less priority given to the bottom one third.  The specific conditions listed in Tables 3 through 11 could be emphasized in species specific training efforts.

Proficiencies and skills.  For new rehabilitators just starting out, the survey could be used to help ensure that the rehabilitator demonstrates readiness to handle the most frequently seen conditions for a specific species.  This means correctly identifying the condition, understanding treatment options, knowing when to handle the situation personally or in consultation with a veterinarian, and the consequences and chances of success associated with the various treatments and conditions.

Facility design. The survey results could aid in the planning and design of new rehabilitation facilities, or in the expansion or refurbishment of existing facilities.  The most frequently seen conditions provide guidance as to the amount and type of medical treatment area needed and specialized recuperation facilities needed.  For example, a high frequency of fractures and head trauma cases in birds might suggest larger numbers of small confinement cages, rather than large, more open flight enclosures.

Medical supplies. Optimizing medical supply inventory is always challenging. The survey results could assist in attempts to match the needs of the animals with adding inventory items, reducing carrying costs of too much inventory, and managing the shelf life of medications.  The results could also help in planning for ample supplies of non-date sensitive items (bandages, fluids, splints, etc).

Research opportunities.  The authors feel the survey data will be useful in comparing training opportunities available to rehabilitators to the most frequently seen conditions.  Gaps or mismatches could suggest fruitful and needed areas of research on new and better techniques in treating certain conditions.  Time consuming and costly research spent on infrequently seen conditions could be redirected to higher payback areas suggested by the survey results. The survey results suggest the need more research in assessing the effectiveness of various methods of treating fractures or head trauma in wildlife, understanding how emotions such as fear impact wildlife in rehabilitation (e.g., affecting immune systems and delaying recovering) and identifying methods used to reduce fear (and thus stress) in wildlife.

Conference and Symposium Design. Program organizers could use the survey to insure common and high priority interests are addressed.  The survey results suggest that more avian programs would reach more animals, and that perhaps less time spent on marine mammals and herptiles.  A conference keynote presentation highlighting a specific endangered salamander might well be interesting, but may not have broad applicability to most of the conference participants unless framed as part of a larger issue, such as habitat changes affecting an ecosystem.  The survey supports much more time allocated to fractures, head trauma, shock, dehydration, wounds and diet, with less time and scheduled sessions directed to disease.



In most cases, the survey will serve to confirm and validate what many rehabilitators may have already have felt were the most frequently seen conditions seen in wildlife admitted to rehabilitation (Table 12 compared to Figure 2).  Most readers of this paper will probably see few surprises in the tabulated results. Since these are national averages, the veteran and novice rehabilitator should overlay his or her own local situation, experience and observation.  The novice rehabilitator who is deciding which species to work with or specialize in, might find the survey portrays a fairly accurate representation of the kinds of conditions encountered most often. 

Though many in the wildlife rehabilitation community often informally share numbers, statistics and case studies at various meetings and conferences, this survey provides perhaps a more complete picture of the numbers and statistics from across the entire United States.  The results were only possible through the time and effort given by the respondents in completing and returning the survey.  The authors are forever grateful to that dedicated group.  We also offer thanks to various rehabilitators and veterinarians around the country who helped us create the survey instrument. 


Literature Cited

Breen, J. F. 1974. Encyclopedia of Reptiles and Amphibians. T.F.H. Publications, Neptune City, NJ.

Fowler, M. E.  1986.  Zoo and Wild Animal Medicine (2nd ed). W. B. Saunders Company, Philadelphia, PA.

Masson, J. M. and S. McCarthy. 1995. When Elephants Weep - The Emotional Lives of Animals. Dell Publishing, New York, NY.

Moore, A. T. and S. Joosten. 1997. Principles of Wildlife Rehabilitation - The Essential Guide for Novice and Experienced Rehabilitators.  National Wildlife Rehabilitators Association, St. Cloud, MN.

Plunkett, J. P.  1993.  Emergency Procedures for the Small Animal Veterinarian. W. B. Saunders Company, Philadelphia, PA.

Porter, V. 1989. Animal Rescue. Ashford, Buchan, and Enright, Leatherhead, Surrey, England.

White, J. 1988.  Basic Wildlife Rehabiliatation 1AB.  International Wildlife Rehabilitation Council, Suisun, CA.

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